Move XGetImage and XCopyArea to tkMacOSXImage.c and completely remove XImage.pixelpower.

1 files changed, 463 insertions, 165 deletions

diff --git a/macosx/tkMacOSXImage.c b/macosx/tkMacOSXImage.c
index 4aea52c..9257829 100644
--- a/macosx/tkMacOSXImage.c
+++ b/macosx/tkMacOSXImage.c
@@ -6,7 +6,7 @@
  * Copyright (c) 1995-1997 Sun Microsystems, Inc.
  * Copyright 2001-2009, Apple Inc.
  * Copyright (c) 2005-2009 Daniel A. Steffen <das@users.sourceforge.net>
- * Copyright 2017-2018 Marc Culler.
+ * Copyright (c) 2017-2020 Marc Culler.
  *
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
@@ -15,14 +15,16 @@
 #include "tkMacOSXPrivate.h"
 #include "xbytes.h"
 
+static CGImageRef CreateCGImageFromPixmap(Drawable pixmap);
+static CGImageRef CreateCGImageFromDrawableRect( Drawable drawable,
+	   int x, int y, unsigned int width, unsigned int height);
+
 #pragma mark XImage handling
 
 int
 _XInitImageFuncPtrs(
-    XImage *image)
+    TCL_UNUSED(XImage *)) /* image */
 {
-    (void)image;
-
     return 0;
 }
 
@@ -43,10 +45,11 @@ _XInitImageFuncPtrs(
  *----------------------------------------------------------------------
  */
 
-static void ReleaseData(void *info, const void *data, size_t size) {
-    (void)data;
-    (void)size;
-
+static void ReleaseData(
+    void *info,
+    TCL_UNUSED(const void *), /* data */
+    TCL_UNUSED(size_t))       /* size */
+{
     ckfree(info);
 }
 
@@ -77,7 +80,7 @@ TkMacOSXCreateCGImageWithXImage(
 	if (image->bitmap_bit_order != MSBFirst) {
 	    char *srcPtr = image->data + image->xoffset;
 	    char *endPtr = srcPtr + len;
-	    char *destPtr = (data = (char *)ckalloc(len));
+	    char *destPtr = (data = ckalloc(len));
 
