/*
 *  R : A Computer Language for Statistical Data Analysis
 *  Copyright (C) 2007-2022  The R Foundation
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, a copy is available at
 *  https://www.R-project.org/Licenses/
 *
 *  Modular Quartz device for macOS
 *
 *  Partially based on code by Byron Ellis
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#if HAVE_AQUA

#include <Defn.h>
#include <Rinternals.h>
#define R_USE_PROTOTYPES 1
#include <R_ext/GraphicsEngine.h>
/* This sets ptr_QuartzBackend as a symbol in this file */
#define IN_AQUA_C 1
#include <R_ext/QuartzDevice.h>

#include "grDevices.h"

#include <CoreFoundation/CoreFoundation.h>

#define DEVQUARTZ_VERSION 1 /* first public Quartz API version */

#define QBE_NATIVE   1  /* either Cocoa or Carbon depending on the macOS version */
#define QBE_COCOA    2  /* internal Cocoa */
#define QBE_CARBON   3  /* internal Carbon */
#define QBE_BITMAP   4  /* bitmap file creating */
#define QBE_PDF      5  /* PDF file creating */

typedef struct moduleTypes_s {
    const char *type;
    const char *subst;
    int qbe; /* Quartz back-end */
} quartz_module_t;

/* list of internally supported output modules */
const quartz_module_t quartz_modules[] = {
    { "",        0,                           QBE_NATIVE  },
    { "native",  0,                           QBE_NATIVE  },
    { "cocoa",   0,                           QBE_COCOA   },
    { "carbon",  0,                           QBE_CARBON  },
    { "pdf",     0,                           QBE_PDF     },
    { "png",     "public.png",                QBE_BITMAP  },
    { "jpeg",    "public.jpeg",               QBE_BITMAP  },
    { "jpg",     "public.jpeg",               QBE_BITMAP  },
    { "jpeg2000","public.jpeg-2000",          QBE_BITMAP  },
    { "tiff",    "public.tiff",               QBE_BITMAP  },
    { "tif",     "public.tiff",               QBE_BITMAP  },
    { "gif",     "com.compuserve.gif",        QBE_BITMAP  },
    { "psd",     "com.adobe.photoshop-image", QBE_BITMAP  },
    { "bmp",     "com.microsoft.bmp",         QBE_BITMAP  },
    { "sgi",     "com.sgi.sgi-image",         QBE_BITMAP  },
    { "pict",    "com.apple.pict",            QBE_BITMAP  },
    { 0, 0, 0} };



/* for compatibility with macOS <10.5 */
#ifndef CGFLOAT_DEFINED
typedef float CGFloat;
#define CGFLOAT_MIN FLT_MIN
#define CGFLOAT_MAX FLT_MAX
#define CGFLOAT_IS_DOUBLE 0
#define CGFLOAT_DEFINED 1
#endif

typedef struct QuartzGradient {
    CGGradientRef gradient;
    CGPoint startPoint;
    CGPoint endPoint;
    CGGradientDrawingOptions options;
    // Just not used for linear gradients
    CGFloat startRadius;
    CGFloat endRadius;
    int type;
} QGradient;

typedef QGradient* QGradientRef;

typedef struct QuartzPatternCallbackInfo {
    CGLayerRef layer;
    CGRect tile;
} QPatternCallbackInfo;

typedef QPatternCallbackInfo* QPatternCallbackInfoRef;

typedef struct QuartzPattern {
    CGPatternRef pattern;
    CGLayerRef layer;
    QPatternCallbackInfoRef info;
} QPattern;

typedef QPattern* QPatternRef;

typedef struct QuartzMask {
    CGContextRef context;
    CGImageRef mask;
} QMask;

typedef QMask* QMaskRef;

#define QNoAppend     0
#define QPatternLayer 1
#define QGroupLayer   2
#define QMaskBitmap   3

typedef struct QuartzPath {
    CGPathRef path;
    int rule;
} QPath;

typedef QPath* QPathRef;

typedef struct QuartzSpecific_s {
    double        ps;
    double        scalex, scaley;  /* resolution correction: px/pt ratio */
    double        width,height;    /* size (in inches) */
    double        tscale;          /* text scale (resolution independent,
                                      i.e. it constitutes a text zoom factor */
    int           dirty;           /* dirtly flag. Not acted upon by the Quartz
                                      core, but QC sets it whenever a drawing
                                      operation is performed (see detailed
				      description in R_ext/QuartzDevice.h) */
    int           gstate;          /* gstate counter */
    int           async;           /* asynchronous drawing (i.e. context was
                                      not ready for an operation) */
    int           bg;              /* background color */
    int           canvas;          /* background color */
    int           antialias,smooth;/* smoothing flags (only aa makes any sense) */
    int           flags;           /* additional QDFLAGs */
    int           holdlevel;       /* hold level */
    int           redraw;          /* redraw flag is set when replaying
		                              and inhibits syncs on Mode */
    CGRect        clipRect;        /* clipping rectangle */
    pDevDesc      dev;             /* device structure holding this one */
    CGFontRef     font;            /* currently used font */

    void*         userInfo;        /* pointer to a module-dependent space */

    int           numPatterns;
    QGradientRef  *gradients;
    QPatternRef   *patterns;
    int           appendingPattern;

    int           numMasks;
    QMaskRef      *masks;
    int           appendingMask;   /* mask we are recording */
    int           currentMask;     /* mask used for masking other output */

    int           numClipPaths;
    QPathRef      *clipPaths;
    int           appending;  /* Also serves filled/stroked paths */

    int           numGroups;
    CGLayerRef    *groups;
    int           appendingGroup;
    /* are we currently appending a pattern or a group (or neither) */
    int           appendingType;  

    int           blendMode; /* Track the current blend mode */

    /* callbacks - except for getCGContext all others are optional */
    CGContextRef (*getCGContext)(QuartzDesc_t dev, void *userInfo);
    int          (*locatePoint)(QuartzDesc_t dev, void *userInfo, double *x, double *y);
    void         (*close)(QuartzDesc_t dev, void *userInfo);
    void         (*newPage)(QuartzDesc_t dev, void *userInfo, int flags);
    void         (*state)(QuartzDesc_t dev,  void *userInfo,  int state);
    void*        (*par)(QuartzDesc_t dev, void *userInfo, int set, const char *key, void *value);
    void         (*sync)(QuartzDesc_t dev, void *userInfo);
    void*        (*cap)(QuartzDesc_t dev, void*userInfo);
} QuartzDesc;

/* coordinates:
   - R graphics (positions etc., usually points)
   - real size (e.g. inches)
   - display view (usually pixels)

   bookkeeping:
   - QuartzDevice.width/height:  inches
   - R GE size (.._Size): points
   - physical (on-screen) coordinates : pixels

the current implementation uses points as plotting units (i.e. this is what
Quartz tells R), but the canvas is specified in pixels. The scalex/y factors
specify the conversion factor between pixels and points.
We are *not* using R's scaling facilities, because R doesn't work with
non-square pixels (e.g. circles become ellipses).

FIXME: yes it does -- ipr is a two-element array.
 -- not entirely, because it uses text (e.g. "o") as symbols which is rendered
 in 1:1 aspect ratio and thus is squished on displays with non-square pixels
(That being a bug in Quartz, then!)

Actually, dp not points are used.
*/

#pragma mark QuartzDevice API (for modules)

/* Update should be called when ps or tscale change.
   Conservatively, it should be called on scale change, too, in case
   we decide to abandon the CTM approach */
static void QuartzDevice_Update(QuartzDesc_t desc);

/* this function must be called after a new context is created.
   it primes the context for drawing */
void QuartzDevice_ResetContext(QuartzDesc_t desc) {
    QuartzDesc *qd = ((QuartzDesc*) desc);
    qd->gstate = 0;
    qd->dirty = 0;
    if (qd->getCGContext) {
        CGContextRef ctx = qd->getCGContext(qd, qd->userInfo);
        if (ctx) {
            CGContextSetAllowsAntialiasing(ctx, qd->antialias);
            CGContextSetShouldSmoothFonts(ctx, qd->smooth);
            CGContextScaleCTM(ctx, qd->scalex, qd->scaley);
            CGContextSaveGState(ctx);
            qd->gstate = 1;
        }
    }
}

/* Uses (e.g. in window title) seems to assume this is 1-based */
int QuartzDevice_DevNumber(QuartzDesc_t desc) {
    return 1 + ndevNumber((((QuartzDesc*) desc)->dev));
}

double QuartzDevice_GetWidth(QuartzDesc_t desc)	{ return ((QuartzDesc*) desc)->width;  }
double QuartzDevice_GetHeight(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->height;   }
void   QuartzDevice_SetSize(QuartzDesc_t desc, double width, double height)
{
    QuartzDesc *qd = ((QuartzDesc*) desc);
    qd->width = width;
    qd->height = height;
    qd->dev->right = width*72.0;
    qd->dev->bottom = height*72.0;
}

double QuartzDevice_GetScaledWidth(QuartzDesc_t desc)   { QuartzDesc *qd=((QuartzDesc*) desc); return qd->scalex*qd->width*72.0; }
double QuartzDevice_GetScaledHeight(QuartzDesc_t desc)  { QuartzDesc *qd=((QuartzDesc*) desc); return qd->scaley*qd->height*72.0; }
void QuartzDevice_SetScaledSize(QuartzDesc_t desc, double width, double height) {
    QuartzDesc *qd=((QuartzDesc*) desc);
    QuartzDevice_SetSize(desc, width/qd->scalex/72.0, height/qd->scaley/72.0);
}

double QuartzDevice_GetXScale(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->scalex;  }
double QuartzDevice_GetYScale(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->scaley;  }
void   QuartzDevice_SetScale(QuartzDesc_t desc, double scalex, double scaley) {
    ((QuartzDesc*) desc)->scalex = scalex;
    ((QuartzDesc*) desc)->scaley = scaley;
    QuartzDevice_Update(desc);
}

double QuartzDevice_GetTextScale(QuartzDesc_t desc) {
    return ((QuartzDesc*) desc)->tscale;
}

void   QuartzDevice_SetTextScale(QuartzDesc_t desc, double scale) {
    ((QuartzDesc*) desc)->tscale = scale;
    QuartzDevice_Update(desc);
}

double QuartzDevice_GetPointSize(QuartzDesc_t desc) {
    return ((QuartzDesc*) desc)->ps;
}

void   QuartzDevice_SetPointSize(QuartzDesc_t desc, double ps) {
    ((QuartzDesc*) desc)->ps = ps;
    QuartzDevice_Update(desc);
}

int   QuartzDevice_GetDirty(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->dirty; }
void  QuartzDevice_SetDirty(QuartzDesc_t desc,int dirty) { ((QuartzDesc*) desc)->dirty = dirty; }

int   QuartzDevice_GetAntialias(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->antialias; }
void  QuartzDevice_SetAntialias(QuartzDesc_t desc,int aa) {
    QuartzDesc *qd = (QuartzDesc*) desc;
    qd->antialias  = aa;
    if(NULL != qd->getCGContext)
        CGContextSetAllowsAntialiasing( qd->getCGContext(qd, qd->userInfo), aa );
}

void QuartzDevice_Kill(QuartzDesc_t desc) {
    pGEDevDesc dd = GEgetDevice(ndevNumber(((QuartzDesc*) desc)->dev));
    if (dd) GEkillDevice(dd);
}

int   QuartzDesc_GetFontSmooth(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->smooth; }
void  QuartzDesc_SetFontSmooth(QuartzDesc_t desc, int fs) {
    QuartzDesc *qd = (QuartzDesc*) desc;
    qd->smooth = fs;
    if(qd->getCGContext)
        CGContextSetShouldSmoothFonts( qd->getCGContext(qd, qd->userInfo), fs);
}

int   QuartzDevice_GetBackground(QuartzDesc_t desc) { return ((QuartzDesc*) desc)->bg; }

static void   QuartzDevice_Update(QuartzDesc_t desc)
{
    QuartzDesc *qd = (QuartzDesc*) desc;
    pDevDesc dev= qd->dev;

    /* pre-scaling happens in Quartz (using CTM), so scales should not be
       reflected in R measurements. We tell R to use 72dpi which corresponds
       to plotting in pt coordinates */
    dev->cra[0] = 0.9*qd->ps*qd->tscale;
    dev->cra[1] = 1.2*qd->ps*qd->tscale;
    dev->ipr[0] = 1.0/72.0;
    dev->ipr[1] = 1.0/72.0;
}

void QuartzDevice_Activate(QuartzDesc_t desc)
{
    QuartzDesc *qd = (QuartzDesc*) desc;
    if (qd) {
	int n = ndevNumber(qd->dev);
	selectDevice(n);
    }
}

void QuartzDevice_ReplayDisplayList(QuartzDesc_t desc)
{
    QuartzDesc *qd = (QuartzDesc*) desc;
    int _dirty = qd->dirty;
    pGEDevDesc gdd = desc2GEDesc(qd->dev);
    qd->redraw = 1;
    /* CHECK this */
    if(gdd->displayList != R_NilValue) GEplayDisplayList(gdd);
    qd->redraw = 0;
    qd->dirty = _dirty; /* we do NOT change the dirty flag */
}

void* QuartzDevice_GetSnapshot(QuartzDesc_t desc, int last)
{
    QuartzDesc *qd = (QuartzDesc*) desc;
    pGEDevDesc gd  = GEgetDevice(ndevNumber(qd->dev));
    SEXP snap;
    if (last)
	snap = desc2GEDesc(qd->dev)->savedSnapshot;
    else
	snap = GEcreateSnapshot(gd);
    if (R_NilValue == VECTOR_ELT(snap, 0))
	snap = 0;
    return (snap == R_NilValue) ? 0 : snap;
}

void QuartzDevice_RestoreSnapshot(QuartzDesc_t desc, void* snap)
{
    QuartzDesc *qd = (QuartzDesc*) desc;
    pGEDevDesc gd  = GEgetDevice(ndevNumber(qd->dev));
    if(NULL == snap) return; /*Aw, hell no!*/
    PROTECT((SEXP)snap);
    if(R_NilValue == VECTOR_ELT(snap,0))
        warning("Tried to restore an empty snapshot?");
    qd->redraw = 1;
    GEplaySnapshot((SEXP)snap, gd);
    qd->redraw = 0;
    qd->dirty = 0; /* we reset the dirty flag */
    UNPROTECT(1);
}

static int quartz_embedding = 0;

static void* QuartzDevice_SetParameter(QuartzDesc_t desc, const char *key, void *value)
{
    if (desc) { /* backend-specific? pass it on */
	QuartzDesc *qd = (QuartzDesc*) desc;
	return (qd->par) ? qd->par(qd, qd->userInfo, 1, key, value) : NULL;
    } else { /* global? try to handle it */
	if (key) {
	    if (!streql(key, QuartzParam_EmbeddingFlags)) {
		if (value) quartz_embedding = ((int*)value)[0];
		return &quartz_embedding;
	    }
	}
    }
    return NULL;
}

void setup_RdotApp(void)
{
    int eflags = QP_Flags_CFLoop | QP_Flags_Cocoa | QP_Flags_Front;
    QuartzDevice_SetParameter(NULL, QuartzParam_EmbeddingFlags, &eflags);
}

static void*  QuartzDevice_GetParameter(QuartzDesc_t desc, const char *key)
{
    if (desc) { /* backend-specific? pass it on */
	QuartzDesc *qd = (QuartzDesc*) desc;
	return (qd->par) ? qd->par(qd, qd->userInfo, 0, key, NULL) : NULL;
    } else { /* global? try to handle it */
	if (key) {
	    if (!streql(key, QuartzParam_EmbeddingFlags)) return &quartz_embedding;
	}
    }
    return NULL;
}

