Reformat some lines - Better follow the Tcl Engineering Manual

1 files changed, 165 insertions, 88 deletions

diff --git a/generic/tkCanvas.c b/generic/tkCanvas.c
index 609ed6e..db33db8 100644
--- a/generic/tkCanvas.c
+++ b/generic/tkCanvas.c
@@ -2139,7 +2139,7 @@ CanvasWidgetCmd(
         int subsample = 1, zoom = 1;
 
         if (objc < 3 && objc > 5) {
-            Tcl_WrongNumArgs(interp, 2, objv, "imagename | image imagename subsample | image imagename subsample zoom");
+            Tcl_WrongNumArgs(interp, 2, objv, "imagename ?subsample? ?zoom?");
             result = TCL_ERROR;
             goto done;
         }
@@ -2152,6 +2152,7 @@ CanvasWidgetCmd(
         /*
          * If we are given a subsample or a zoom then grab them.
          */
+
         if (objc >= 4 && Tcl_GetIntFromObj(interp, objv[3], &subsample) != TCL_OK) {
             result = TCL_ERROR;
             goto done;
@@ -2162,9 +2163,10 @@ CanvasWidgetCmd(
         }
 
         /*
-         * Set the image size to zero, which allows the DrawCanvas() function to expand the image automatically when
-         * it copies the pixmap into it.
+         * Set the image size to zero, which allows the DrawCanvas() function
+         * to expand the image automatically when it copies the pixmap into it.
          */
+
         if (Tk_PhotoSetSize(interp, photohandle, 0, 0) != TCL_OK) {
             result = TCL_ERROR;
             goto done;
@@ -2487,6 +2489,7 @@ DecomposeMaskToShiftAndBits(
     /*
      * Find the lowest '1' bit in the mask.
      */
+
     for (i = 0; i < 32; ++i) {
         if (mask & 1 << i)
             break;
@@ -2497,6 +2500,7 @@ DecomposeMaskToShiftAndBits(
         /*
         * Now find the next '0' bit and the width of the mask.
         */
+ 
         for ( ; i < 32; ++i) {
             if ((mask & 1 << i) == 0)
                 break;
@@ -2507,6 +2511,7 @@ DecomposeMaskToShiftAndBits(
         /*
         * Limit to the top 8 bits if the mask was wider than 8.
         */
+
         if (*bits > 8) {
             *shift += *bits - 8;
             *bits = 8;
@@ -2534,9 +2539,12 @@ DecomposeMaskToShiftAndBits(
  *----------------------------------------------------------------------
  */
 
-#define OVERDRAW_PIXELS 32        /* How much larger we make the pixmap that the canvas objects are drawn into */
+#define OVERDRAW_PIXELS 32        /* How much larger we make the pixmap
+                                   * that the canvas objects are drawn into */
+
 /* From stackoverflow.com/questions/2100331/c-macro-definition-to-determine-big-endian-or-little-endian-machine */
 #define IS_BIG_ENDIAN (*(unsigned short *)"\0\xff" < 0x100)
+
 #define BYTE_SWAP16(n) ((((unsigned short)n)>>8) | (((unsigned short)n)<<8))
 #define BYTE_SWAP32(n) (((n>>24)&0x000000FF) | ((n<<8)&0x00FF0000) | ((n>>8)&0x0000FF00) | ((n<<24)&0xFF000000))
 
@@ -2563,6 +2571,7 @@ DrawCanvas(
         pixmapX1, pixmapY1, pixmapX2, pixmapY2, pmWidth, pmHeight,
         bitsPerPixel, bytesPerPixel, x, y, result = TCL_OK,
         rshift, gshift, bshift, rbits, gbits, bbits;
+
 #ifdef DEBUG_DRAWCANVAS
     char buffer[128];
 #endif
@@ -2574,10 +2583,11 @@ DrawCanvas(
     }
 
     /*
-     * If this canvas is unmapped, then we won't have a window id, so we will try
-     * the ancestors of the canvas until we find a window that has a valid window id.
-     * The Tk_GetPixmap() call requires a valid window id.
+     * If this canvas is unmapped, then we won't have a window id, so we will
+     * try the ancestors of the canvas until we find a window that has a
+     * valid window id. The Tk_GetPixmap() call requires a valid window id.
      */
+
     do {
 
         if ((displayPtr = Tk_Display(tkwin)) == NULL) {
@@ -2612,7 +2622,9 @@ DrawCanvas(
     * that didn't do that for the final coordinates yet. This can be
     * determined by the FORCE_REDRAW flag.
     */
-    for (itemPtr = canvasPtr -> firstItemPtr; itemPtr != NULL; itemPtr = itemPtr -> nextPtr) {
+
+    for (itemPtr = canvasPtr -> firstItemPtr; itemPtr != NULL; 
+            itemPtr = itemPtr -> nextPtr) {
         if (itemPtr -> redraw_flags & FORCE_REDRAW) {
             itemPtr -> redraw_flags &= ~FORCE_REDRAW;
             EventuallyRedrawItem(canvasPtr, itemPtr);
@@ -2621,11 +2633,14 @@ DrawCanvas(
     }
 
