Fix for images with alpha channel data on Mavericks; thanks to Mark Culler for the patch.

4 files changed, 136 insertions, 113 deletions

diff --git a/macosx/tkMacOSXDraw.c b/macosx/tkMacOSXDraw.c
index 0727b26..1589e43 100644
--- a/macosx/tkMacOSXDraw.c
+++ b/macosx/tkMacOSXDraw.c
@@ -114,6 +114,70 @@ TkMacOSXInitCGDrawing(
 /*
  *----------------------------------------------------------------------
  *
+ * BitmapRepFromDrawableRect
+ *
+ *	Extract bitmap data from a MacOSX drawable as an NSBitmapImageRep.
+ *
+ * Results:
+ *	Returns an NSBitmapRep representing the image of the given rectangle of
+ *      the given drawable.
+ *
+ *      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:
+ *     Allocates an NSBitmapImageRep, which must be released.
+ *
+ *----------------------------------------------------------------------
+ */
+NSBitmapImageRep*
+BitmapRepFromDrawableRect(
+        MacDrawable *drawable,
+	int x,
+	int y,
+	unsigned int width,
+	unsigned int height)
+{
+    CGImageRef cg_image=NULL, sub_cg_image=NULL;
+    NSBitmapImageRep *bitmap_rep=NULL;
+    NSView *view=NULL;
+
+    if ( drawable->flags & TK_IS_PIXMAP  && drawable->context) {
+	/* This means that the MacDrawable is functioning as a Tk Pixmap, so its view
+	   field is NULL and its context field points to a CGBitmapContext.
+	*/
+	CGRect image_rect = CGRectMake(x, y, width, height);
+	cg_image = CGBitmapContextCreateImage( (CGContextRef) drawable->context);
+	sub_cg_image = CGImageCreateWithImageInRect(cg_image, image_rect);
+	if ( sub_cg_image ) {
+	    bitmap_rep = [NSBitmapImageRep alloc];
+	    [bitmap_rep initWithCGImage:sub_cg_image];
+	    CGImageRelease(sub_cg_image);
+	}
+	if ( cg_image ) {
+	    CGImageRelease(cg_image);
+	}
+    } else if ( (view = TkMacOSXDrawableView(drawable)) ) {
+	/* convert top-left coordinates to NSView coordinates */
+	int view_height = [view bounds].size.height;
+	NSRect view_rect = NSMakeRect(x + drawable->xOff,
+				      view_height - height - y - drawable->yOff,
+				      width,height);
+	bitmap_rep = [NSBitmapImageRep alloc];
+	[view lockFocus];
+	[bitmap_rep initWithFocusedViewRect:view_rect];
+	[view unlockFocus];
+    } else {
+	TkMacOSXDbgMsg("Invalid source drawable");
+    }
+    
+    return bitmap_rep;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * XCopyArea --
  *
  *	Copies data from one drawable to another using block transfer
@@ -134,86 +198,45 @@ XCopyArea(
     Display *display,		/* Display. */
     Drawable src,		/* Source drawable. */
     Drawable dst,		/* Destination drawable. */
-    GC gc,			/* GC to use. */
+    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 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;
+    NSBitmapImageRep *bitmap_rep = NULL;
 