/*
 ***************************
 * Context switching
 * Where should drawing go to ?
 * Used by DEVSPEC and DRAWSPEC
 */
static CGContextRef QuartzGetCurrentContext(QuartzDesc *xd)
{
    if (xd->appendingPattern >= 0 && 
        xd->appendingType == QPatternLayer) {
        return CGLayerGetContext(xd->patterns[xd->appendingPattern]->layer);
    } else if (xd->appendingGroup >= 0 &&
               xd->appendingType == QGroupLayer) {
        return CGLayerGetContext(xd->groups[xd->appendingGroup]);
    } else if (xd->appendingMask >= 0 &&
               xd->appendingType == QMaskBitmap) {
        return xd->masks[xd->appendingMask]->context;
    } else {
        return xd->getCGContext(xd, xd->userInfo);
    }
}

/*
 ***************************
 * Patterns
 *
 ***************************
 */

/* Just a starting value */
#define maxPatterns 64

static void QuartzInitPatterns(QuartzDesc *xd)
{
    int i;
    xd->numPatterns = maxPatterns;
    /* Gradients and tiling patterns are different types so need 
     * separate arrays */
    xd->gradients = malloc(sizeof(QGradientRef) * xd->numPatterns);
    xd->patterns = malloc(sizeof(QPatternRef) * xd->numPatterns);
    for (i = 0; i < xd->numPatterns; i++) {
        xd->gradients[i] = NULL;
        xd->patterns[i] = NULL;
    }
    xd->appendingPattern = -1;
}

static int QuartzGrowPatterns(QuartzDesc *xd)
{
    int i, newMax = 2*xd->numPatterns;
    void *tmp;
    tmp = realloc(xd->gradients, sizeof(QGradientRef) * newMax);
    if (!tmp) { 
        warning(_("Quartz gradients exhausted (failed to increase maxPatterns)"));
        return 0;
    }
    xd->gradients = tmp;
    tmp = realloc(xd->patterns, sizeof(QPatternRef) * newMax);
    if (!tmp) { 
        warning(_("Quartz patterns exhausted (failed to increase maxPatterns)"));
        return 0;
    }
    xd->patterns = tmp;
    for (i = xd->numPatterns; i < newMax; i++) {
        xd->gradients[i] = NULL;
        xd->patterns[i] = NULL;
    }
    xd->numPatterns = newMax;
    return 1;
}

static void QuartzCleanPatterns(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numPatterns; i++) {
        if (xd->gradients[i] != NULL) {
            CGGradientRelease(xd->gradients[i]->gradient);
            free(xd->gradients[i]);
            xd->gradients[i] = NULL;
        }
        if (xd->patterns[i] != NULL) {
            CGPatternRelease(xd->patterns[i]->pattern);
	    /* layer and info get released by the pattern finaliser */
            free(xd->patterns[i]);
            xd->patterns[i] = NULL;
        }
    }    
}

static void QuartzReleasePattern(int i, QuartzDesc *xd)
{
    if (xd->gradients[i]) {
        CGGradientRelease(xd->gradients[i]->gradient);
        free(xd->gradients[i]);
        xd->gradients[i] = NULL;
    } else if (xd->patterns[i]) {
        CGPatternRelease(xd->patterns[i]->pattern);
        free(xd->patterns[i]);
        xd->patterns[i] = NULL;
    } else {
        warning(_("Attempt to release non-existent pattern"));
    }
}

static void QuartzDestroyPatterns(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numPatterns; i++) {
        if (xd->gradients[i] != NULL) {
            CGGradientRelease(xd->gradients[i]->gradient);
            free(xd->gradients[i]);
        }
    }    
    for (i = 0; i < xd->numPatterns; i++) {
        if (xd->patterns[i] != NULL) {
            CGPatternRelease(xd->patterns[i]->pattern);
            free(xd->patterns[i]);
        }
    }    
    free(xd->gradients);
    free(xd->patterns);
}

static int QuartzNewPatternIndex(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numPatterns; i++) {
        if ((xd->gradients[i] == NULL) && (xd->patterns[i] == NULL)) {
            return i;
        } else {
            if (i == (xd->numPatterns - 1) &&
                !QuartzGrowPatterns(xd)) {
                return -1;
            }
        }
    }    
    /* Should never get here, but just in case */
    warning(_("Quartz patterns exhausted"));
    return -1;
}

static Rboolean QuartzGradientFill(SEXP pattern, QuartzDesc *xd) {
    if (pattern == R_NilValue) {
        return FALSE;
    } else {
        int index = INTEGER(pattern)[0];
        QGradientRef quartz_gradient = xd->gradients[index];
        return quartz_gradient != NULL &&
            (quartz_gradient->type == R_GE_linearGradientPattern ||
             quartz_gradient->type == R_GE_radialGradientPattern);
    }
}

static Rboolean QuartzPatternFill(SEXP pattern, QuartzDesc *xd) {
    if (pattern == R_NilValue) {
        return FALSE;
    } else {
        int index = INTEGER(pattern)[0];
        QPatternRef quartz_pattern = xd->patterns[index];
        return quartz_pattern != NULL;
    }
}

static void QuartzDrawGradientFill(CGContextRef ctx, SEXP pattern, 
                                   QuartzDesc *xd) {
    int index = INTEGER(pattern)[0];
    QGradientRef quartz_gradient = xd->gradients[index];
    switch (quartz_gradient->type) {
    case R_GE_linearGradientPattern:
        CGContextDrawLinearGradient(ctx, 
                                    quartz_gradient->gradient,
                                    quartz_gradient->startPoint, 
                                    quartz_gradient->endPoint,
                                    quartz_gradient->options);
        break;
    case R_GE_radialGradientPattern:
        CGContextDrawRadialGradient(ctx, 
                                    quartz_gradient->gradient,
                                    quartz_gradient->startPoint, 
                                    quartz_gradient->startRadius,
                                    quartz_gradient->endPoint, 
                                    quartz_gradient->endRadius,
                                    quartz_gradient->options);
        break;
    }
}

static void QuartzSetPatternFill(CGContextRef ctx, SEXP pattern, 
                                  QuartzDesc *xd) {
    int index = INTEGER(pattern)[0];
    QPatternRef quartz_pattern = xd->patterns[index];
    CGColorSpaceRef patternSpace = CGColorSpaceCreatePattern (NULL);
    CGContextSetFillColorSpace(ctx, patternSpace);
    CGColorSpaceRelease (patternSpace);
    CGFloat alpha = 1;
    CGContextSetFillPattern(ctx, quartz_pattern->pattern, &alpha);
}

static QGradientRef QuartzCreateGradient(SEXP gradient, int type, 
                                         QuartzDesc *xd) {
    int i;
    unsigned int col;
    QGradientRef quartz_gradient = malloc(sizeof(QGradient));
    if (!quartz_gradient) error(_("Failed to create gradient"));
    size_t num_locations;
    CGColorSpaceRef colorspace;
    CGFloat *locations; 
    CGFloat *components;
    
    quartz_gradient->type = type;
    switch (type) {
    case R_GE_linearGradientPattern:
        quartz_gradient->startPoint.x = R_GE_linearGradientX1(gradient);
        quartz_gradient->startPoint.y = R_GE_linearGradientY1(gradient);
        quartz_gradient->endPoint.x = R_GE_linearGradientX2(gradient);
        quartz_gradient->endPoint.y = R_GE_linearGradientY2(gradient);
        num_locations = R_GE_linearGradientNumStops(gradient);
        locations = malloc(sizeof(CGFloat) * num_locations);
        if (!locations) error(_("Failed to create gradient"));
        components = malloc(sizeof(CGFloat) * num_locations * 4);
        if (!components) error(_("Failed to create gradient"));
        for (i = 0; i < num_locations; i++) {
            locations[i] = R_GE_linearGradientStop(gradient, i);
            col = R_GE_linearGradientColour(gradient, i);
            components[i*4] = R_RED(col)/255.0;
            components[i*4 + 1] = R_GREEN(col)/255.0;
            components[i*4 + 2] = R_BLUE(col)/255.0;
            components[i*4 + 3] = R_ALPHA(col)/255.0;
        }
        switch (R_GE_linearGradientExtend(gradient)) {
        case R_GE_patternExtendNone:
            quartz_gradient->options = 0;
            break;
        case R_GE_patternExtendRepeat:
        case R_GE_patternExtendReflect:
            warning(_("Unsupported gradient fill extend type; using 'pad'"));
        case R_GE_patternExtendPad:
            quartz_gradient->options = kCGGradientDrawsBeforeStartLocation |
                kCGGradientDrawsAfterEndLocation;
            break;
        }
        break;
    case R_GE_radialGradientPattern:
        quartz_gradient->startPoint.x = R_GE_radialGradientCX1(gradient);
        quartz_gradient->startPoint.y = R_GE_radialGradientCY1(gradient);
        quartz_gradient->endPoint.x = R_GE_radialGradientCX2(gradient);
        quartz_gradient->endPoint.y = R_GE_radialGradientCY2(gradient);
        quartz_gradient->startRadius = R_GE_radialGradientR1(gradient);
        quartz_gradient->endRadius = R_GE_radialGradientR2(gradient);
        num_locations = R_GE_radialGradientNumStops(gradient);
        locations = malloc(sizeof(CGFloat) * num_locations);
        if (!locations) error(_("Failed to create gradient"));
        components = malloc(sizeof(CGFloat) * num_locations * 4);
        if (!components) error(_("Failed to create gradient"));
        for (i = 0; i < num_locations; i++) {
            locations[i] = R_GE_radialGradientStop(gradient, i);
            col = R_GE_radialGradientColour(gradient, i);
            components[i*4] = R_RED(col)/255.0;
            components[i*4 + 1] = R_GREEN(col)/255.0;
            components[i*4 + 2] = R_BLUE(col)/255.0;
            components[i*4 + 3] = R_ALPHA(col)/255.0;
        }
        switch (R_GE_radialGradientExtend(gradient)) {
        case R_GE_patternExtendNone:
            quartz_gradient->options = 0;
            break;
        case R_GE_patternExtendRepeat:
        case R_GE_patternExtendReflect:
            warning(_("Unsupported gradient fill extend type; using 'pad'"));
        case R_GE_patternExtendPad:
            quartz_gradient->options = kCGGradientDrawsBeforeStartLocation |
                kCGGradientDrawsAfterEndLocation;
            break;
        }
        break;
    }
    colorspace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
    quartz_gradient->gradient = 
        CGGradientCreateWithColorComponents(colorspace, 
                                            components,
                                            locations, 
                                            num_locations);
    free(locations);
    free(components);
    return quartz_gradient;
}

/* Pattern finaliser callback */
static void QuartzPatternReleaseCallback(void *info) {
    QPatternCallbackInfo *patternInfo = (QPatternCallbackInfo*) info;
    CGLayerRef layer = patternInfo->layer;
    CGLayerRelease(layer);
    free(info);
}

/* Called to draw the pattern.
 * Will be passed the pattern layer via 'info' */
static void QuartzPatternCallback(void *info, CGContextRef ctx) {
    QPatternCallbackInfo *patternInfo = (QPatternCallbackInfo*) info;
    CGLayerRef layer = patternInfo->layer;
    CGRect tile = patternInfo->tile;
    CGContextSaveGState(ctx);
    CGContextClipToRect(ctx, tile);
    CGPoint contextOrigin = CGPointMake(0 ,0);
    CGContextDrawLayerAtPoint(ctx, contextOrigin, layer);
    CGContextRestoreGState(ctx);
}

static QPatternRef QuartzCreatePattern(SEXP pattern, CGContextRef ctx,
                                       QuartzDesc *xd) {
    QPatternRef quartz_pattern = malloc(sizeof(QPattern));
    if (!quartz_pattern) error(_("Failed to create pattern"));
    double devWidth = QuartzDevice_GetScaledWidth(xd);
    double devHeight = QuartzDevice_GetScaledHeight(xd);
    CGSize size = CGSizeMake(devWidth, devHeight);
    CGLayerRef layer = CGLayerCreateWithContext(ctx, size, NULL);
    double x = R_GE_tilingPatternX(pattern);
    double y = R_GE_tilingPatternY(pattern);
    double width = R_GE_tilingPatternWidth(pattern);
    double height = R_GE_tilingPatternHeight(pattern);

    /* Translate tile to centre of layer 
     * (so that tile drawing is not clipped to edge of layer) */
    CGContextRef layerCTX = CGLayerGetContext(layer);
    CGContextTranslateCTM(layerCTX, 
                          devWidth/2 - width/2, devHeight/2 - height/2);
    CGContextTranslateCTM(layerCTX, -x, -y);

    double xStep, yStep;
    if (R_GE_tilingPatternExtend(pattern) == R_GE_patternExtendNone) {
        xStep = 0;
        yStep = 0;
    } else {
        if (R_GE_tilingPatternExtend(pattern) != R_GE_patternExtendRepeat) {
            warning(_("Unsupported pattern extend mode;  using \"repeat\""));
        }
        xStep = width;
        yStep = height;
    }
    /* Pattern space (so centre of pattern space) */
    CGRect bounds = CGRectMake(devWidth/2 - width/2, devHeight/2 - height/2, 
                               width, height);
    CGPatternCallbacks callback = { 0, &QuartzPatternCallback, &QuartzPatternReleaseCallback };
    QPatternCallbackInfoRef info = malloc(sizeof(QPatternCallbackInfo));
    if (!info) error(_("Failed to create pattern"));
    info->layer = layer;
    info->tile = bounds;
    quartz_pattern->info = info;

    /* Pattern CTM 
     * (reverse the translation to centre of layer) */
    CGContextSaveGState(ctx);
    CGContextTranslateCTM(ctx, 
                          -(devWidth/2 - width/2), -(devHeight/2 - height/2));
    CGContextTranslateCTM(ctx, x, y);
    CGAffineTransform patternCTM = CGContextGetCTM(ctx);
    CGContextRestoreGState(ctx);
    
    quartz_pattern->pattern = CGPatternCreate((void*) info,
                                              bounds,
                                              patternCTM, 
                                              xStep, yStep, /* xStep, yStep */
                                              kCGPatternTilingNoDistortion,
                                              true,
                                              &callback);
    quartz_pattern->layer = layer;
    return quartz_pattern;
}

/*
 ***************************
 * Clipping paths
 *
 ***************************
 */