 	    while (srcPtr < endPtr) {
 		*destPtr++ = xBitReverseTable[(unsigned char)(*(srcPtr++))];
@@ -136,142 +139,6 @@ TkMacOSXCreateCGImageWithXImage(
 /*
  *----------------------------------------------------------------------
  *
- * XGetImage --
- *
- *	This function copies data from a pixmap or window into an XImage.  It
- *      is essentially never used. At one time it was called by
- *      pTkImgPhotoDisplay, but that is no longer the case. Currently it is
- *      called two places, one of which is requesting an XY image which we do
- *      not support.  It probably does not work correctly -- see the comments
- *      for TkMacOSXBitmapRepFromDrawableRect.
- *
- * Results:
- *	Returns a newly allocated XImage containing the data from the given
- *	rectangle of the given drawable, or NULL if the XImage could not be
- *	constructed.  NOTE: If we are copying from a window on a Retina
- *	display, the dimensions of the XImage will be 2*width x 2*height.
- *
- * Side effects:
- *	None.
- *
- *----------------------------------------------------------------------
- */
-struct pixel_fmt {int r; int g; int b; int a;};
-static struct pixel_fmt bgra = {2, 1, 0, 3};
-static struct pixel_fmt abgr = {3, 2, 1, 0};
-
-XImage *
-XGetImage(
-    Display *display,
-    Drawable drawable,
-    int x,
-    int y,
-    unsigned int width,
-    unsigned int height,
-    unsigned long plane_mask,
-    int format)
-{
-    NSBitmapImageRep* bitmap_rep = NULL;
-    NSUInteger bitmap_fmt = 0;
-    XImage* imagePtr = NULL;
-    char* bitmap = NULL;
-    char R, G, B, A;
-    int depth = 32, offset = 0, bitmap_pad = 0;
-    unsigned int bytes_per_row, size, row, n, m;
-    unsigned int scalefactor=1, scaled_height=height, scaled_width=width;
-    NSWindow *win = TkMacOSXDrawableWindow(drawable);
-    static enum {unknown, no, yes} has_retina = unknown;
-    (void)plane_mask;
-
-    if (win && has_retina == unknown) {
-#ifdef __clang__
-	has_retina = [win respondsToSelector:@selector(backingScaleFactor)] ?
-		yes : no;
-#else
-	has_retina = no;
-#endif
-    }
-
-    if (has_retina == yes) {
-	/*
-	 * We only allow scale factors 1 or 2, as Apple currently does.
-	 */
-
-#ifdef __clang__
-	scalefactor = [win backingScaleFactor] == 2.0 ? 2 : 1;
-#endif
-	scaled_height *= scalefactor;
-	scaled_width *= scalefactor;
-    }
-
-    if (format == ZPixmap) {
-	if (width == 0 || height == 0) {
-	    return NULL;
-	}
-
-	bitmap_rep = TkMacOSXBitmapRepFromDrawableRect(drawable,
-		x, y, width, height);
-	if (!bitmap_rep) {
-	    TkMacOSXDbgMsg("XGetImage: Failed to construct NSBitmapRep");
-	    return NULL;
-	}
-	bitmap_fmt = [bitmap_rep bitmapFormat];
-	size = [bitmap_rep bytesPerPlane];
-	bytes_per_row = [bitmap_rep bytesPerRow];
-	bitmap = (char *)ckalloc(size);
-	if (!bitmap
-		|| (bitmap_fmt != 0 && bitmap_fmt != 1)
-		|| [bitmap_rep samplesPerPixel] != 4
-		|| [bitmap_rep isPlanar] != 0
-		|| bytes_per_row < 4 * scaled_width
-		|| size != bytes_per_row * scaled_height) {
-	    TkMacOSXDbgMsg("XGetImage: Unrecognized bitmap format");
-	    CFRelease(bitmap_rep);
-	    return NULL;
-	}
-	memcpy(bitmap, (char *)[bitmap_rep bitmapData], size);
-	CFRelease(bitmap_rep);
-
-	/*
-	 * When Apple extracts a bitmap from an NSView, it may be in either
-	 * BGRA or ABGR format.  For an XImage we need RGBA.
-	 */
-
-	struct pixel_fmt pixel = bitmap_fmt == 0 ? bgra : abgr;
-
-	for (row = 0, n = 0; row < scaled_height; row++, n += bytes_per_row) {
-	    for (m = n; m < n + 4*scaled_width; m += 4) {
-		R = *(bitmap + m + pixel.r);
-		G = *(bitmap + m + pixel.g);
-		B = *(bitmap + m + pixel.b);
-		A = *(bitmap + m + pixel.a);
-
-		*(bitmap + m)     = R;
-		*(bitmap + m + 1) = G;
-		*(bitmap + m + 2) = B;
-		*(bitmap + m + 3) = A;
-	    }
-	}
-	imagePtr = XCreateImage(display, NULL, depth, format, offset,
-		(char*) bitmap, scaled_width, scaled_height,
-		bitmap_pad, bytes_per_row);
-	if (scalefactor == 2) {
-	    imagePtr->pixelpower = 1;
-	}
-    } else {
-	/*
-	 * There are some calls to XGetImage in the generic Tk code which pass
-	 * an XYPixmap rather than a ZPixmap.  XYPixmaps should be handled
-	 * here.
-	 */
-	TkMacOSXDbgMsg("XGetImage does not handle XYPixmaps at the moment.");
-    }
-    return imagePtr;
-}
-
-/*
- *----------------------------------------------------------------------
- *
  * DestroyImage --
  *
  *	Destroys storage associated with an image.
@@ -456,7 +323,7 @@ ImagePutPixel(
 XImage *
 XCreateImage(
     Display* display,
-    Visual* visual,
+    TCL_UNUSED(Visual*),  /* visual */
     unsigned int depth,
     int format,
     int offset,
@@ -467,10 +334,9 @@ XCreateImage(
     int bytes_per_line)
 {
     XImage *ximage;
-    (void)visual;
 
     display->request++;
-    ximage = (XImage *)ckalloc(sizeof(XImage));
+    ximage = ckalloc(sizeof(XImage));
 
     ximage->height = height;
     ximage->width = width;
@@ -480,13 +346,6 @@ XCreateImage(
     ximage->data = data;
     ximage->obdata = NULL;
 