     display->request++;
     if (!width || !height) {
-	/* TkMacOSXDbgMsg("Drawing of emtpy area requested"); */
+	/* TkMacOSXDbgMsg("Drawing of empty area requested"); */
 	return;
     }
-    if (srcDraw->flags & TK_IS_PIXMAP) {
-	if (!TkMacOSXSetupDrawingContext(dst, gc, 1, &dc)) {
-	    return;
-	}
-	if (dc.context) {
-	    CGImageRef img = TkMacOSXCreateCGImageWithDrawable(src);
-
-	    if (img) {
-		DrawCGImage(dst, gc, dc.context, img, gc->foreground,
-			gc->background, CGRectMake(0, 0,
-			srcDraw->size.width, srcDraw->size.height),
-			CGRectMake(src_x, src_y, width, height),
-			CGRectMake(dest_x, dest_y, width, height));
-		CFRelease(img);
-	    } else {
-		TkMacOSXDbgMsg("Invalid source drawable");
-	    }
-	} else {
-	    TkMacOSXDbgMsg("Invalid destination drawable");
-	}
-	TkMacOSXRestoreDrawingContext(&dc);
-    } else if (TkMacOSXDrawableWindow(src)) {
-	NSView *view = TkMacOSXDrawableView(srcDraw);
-	NSWindow *w = [view window];
-	NSInteger gs = [w windowNumber] > 0 ? [w gState] : 0;
-	/* // alternative using per-view gState:
-	NSInteger gs = [view gState];
-	if (!gs) {
-	    [view allocateGState];
-	    if ([view lockFocusIfCanDraw]) {
-		[view unlockFocus];
-	    }
-	    gs = [view gState];
-	}
-	*/
-	if (!gs || !TkMacOSXSetupDrawingContext(dst, gc, 1, &dc)) {
-	    return;
-	}
-	if (dc.context) {
-	    NSGraphicsContext *gc = nil;
-	    CGFloat boundsH = [view bounds].size.height;
-	    NSRect srcRect = NSMakeRect(srcDraw->xOff + src_x, boundsH -
-		    height - (srcDraw->yOff + src_y), width, height);
-
-	    if (((MacDrawable *) dst)->flags & TK_IS_PIXMAP) {
-		gc = [NSGraphicsContext graphicsContextWithGraphicsPort:
-			dc.context flipped:NO];
-		if (gc) {
-		    [NSGraphicsContext saveGraphicsState];
-		    [NSGraphicsContext setCurrentContext:gc];
+    if (!TkMacOSXSetupDrawingContext(dst, gc, 1, &dc)) {
+	TkMacOSXDbgMsg("Invalid destination drawable");
+    }
+    if (dc.context) {
+	bitmap_rep =  BitmapRepFromDrawableRect(srcDraw, src_x, src_y, width, height);
+	if ( bitmap_rep ) {
+		CGImageRef img = [bitmap_rep CGImage];
+		CGRect image_rect = CGRectMake(0, 0,
+					       srcDraw->size.width, srcDraw->size.height);
+		if (img) {
+		    DrawCGImage(dst, gc, dc.context, img, gc->foreground,
+				gc->background, image_rect,
+				CGRectMake(src_x, src_y, width, height),
+				CGRectMake(dest_x, dest_y, width, height));
+		    CFRelease(img);
 		}
-	    }
-	    NSCopyBits(gs, srcRect, NSMakePoint(dest_x,
-		    dc.portBounds.size.height - dest_y));
-	    if (gc) {
-		[NSGraphicsContext restoreGraphicsState];
-	    }
-	} else {
-	    TkMacOSXDbgMsg("Invalid destination drawable");
+		[bitmap_rep release];
+	    } else {
+	    TkMacOSXDbgMsg("Invalid source drawable");
 	}
-	TkMacOSXRestoreDrawingContext(&dc);
-    } else {
-	TkMacOSXDbgMsg("Invalid source drawable");
     }
+    TkMacOSXRestoreDrawingContext(&dc);
 }
 
 /*
@@ -254,7 +277,7 @@ XCopyPlane(
 
     display->request++;
     if (!width || !height) {
-	/* TkMacOSXDbgMsg("Drawing of emtpy area requested"); */
+	/* TkMacOSXDbgMsg("Drawing of empty area requested"); */
 	return;
     }
     if (plane != 1) {
diff --git a/macosx/tkMacOSXPrivate.h b/macosx/tkMacOSXPrivate.h
index 034c450..9220397 100644
--- a/macosx/tkMacOSXPrivate.h
+++ b/macosx/tkMacOSXPrivate.h
@@ -230,6 +230,8 @@ MODULE_SCOPE WindowClass TkMacOSXWindowClass(TkWindow *winPtr);
 MODULE_SCOPE int	TkMacOSXIsWindowZoomed(TkWindow *winPtr);
 MODULE_SCOPE int	TkGenerateButtonEventForXPointer(Window window);
 MODULE_SCOPE EventModifiers TkMacOSXModifierState(void);
+MODULE_SCOPE NSBitmapImageRep* BitmapRepFromDrawableRect(MacDrawable *drawable,
+			    int x, int y, unsigned int width, unsigned int height);
 MODULE_SCOPE int	TkMacOSXSetupDrawingContext(Drawable d, GC gc,
 			    int useCG, TkMacOSXDrawingContext *dcPtr);
 MODULE_SCOPE void	TkMacOSXRestoreDrawingContext(
diff --git a/macosx/tkMacOSXSubwindows.c b/macosx/tkMacOSXSubwindows.c
index 18276fb..29bc4a3 100644
--- a/macosx/tkMacOSXSubwindows.c
+++ b/macosx/tkMacOSXSubwindows.c
@@ -1277,7 +1277,7 @@ UpdateOffsets(
  *	Returns a handle to a new pixmap.
  *
  * Side effects:
- *	Allocates a new Macintosh GWorld.
+ *	Allocates a new CGBitmapContext.
  *
  *----------------------------------------------------------------------
  */
@@ -1323,7 +1323,7 @@ Tk_GetPixmap(
  *	None.
  *
  * Side effects:
- *	Deletes the Macintosh GWorld created by Tk_GetPixmap.
+ *	Deletes the CGBitmapContext created by Tk_GetPixmap.
  *
  *----------------------------------------------------------------------
  */
diff --git a/macosx/tkMacOSXXStubs.c b/macosx/tkMacOSXXStubs.c
index 848b49c..f009b52 100644
--- a/macosx/tkMacOSXXStubs.c
+++ b/macosx/tkMacOSXXStubs.c
@@ -842,7 +842,7 @@ XCreateImage(
  *	This function copies data from a pixmap or window into an XImage.
  *
  * Results:
- *	Returns a newly allocated image containing the data from the given
+ *	Returns a newly allocated XImage containing the data from the given
  *	rectangle of the given drawable.
  *
  * Side effects:
@@ -863,59 +863,57 @@ XGetImage(
     int format)
 {
     MacDrawable *macDraw = (MacDrawable *) d;
-    XImage *   imagePtr = NULL;
-    Pixmap     pixmap = (Pixmap) NULL;
-    Tk_Window  win = (Tk_Window) macDraw->winPtr;
-    GC	       gc;
-    char *     data = NULL;
-    int	       depth = 32;
-    int	       offset = 0;
-    int	       bitmap_pad = 0;
-    int	       bytes_per_line = 0;
-
+    NSBitmapImageRep *bitmap_rep;
+    XImage *       imagePtr = NULL;
+    char *           bitmap = NULL;
+    char *           image_data=NULL;
+    int	        depth = 32;
+    int	        offset = 0;
+    int	        bitmap_pad = 0;
+    int	        bytes_per_row = 4*width;
+    int                size;
     if (format == ZPixmap) {
-	if (width > 0 && height > 0) {
-	    /*
-	     * Tk_GetPixmap fails for zero width or height.
-	     */
-
-	    pixmap = Tk_GetPixmap(display, d, width, height, depth);
+	if (width == 0 || height == 0) {
+	    return NULL;
 	}
-	if (win) {
-	    XGCValues values;
 