/* Just a starting value */
#define maxClipPaths 64

static void QuartzInitClipPaths(QuartzDesc *xd)
{
    int i;
    /* Zero clip paths */
    xd->numClipPaths = maxClipPaths;
    xd->clipPaths = malloc(sizeof(QPathRef) * xd->numClipPaths);
    for (i = 0; i < xd->numClipPaths; i++) {
        xd->clipPaths[i] = NULL;
    }
}

static int QuartzGrowClipPaths(QuartzDesc *xd)
{
    int i, newMax = 2*xd->numClipPaths;
    void *tmp;
    tmp = realloc(xd->clipPaths, sizeof(QPathRef) * newMax);
    if (!tmp) { 
        warning(_("Quartz clipping paths exhausted (failed to increase maxClipPaths)"));
        return 0;
    }
    xd->clipPaths = tmp;
    for (i = xd->numClipPaths; i < newMax; i++) {
        xd->clipPaths[i] = NULL;
    }
    xd->numClipPaths = newMax;
    return 1;
}

static void QuartzCleanClipPaths(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numClipPaths; i++) {
        if (xd->clipPaths[i] != NULL) {
            CGPathRelease(xd->clipPaths[i]->path);
            free(xd->clipPaths[i]);
            xd->clipPaths[i] = NULL;
        }
    }    
}

static void QuartzDestroyClipPaths(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numClipPaths; i++) {
        if (xd->clipPaths[i] != NULL) {
            CGPathRelease(xd->clipPaths[i]->path);
            free(xd->clipPaths[i]);
            xd->clipPaths[i] = NULL;
        }
    }    
    free(xd->clipPaths);
}

static int QuartzNewClipPathIndex(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numClipPaths; i++) {
        if (xd->clipPaths[i] == NULL) {
            return i;
        } else {
            if (i == (xd->numClipPaths - 1) &&
                !QuartzGrowClipPaths(xd)) {
                return -1;
            }
        }
    }    
    warning(_("Quartz clipping paths exhausted"));
    return -1;
}

static QPathRef QuartzCreateClipPath(SEXP clipPath, int index, 
                                     CGContextRef ctx, QuartzDesc *xd)
{
    QPathRef quartz_clipPath = malloc(sizeof(QPath));
    if (!quartz_clipPath) error(_("Failed to create clipping path"));
    SEXP R_fcall;
    /* Save the current path */
    CGPathRef quartz_saved_path = CGContextCopyPath(ctx);
    /* Increment the "appending" count */
    xd->appending++;
    /* Clear the current path */
    CGContextBeginPath(ctx);
    /* Play the clipPath function to build the clipping path */
    R_fcall = PROTECT(lang1(clipPath));
    eval(R_fcall, R_GlobalEnv);
    UNPROTECT(1);
    /* Save the clipping path (for reuse) */
    quartz_clipPath->path = CGContextCopyPath(ctx);
    quartz_clipPath->rule = R_GE_clipPathFillRule(clipPath);
    /* Set the clipping region from the path 
     * (applying the path fill rule) */
    if(xd->gstate > 0) {
        --xd->gstate;
        CGContextRestoreGState(ctx);
    }
    CGContextSaveGState(ctx);
    xd->gstate++;
    switch (quartz_clipPath->rule) {
    case R_GE_nonZeroWindingRule: 
        CGContextClip(ctx); break;
    case R_GE_evenOddRule:
        CGContextEOClip(ctx); break;
    }
    /* Clear the path again */
    CGContextBeginPath(ctx);
    /* Decrement the "appending" count */
    xd->appending--;
    /* Restore the saved path */
    CGContextAddPath(ctx, quartz_saved_path);
    /* Destroy the saved path */
    CGPathRelease(quartz_saved_path);
    /* Return the clipping path */
    return quartz_clipPath;
}

static void QuartzReuseClipPath(QPathRef quartz_clipPath,
                                CGContextRef ctx, QuartzDesc *xd)
{
    /* Save the current path */
    CGPathRef quartz_saved_path = CGContextCopyPath(ctx);
    /* Clear the current path */
    CGContextBeginPath(ctx);
    /* Append the clipping path */
    CGContextAddPath(ctx, quartz_clipPath->path);
    /* Set the clipping region from the path (which clears the path) */
    if(xd->gstate > 0) {
        --xd->gstate;
        CGContextRestoreGState(ctx);
    }
    CGContextSaveGState(ctx);
    xd->gstate++;
    switch (quartz_clipPath->rule) {
    case R_GE_nonZeroWindingRule: 
        CGContextClip(ctx); break;
    case R_GE_evenOddRule:
        CGContextEOClip(ctx); break;
    }
    /* Restore the saved path */
    CGContextAddPath(ctx, quartz_saved_path);
    /* Destroy the saved path */
    CGPathRelease(quartz_saved_path);
}

/*
 ***************************
 * Masks
 ***************************
 */

static void QuartzInitMasks(QuartzDesc *xd)
{
    int i;
    xd->numMasks = 20;
    xd->masks = malloc(sizeof(QMaskRef) * xd->numMasks);
    for (i = 0; i < xd->numMasks; i++) {
        xd->masks[i] = NULL;
    }
    xd->appendingMask = -1;
    xd->currentMask = -1;
}

static int QuartzGrowMasks(QuartzDesc *xd)
{
    int i, newMax = 2*xd->numMasks;
    void *tmp;
    tmp = realloc(xd->masks, sizeof(QMaskRef) * newMax);
    if (!tmp) { 
        warning(_("Quartz masks exhausted (failed to increase maxMasks)"));
        return 0;
    }
    xd->masks = tmp;
    for (i = xd->numMasks; i < newMax; i++) {
        xd->masks[i] = NULL;
    }
    xd->numMasks = newMax;
    return 1;
}

static void QuartzCleanMasks(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numMasks; i++) {
        if (xd->masks[i] != NULL) {
            CGContextRelease(xd->masks[i]->context);
            CGImageRelease(xd->masks[i]->mask);
            xd->masks[i] = NULL;
        }
    }    
    xd->appendingMask = -1;
    xd->currentMask = -1;
}

static void QuartzDestroyMasks(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numMasks; i++) {
        if (xd->masks[i] != NULL) {
            CGContextRelease(xd->masks[i]->context);
            CGImageRelease(xd->masks[i]->mask);
            xd->masks[i] = NULL;
        }
    }    
    free(xd->masks);
}

static int QuartzNewMaskIndex(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numMasks; i++) {
        if (xd->masks[i] == NULL) {
            return i;
        } else {
            if (i == (xd->numMasks - 1) &&
                !QuartzGrowMasks(xd)) {
                return -1;
            }
        }
    }    
    warning(_("Quartz masks exhausted"));
    return -1;
}

static int QuartzCreateMask(SEXP mask, 
                            CGContextRef ctx, QuartzDesc *xd)
{
    SEXP R_fcall;
    CGContextRef quartz_bitmap;
    CGColorSpaceRef cs;
    double devWidth = QuartzDevice_GetScaledWidth(xd);
    double devHeight = QuartzDevice_GetScaledHeight(xd);
    
    int index = QuartzNewMaskIndex(xd);
    if (index >= 0) {        
        QMaskRef quartz_mask = malloc(sizeof(QMaskRef));
        if (!quartz_mask) error(_("Failed to create Quartz mask"));

        cs = CGColorSpaceCreateDeviceGray();
        
        /* For alpha masks, create a bitmap with only an alpha channel */
        uint32_t bitmapInfo = kCGImageAlphaNone;
        if (R_GE_maskType(mask) == R_GE_alphaMask) {
            bitmapInfo = kCGImageAlphaOnly;
        }

        /* Create bitmap grahics context 
         * drawing is redirected to this context */
        quartz_bitmap = CGBitmapContextCreate(NULL,
                                              (size_t) devWidth,
                                              (size_t) devHeight,
                                              8,
                                              0,
                                              cs,
                                              bitmapInfo);
    
        quartz_mask->context = quartz_bitmap;
        xd->masks[index] = quartz_mask;

        int savedMask = xd->appendingMask;
        int savedType = xd->appendingType;
        xd->appendingMask = index;
        xd->appendingType = QMaskBitmap;

        /* Play the mask function to build the mask */
        R_fcall = PROTECT(lang1(mask));
        eval(R_fcall, R_GlobalEnv);
        UNPROTECT(1);

        /* When working with an alpha mask, convert into a grayscale bitmap */
        if (R_GE_maskType(mask) == R_GE_alphaMask) {
            CGContextRef alpha_bitmap = quartz_bitmap;

            /* Create a new grayscale bitmap with no alpha channel */
            int stride = CGBitmapContextGetBytesPerRow(alpha_bitmap);
            quartz_bitmap = CGBitmapContextCreate(NULL,
                                                  (size_t) devWidth,
                                                  (size_t) devHeight,
                                                  8,
                                                  stride,
                                                  cs,
                                                  kCGImageAlphaNone);
            quartz_mask->context = quartz_bitmap;
            
            void *alpha_data = CGBitmapContextGetData(alpha_bitmap);
            void *gray_data = CGBitmapContextGetData(quartz_bitmap);

            /* Copy the alpha channel data into the grayscale bitmap */
            memcpy(gray_data, alpha_data, stride * devHeight);

            /* We're finished with the alpha channel bitmap now */
            CGContextRelease(alpha_bitmap);
        }

        /* Create image from bitmap context */
        CGImageRef maskImage;
        maskImage = CGBitmapContextCreateImage(quartz_bitmap);
        xd->masks[index]->mask = maskImage;

        xd->currentMask = index;

        /* tidy up */
        CGColorSpaceRelease(cs);
        xd->appendingMask = savedMask;
        xd->appendingType = savedType;
    }
    return index;
}

/*
 ***************************
 * Groups
 *
 ***************************
 */

/* Just a starting value */
#define maxGroups 64

static void QuartzInitGroups(QuartzDesc *xd)
{
    int i;
    xd->numGroups = maxGroups;
    xd->groups = malloc(sizeof(CGLayerRef) * xd->numGroups);
    for (i = 0; i < xd->numGroups; i++) {
        xd->groups[i] = NULL;
    }
    xd->appendingGroup = -1;
}

static int QuartzGrowGroups(QuartzDesc *xd)
{
    int i, newMax = 2*xd->numGroups;
    void *tmp;
    tmp = realloc(xd->groups, sizeof(CGLayerRef) * newMax);
    if (!tmp) { 
        warning(_("Quartz groups exhausted (failed to increase maxGroups)"));
        return 0;
    }
    xd->groups = tmp;
    for (i = xd->numGroups; i < newMax; i++) {
        xd->groups[i] = NULL;
    }
    xd->numGroups = newMax;
    return 1;
}

static void QuartzCleanGroups(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numGroups; i++) {
        if (xd->groups[i] != NULL) {
            CGLayerRelease(xd->groups[i]);
            xd->groups[i] = NULL;
        }
    }    
}

static void QuartzReleaseGroups(int i, QuartzDesc *xd)
{
    if (xd->groups[i]) {
        CGLayerRelease(xd->groups[i]);
        xd->groups[i] = NULL;
    } else {
        warning(_("Attempt to release non-existent group"));
    }
}

static void QuartzDestroyGroups(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numGroups; i++) {
        if (xd->groups[i] != NULL) {
            CGLayerRelease(xd->groups[i]);
        }
    }    
    free(xd->groups);
}

static int QuartzNewGroupIndex(QuartzDesc *xd)
{
    int i;
    for (i = 0; i < xd->numGroups; i++) {
        if (xd->groups[i] == NULL) {
            return i;
        } else {
            if (i == (xd->numGroups - 1) &&
                !QuartzGrowGroups(xd)) {
                return -1;
            }
        }
    }    
    /* Should never get here, but just in case */
    warning(_("Quartz groups exhausted"));
    return -1;
}

static int QuartzOperator(int op) {
    int blendmode = kCGBlendModeNormal;
    switch(op) {
    case R_GE_compositeClear: blendmode = kCGBlendModeClear; break;
    case R_GE_compositeSource: blendmode = kCGBlendModeCopy; break;
    case R_GE_compositeOver: blendmode = kCGBlendModeNormal; break;
    case R_GE_compositeIn: blendmode = kCGBlendModeSourceIn; break;
    case R_GE_compositeOut: blendmode = kCGBlendModeSourceOut; break;
    case R_GE_compositeAtop: blendmode = kCGBlendModeSourceAtop; break;
    /* case R_GE_compositeDest is implemented "manually" */
    case R_GE_compositeDestOver: blendmode = kCGBlendModeDestinationOver; break;
    case R_GE_compositeDestIn: blendmode = kCGBlendModeDestinationIn; break;
    case R_GE_compositeDestOut: blendmode = kCGBlendModeDestinationOut; break;
    case R_GE_compositeDestAtop: blendmode = kCGBlendModeDestinationAtop; break;
    case R_GE_compositeXor: blendmode = kCGBlendModeXOR; break;
    case R_GE_compositeAdd: 
        warning(_("Add compositing operator not supported; falling back to over"));
        blendmode = kCGBlendModeNormal; 
        break;
    case R_GE_compositeSaturate: blendmode = kCGBlendModeSaturation; break;
    case R_GE_compositeMultiply: blendmode = kCGBlendModeMultiply; break;
    case R_GE_compositeScreen: blendmode = kCGBlendModeScreen; break;
    case R_GE_compositeOverlay: blendmode = kCGBlendModeOverlay; break;
    case R_GE_compositeDarken: blendmode = kCGBlendModeDarken; break;
    case R_GE_compositeLighten: blendmode = kCGBlendModeLighten; break;
    case R_GE_compositeColorDodge: blendmode = kCGBlendModeColorDodge; break;
    case R_GE_compositeColorBurn: blendmode = kCGBlendModeColorBurn; break;
    case R_GE_compositeHardLight: blendmode = kCGBlendModeHardLight; break;
    case R_GE_compositeSoftLight: blendmode = kCGBlendModeSoftLight; break;
    case R_GE_compositeDifference: blendmode = kCGBlendModeDifference; break;
    case R_GE_compositeExclusion: blendmode = kCGBlendModeExclusion; break;
    }
    return blendmode;
}

static SEXP QuartzCreateGroup(SEXP src, int op, SEXP dst, 
                              CGContextRef ctx, QuartzDesc *xd) {
    int index;
    SEXP R_fcall, result;

    index = QuartzNewGroupIndex(xd);
    int savedGroup = xd->appendingGroup;
    int savedType = xd->appendingType;

    double devWidth = QuartzDevice_GetScaledWidth(xd);
    double devHeight = QuartzDevice_GetScaledHeight(xd);
    CGSize size = CGSizeMake(devWidth, devHeight);
    CGLayerRef layer = CGLayerCreateWithContext(ctx, size, NULL);
    xd->groups[index] = layer;
    xd->appendingGroup = index;
    xd->appendingType = QGroupLayer;

    /* Work with the group layer context */
    CGContextRef layerContext = CGLayerGetContext(layer);

    /* Start with OVER operator */
    xd->blendMode = R_GE_compositeOver;
    CGContextSetBlendMode(layerContext, kCGBlendModeNormal);
    
    if (dst != R_NilValue) {
        /* Play the destination function to draw the destination */
        R_fcall = PROTECT(lang1(dst));
        eval(R_fcall, R_GlobalEnv);
        UNPROTECT(1);
    }
    /* Set the group operator */
    if (op == R_GE_compositeDest) {
        /* There is no DEST operator in Quartz, but can implement by just 
         * NOT drawing 'src'.
         * This works because DEST is always drawn with the OVER operator. */
    } else {
        xd->blendMode = op;
        CGContextSetBlendMode(layerContext, QuartzOperator(op));
        /* Play the source function to draw the source */
        R_fcall = PROTECT(lang1(src));
        eval(R_fcall, R_GlobalEnv);
        UNPROTECT(1);
    }
    
    xd->appendingGroup = savedGroup;
    xd->appendingType = savedType;

    /* Return group index */
    PROTECT(result = allocVector(INTSXP, 1));
    INTEGER(result)[0] = index;
    UNPROTECT(1);
    return result;
}

static Rboolean QuartzBegin(CGContextRef *ctx,
                            CGLayerRef *layer,
                            QuartzDesc *xd);

static void QuartzEnd(Rboolean grouping,
                      CGLayerRef layer,
                      CGContextRef ctx,
                      CGContextRef savedCTX,
                      QuartzDesc *xd);

static void QuartzUseGroup(SEXP ref, SEXP trans, 
                           CGContextRef ctx, QuartzDesc *xd) {
    int index = INTEGER(ref)[0];

    if (index < 0) {
        warning(_("Groups exhausted"));
        return;
    }

    if (index >= 0 && !xd->groups[index]) {
        warning("Unknown group ");
        return;
    } 

    CGLayerRef layer = xd->groups[index];
    CGPoint contextOrigin = CGPointMake(0 ,0);
    Rboolean grouping = FALSE;
    CGContextRef savedCTX = ctx;
    CGLayerRef implicitLayer;

    if (!xd->appending) {
        grouping = QuartzBegin(&ctx, &implicitLayer, xd);
    }

    CGContextSaveGState(ctx);
    if (trans != R_NilValue) {
        CGAffineTransform transform = 
            CGAffineTransformMake(REAL(trans)[0],
                                  REAL(trans)[3],
                                  REAL(trans)[1],
                                  REAL(trans)[4],
                                  REAL(trans)[2],
                                  REAL(trans)[5]);
        CGContextConcatCTM(ctx, transform);
    } 
    CGContextDrawLayerAtPoint(ctx, contextOrigin, layer);
    CGContextRestoreGState(ctx);    

    if (!xd->appending) {
        QuartzEnd(grouping, implicitLayer, ctx, savedCTX, xd);
    }
}