-    /*
-     * The default pixelpower is 0.  This must be explicitly set to 1 in the
-     * case of an XImage extracted from a Retina display.
-     */
-
-    ximage->pixelpower = 0;
-
     if (format == ZPixmap) {
 	ximage->bits_per_pixel = 32;
 	ximage->bitmap_unit = 32;
@@ -581,17 +440,8 @@ XPutImage(
 	}
 	if (img) {
 
-	    /*
-	     * If the XImage has big pixels, the source is rescaled to reflect
-	     * the actual pixel dimensions.  This is not currently used, but
-	     * could arise if the image were copied from a retina monitor and
-	     * redrawn on an ordinary monitor.
-	     */
-
-	    int pp = image->pixelpower;
-
 	    bounds = CGRectMake(0, 0, image->width, image->height);
-	    srcRect = CGRectMake(src_x<<pp, src_y<<pp, width<<pp, height<<pp);
+	    srcRect = CGRectMake(src_x, src_y, width, height);
 	    dstRect = CGRectMake(dest_x, dest_y, width, height);
 	    TkMacOSXDrawCGImage(drawable, gc, dc.context,
 				img, gc->foreground, gc->background,
@@ -608,6 +458,454 @@ XPutImage(
 }
 
 /*
+ *----------------------------------------------------------------------
+ *
+ * CreateCGImageFromDrawableRect
+ *
+ *	Extract image data from a MacOSX drawable as a CGImage.
+ *
+ *      This is only called by XGetImage and XCopyArea.  The Tk core uses
+ *      these functions on some platforms, but on macOS the core does not
+ *      call them with a source drawable which is a window.  Such calls are
+ *      used only for double-buffered drawing.  Since macOS defines the
+ *      macro TK_NO_DOUBLE_BUFFERING, the generic code never calls XGetImage
+ *      or XCopyArea on macOS.  Nonetheless, these function are in the stubs
+ *      table and therefore could be used by extensions.
+ *      
+ *      This implementation does not work correctly.  Originally it relied on
+ *      [NSBitmapImageRep initWithFocusedViewRect:view_rect] which was
+ *      deprecated by Apple in OSX 10.14 and also required the use of other
+ *      deprecated functions such as [NSView lockFocus]. Apple's suggested
+ *      replacement is [NSView cacheDisplayInRect: toBitmapImageRep:] and that
+ *      is what is being used here.  However, that method only works when the
+ *      view has a valid CGContext, and a view is only guaranteed to have a
+ *      valid context during a call to [NSView drawRect]. To further complicate
+ *      matters, cacheDisplayInRect calls [NSView drawRect]. Essentially it is
+ *      asking the view to draw a subrectangle of itself using a special
+ *      graphics context which is linked to the BitmapImageRep. But our
+ *      implementation of [NSView drawRect] does not allow recursive calls. If
+ *      called recursively it returns immediately without doing any drawing.
+ *      So the bottom line is that this function either returns a NULL pointer
+ *      or a black image. To make it useful would require a significant amount
+ *      of rewriting of the drawRect method. Perhaps the next release of OSX
+ *      will include some more helpful ways of doing this.
+ *
+ * Results:
+ *	Returns an NSBitmapRep representing the image of the given rectangle of
+ *      the given drawable. This object is retained. The caller is responsible
+ *      for releasing it.
+ *
+ *      NOTE: The x,y coordinates should be relative to a coordinate system
+ *      with origin at the top left, as used by XImage and CGImage, not bottom
+ *      left as used by NSView.
+ *
+ * Side effects:
+ *     None
+ *
+ *----------------------------------------------------------------------
+ */
+
+static CGImageRef
+CreateCGImageFromDrawableRect(
+    Drawable drawable,
+    int x,
+    int y,
+    unsigned int width,
+    unsigned int height)
+{
+    MacDrawable *mac_drawable = (MacDrawable *) drawable;