-	    gc = Tk_GetGC(win, 0, &values);
-	} else {
-	    gc = XCreateGC(display, pixmap, 0, NULL);
-	}
-	if (pixmap) {
-	    CGContextRef context;
-
-	    XCopyArea(display, d, pixmap, gc, x, y, width, height, 0, 0);
-	    context = ((MacDrawable *) pixmap)->context;
-	    if (context) {
-		data = CGBitmapContextGetData(context);
-		bytes_per_line = CGBitmapContextGetBytesPerRow(context);
+	bitmap_rep =  BitmapRepFromDrawableRect(macDraw, x, y,width, height);
+	NSSize image_size = NSMakeSize(width, height);
+	NSImage* ns_image = [[NSImage alloc]initWithSize:image_size];
+	[ns_image addRepresentation:bitmap_rep];
+ 
+	/* Assume premultiplied nonplanar data with 4 bytes per pixel and alpha last.*/
+	if ( [bitmap_rep bitmapFormat] == 0 &&
+	     [bitmap_rep isPlanar ] == 0 &&
+	     [bitmap_rep samplesPerPixel] == 4 ) {
+	    bytes_per_row = [bitmap_rep bytesPerRow];
+	    size = bytes_per_row*height;
+	    image_data = (char*)[bitmap_rep bitmapData];
+	    if ( image_data ) {
+		int row, n, m;
+		bitmap = ckalloc(size);
+		/*
+		  Oddly enough, the bitmap has the top row at the beginning,
+		  and the pixels are in BGRA format.
+		*/
+		for (row=0, n=0; row<height; row++, n+=bytes_per_row) {
+		    for (m=n; m<n+bytes_per_row; m+=4) {
+			*(bitmap+m)     = *(image_data+m+2);
+			*(bitmap+m+1) = *(image_data+m+1);
+			*(bitmap+m+2) = *(image_data+m);
+			*(bitmap+m+3) = *(image_data+m+3);
+		    }
+		}
 	    }
 	}
-	if (data) {
+	if (bitmap) {
 	    imagePtr = XCreateImage(display, NULL, depth, format, offset,
-		    data, width, height, bitmap_pad, bytes_per_line);
-
-	    /*
-	     * Track Pixmap underlying the XImage in the unused obdata field
-	     * so that we can treat XImages coming from XGetImage specially.
-	     */
-
-	    imagePtr->obdata = (XPointer) pixmap;
-	} else if (pixmap) {
-	    Tk_FreePixmap(display, pixmap);
-	}
-	if (!win) {
-	    XFreeGC(display, gc);
+				    (char*)bitmap, width, height, bitmap_pad, bytes_per_row);
+	    [ns_image removeRepresentation:bitmap_rep]; /*releases the rep*/
+	    [ns_image release];
 	}
     } else {
-	TkMacOSXDbgMsg("Invalid image format");
+	TkMacOSXDbgMsg("Could not extract image from drawable.");
     }
     return imagePtr;
 }