/* END definitions */

#pragma mark RGD API Function Prototypes

static void     RQuartz_Close(pDevDesc);
static void     RQuartz_Activate(pDevDesc);
static void     RQuartz_Deactivate(pDevDesc);
static void     RQuartz_Size(double*, double*, double*, double*, pDevDesc);
static void     RQuartz_NewPage(const pGEcontext, pDevDesc);
static int      RQuartz_HoldFlush(pDevDesc, int);
static void     RQuartz_Clip(double, double, double, double, pDevDesc);
static double   RQuartz_StrWidth(const char*, const pGEcontext, pDevDesc);
static void     RQuartz_Text(double, double, const char*, double, double, const pGEcontext, pDevDesc);
static void     RQuartz_Rect(double, double, double, double, const pGEcontext, pDevDesc);
static void     RQuartz_Raster(unsigned int *raster, int w, int h,
                       double x, double y, double width, double height,
                       double rot, Rboolean interpolate,
                       const pGEcontext gc, pDevDesc dd);
static SEXP     RQuartz_Cap(pDevDesc dd);
static void     RQuartz_Circle(double, double, double, const pGEcontext, pDevDesc);
static void     RQuartz_Line(double, double, double, double, const pGEcontext, pDevDesc);
static void     RQuartz_Polyline(int, double*, double*, const pGEcontext, pDevDesc);
static void     RQuartz_Polygon(int, double*, double*, const pGEcontext, pDevDesc);
static void     RQuartz_Path(double*, double*, int, int*, Rboolean, const pGEcontext, pDevDesc);
static Rboolean RQuartz_Locator(double*, double*, pDevDesc);
static void     RQuartz_Mode(int mode, pDevDesc);
static void     RQuartz_MetricInfo(int, const pGEcontext , double*, double*, double*, pDevDesc);
static SEXP     RQuartz_setPattern(SEXP pattern, pDevDesc dd);
static void     RQuartz_releasePattern(SEXP ref, pDevDesc dd);
static SEXP     RQuartz_setClipPath(SEXP path, SEXP ref, pDevDesc dd);
static void     RQuartz_releaseClipPath(SEXP ref, pDevDesc dd);
static SEXP     RQuartz_setMask(SEXP path, SEXP ref, pDevDesc dd);
static void     RQuartz_releaseMask(SEXP ref, pDevDesc dd);
static SEXP     RQuartz_defineGroup(SEXP source, int op, SEXP destination, 
                                    pDevDesc dd);
static void     RQuartz_useGroup(SEXP ref, SEXP trans, pDevDesc dd);
static void     RQuartz_releaseGroup(SEXP ref, pDevDesc dd);
static void     RQuartz_stroke(SEXP path, const pGEcontext gc, pDevDesc dd);
static void     RQuartz_fill(SEXP path, int rule, const pGEcontext gc, 
                             pDevDesc dd);
static void     RQuartz_fillStroke(SEXP path, int rule, const pGEcontext gc, 
                                   pDevDesc dd);
static SEXP     RQuartz_capabilities(SEXP cap);
static void     RQuartz_glyph(int n, int *glyphs, double *x, double *y, 
                              SEXP font, double size,
                              int colour, double rot, pDevDesc dd);

#pragma mark Quartz device implementation

void* QuartzDevice_Create(void *_dev, QuartzBackend_t *def)
{
    pDevDesc dev = _dev;

    dev->startfill = def->bg;
    dev->startcol  = R_RGB(0, 0, 0);
    dev->startps   = def->pointsize;
    dev->startfont = 1;
    dev->startlty  = LTY_SOLID;
    dev->startgamma= 1;

    /* Set up some happy pointers */
    dev->close        = RQuartz_Close;
    dev->activate     = RQuartz_Activate;
    dev->deactivate   = RQuartz_Deactivate;
    dev->size         = RQuartz_Size;
    dev->newPage      = RQuartz_NewPage;
    dev->clip         = RQuartz_Clip;
    dev->strWidth     = RQuartz_StrWidth;
    dev->text         = RQuartz_Text;
    dev->rect         = RQuartz_Rect;
    dev->raster       = RQuartz_Raster;
    dev->cap          = RQuartz_Cap;
    dev->circle       = RQuartz_Circle;
    dev->line         = RQuartz_Line;
    dev->polyline     = RQuartz_Polyline;
    dev->polygon      = RQuartz_Polygon;
    dev->path         = RQuartz_Path;
    dev->locator      = RQuartz_Locator;
    dev->mode         = RQuartz_Mode;
    dev->metricInfo   = RQuartz_MetricInfo;
    dev->holdflush    = RQuartz_HoldFlush;
    dev->hasTextUTF8  = TRUE;
    dev->textUTF8     = RQuartz_Text;
    dev->strWidthUTF8 = RQuartz_StrWidth;

    dev->left = 0;
    dev->top  = 0;


    /* Magic numbers from on high. */
    dev->xCharOffset = 0.4900;
    dev->yCharOffset = 0.3333;
    dev->yLineBias   = 0.20; /* This is .2 for PS/PDF devices... */

    dev->canClip       = TRUE;
    dev->canHAdj       = 2;
    dev->canChangeGamma= FALSE;
    dev->displayListOn = (def->flags & QDFLAG_DISPLAY_LIST) ? TRUE : FALSE;

    dev->haveTransparency = 2;
    dev->haveTransparentBg = 3; /* FIXME: depends on underlying device */
    dev->haveRaster = 2;
    dev->haveCapture = (def->cap) ? 2 : 1;
    dev->haveLocator = (def->locatePoint) ? 2 : 1;

    dev->setPattern      = RQuartz_setPattern;
    dev->releasePattern  = RQuartz_releasePattern;
    dev->setClipPath     = RQuartz_setClipPath;
    dev->releaseClipPath = RQuartz_releaseClipPath;
    dev->setMask         = RQuartz_setMask;
    dev->releaseMask     = RQuartz_releaseMask;
    dev->deviceClip      = FALSE;
    dev->defineGroup     = RQuartz_defineGroup;
    dev->useGroup        = RQuartz_useGroup;
    dev->releaseGroup    = RQuartz_releaseGroup;
    dev->stroke          = RQuartz_stroke;
    dev->fill            = RQuartz_fill;
    dev->fillStroke      = RQuartz_fillStroke;
    dev->capabilities    = RQuartz_capabilities;
    dev->glyph           = RQuartz_glyph;
    dev->deviceVersion   = R_GE_glyphs;

    QuartzDesc *qd = calloc(1, sizeof(QuartzDesc));
    qd->width      = def->width;
    qd->height     = def->height;
    qd->userInfo   = def->userInfo;
    qd->getCGContext=def->getCGContext;
    qd->locatePoint= def->locatePoint;
    qd->close      = def->close;
    qd->newPage    = def->newPage;
    qd->state      = def->state;
    qd->sync       = def->sync;
    qd->cap        = def->cap;
    qd->scalex     = def->scalex;
    qd->scaley     = def->scaley;
    qd->tscale     = 1.0;
    qd->ps         = def->pointsize;
    qd->bg         = def->bg;
    qd->canvas     = def->canvas;
    qd->antialias  = (def->flags & QPFLAG_ANTIALIAS) ? 1 : 0;
    qd->flags      = def->flags;
    qd->gstate     = 0;
    qd->font       = NULL;

    QuartzInitPatterns(qd);
    QuartzInitClipPaths(qd);
    QuartzInitMasks(qd);
    QuartzInitGroups(qd);
    qd->appending = 0;
    qd->appendingType = QNoAppend;
    qd->blendMode = R_GE_compositeOver;

    dev->deviceSpecific = qd;
    qd->dev             = dev;

    QuartzDevice_Update(qd);

    /* Re-set for bitmap devices later */
     dev->right = def->width*72.0;
     dev->bottom= def->height*72.0;

    qd->clipRect = CGRectMake(0, 0, dev->right, dev->bottom);

    qd->dirty = 0;
    qd->redraw= 0;
    qd->async = 0;
    qd->holdlevel = 0;
    return (QuartzDesc_t)qd;
}

static QuartzFunctions_t qfn = {
    QuartzDevice_Create,
    QuartzDevice_DevNumber,
    QuartzDevice_Kill,
    QuartzDevice_ResetContext,
    QuartzDevice_GetWidth,
    QuartzDevice_GetHeight,
    QuartzDevice_SetSize,
    QuartzDevice_GetScaledWidth,
    QuartzDevice_GetScaledHeight,
    QuartzDevice_SetScaledSize,
    QuartzDevice_GetXScale,
    QuartzDevice_GetYScale,
    QuartzDevice_SetScale,
    QuartzDevice_SetTextScale,
    QuartzDevice_GetTextScale,
    QuartzDevice_SetPointSize,
    QuartzDevice_GetPointSize,
    QuartzDevice_GetDirty,
    QuartzDevice_SetDirty,
    QuartzDevice_ReplayDisplayList,
    QuartzDevice_GetSnapshot,
    QuartzDevice_RestoreSnapshot,
    QuartzDevice_GetAntialias,
    QuartzDevice_SetAntialias,
    QuartzDevice_GetBackground,
    QuartzDevice_Activate,
    QuartzDevice_SetParameter,
    QuartzDevice_GetParameter
};

/* currrently unused: was used by R.app via aqua.c */
QuartzFunctions_t *getQuartzAPI(void) {
    return &qfn;
}

/*
 ***************************
 * Fonts
 ***************************
 */

/* old macOS versions has different names for some of the CGFont stuff */
#if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_4
#define CGFontCreateWithFontName CGFontCreateWithName
#define CGFontGetGlyphBBoxes CGFontGetGlyphBoundingBoxes
/* The following is a real pain. We have to work around bugs in CoreGraphics
   and Apple's dyloader simultaneously so a 10.4 binary runs on 10.5 as well. */
typedef void (*RQFontGetGlyphsForUnichars_t)(CGFontRef a, const UniChar b[], CGGlyph c[], size_t d);
static RQFontGetGlyphsForUnichars_t RQFontGetGlyphsForUnichars;
#include <dlfcn.h> /* dynamically find the right entry point on initialization */
__attribute__((constructor)) static void RQ_init() {
    void *r;
    if ((r = dlsym(RTLD_NEXT, "CGFontGetGlyphsForUnichars")) || (r = dlsym(RTLD_NEXT, "CGFontGetGlyphsForUnicodes")) ||
	(r = dlsym(RTLD_DEFAULT, "CGFontGetGlyphsForUnichars")) || (r = dlsym(RTLD_DEFAULT, "CGFontGetGlyphsForUnicodes")))
	RQFontGetGlyphsForUnichars = (RQFontGetGlyphsForUnichars_t) r;
    else
	error("Cannot load CoreGraphics"); /* this should never be reached but I suppose it's better than a hidden segfault */
}
#define CGFontGetGlyphsForUnichars RQFontGetGlyphsForUnichars
/* and some missing declarations */
extern CGFontRef CGFontCreateWithName(CFStringRef);
extern bool CGFontGetGlyphAdvances(CGFontRef font, const CGGlyph glyphs[], size_t count, int advances[]);
extern int CGFontGetUnitsPerEm(CGFontRef font);
extern bool CGFontGetGlyphBBoxes(CGFontRef font, const CGGlyph glyphs[], size_t count, CGRect bboxes[]);
#else
extern void CGFontGetGlyphsForUnichars(CGFontRef, const UniChar[], CGGlyph[], size_t);
#endif

extern CGFontRef CGContextGetFont(CGContextRef);

#define DEVDESC pDevDesc dd
#define CTXDESC const pGEcontext gc, pDevDesc dd

#define DEVSPEC QuartzDesc *xd = (QuartzDesc*) dd->deviceSpecific; CGContextRef ctx = QuartzGetCurrentContext(xd)
#define DRAWSPEC QuartzDesc *xd = (QuartzDesc*) dd->deviceSpecific; CGContextRef ctx = QuartzGetCurrentContext(xd); xd->dirty = 1
#define XD QuartzDesc *xd = (QuartzDesc*) dd->deviceSpecific

#pragma mark Quartz Font Cache

/* Font lookup is expesive yet frequent. Therefore we cache all used CG fonts (which are global to the app). */

typedef struct font_cache_entry_s {
    CGFontRef font;
    char *family;
    int  face;
} font_cache_entry_t;

#define max_fonts_per_block 32

typedef struct font_cache_s {
    font_cache_entry_t e[max_fonts_per_block];
    int fonts;
    struct font_cache_s *next;
} font_cache_t;

font_cache_t font_cache, *font_cache_tail = &font_cache;

static CGFontRef RQuartz_CacheGetFont(const char *family, int face) {
    font_cache_t *fc = &font_cache;
    while (fc) {
        int i = 0, j = fc->fonts;
        while (i < j) {
            if (face == fc->e[i].face && streql(family, fc->e[i].family))
                return fc->e[i].font;
            i++;
        }
        fc = fc->next;
    }
    return 0;
}

static void RQuartz_CacheAddFont(const char *family, int face, CGFontRef font) {
    if (font_cache_tail->fonts >= max_fonts_per_block)
        font_cache_tail = font_cache_tail->next = (font_cache_t*) calloc(1, sizeof(font_cache_t));
    {
        int i = font_cache_tail->fonts;
        font_cache_tail->e[i].font = font;
        font_cache_tail->e[i].family = Rstrdup(family);
        font_cache_tail->e[i].face = face;
        font_cache_tail->fonts++;
    }
}

#ifdef UNUSED
static void RQuartz_CacheRelease() {
    font_cache_t *fc = &font_cache;
    while (fc) {
        font_cache_t *next = fc->next;
        int i = 0, j = fc->fonts;
        while (i < j) free(fc->e[i++].family);
        if (fc != &font_cache) free(fc);
        fc = next;
    }
    font_cache.fonts = 0;
}
#endif

#pragma mark Device Implementation

/* mapping of virtual family names (e.g "serif") and face to real font names using .Quartzenv$.Quartz.Fonts list */
const char *RQuartz_LookUpFontName(int fontface, const char *fontfamily)
{
    const char *mappedFont = 0;
    SEXP ns, env, db, names;
    PROTECT_INDEX index;
    PROTECT(ns = R_FindNamespace(ScalarString(mkChar("grDevices"))));
    PROTECT_WITH_INDEX(env = findVar(install(".Quartzenv"), ns), &index);
    if(TYPEOF(env) == PROMSXP)
        REPROTECT(env = eval(env,ns) ,index);
    PROTECT(db    = findVar(install(".Quartz.Fonts"), env));
    PROTECT(names = getAttrib(db, R_NamesSymbol));
    if (*fontfamily) {
        int i;
        for(i = 0; i < length(names); i++)
            if(streql(fontfamily, CHAR(STRING_ELT(names, i)))) {
                mappedFont = CHAR(STRING_ELT(VECTOR_ELT(db, i), fontface - 1));
                break;
            }
    }
    UNPROTECT(4);
    return mappedFont;
}