+    CGContextRef cg_context = NULL;
+    CGImageRef cg_image = NULL, result = NULL;
+    NSBitmapImageRep *bitmapRep = NULL;
+    NSView *view = NULL;
+    if (mac_drawable->flags & TK_IS_PIXMAP) {
+	/*
+	 * This MacDrawable is a bitmap, so its view is NULL.
+	 */
+
+	CGRect image_rect = CGRectMake(x, y, width, height);
+
+	cg_context = TkMacOSXGetCGContextForDrawable(drawable);
+	cg_image = CGBitmapContextCreateImage((CGContextRef) cg_context);
+	if (cg_image) {
+	    result = CGImageCreateWithImageInRect(cg_image, image_rect);
+	    CGImageRelease(cg_image);
+	}
+    } else if (TkMacOSXDrawableView(mac_drawable) != NULL) {
+
+	/*
+	 * Convert Tk top-left to NSView bottom-left coordinates.
+	 */
+
+	int view_height = [view bounds].size.height;
+	NSRect view_rect = NSMakeRect(x + mac_drawable->xOff,
+		view_height - height - y - mac_drawable->yOff,
+		width, height);
+
+	/*
+	 * Attempt to copy from the view to a bitmapImageRep.  If the view does
+	 * not have a valid CGContext, doing this will silently corrupt memory
+	 * and make a big mess. So, in that case, we just return NULL.
+	 */
+
+	if (view == [NSView focusView]) {
+	    bitmapRep = [view bitmapImageRepForCachingDisplayInRect: view_rect];
+	    [view cacheDisplayInRect:view_rect toBitmapImageRep:bitmapRep];
+	    result = [bitmapRep CGImage];
+	    CFRelease(bitmapRep);
+	} else {
+	    TkMacOSXDbgMsg("No CGContext - cannot copy from screen to bitmap.");
+	    result = NULL;
+	}
+    } else {
+	TkMacOSXDbgMsg("Invalid source drawable");
+    }
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * CreateCGImageFromPixmap --
+ *
+ *	Create a CGImage from an X Pixmap.
+ *
+ * Results:
+ *	CGImage, release after use.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static CGImageRef
+CreateCGImageFromPixmap(
+    Drawable pixmap)
+{
+    CGImageRef img = NULL;
+    CGContextRef context = TkMacOSXGetCGContextForDrawable(pixmap);
+
+    if (context) {
+	img = CGBitmapContextCreateImage(context);
+    }
+    return img;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * XGetImage --
+ *
+ *	This function copies data from a pixmap or window into an XImage.  It
+ *      is essentially never used. At one time it was called by
+ *      pTkImgPhotoDisplay, but that is no longer the case. Currently it is
+ *      called two places, one of which is requesting an XY image which we do
+ *      not support.  It probably does not work correctly -- see the comments
+ *      for CGImageFromDrawableRect.
+ *
+ * Results:
+ *	Returns a newly allocated XImage containing the data from the given
+ *	rectangle of the given drawable, or NULL if the XImage could not be
+ *	constructed.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+struct pixel_fmt {int r; int g; int b; int a;};
+static struct pixel_fmt bgra = {2, 1, 0, 3};
+static struct pixel_fmt abgr = {3, 2, 1, 0};
+
+XImage *
+XGetImage(
+    Display *display,
+    Drawable drawable,
+    int x,
+    int y,
+    unsigned int width,
+    unsigned int height,
+    TCL_UNUSED(unsigned long), /* plane_mask */
+    int format)
+{
+    NSBitmapImageRep* bitmapRep = NULL;
+    NSUInteger bitmap_fmt = 0;
+    XImage* imagePtr = NULL;
+    char* bitmap = NULL;
+    char R, G, B, A;
+    int depth = 32, offset = 0, bitmap_pad = 0;
+    unsigned int bytes_per_row, size, row, n, m;
+
+    if (format == ZPixmap) {
+	CGImageRef cgImage;
+	if (width == 0 || height == 0) {
+	    return NULL;
+	}
+
+	cgImage = CreateCGImageFromDrawableRect(drawable, x, y, width, height);
+	if (cgImage) {
+	    bitmapRep = [NSBitmapImageRep alloc];
+	    [bitmapRep initWithCGImage:cgImage];
+	    CFRelease(cgImage);
+	} else {
+	    TkMacOSXDbgMsg("XGetImage: Failed to construct CGImage");