/* get a font according to the current graphics context */
CGFontRef RQuartz_Font(CTXDESC)
{
    const char *fontName = NULL, *fontFamily = gc->fontfamily;
    CGFontRef cgFont = 0;
    int fontFace = gc->fontface;
    if (fontFace < 1 || fontFace > 5) fontFace = 1; /* just being paranoid */
    if (fontFace == 5)
        fontName = "Symbol";
    else
        fontName = RQuartz_LookUpFontName(fontFace, fontFamily[0] ? fontFamily : "default");
    if (fontName) {
        cgFont = RQuartz_CacheGetFont(fontName, 0); /* face is 0 because we are passing a true font name */
        if (!cgFont) { /* not in the cache, get it */
            CFStringRef cfFontName = CFStringCreateWithCString(NULL, fontName, kCFStringEncodingUTF8);
            cgFont = CGFontCreateWithFontName(cfFontName);
            CFRelease(cfFontName);
            if (!cgFont) {
                warning(_("font \"%s\" could not be found for family \"%s\""), fontName, fontFamily);
                return NULL;
            }
            RQuartz_CacheAddFont(fontName, 0, cgFont);
        }
    } else { /* the real font name could not be looked up. We must use cache and/or find the right font by family and face */
        if (!fontFamily[0]) fontFamily = "Arial"; 
	/* Arial is the default, because Helvetica doesn't have Oblique 
	   on 10.4 - maybe change later? */
        cgFont = RQuartz_CacheGetFont(fontFamily, fontFace);
        if (!cgFont) { /* not in the cache? Then we need to find the 
			   proper font name from the family name and face */
            /* as it turns out kATSFontFilterSelectorFontFamily is not 
	       implemented in macOS (!!) so there is no way to query for a 
	       font from a specific family. Therefore we have to use 
	       text-matching heuristics ... very nasty ... */
            char compositeFontName[256];
            /* CFStringRef cfFontName; */
            if (strlen(fontFamily) > 210) error(_("font family name is too long"));
            while (!cgFont) { /* try different faces until exhausted or successful */
                strcpy(compositeFontName, fontFamily);
                if (fontFace == 2 || fontFace == 4) strcat(compositeFontName, " Bold");
                if (fontFace == 3 || fontFace == 4) strcat(compositeFontName, " Italic");
                CFStringRef cfFontName = CFStringCreateWithCString(NULL, compositeFontName, kCFStringEncodingUTF8);
                cgFont = CGFontCreateWithFontName(cfFontName);
                CFRelease(cfFontName);
                if (!cgFont) {
                    if (fontFace == 1) { /* more guessing - fontFace == 1 may need Regular or Roman */
                        strcat(compositeFontName," Regular");
                        cfFontName = CFStringCreateWithCString(NULL, compositeFontName, kCFStringEncodingUTF8);
                        cgFont = CGFontCreateWithFontName(cfFontName);
                        CFRelease(cfFontName);
                        if (!cgFont) {
                            strcpy(compositeFontName, fontFamily);
                            strcat(compositeFontName," Roman");
                            cfFontName = CFStringCreateWithCString(NULL, compositeFontName, kCFStringEncodingUTF8);
                            cgFont = CGFontCreateWithFontName(cfFontName);
                            CFRelease(cfFontName);
                        }
                    } else if (fontFace == 3 || fontFace == 4) { /* Oblique is sometimes used instead of Italic (e.g. in Helvetica) */
                        strcpy(compositeFontName, fontFamily);
                        if (fontFace == 4) strcat(compositeFontName, " Bold");
                        strcat(compositeFontName," Oblique");
                        cfFontName = CFStringCreateWithCString(NULL, compositeFontName, kCFStringEncodingUTF8);
                        cgFont = CGFontCreateWithFontName(cfFontName);
                        CFRelease(cfFontName);                    
                    }
                }
                if (!cgFont) { /* try to fall back to a more plain face */
                    if (fontFace == 4) fontFace = 2;
                    else if (fontFace != 1) fontFace = 1;
                    else break;
                    cgFont = RQuartz_CacheGetFont(fontFamily, fontFace);
                    if (cgFont) break;
                }
            }
            if (!cgFont)
                warning(_("no font could be found for family \"%s\""), fontFamily);
            else
                RQuartz_CacheAddFont(fontFamily, fontFace, cgFont);
        }
    }

    return cgFont;
}

#define RQUARTZ_FILL   (1)
#define RQUARTZ_STROKE (1<<1)
#define RQUARTZ_LINE   (1<<2)

static void RQuartz_SetFont(CGContextRef ctx, const pGEcontext gc, QuartzDesc *xd) {
    CGFontRef font = RQuartz_Font(gc, NULL);
    if (font) {
        CGContextSetFont(ctx, font);
        if (font != xd->font) {
            if (xd->font) CGFontRelease(xd->font);
            CGFontRetain(font);
            xd->font = font;
        }
    }
    CGContextSetFontSize(ctx, gc->cex * gc->ps);
}

/* pre-10.5 doesn't have kCGColorSpaceGenericRGB so fall back to kCGColorSpaceGenericRGB */
#if MAC_OS_X_VERSION_10_4 >= MAC_OS_X_VERSION_MAX_ALLOWED
#define kCGColorSpaceSRGB kCGColorSpaceGenericRGB
#endif

void RQuartz_Set(CGContextRef ctx,const pGEcontext gc,int flags) {
    CGColorSpaceRef cs = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
    if(flags & RQUARTZ_FILL) {
        int fill = gc->fill;
        CGFloat fillColor[] = { R_RED(fill)/255.0, 
                                R_GREEN(fill)/255.0, 
                                R_BLUE(fill)/255.0, 
                                R_ALPHA(fill)/255.0 };
        CGColorRef fillColorRef = CGColorCreate(cs, fillColor);
        CGContextSetFillColorWithColor(ctx, fillColorRef);
        CGColorRelease(fillColorRef);
    }
    if(flags & RQUARTZ_STROKE) {
        int stroke = gc->col;
        CGFloat strokeColor[] = { R_RED(stroke)/255.0, 
                                  R_GREEN(stroke)/255.0, 
                                  R_BLUE(stroke)/255.0, 
                                  R_ALPHA(stroke)/255.0 };
        CGColorRef strokeColorRef = CGColorCreate(cs, strokeColor);
        CGContextSetStrokeColorWithColor(ctx, strokeColorRef);
        CGColorRelease(strokeColorRef);
    }
    if(flags & RQUARTZ_LINE) {
        CGFloat dashlist[8];
        int   i, ndash = 0;
        int   lty = gc->lty;
	float lwd = (float)(gc->lwd * 0.75);
        CGContextSetLineWidth(ctx, lwd);

        for(i = 0; i < 8 && lty; i++) {
            dashlist[ndash++] = (lwd >= 1 ? lwd : 1) * (lty & 15);
            lty >>= 4;
        }
        CGContextSetLineDash(ctx, 0, dashlist, ndash);
        CGLineCap cap = kCGLineCapButt;
        switch(gc->lend) {
            case GE_ROUND_CAP:  cap = kCGLineCapRound;  break;
            case GE_BUTT_CAP:   cap = kCGLineCapButt;   break;
            case GE_SQUARE_CAP: cap = kCGLineCapSquare; break;
        }
        CGContextSetLineCap(ctx,cap);
        CGLineJoin join = kCGLineJoinRound;
        switch(gc->ljoin) {
            case GE_ROUND_JOIN: join = kCGLineJoinRound; break;
            case GE_MITRE_JOIN: join = kCGLineJoinMiter; break;
            case GE_BEVEL_JOIN: join = kCGLineJoinBevel; break;
        }
        CGContextSetLineJoin(ctx, join);
        CGContextSetMiterLimit(ctx, gc->lmitre);
    }
    CGColorSpaceRelease(cs);
}

#define SET(X) RQuartz_Set(ctx, gc, (X))
#define NOCTX { xd->async = 1; return; }
#define NOCTXR(V) { xd->async = 1; return(V); }


static void RQuartz_Close(DEVDESC)
{
    XD;
    if (xd->close) xd->close(xd, xd->userInfo);
    QuartzDestroyPatterns(xd);
    QuartzDestroyClipPaths(xd);
    QuartzDestroyMasks(xd);
    QuartzDestroyGroups(xd);
}

static void RQuartz_Activate(DEVDESC)
{
    XD;
    if (xd->state) xd->state(xd, xd->userInfo, 1);
}

static void RQuartz_Deactivate(DEVDESC)
{
    XD;
    if (xd->state) xd->state(xd, xd->userInfo, 0);
}

static void RQuartz_Size(double *left, double *right, double *bottom, double *top, DEVDESC)
{
    XD;
    *left = *top = 0;
    *right  = QuartzDevice_GetWidth(xd) * 72.0;
    *bottom = QuartzDevice_GetHeight(xd) * 72.0;
}

static void RQuartz_NewPage(CTXDESC)
{
    {
        DRAWSPEC;
        ctx = NULL;
        if (xd->newPage) xd->newPage(xd, xd->userInfo, xd->redraw ? QNPF_REDRAW : 0);
    }
    { /* we have to re-fetch the status *after* newPage since it may have changed it */
        DRAWSPEC;
        if (!ctx) NOCTX;
        {
            xd->appendingPattern = -1;
            xd->appendingGroup = -1;
            xd->appendingType = QNoAppend;
            xd->blendMode = R_GE_compositeOver;

            CGRect bounds = CGRectMake(0, 0,
				       QuartzDevice_GetScaledWidth(xd) * 72.0,
				       QuartzDevice_GetScaledHeight(xd) * 72.0);
	    /* reset the clipping region by restoring the base GC.
	       If there is no GC on the stack then the clipping region was never set. */
	    if (xd->gstate > 0) {
		CGContextRestoreGState(ctx);
		CGContextSaveGState(ctx);
		/* no need to modify gstate since we don't modify the stack */
	    }
	    /* The logic is to paint the canvas then gc->fill.
	       (The canvas colour is set to 0 on non-screen devices.)
	     */
	    if (R_ALPHA(xd->canvas) > 0 && !R_OPAQUE(gc->fill)) {
		/* Paint the canvas colour. */
		int savefill = gc->fill;
		CGContextClearRect(ctx, bounds);
		gc->fill = xd->canvas;
		SET(RQUARTZ_FILL);
		CGContextFillRect(ctx, bounds);
		gc->fill = savefill;
	    }
	    SET(RQUARTZ_FILL); /* this will fill with gc->fill */
            CGContextFillRect(ctx, bounds);
        }
    }
}

static int RQuartz_HoldFlush(DEVDESC, int level)
{
    int ol;
    XD;
    /* FIXME: should we check for interactive? */
    ol = xd->holdlevel;
    xd->holdlevel += level;
    if (xd->holdlevel < 0) xd->holdlevel = 0;
    if (xd->holdlevel == 0) { /* flush */
	/* trigger flush */
        if (xd->sync)
            xd->sync(xd, xd->userInfo);
        else {
	    CGContextRef ctx = xd->getCGContext(xd, xd->userInfo);
	    if (ctx)
		CGContextSynchronize(ctx);
	}
    } else if (ol == 0) { /* first hold */
	/* could display a wait cursor or something ... */
    }
    return xd->holdlevel;
}

static void RQuartz_Clip(double x0, double x1, double y0, double y1, DEVDESC)
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    if(xd->gstate > 0) {
        --xd->gstate;
        CGContextRestoreGState(ctx);
    }
    CGContextSaveGState(ctx);
    xd->gstate++;
    if(x1 > x0) { double t = x1; x1 = x0;x0 = t; }
    if(y1 > y0) { double t = y1; y1 = y0;y0 = t; }
    xd->clipRect = CGRectMake(x0, y0, x1 - x0, y1 - y0);
    CGContextClipToRect(ctx, xd->clipRect);
}

/* non-symbol text is sent in UTF-8 */
static CFStringRef text2unichar(CTXDESC, const char *text, UniChar **buffer, int *free)
{
    CFStringRef str;
    if(gc->fontface == 5)
        str = CFStringCreateWithCString(NULL, text, kCFStringEncodingMacSymbol);
    else {
        str = CFStringCreateWithCString(NULL, text, kCFStringEncodingUTF8);
        /* Try fallback Latin1 encoding if UTF8 doesn't work 
	   -- should no longer be needed. */
        if(!str)
            CFStringCreateWithCString(NULL, text, kCFStringEncodingISOLatin1);
    }
    if (!str) return NULL;
    *buffer = (UniChar*) CFStringGetCharactersPtr(str);
    if (*buffer == NULL) {
        CFIndex length = CFStringGetLength(str);
        *buffer = malloc(length * sizeof(UniChar));
	if (buffer == NULL) error("allocation failure in text2unichar");
        CFStringGetCharacters(str, CFRangeMake(0, length), *buffer);
        *free = 1;
    }
    return str;
}

static double RQuartz_StrWidth(const char *text, CTXDESC)
{
    DEVSPEC;

    CGFontRef font = 0;
    if (!ctx) { /* if there is no context then don't set the font */
        xd->async = 1; /* flag us as not having a context */
        font = RQuartz_Font(gc, NULL);
        if (!font) return (strlen(text) * 10.0); /* for sanity reasons */
    } else {
        RQuartz_SetFont(ctx, gc, xd);
        font = CGContextGetFont(ctx);
    }
    float aScale   = (float)((gc->cex * gc->ps * xd->tscale) /
			     CGFontGetUnitsPerEm(font));
    UniChar *buffer;
    CGGlyph *glyphs;
    int     *advances;
    int Free = 0, len;
    CFStringRef str = text2unichar(gc, dd, text, &buffer, &Free);
    if (!str) return 0.0; /* invalid text contents */
    len = (int) CFStringGetLength(str);
    glyphs = malloc(sizeof(CGGlyph) * len);
    if (!glyphs) error("allocation failure in RQuartz_StrWidth");
    advances = malloc(sizeof(int) * len);
    if (!advances) error("allocation failure in RQuartz_StrWidth");
    CGFontGetGlyphsForUnichars(font, buffer, glyphs, len);
    CGFontGetGlyphAdvances(font, glyphs, len, advances);
    float width = 0.0; /* aScale*CGFontGetLeading(CGContextGetFont(ctx)); */
    for(int i = 0; i < len; i++) width += aScale * advances[i];
    free(advances);
    free(glyphs);
    if(Free) free(buffer);
    CFRelease(str);
    return width;
}

static void RQuartz_Text(double x, double y, const char *text, double rot, double hadj, CTXDESC)
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    /* Not able to add glyphs to the current path. */
    if (xd->appending) 
        return;

    Rboolean grouping = QuartzBegin(&ctx, &layer, xd);

    /* A stupid hack because R isn't consistent. */
    int fill = gc->fill;
    gc->fill = gc->col;
    SET(RQUARTZ_FILL | RQUARTZ_STROKE);
    RQuartz_SetFont(ctx, gc, xd);
    gc->fill = fill;
    CGFontRef font = CGContextGetFont(ctx);
    float aScale   = (float) ((gc->cex * gc->ps * xd->tscale) /
			      CGFontGetUnitsPerEm(font));
    UniChar *buffer;
    CGGlyph   *glyphs;

    int Free = 0, len, i;
    float width = 0.0;
    CFStringRef str = text2unichar(gc, dd, text, &buffer, &Free);
    if (!str) return; /* invalid text contents */
    len = (int) CFStringGetLength(str);
    glyphs = malloc(sizeof(CGGlyph) * len);
    if (!glyphs) error("allocation failure in RQuartz_Text");
    CGFontGetGlyphsForUnichars(font, buffer, glyphs, len);
    int      *advances = malloc(sizeof(int) * len);
    CGSize   *g_adv    = malloc(sizeof(CGSize) * len);

    CGFontGetGlyphAdvances(font, glyphs, len, advances);
    for(i =0 ; i < len; i++) {
	width += advances[i] * aScale;
	g_adv[i] = CGSizeMake(aScale * advances[i] * cos(-DEG2RAD*rot), aScale*advances[i]*sin(-DEG2RAD * rot));
    }
    free(advances);
    CGContextSetTextMatrix(ctx,
			   CGAffineTransformConcat(CGAffineTransformMakeScale(1.0, -1.0),
						   CGAffineTransformMakeRotation(-DEG2RAD * rot)));
    double ax = (width * hadj) * cos(-DEG2RAD * rot);
    double ay = (width * hadj) * sin(-DEG2RAD * rot);
    /*      double h  = CGFontGetXHeight(CGContextGetFont(ctx))*aScale; */
    CGContextSetTextPosition(ctx, x - ax, y - ay);
    /*      Rprintf("%s,%.2f %.2f (%.2f,%.2f) (%d,%f)\n",text,hadj,width,ax,ay,CGFontGetUnitsPerEm(CGContextGetFont(ctx)),CGContextGetFontSize(ctx));       */
    CGContextShowGlyphsWithAdvances(ctx,glyphs, g_adv, len);

    QuartzEnd(grouping, layer, ctx, savedCTX, xd);

    free(glyphs);
    free(g_adv);
    if(Free) free(buffer);
    CFRelease(str);
}

static Rboolean implicitGroup(QuartzDesc *xd) {
    int op = xd->blendMode;
    return xd->appendingGroup >= 0 &&
        (op == R_GE_compositeClear ||
         op == R_GE_compositeSource ||
         op == R_GE_compositeIn ||
         op == R_GE_compositeOut ||
         op == R_GE_compositeDestIn ||
         op == R_GE_compositeDestAtop);
}

static Rboolean QuartzBegin(CGContextRef *ctx,
                            CGLayerRef *layer,
                            QuartzDesc *xd)
{
    double devWidth, devHeight;
    Rboolean grouping = implicitGroup(xd);
    if (grouping) {
        devWidth = QuartzDevice_GetScaledWidth(xd);
        devHeight = QuartzDevice_GetScaledHeight(xd);
        *layer = CGLayerCreateWithContext(*ctx, 
                                          CGSizeMake(devWidth, devHeight), 
                                          NULL);
        *ctx = CGLayerGetContext(*layer);
    }
    if (xd->currentMask >= 0) {
        /* Set the clipping region from the mask */
        CGContextSaveGState(*ctx); 
        devWidth = QuartzDevice_GetScaledWidth(xd);
        devHeight = QuartzDevice_GetScaledHeight(xd);
        CGContextClipToMask(*ctx, CGRectMake(0, 0, devWidth, devHeight), 
                            xd->masks[xd->currentMask]->mask);
    }
    return grouping;
}

static void QuartzEnd(Rboolean grouping,
                      CGLayerRef layer,
                      CGContextRef ctx,
                      CGContextRef savedCTX,
                      QuartzDesc *xd)
{
    if (xd->currentMask >= 0) {
        CGContextRestoreGState(ctx); 
    }
    if (grouping) {
        CGContextDrawLayerAtPoint(savedCTX, CGPointMake(0, 0), layer);
        CGLayerRelease(layer);
    }
}

static void qFill(CGContextRef ctx, const pGEcontext gc, QuartzDesc *xd,
                  Rboolean winding) 
{
    SET(RQUARTZ_FILL);
    if (QuartzGradientFill(gc->patternFill, xd)) {
        if (!CGContextIsPathEmpty(ctx)) {
            CGContextSaveGState(ctx);
            if (winding)
                CGContextClip(ctx);
            else
                CGContextEOClip(ctx);            
            QuartzDrawGradientFill(ctx, gc->patternFill, xd);
            CGContextRestoreGState(ctx);
        }
    } else {
        if (QuartzPatternFill(gc->patternFill, xd)) {
            /* Override simple colour fill */
            QuartzSetPatternFill(ctx, gc->patternFill, xd);
        }
        if (winding)
            CGContextDrawPath(ctx, kCGPathFill);
        else 
            CGContextDrawPath(ctx, kCGPathEOFill);
    }
}

static void QuartzFill(CGContextRef ctx, const pGEcontext gc, QuartzDesc *xd) 
{
    qFill(ctx, gc, xd, TRUE);
}

static void QuartzEOFill(CGContextRef ctx, const pGEcontext gc, QuartzDesc *xd) 
{
    qFill(ctx, gc, xd, FALSE);
}

static void QuartzStroke(CGContextRef ctx, const pGEcontext gc, QuartzDesc *xd) 
{
    SET(RQUARTZ_STROKE | RQUARTZ_LINE);
    CGContextDrawPath(ctx, kCGPathStroke);
}

static void QuartzRectPath(double x0, double y0, double x1, double y1,
                           CGContextRef ctx)
{
    CGContextAddRect(ctx, CGRectMake(x0, y0, x1 - x0, y1 - y0));
}

static void QuartzRect(double x0, double y0, double x1, double y1, 
                       CGContextRef ctx, const pGEcontext gc, 
                       QuartzDesc *xd, int op)
{
    Rboolean grouping;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    grouping = QuartzBegin(&ctx, &layer, xd);
    CGContextBeginPath(ctx);
    QuartzRectPath(x0, y0, x1, y1, ctx);
    if (op) {
        QuartzFill(ctx, gc, xd);
    } else {
        QuartzStroke(ctx, gc, xd);
    }
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_Rect(double x0, double y0, double x1, double y1, CTXDESC)
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    if (xd->flags & QDFLAG_RASTERIZED) {
        /* in the case of borderless rectangles snap them to pixels.
           this solves issues with image() without introducing other artifacts.
           other approaches (disabling anti-aliasing, drawing background first,
           snapping rect with borders) don't work as well, because they have
           unwanted visual side-effects. */
        if (R_ALPHA(gc->fill) > 0 && R_ALPHA(gc->col) == 0) {
	    /* store original values in case we need to go back */
	    double ox0 = x0, ox1 = x1, oy0 = y0, oy1 = y1;
            x0 = (round(x0 * xd->scalex)) / xd->scalex;
            x1 = (round(x1 * xd->scalex)) / xd->scalex;
            y0 = (round(y0 * xd->scaley)) / xd->scaley;
            y1 = (round(y1 * xd->scaley)) / xd->scaley;
	    /* work-around for PR#13744 - make sure the width or height
	       does not drop to 0 because of aligning. */
	    if (x0 == x1 && (ox0 != ox1)) x1 += ox1 - ox0;
	    if (y0 == y1 && (oy0 != oy1)) y1 += oy1 - oy0;
        }
    }

    if (xd->appending) {
        QuartzRectPath(x0, y0, x1, y1, ctx);
    } else {
        Rboolean fill = (gc->patternFill != R_NilValue) || 
            (R_ALPHA(gc->fill) > 0);
        Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
        if (fill && stroke) {
            QuartzRect(x0, y0, x1, y1, ctx, gc, xd, 1); /* fill */
            QuartzRect(x0, y0, x1, y1, ctx, gc, xd, 0); /* stroke */
        } else if (fill) {
            QuartzRect(x0, y0, x1, y1, ctx, gc, xd, 1);
        } else if (stroke) {
            QuartzRect(x0, y0, x1, y1, ctx, gc, xd, 0);
        }        
    }
}

static void RQuartz_Raster(unsigned int *raster, int w, int h,
                           double x, double y, 
                           double width, double height,
                           double rot, 
                           Rboolean interpolate,
                           const pGEcontext gc, pDevDesc dd)
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    CGDataProviderRef dp;
    CGColorSpaceRef cs;
    CGImageRef img;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    /* 
     * A raster image adds nothing to a (clipping) path
     */
    if (xd->appending) 
        return;
    
    /* Create a "data provider" containing the raster data */
    dp = CGDataProviderCreateWithData(NULL, (void *) raster, 4*w*h, NULL);

    cs = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);

    /* Create a quartz image from the data provider */
    img = CGImageCreate(w, h, 
                        8,   /* bits per channel */
                        32,  /* bits per pixel */
                        4*w, /* bytes per row */
                        cs,  /* color space */
			/* R uses AGBR which is so unusual (inverted RGBA) that it corresponds to endinness inverse(!) to the host with alpha last (=RGBA).  */
#ifdef __BIG_ENDIAN__
                        kCGImageAlphaLast | kCGBitmapByteOrder32Little,
#else
                        kCGImageAlphaLast | kCGBitmapByteOrder32Big,
#endif
                        dp,  /* data provider */
                        NULL,/* decode array */
                        1,   /* interpolate (interpolation type below) */
                        kCGRenderingIntentDefault);

    if (height < 0) {
        y = y + height;
        height = -height;
    }

    Rboolean grouping = QuartzBegin(&ctx, &layer, xd);

    CGContextSaveGState(ctx);
    /* Translate by height of image */
    CGContextTranslateCTM(ctx, 0.0, height);
    /* Flip vertical */
    CGContextScaleCTM(ctx, 1.0, -1.0);
    /* Translate to position */
    CGContextTranslateCTM(ctx, x, -y);
    /* Rotate */
    CGContextRotateCTM(ctx, rot*M_PI/180.0);
    /* Determine interpolation method */
    if (interpolate)
        CGContextSetInterpolationQuality(ctx, kCGInterpolationDefault);
    else
        CGContextSetInterpolationQuality(ctx, kCGInterpolationNone);
    /* Draw the quartz image */
    CGContextDrawImage(ctx, CGRectMake(0, 0, width, height), img);
    CGContextRestoreGState(ctx);

    QuartzEnd(grouping, layer, ctx, savedCTX, xd);

    /* Tidy up */
    CGColorSpaceRelease(cs);
    CGDataProviderRelease(dp);
    CGImageRelease(img);
}

static SEXP RQuartz_Cap(pDevDesc dd)
{
    SEXP raster = R_NilValue;
    DRAWSPEC;
    if (!ctx) NOCTXR(raster);

    if (xd->cap) 
        raster = (SEXP) xd->cap(xd, xd->userInfo);

    return raster;
}

static void QuartzCirclePath(double x, double y, double r,
                             CGContextRef ctx)
{
    double r2 = 2.0*r;
    CGContextAddEllipseInRect(ctx, CGRectMake(x-r, y-r, r2, r2));
}

static void QuartzCircle(double x, double y, double r,
                         CGContextRef ctx, const pGEcontext gc, 
                         QuartzDesc *xd, int op)
{
    Rboolean grouping;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    grouping = QuartzBegin(&ctx, &layer, xd);
    CGContextBeginPath(ctx);
    QuartzCirclePath(x, y, r, ctx);
    if (op) {
        QuartzFill(ctx, gc, xd);
    } else {
        QuartzStroke(ctx, gc, xd);
    }
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_Circle(double x, double y, double r, CTXDESC)
{
    DRAWSPEC;
    if (!ctx) NOCTX;

    if (xd->appending) {
        QuartzCirclePath(x, y, r, ctx);
    } else {
        Rboolean fill = (gc->patternFill != R_NilValue) || 
            (R_ALPHA(gc->fill) > 0);
        Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
        if (fill && stroke) {
            QuartzCircle(x, y, r, ctx, gc, xd, 1); /* fill */
            QuartzCircle(x, y, r, ctx, gc, xd, 0); /* stroke */
        } else if (fill) {
            QuartzCircle(x, y, r, ctx, gc, xd, 1);
        } else if (stroke) {
            QuartzCircle(x, y, r, ctx, gc, xd, 0);
        }        
    }
}

static void QuartzLinePath(double x1, double y1, double x2, double y2,
                           CGContextRef ctx)
{
    CGContextMoveToPoint(ctx, x1, y1);
    CGContextAddLineToPoint(ctx, x2, y2);
}
    
static void QuartzLine(double x1, double y1, double x2, double y2,
                       CGContextRef ctx, const pGEcontext gc, 
                       QuartzDesc *xd)
{
    Rboolean grouping;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    grouping = QuartzBegin(&ctx, &layer, xd);
    CGContextBeginPath(ctx);
    QuartzLinePath(x1, y1, x2, y2, ctx);
    QuartzStroke(ctx, gc, xd);
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_Line(double x1, double y1, double x2, double y2, CTXDESC)
{
    DRAWSPEC;
    if (!ctx) NOCTX;

    if (xd->appending) {
        QuartzLinePath(x1, y1, x2, y2, ctx);
    } else {
        Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
        if (stroke) {
            QuartzLine(x1, y1, x2, y2, ctx, gc, xd);
        }        
    }
}

static void QuartzPolylinePath(int n, double *x, double *y,
                               CGContextRef ctx)
{
    /* CGContextStrokeLineSegments turned out to be a bad idea due to
       Leopard restarting dashes for each segment.
       CGContextAddLineToPoint is fast enough. 
       R < 4.2.0 broke up paths of more than 100 points, but that
       causes issues with dashing since the phase is reset for all
       subpaths, e.g: plot(log10(1:1e4), lty = 2, type="l")
       so now we create one path and hope the rendering engine is
       good enough. */
    int i = 0;
    CGContextMoveToPoint(ctx, x[0], y[0]);
    while(++i < n)
	CGContextAddLineToPoint(ctx, x[i], y[i]);
}

static void QuartzPolyline(int n, double *x, double *y,
                           CGContextRef ctx, const pGEcontext gc, 
                           QuartzDesc *xd)
{
    Rboolean grouping;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    grouping = QuartzBegin(&ctx, &layer, xd);
    CGContextBeginPath(ctx);
    QuartzPolylinePath(n, x, y, ctx);
    QuartzStroke(ctx, gc, xd);
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_Polyline(int n, double *x, double *y, CTXDESC)
{
    if (n < 2) return;
    DRAWSPEC;
    if (!ctx) NOCTX;

    if (xd->appending) {
        QuartzPolylinePath(n, x, y, ctx);
    } else {
        Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
        if (stroke) {
            QuartzPolyline(n, x, y, ctx, gc, xd);
        }        
    }
}

static void QuartzPolygonPath(int n, double *x, double *y,
                              CGContextRef ctx)
{
    int i;
    CGContextMoveToPoint(ctx, x[0], y[0]);
    for(i = 1; i < n; i++)
	CGContextAddLineToPoint(ctx, x[i], y[i]);
    CGContextClosePath(ctx);
}

static void QuartzPolygon(int n, double *x, double *y,
                          CGContextRef ctx, const pGEcontext gc, 
                          QuartzDesc *xd, int op)
{
    Rboolean grouping;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    grouping = QuartzBegin(&ctx, &layer, xd);
    CGContextBeginPath(ctx);
    QuartzPolygonPath(n, x, y, ctx);
    if (op) {
        QuartzFill(ctx, gc, xd);
    } else {
        QuartzStroke(ctx, gc, xd);
    }
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_Polygon(int n, double *x, double *y, CTXDESC)
{
    if (n < 2) return;
    DRAWSPEC;
    if (!ctx) NOCTX;

    if (xd->appending) {
        QuartzPolygonPath(n, x, y, ctx);
    } else {
        Rboolean fill = (gc->patternFill != R_NilValue) || 
            (R_ALPHA(gc->fill) > 0);
        Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
        if (fill && stroke) {
            QuartzPolygon(n, x, y, ctx, gc, xd, 1); /* fill */
            QuartzPolygon(n, x, y, ctx, gc, xd, 0); /* stroke */
        } else if (fill) {
            QuartzPolygon(n, x, y, ctx, gc, xd, 1);
        } else if (stroke) {
            QuartzPolygon(n, x, y, ctx, gc, xd, 0);
        }        
    }
}

static void QuartzPathPath(double *x, double *y, 
                           int npoly, int* nper,
                           CGContextRef ctx)
{
    int i, j, index;
    index = 0;
    for (i=0; i < npoly; i++) {
        CGContextMoveToPoint(ctx, x[index], y[index]);
        index++;
        for(j=1; j < nper[i]; j++) {
            CGContextAddLineToPoint(ctx, x[index], y[index]);
            index++;
        }
        CGContextClosePath(ctx);
    }
}

static void QuartzPath(double *x, double *y, 
                       int npoly, int* nper,
                       Rboolean winding,
                       CGContextRef ctx, const pGEcontext gc, 
                       QuartzDesc *xd, int op)
{
    Rboolean grouping;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    grouping = QuartzBegin(&ctx, &layer, xd);
    CGContextBeginPath(ctx);
    QuartzPathPath(x, y, npoly, nper, ctx);
    if (op) {
        if (winding) {
            QuartzFill(ctx, gc, xd);
        } else {
            QuartzEOFill(ctx, gc, xd);
        }
    } else {
        QuartzStroke(ctx, gc, xd);
    }
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_Path(double *x, double *y, 
                         int npoly, int* nper,
                         Rboolean winding, 
                         CTXDESC)
{
    DRAWSPEC;
    if (!ctx) NOCTX;

    if (xd->appending) {
        QuartzPathPath(x, y, npoly, nper, ctx);
    } else {
        Rboolean fill = (gc->patternFill != R_NilValue) || 
            (R_ALPHA(gc->fill) > 0);
        Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
        if (fill && stroke) {
            QuartzPath(x, y, npoly, nper, winding, ctx, gc, xd, 1); /* fill */
            QuartzPath(x, y, npoly, nper, winding, ctx, gc, xd, 0); /* stroke */
        } else if (fill) {
            QuartzPath(x, y, npoly, nper, winding, ctx, gc, xd, 1);
        } else if (stroke) {
            QuartzPath(x, y, npoly, nper, winding, ctx, gc, xd, 0);
        }        
    }
}

static void RQuartz_Mode(int mode, DEVDESC)
{
    DEVSPEC;
    if (!ctx) NOCTX;
    /* don't do anything in redraw as we can signal the end */
    if (xd->redraw) return;
    /* mode=0 -> drawing complete, signal sync */
    if (mode == 0 && xd->holdlevel == 0) {
        if (xd->sync)
            xd->sync(xd, xd->userInfo);
        else
            CGContextSynchronize(ctx);
    }
}

static void
RQuartz_MetricInfo(int c, const pGEcontext gc,
		   double *ascent, double *descent, double *width,
		   pDevDesc dd)
{
    DRAWSPEC;
    CGFontRef font = 0;

    if (!ctx) {
        xd->async = 1; /* flag us as not having a context */
        font = RQuartz_Font(gc, NULL);
        if (!font) {
            /* dummy data if we have no font at all, for sanity reasons */
            *ascent = 10.0;
            *descent= 2.0;
            *width  = 9.0;
            return;
        }
    } else {
        RQuartz_SetFont(ctx, gc, xd);
        font = CGContextGetFont(ctx);
    }