+	    return NULL;
+	}
+	bitmap_fmt = [bitmapRep bitmapFormat];
+	size = [bitmapRep bytesPerPlane];
+	bytes_per_row = [bitmapRep bytesPerRow];
+	bitmap = ckalloc(size);
+	if (!bitmap
+		|| (bitmap_fmt != 0 && bitmap_fmt != 1)
+		|| [bitmapRep samplesPerPixel] != 4
+		|| [bitmapRep isPlanar] != 0
+		|| bytes_per_row < 4 * width
+		|| size != bytes_per_row * height) {
+	    TkMacOSXDbgMsg("XGetImage: Unrecognized bitmap format");
+	    CFRelease(bitmapRep);
+	    return NULL;
+	}
+	memcpy(bitmap, (char *)[bitmapRep bitmapData], size);
+	CFRelease(bitmapRep);
+
+	/*
+	 * When Apple extracts a bitmap from an NSView, it may be in either
+	 * BGRA or ABGR format.  For an XImage we need RGBA.
+	 */
+
+	struct pixel_fmt pixel = bitmap_fmt == 0 ? bgra : abgr;
+
+	for (row = 0, n = 0; row < height; row++, n += bytes_per_row) {
+	    for (m = n; m < n + 4*width; m += 4) {
+		R = *(bitmap + m + pixel.r);
+		G = *(bitmap + m + pixel.g);
+		B = *(bitmap + m + pixel.b);
+		A = *(bitmap + m + pixel.a);
+
+		*(bitmap + m)     = R;
+		*(bitmap + m + 1) = G;
+		*(bitmap + m + 2) = B;
+		*(bitmap + m + 3) = A;
+	    }
+	}
+	imagePtr = XCreateImage(display, NULL, depth, format, offset,
+		(char*) bitmap, width, height,
+		bitmap_pad, bytes_per_row);
+    } else {
+	/*
+	 * There are some calls to XGetImage in the generic Tk code which pass
+	 * an XYPixmap rather than a ZPixmap.  XYPixmaps should be handled
+	 * here.
+	 */
+	TkMacOSXDbgMsg("XGetImage does not handle XYPixmaps at the moment.");
+    }
+    return imagePtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * XCopyArea --
+ *
+ *	Copies image data from one drawable to another.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Image data is moved from a window or bitmap to a second window or bitmap.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+XCopyArea(
+    Display *display,		/* Display. */
+    Drawable src,		/* Source drawable. */
+    Drawable dst,		/* Destination drawable. */
+    GC gc,			/* GC to use. */
+    int src_x,			/* X & Y, width & height */
+    int src_y,			/* define the source rectangle */
+    unsigned int width,		/* that will be copied. */
+    unsigned int height,
+    int dest_x,			/* Dest X & Y on dest rect. */
+    int dest_y)
+{
+    TkMacOSXDrawingContext dc;
+    MacDrawable *srcDraw = (MacDrawable *) src;
+    CGImageRef img = NULL;
+    CGRect bounds, srcRect, dstRect;
+
+    display->request++;
+    if (!width || !height) {
+	return BadDrawable;
+    }
+
+    if (!TkMacOSXSetupDrawingContext(dst, gc, &dc)) {
+	TkMacOSXDbgMsg("Failed to setup drawing context.");
+	return BadDrawable;
+    }
+
+    if (!dc.context) {
+	TkMacOSXDbgMsg("Invalid destination drawable - no context.");
+	return BadDrawable;
+    }
+
+    if (srcDraw->flags & TK_IS_PIXMAP) {
+	img = CreateCGImageFromPixmap(src);
+    } else if (TkMacOSXDrawableWindow(src)) {
+	img = CreateCGImageFromDrawableRect(src, src_x, src_y, width, height);
+    } else {
+	TkMacOSXDbgMsg("Invalid source drawable - neither window nor pixmap.");
+    }
+
+    if (img) {
+	bounds = CGRectMake(0, 0, srcDraw->size.width, srcDraw->size.height);
+	srcRect = CGRectMake(src_x, src_y, width, height);
+	dstRect = CGRectMake(dest_x, dest_y, width, height);
+	TkMacOSXDrawCGImage(dst, gc, dc.context, img,
+		gc->foreground, gc->background, bounds, srcRect, dstRect);
+	CFRelease(img);
+    } else {
+	TkMacOSXDbgMsg("Failed to construct CGImage.");
+    }
+
+    TkMacOSXRestoreDrawingContext(&dc);
+    return Success;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * XCopyPlane --
+ *
+ *	Copies a bitmap from a source drawable to a destination drawable. The
+ *	plane argument specifies which bit plane of the source contains the