    {
        float aScale   = (float)((gc->cex * gc->ps * xd->tscale) /
				 CGFontGetUnitsPerEm(font));
	UniChar  *buffer, single;
        CGGlyph  glyphs[8];
	CFStringRef str = NULL;
        int free_buffer = 0, len;
	*width = *ascent = *descent = 0.0; /* data for bail-out cases */
	if (c >= 0 && c <= ((mbcslocale && gc->fontface != 5) ? 127 : 255)) {
	    char    text[2] = { (char)c, 0 };
	    str = text2unichar(gc, dd, text, &buffer, &free_buffer);
	    if(!str) return;
	    len = (int) CFStringGetLength(str);
	    if (len > 7) return; /* this is basically impossible,
				    but you never know */
	} else {
	    single = (UniChar) ((c < 0) ? -c : c);
	    buffer = &single;
	    len = 1;
	}
        *width = 0.0;
        CGFontGetGlyphsForUnichars(font, buffer, glyphs, len);
        {
	    int i;
            int    advances[8];
            CGRect bboxes[8];
            CGFontGetGlyphAdvances(font, glyphs, len, advances);
            CGFontGetGlyphBBoxes(font, glyphs, len, bboxes);
            for(i = 0; i < len; i++)
                *width += advances[i] * aScale;
            *ascent  = aScale * (bboxes[0].size.height + bboxes[0].origin.y);
            *descent = -aScale * bboxes[0].origin.y;
        }
        if (free_buffer) free(buffer);
        if (str) CFRelease(str);
    }
}

static Rboolean RQuartz_Locator(double *x, double *y, DEVDESC)
{
    Rboolean res;
    DEVSPEC;
    ctx = NULL;
    if (!xd->locatePoint)
        return FALSE;
    res = xd->locatePoint(xd, xd->userInfo, x, y);
    *x/=xd->scalex;
    *y/=xd->scaley;
    return res;
}

static SEXP RQuartz_setPattern(SEXP pattern, pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTXR(R_NilValue);
    SEXP ref;
    PROTECT(ref = allocVector(INTSXP, 1));
    int index = 0;
    int patternType = R_GE_patternType(pattern);
    if (patternType == R_GE_linearGradientPattern ||
        patternType == R_GE_radialGradientPattern) {
        index = QuartzNewPatternIndex(xd);
        QGradientRef quartz_gradient = 
            QuartzCreateGradient(pattern, patternType, xd);
        xd->gradients[index] = quartz_gradient;
    } else {
        index = QuartzNewPatternIndex(xd);
        int savedPattern = xd->appendingPattern;
        int savedType = xd->appendingType; 
        xd->appendingPattern = index;
        xd->appendingType = QPatternLayer;
        QPatternRef quartz_pattern = 
            QuartzCreatePattern(pattern, ctx, xd);
        xd->patterns[index] = quartz_pattern;

        /* Play the pattern function to draw the pattern on the pattern layer*/
        SEXP R_fcall = PROTECT(lang1(R_GE_tilingPatternFunction(pattern)));
        eval(R_fcall, R_GlobalEnv);
        UNPROTECT(1);

        xd->appendingPattern = savedPattern;
        xd->appendingType = savedType;
    }
    INTEGER(ref)[0] = index;
    UNPROTECT(1);
    return ref;
}

static void RQuartz_releasePattern(SEXP ref, pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTX;
    /* NULL means release all patterns */
    if (ref == R_NilValue) {
        QuartzCleanPatterns(xd);
    } else {
        QuartzReleasePattern(INTEGER(ref)[0], xd);
    }
} 

static SEXP RQuartz_setClipPath(SEXP path, SEXP ref, pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTXR(R_NilValue);
    SEXP newref = R_NilValue;
    int index;

    if (isNull(ref)) {
        /* Must generate new ref */
        index = QuartzNewClipPathIndex(xd);
        if (index < 0) {
            /* Unless we have run out of space */
        } else {
            /* Create this clipping path */
            xd->clipPaths[index] = QuartzCreateClipPath(path, index, ctx, xd);
            PROTECT(newref = allocVector(INTSXP, 1));
            INTEGER(newref)[0] = index;
            UNPROTECT(1);
        }
    } else {
        /* Reuse indexed clip path */
        int index = INTEGER(ref)[0];
        if (xd->clipPaths[index]) {
            QuartzReuseClipPath(xd->clipPaths[index], ctx, xd);
        } else {
            /* BUT if index clip path does not exist, create a new one */
            xd->clipPaths[index] = QuartzCreateClipPath(path, index, ctx, xd);
            warning(_("Attempt to reuse non-existent clipping path"));
        }
    }

    return newref;
}

static void RQuartz_releaseClipPath(SEXP ref, pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTX;
    /* NULL means release all patterns */
    if (isNull(ref)) {
        QuartzCleanClipPaths(xd);
    } else {
        int i;
        for (i = 0; i < LENGTH(ref); i++) {
            if (xd->clipPaths[i]) {
                CGPathRelease(xd->clipPaths[i]->path);
                free(xd->clipPaths[i]);
                xd->clipPaths[i] = NULL;
            } else {
                warning(_("Attempt to release non-existent clipping path"));
            }
        }
    }
}

static SEXP RQuartz_setMask(SEXP mask, SEXP ref, pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTXR(R_NilValue);
    int index;
    SEXP newref = R_NilValue;

    if (isNull(mask)) {
        /* Set NO mask */
        index = -1;
    } else {
        if (isNull(ref)) {
            /* Create a new mask */
            index = QuartzCreateMask(mask, ctx, xd);
        } else {
            /* Reuse existing mask */
            index = INTEGER(ref)[0];
            if (index >= 0 && !xd->masks[index]) {
                /* But if it does not exist, make a new one */
                index = QuartzCreateMask(mask, ctx, xd);
            }
        }
        newref = PROTECT(allocVector(INTSXP, 1));
        INTEGER(newref)[0] = index;
        UNPROTECT(1);
    }

    xd->currentMask = index;

    return newref;
}

static void RQuartz_releaseMask(SEXP ref, pDevDesc dd) 
{
    DEVSPEC;
    if (!ctx) NOCTX;
    if (isNull(ref)) {
        QuartzCleanMasks(xd);
    } else {
        int i;
        for (i = 0; i < LENGTH(ref); i++) {
            if (xd->masks[i]) {
                CGContextRelease(xd->masks[i]->context);
                CGImageRelease(xd->masks[i]->mask);
                xd->masks[i] = NULL;
            } else {
                warning(_("Attempt to release non-existent mask"));
            }
        }
    }
}

static SEXP RQuartz_defineGroup(SEXP source, int op, SEXP destination, 
                                    pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTXR(R_NilValue);
    return QuartzCreateGroup(source, op, destination, ctx, xd);
}

static void RQuartz_useGroup(SEXP ref, SEXP trans, pDevDesc dd) {
    DRAWSPEC;
    if (!ctx) NOCTX;
    QuartzUseGroup(ref, trans, ctx, xd);
}

static void RQuartz_releaseGroup(SEXP ref, pDevDesc dd) {
    DEVSPEC;
    if (!ctx) NOCTX;
    /* NULL means release all patterns */
    if (ref == R_NilValue) {
        QuartzCleanGroups(xd);
    } else {
        QuartzReleaseGroups(INTEGER(ref)[0], xd);
    }
}

static void RQuartz_stroke(SEXP path, const pGEcontext gc, pDevDesc dd) 
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    SEXP R_fcall;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;
    Rboolean grouping;

    Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
    if (!stroke) 
        return;

    if (!xd->appending) {
        grouping = QuartzBegin(&ctx, &layer, xd);
    }

    /* Increment the "appending" count */
    xd->appending++;
    /* Clear the current path */
    CGContextBeginPath(ctx);
    /* Play the path function to build the path */
    R_fcall = PROTECT(lang1(path));
    eval(R_fcall, R_GlobalEnv);
    UNPROTECT(1);
    /* Decrement the "appending" count */
    xd->appending--;
    /* Stroke the path */

    if (!xd->appending) {
        QuartzStroke(ctx, gc, xd);
        QuartzEnd(grouping, layer, ctx, savedCTX, xd);
    }
}

static void RQuartz_fill(SEXP path, int rule, const pGEcontext gc, 
                         pDevDesc dd) 
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    SEXP R_fcall;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;
    Rboolean grouping;

    Rboolean fill = (gc->patternFill != R_NilValue) || (R_ALPHA(gc->fill) > 0);
    if (!fill)
        return;

    if (!xd->appending) {
        grouping = QuartzBegin(&ctx, &layer, xd);
    }

    /* Increment the "appending" count */
    xd->appending++;
    /* Clear the current path */
    CGContextBeginPath(ctx);
    /* Play the path function to build the path */
    R_fcall = PROTECT(lang1(path));
    eval(R_fcall, R_GlobalEnv);
    UNPROTECT(1);
    /* Decrement the "appending" count */
    xd->appending--;
    /* Fill the path */

    if (!xd->appending) {
        switch(rule) {
        case R_GE_nonZeroWindingRule:
            QuartzFill(ctx, gc, xd); break;
        case R_GE_evenOddRule:
            QuartzEOFill(ctx, gc, xd); break;
        }
        QuartzEnd(grouping, layer, ctx, savedCTX, xd);
    }
}

static void QuartzFillStrokePath(SEXP path, CGContextRef ctx, QuartzDesc *xd)
{
    SEXP R_fcall;
    /* Increment the "appending" count */
    xd->appending++;
    /* Clear the current path */
    CGContextBeginPath(ctx);
    /* Play the path function to build the path */
    R_fcall = PROTECT(lang1(path));
    eval(R_fcall, R_GlobalEnv);
    UNPROTECT(1);
    /* Decrement the "appending" count */
    xd->appending--;
}

static void QuartzFillStroke(SEXP path, int rule, const pGEcontext gc, 
                             CGContextRef ctx, QuartzDesc *xd, int op)
{
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;
    Rboolean grouping;

    grouping = QuartzBegin(&ctx, &layer, xd);
    QuartzFillStrokePath(path, ctx, xd);
    if (op) { /* fill */
        switch(rule) {
        case R_GE_nonZeroWindingRule:
            QuartzFill(ctx, gc, xd); break;
        case R_GE_evenOddRule:
            QuartzEOFill(ctx, gc, xd); break;
        }
    } else {
        QuartzStroke(ctx, gc, xd);
    }
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

static void RQuartz_fillStroke(SEXP path, int rule, const pGEcontext gc, 
                               pDevDesc dd) 
{
    DRAWSPEC;
    if (!ctx) NOCTX;

    Rboolean fill = (gc->patternFill != R_NilValue) || (R_ALPHA(gc->fill) > 0);
    Rboolean stroke = (R_ALPHA(gc->col) > 0 && gc->lty != -1);
    if (!(stroke || fill))
        return;

    if (xd->appending) {
        QuartzFillStrokePath(path, ctx, xd);
    } else {
        if (fill && stroke) {
            QuartzFillStroke(path, rule, gc, ctx, xd, 1);
            QuartzFillStroke(path, rule, gc, ctx, xd, 0);
        } else if (fill) {
            QuartzFillStroke(path, rule, gc, ctx, xd, 1);
        } else if (stroke) {
            QuartzFillStroke(path, rule, gc, ctx, xd, 0);
        }
    }
}

static SEXP RQuartz_capabilities(SEXP capabilities) { 
    SEXP patterns, clippingPaths, masks, compositing, transforms, paths;

    PROTECT(patterns = allocVector(INTSXP, 3));
    INTEGER(patterns)[0] = R_GE_linearGradientPattern;
    INTEGER(patterns)[1] = R_GE_radialGradientPattern;
    INTEGER(patterns)[2] = R_GE_tilingPattern;
    SET_VECTOR_ELT(capabilities, R_GE_capability_patterns, patterns);
    UNPROTECT(1);

    PROTECT(clippingPaths = allocVector(INTSXP, 1));
    INTEGER(clippingPaths)[0] = 1;
    SET_VECTOR_ELT(capabilities, R_GE_capability_clippingPaths, clippingPaths);
    UNPROTECT(1);


    PROTECT(masks = allocVector(INTSXP, 2));
    INTEGER(masks)[0] = R_GE_luminanceMask;
    INTEGER(masks)[1] = R_GE_alphaMask;
    SET_VECTOR_ELT(capabilities, R_GE_capability_masks, masks);
    UNPROTECT(1);

    PROTECT(compositing = allocVector(INTSXP, 24));
    INTEGER(compositing)[0] = R_GE_compositeMultiply;
    INTEGER(compositing)[1] = R_GE_compositeScreen;
    INTEGER(compositing)[2] = R_GE_compositeOverlay;
    INTEGER(compositing)[3] = R_GE_compositeDarken;
    INTEGER(compositing)[4] = R_GE_compositeLighten;
    INTEGER(compositing)[5] = R_GE_compositeColorDodge;
    INTEGER(compositing)[6] = R_GE_compositeColorBurn;
    INTEGER(compositing)[7] = R_GE_compositeHardLight;
    INTEGER(compositing)[8] = R_GE_compositeSoftLight;
    INTEGER(compositing)[9] = R_GE_compositeDifference;
    INTEGER(compositing)[10] = R_GE_compositeExclusion;
    INTEGER(compositing)[11] = R_GE_compositeClear;
    INTEGER(compositing)[12] = R_GE_compositeSource;
    INTEGER(compositing)[13] = R_GE_compositeOver;
    INTEGER(compositing)[14] = R_GE_compositeIn;
    INTEGER(compositing)[15] = R_GE_compositeOut;
    INTEGER(compositing)[16] = R_GE_compositeAtop;
    INTEGER(compositing)[17] = R_GE_compositeDest;
    INTEGER(compositing)[18] = R_GE_compositeDestOver;
    INTEGER(compositing)[19] = R_GE_compositeDestIn;
    INTEGER(compositing)[20] = R_GE_compositeDestOut;
    INTEGER(compositing)[21] = R_GE_compositeDestAtop;
    INTEGER(compositing)[22] = R_GE_compositeXor;
    INTEGER(compositing)[23] = R_GE_compositeSaturate;
    SET_VECTOR_ELT(capabilities, R_GE_capability_compositing, compositing);
    UNPROTECT(1);