+ *	bitmap. Note that this implementation ignores the gc->function.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Changes the destination drawable.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+XCopyPlane(
+    Display *display,		/* Display. */
+    Drawable src,		/* Source drawable. */
+    Drawable dst,		/* Destination drawable. */
+    GC gc,				/* GC to use. */
+    int src_x,			/* X & Y, width & height */
+    int src_y,			/* define the source rectangle */
+    unsigned int width,	/* that will be copied. */
+    unsigned int height,
+    int dest_x,			/* Dest X & Y on dest rect. */
+    int dest_y,
+    unsigned long plane)	/* Which plane to copy. */
+{
+    TkMacOSXDrawingContext dc;
+    MacDrawable *srcDraw = (MacDrawable *) src;
+    MacDrawable *dstDraw = (MacDrawable *) dst;
+    CGRect bounds, srcRect, dstRect;
+    display->request++;
+    if (!width || !height) {
+	/* TkMacOSXDbgMsg("Drawing of empty area requested"); */
+	return BadDrawable;
+    }
+    if (plane != 1) {
+	Tcl_Panic("Unexpected plane specified for XCopyPlane");
+    }
+    if (srcDraw->flags & TK_IS_PIXMAP) {
+	if (!TkMacOSXSetupDrawingContext(dst, gc, &dc)) {
+	    return BadDrawable;
+	}
+
+	CGContextRef context = dc.context;
+
+	if (context) {
+	    CGImageRef img = CreateCGImageFromPixmap(src);
+
+	    if (img) {
+		TkpClipMask *clipPtr = (TkpClipMask *) gc->clip_mask;
+		unsigned long imageBackground  = gc->background;
+
+                if (clipPtr && clipPtr->type == TKP_CLIP_PIXMAP) {
+		    srcRect = CGRectMake(src_x, src_y, width, height);
+		    CGImageRef mask = CreateCGImageFromPixmap(
+			    clipPtr->value.pixmap);
+		    CGImageRef submask = CGImageCreateWithImageInRect(
+			    img, srcRect);
+		    CGRect rect = CGRectMake(dest_x, dest_y, width, height);
+
+		    rect = CGRectOffset(rect, dstDraw->xOff, dstDraw->yOff);
+		    CGContextSaveGState(context);
+
+		    /*
+		     * Move the origin of the destination to top left.
+		     */
+
+		    CGContextTranslateCTM(context,
+			    0, rect.origin.y + CGRectGetMaxY(rect));
+		    CGContextScaleCTM(context, 1, -1);
+
+		    /*
+		     * Fill with the background color, clipping to the mask.
+		     */
+
+		    CGContextClipToMask(context, rect, submask);
+		    TkMacOSXSetColorInContext(gc, gc->background, dc.context);
+		    CGContextFillRect(context, rect);
+
+		    /*
+		     * Fill with the foreground color, clipping to the
+		     * intersection of img and mask.
+		     */
+
+		    CGImageRef subimage = CGImageCreateWithImageInRect(
+			    img, srcRect);
+		    CGContextClipToMask(context, rect, subimage);
+		    TkMacOSXSetColorInContext(gc, gc->foreground, context);
+		    CGContextFillRect(context, rect);
+		    CGContextRestoreGState(context);
+		    CGImageRelease(img);
+		    CGImageRelease(mask);
+		    CGImageRelease(submask);
+		    CGImageRelease(subimage);
+		} else {
+		    bounds = CGRectMake(0, 0,
+			    srcDraw->size.width, srcDraw->size.height);
+		    srcRect = CGRectMake(src_x, src_y, width, height);
+		    dstRect = CGRectMake(dest_x, dest_y, width, height);
+		    TkMacOSXDrawCGImage(dst, gc, dc.context, img,
+			    gc->foreground, imageBackground, bounds,
+			    srcRect, dstRect);
+		    CGImageRelease(img);
+		}
+	    } else {
+		/* no image */
+		TkMacOSXDbgMsg("Invalid source drawable");
+	    }
+	} else {
+	    TkMacOSXDbgMsg("Invalid destination drawable - "
+		    "could not get a bitmap context.");
+	}
+	TkMacOSXRestoreDrawingContext(&dc);
+	return Success;
+    } else {
+	/*
+	 * Source drawable is a Window, not a Pixmap.
+	 */
+
+	return XCopyArea(display, src, dst, gc, src_x, src_y, width, height,
+		dest_x, dest_y);
+    }
+}
+
+/*
  * Local Variables:
  * mode: objc
  * c-basic-offset: 4