    PROTECT(transforms = allocVector(INTSXP, 1));
    INTEGER(transforms)[0] = 1;
    SET_VECTOR_ELT(capabilities, R_GE_capability_transformations, transforms);
    UNPROTECT(1);

    PROTECT(paths = allocVector(INTSXP, 1));
    INTEGER(paths)[0] = 1;
    SET_VECTOR_ELT(capabilities, R_GE_capability_paths, paths);
    UNPROTECT(1);

    return capabilities; 
}

void RQuartz_glyph(int n, int *glyphs, double *x, double *y, 
                   SEXP font, double size,
                   int colour, double rot, pDevDesc dd)
{
    DRAWSPEC;
    if (!ctx) NOCTX;
    CGContextRef savedCTX = ctx;
    CGLayerRef layer;

    if (n < 1) 
        return;

    /* Not able to add glyphs to the current path. */
    if (xd->appending) 
        return;

    Rboolean grouping = QuartzBegin(&ctx, &layer, xd);

    const char* path = R_GE_glyphFontFile(font);
    CFURLRef cfFontURL = CFURLCreateFromFileSystemRepresentation(NULL, (const UInt8*)path, strlen(path), false);
    if (!cfFontURL)
        error(_("Invalid font path: \"%s\""), path);
    CFArrayRef cfFontDescriptors = 
        CTFontManagerCreateFontDescriptorsFromURL(cfFontURL);
    CFRelease(cfFontURL);
    if (cfFontDescriptors) {
        /* NOTE: that the font needs an inversion (in y) matrix
           because the device has an inversion in user space 
           (for bitmap devices anyway) */
        CGAffineTransform trans = CGAffineTransformMakeScale(1.0, -1.0);
        if (rot != 0.0) trans = CGAffineTransformRotate(trans, rot/180.*M_PI);
        CTFontRef ctFont = 
            CTFontCreateWithFontDescriptor((CTFontDescriptorRef) CFArrayGetValueAtIndex(cfFontDescriptors, 0), size, &trans);

        CGColorSpaceRef cs = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
        CGFloat fillColor[] = { R_RED(colour)/255.0, 
                                R_GREEN(colour)/255.0, 
                                R_BLUE(colour)/255.0, 
                                R_ALPHA(colour)/255.0 };
        CGColorRef fillColorRef = CGColorCreate(cs, fillColor);
        CGContextSetFillColorWithColor(ctx, fillColorRef);
        int i;
        for (i=0; i<n; i++) {
            CGGlyph glyph = glyphs[i];
            CGPoint loc = CGPointMake(x[i], y[i]);
            CTFontDrawGlyphs(ctFont, &glyph, &loc, 1, ctx);
        }
        CGColorRelease(fillColorRef);
        CFRelease(ctFont);
        CFRelease(cfFontDescriptors);
    } else {
        warning(_("Failed to load font"));
    }
    
    QuartzEnd(grouping, layer, ctx, savedCTX, xd);
}

#pragma mark -
#pragma mark R Interface

#include "qdCocoa.h"
#include "qdBitmap.h"
#include "qdPDF.h"
/* disabled for now until we get to test in on 10.3 #include "qdCarbon.h" */

/* current fake */
QuartzDesc_t 
QuartzCarbon_DeviceCreate(pDevDesc dd, QuartzFunctions_t *fn, QuartzParameters_t *par)
{
    return NULL;
}

#define ARG(HOW,WHAT) HOW(CAR(WHAT));WHAT = CDR(WHAT)

/* C version of the Quartz call (experimental)
   Quartz descriptor on success, NULL on failure. 
   If errorCode is not NULL, it will contain the error code on exit */
QuartzDesc_t 
Quartz_C(QuartzParameters_t *par, quartz_create_fn_t q_create, int *errorCode)
{
    if (!q_create || !par) {
	if (errorCode) errorCode[0] = -4;
	return NULL;
    }
    {
        const void *vmax = vmaxget();
	QuartzDesc_t qd = NULL;
	R_GE_checkVersionOrDie(R_GE_version);
        R_CheckDeviceAvailable();
        {
	    const char *devname = "quartz_off_screen";
	    /* FIXME: check this allocation */
            pDevDesc dev    = calloc(1, sizeof(DevDesc));

            if (!dev) {
		if (errorCode) errorCode[0] = -2;
		return NULL;
	    }
            if (!(qd = q_create(dev, &qfn, par))) {
                vmaxset(vmax);
                free(dev);
		if (errorCode) errorCode[0] = -3;
		return NULL;
            }
	    if(streql(par->type, "") || streql(par->type, "native")
	       || streql(par->type, "cocoa") || streql(par->type, "carbon"))
		devname = "quartz";
            gsetVar(R_DeviceSymbol, mkString(devname), R_BaseEnv);
            pGEDevDesc dd = GEcreateDevDesc(dev);
            GEaddDevice(dd);
            GEinitDisplayList(dd);
            vmaxset(vmax);
        }
	return qd;
    }
}

/* ARGS: type, file, width, height, ps, family, antialias,
   title, bg, canvas, dpi */
SEXP Quartz(SEXP args)
{
    SEXP tmps, bgs, canvass;
    double   width, height, ps;
    Rboolean antialias;
    int      bg, canvas, module = 0;
    double   mydpi[2], *dpi = 0;
    const char *type, *mtype = 0, *family, *title;
    char *file = NULL;
    QuartzDesc_t qd = NULL;

    const void *vmax = vmaxget();
    /* Get function arguments */
    args = CDR(args); /* Skip the call */
    if (TYPEOF(CAR(args)) != STRSXP || LENGTH(CAR(args)) < 1)
        type = "";
    else
        type  = CHAR(STRING_ELT(CAR(args), 0));
    args = CDR(args);
    /* we may want to support connections at some point, but not yet ... */
    tmps = CAR(args);    args = CDR(args);
    if (isNull(tmps)) 
	file = NULL;
    else if (isString(tmps) && LENGTH(tmps) >= 1) {
	SEXP tmp1 = STRING_ELT(tmps, 0);
	if(tmp1 == NA_STRING)
	    error(_("invalid 'file' argument"));
        const char *tmp = R_ExpandFileName(CHAR(tmp1));
	file = R_alloc(strlen(tmp) + 1, sizeof(char));
	strcpy(file, tmp);
    } else
        error(_("invalid 'file' argument"));
    width     = ARG(asReal,args);
    height    = ARG(asReal,args);
    ps        = ARG(asReal,args);
    family    = CHAR(STRING_ELT(CAR(args), 0)); args = CDR(args);
    antialias = ARG(asLogical,args);
    title     = CHAR(STRING_ELT(CAR(args), 0)); args = CDR(args);
    bgs       = CAR(args); args = CDR(args);
    bg        = RGBpar(bgs, 0);
    canvass   = CAR(args); args = CDR(args);
    canvas    = RGBpar(canvass, 0) | 0xff000000; /* force opaque */
    tmps      = CAR(args); args = CDR(args);
    if (!isNull(tmps)) {
        tmps = coerceVector(tmps, REALSXP);
        if (LENGTH(tmps) > 0) {
            dpi = mydpi;
            mydpi[0] = REAL(tmps)[0];
            if (LENGTH(tmps) > 1)
                mydpi[1] = REAL(tmps)[1];
            else
                mydpi[1] = mydpi[0];
        }
    }
    /* just in case someone passed NAs/NaNs */
    if (dpi && (ISNAN(dpi[0]) || ISNAN(dpi[1]))) dpi=0;

    if (ISNAN(width) || ISNAN(height) || width <= 0.0 || height <= 0.0)
        error(_("invalid quartz() device size"));

    if (type) {
        const quartz_module_t *m = quartz_modules;
	mtype = type;
        while (m->type) {
            if (!strcasecmp(type, m->type)) {
                module = m->qbe;
                if (m->subst) mtype = m->subst;
                break;
            }
            m++;
        }

	if (!strncasecmp(type, "bitmap:", 7)) {
	    module = QBE_BITMAP;
	    mtype = mtype + 7;
	}
    }

//    quartzpos = 1;

    R_GE_checkVersionOrDie(R_GE_version);
    R_CheckDeviceAvailable();
    BEGIN_SUSPEND_INTERRUPTS {
	pDevDesc dev = calloc(1, sizeof(DevDesc));

	if (!dev)
	    error(_("unable to create device description"));

	QuartzParameters_t qpar = {
	    sizeof(qpar),
	    mtype, file, title,
	    -1.0, -1.0, width, height, ps,
	    family,
	    antialias ? QPFLAG_ANTIALIAS: 0,
	    -1, /* connection */
	    bg, canvas,
	    dpi
	};

	/* re-routed code has the first shot */
	if (ptr_QuartzBackend)
	    qd = ptr_QuartzBackend(dev, &qfn, &qpar);

	if (qd == NULL) { /* try internal modules next */
	    switch (module) {
            case QBE_COCOA:
                qd = QuartzCocoa_DeviceCreate(dev, &qfn, &qpar);
                break;
            case QBE_NATIVE:
                /* native is essentially cocoa with carbon fall-back */
                qd = QuartzCocoa_DeviceCreate(dev, &qfn, &qpar);
                if (qd) break;
            case QBE_CARBON:
                qd = QuartzCarbon_DeviceCreate(dev, &qfn, &qpar);
                break;
            case QBE_PDF:
		qpar.canvas = 0; /* so not used */
                qd = QuartzPDF_DeviceCreate(dev, &qfn, &qpar);
                break;
            case QBE_BITMAP:
		/* we need to set up the default file name here, where we
		   know the original type name. */
		if (file == NULL) {
		    static char deffile[30];
		    snprintf(deffile, 30, "%s.%s", "Rplot%03d", type);
		    qpar.file = deffile;
		}
		qpar.canvas = 0; /* so not used */
		qd = QuartzBitmap_DeviceCreate(dev, &qfn, &qpar);
		break;
	    }
	}

	if (qd == NULL) {
	    vmaxset(vmax);
	    free(dev);
	    error(_("unable to create quartz() device target, given type may not be supported"));
	}
	const char *devname = "quartz_off_screen";
	if(streql(type, "") || streql(type, "native") || streql(type, "cocoa") 
	   || streql(type, "carbon")) devname = "quartz";
	SEXP f = PROTECT(mkString(devname));
	if(file) setAttrib(f, install("filepath"), mkString(file));
 	gsetVar(R_DeviceSymbol, f, R_BaseEnv);
	UNPROTECT(1);
	pGEDevDesc dd = GEcreateDevDesc(dev);
	GEaddDevice(dd);
	GEinitDisplayList(dd);
    } END_SUSPEND_INTERRUPTS;
    vmaxset(vmax);
    return R_NilValue;
}

#include <sys/sysctl.h>

static double cached_darwin_version = 0.0;

/* Darwin version X.Y maps to macOS version 10.(X - 4).Y */
static double darwin_version(void) {
    char ver[32];
    size_t len = sizeof(ver) - 1;
    int mib[2] = { CTL_KERN, KERN_OSRELEASE };
    if (cached_darwin_version > 0.0)
	return cached_darwin_version;
    sysctl(mib, 2, &ver, &len, 0, 0);
    return (cached_darwin_version = atof(ver));
}

#include <mach/mach.h>
#include <servers/bootstrap.h>

/* even as of Darwin 9 there is no entry for bootstrap_info in bootrap headers */
extern kern_return_t bootstrap_info(mach_port_t , /* bootstrap port */
                                    name_array_t*, mach_msg_type_number_t*,  /* service */
                                    name_array_t*, mach_msg_type_number_t*,  /* server */
                                    bool_array_t*, mach_msg_type_number_t*); /* active */

/* returns 1 if window server session service
   (com.apple.windowserver.session) is present in the boostrap
   namespace (pre-Lion) or when a current session is present, active
   and there is no SSH_CONNECTION (Lion and later).
   returns 0 if an error occurred or the service is not
   present. For all practical purposes this returns 1 only if run
   interactively via LS. Although ssh to a machine that has a running
   session for the same user will allow a WS connection, this function
   will still return 0 in that case.
   NOTE: on macOS 10.5 we are currently NOT searching the parent
   namespaces. This is currently OK, because the session service will
   be registered in the session namespace which is the last in the
   chain. However, this could change in the future.
 */
static int has_wss(void) {
    int res = 0;

    if (darwin_version() < 11.0) { /* before Lion we get reliable information from the bootstrap info */
	kern_return_t kr;
	mach_port_t self = mach_task_self();
	mach_port_t bport = MACH_PORT_NULL;
	kr = task_get_bootstrap_port(self, &bport);
	if (kr == KERN_SUCCESS) {
	    kern_return_t           kr;
	    name_array_t            serviceNames;
	    mach_msg_type_number_t  serviceNameCount;
	    name_array_t            serverNames;
	    mach_msg_type_number_t  serverNameCount;
	    bool_array_t            active;
	    mach_msg_type_number_t  activeCount;
	    
	    serviceNames  = NULL;
	    serverNames   = NULL;
	    active        = NULL;
	    
	    kr = bootstrap_info(bport, 
				&serviceNames, &serviceNameCount, 
				&serverNames, &serverNameCount, 
				&active, &activeCount);
	    if (kr == KERN_SUCCESS) {
		unsigned int i = 0;
		while (i < serviceNameCount) {
		    if (!strcmp(serviceNames[i], "com.apple.windowserver.session")) {
			res = 1;
			break;
		    }
		    i++;
		}
	    }
	}
	if (bport != MACH_PORT_NULL)
	    mach_port_deallocate(mach_task_self(), bport);
    } else {
	/* On macOS 10.7 (Lion) and higher two things changed:
	   a) there is no com.apple.windowserver.session anymore 
	   so the above will fail
	   b) every process has now the full bootstrap info, 
	   so in fact even remote connections will be able to 
	   run on-screen tasks if the user is logged in
	   So we need to add some heuristics to decide when the user 
	   actually wants Quartz ... */   
	/* check user's session */
	CFDictionaryRef dict = CGSessionCopyCurrentDictionary();
	if (dict) { /* allright, let's see if the session is current */
	    CFTypeRef obj = CFDictionaryGetValue(dict, CFSTR("kCGSSessionOnConsoleKey"));
	    if (obj && CFGetTypeID(obj) == CFBooleanGetTypeID()) {
		/* even if this session is active, we don't use Quartz for SSH connections */
		if (CFBooleanGetValue(obj) && (!getenv("SSH_CONNECTION") || getenv("SSH_CONNECTION")[0] == 0))
		    res = 1;
	    }
	    CFRelease(dict);
	}
    }

    return res;
}

SEXP makeQuartzDefault(void) {
    return ScalarLogical(has_wss());
}

#else
/* --- no AQUA support = no Quartz --- */

#include "grDevices.h"
#include <R_ext/QuartzDevice.h>

SEXP Quartz(SEXP args)
{
    warning(_("Quartz device is not available on this platform"));
    return R_NilValue;
}

SEXP makeQuartzDefault(void) {
    return ScalarLogical(FALSE);
}

QuartzDesc_t 
Quartz_C(QuartzParameters_t *par, quartz_create_fn_t q_create, int *errorCode)
{
    if (errorCode) errorCode[0] = -1;
    return NULL;
}

void *getQuartzAPI(void)
{
    return NULL;
}

#endif