     /*
-     * The DisplayCanvas() function works out the region that needs redrawing, but we don't do this. We grab the whole
-     * scrollregion or canvas window area. If we have a defined -scrollregion we use that as the drawing region, otherwise
-     * use the canvas window height and width with an origin of 0,0.
+     * The DisplayCanvas() function works out the region that needs redrawing,
+     * but we don't do this. We grab the whole scrollregion or canvas window
+     * area. If we have a defined -scrollregion we use that as the drawing
+     * region, otherwise use the canvas window height and width with an origin
+     * of 0,0.
      */
-    if (canvasPtr->scrollX1 != 0 || canvasPtr->scrollY1 != 0 || canvasPtr->scrollX2 != 0 || canvasPtr->scrollY2 != 0) {
+    if (canvasPtr->scrollX1 != 0 || canvasPtr->scrollY1 != 0 ||
+            canvasPtr->scrollX2 != 0 || canvasPtr->scrollY2 != 0) {
 
         canvasX1 = canvasPtr->scrollX1;
         canvasY1 = canvasPtr->scrollY1;
@@ -2645,24 +2660,29 @@ DrawCanvas(
     }
     
     /*
-     * Allocate a pixmap to draw into. We add OVERDRAW_PIXELS in the same way that DisplayCanvas() does
-     * to avoid problems on some systems when objects are being drawn too close to the edge.
+     * Allocate a pixmap to draw into. We add OVERDRAW_PIXELS in the same way
+     * that DisplayCanvas() does to avoid problems on some systems when objects
+     * are being drawn too close to the edge.
      */
+
     pixmapX1 = canvasX1 - OVERDRAW_PIXELS;
     pixmapY1 = canvasY1 - OVERDRAW_PIXELS;
     pixmapX2 = canvasX2 + OVERDRAW_PIXELS;
     pixmapY2 = canvasY2 + OVERDRAW_PIXELS;
     pmWidth = pixmapX2 - pixmapX1 + 1;
     pmHeight = pixmapY2 - pixmapY1 + 1;
-    if ((pixmap = Tk_GetPixmap(displayPtr, Tk_WindowId(tkwin), pmWidth, pmHeight, bitsPerPixel)) == 0) {
+    if ((pixmap = Tk_GetPixmap(displayPtr, Tk_WindowId(tkwin), pmWidth, pmHeight,
+            bitsPerPixel)) == 0) {
         Tcl_AppendResult(interp, "failed to create drawing Pixmap", NULL);
         result = TCL_ERROR;
         goto done;
     }
 
     /*
-     * Before we can draw the canvas objects into the pixmap it's background should be filled with canvas background colour.
+     * Before we can draw the canvas objects into the pixmap it's background
+     * should be filled with canvas background colour.
      */
+
     xgcValues.function = GXcopy;
     xgcValues.foreground = Tk_3DBorderColor(canvasPtr->bgBorder)->pixel;
     xgc = XCreateGC(displayPtr, pixmap, GCFunction|GCForeground, &xgcValues);
@@ -2671,26 +2691,35 @@ DrawCanvas(
     /*
      * Draw all the cavas items into the pixmap
      */
+
     canvasPtr->drawableXOrigin = pixmapX1;
     canvasPtr->drawableYOrigin = pixmapY1;
-    for (itemPtr = canvasPtr->firstItemPtr; itemPtr != NULL; itemPtr = itemPtr->nextPtr) {
-        if ((itemPtr->x1 >= pixmapX2) || (itemPtr->y1 >= pixmapY2) || (itemPtr->x2 < pixmapX1) || (itemPtr->y2 < pixmapY1)) {
+    for (itemPtr = canvasPtr->firstItemPtr; itemPtr != NULL;
+            itemPtr = itemPtr->nextPtr) {
+        if ((itemPtr->x1 >= pixmapX2) || (itemPtr->y1 >= pixmapY2) ||
+                (itemPtr->x2 < pixmapX1) || (itemPtr->y2 < pixmapY1)) {
             if (!AlwaysRedraw(itemPtr)) {
                 continue;
             }
         }
-        if (itemPtr -> state == TK_STATE_HIDDEN || (itemPtr -> state == TK_STATE_NULL && canvasPtr -> canvas_state == TK_STATE_HIDDEN)) {
+        if (itemPtr->state == TK_STATE_HIDDEN || 
+                (itemPtr->state == TK_STATE_NULL && canvasPtr->canvas_state
+                == TK_STATE_HIDDEN)) {
             continue;
         }
-        ItemDisplay(canvasPtr, itemPtr, pixmap, pixmapX1, pixmapY1, pmWidth, pmHeight);
+        ItemDisplay(canvasPtr, itemPtr, pixmap, pixmapX1, pixmapY1, pmWidth,
+                pmHeight);
     }
     
     /*
-     * Copy the Pixmap into an ZPixmap format XImage so we can copy it across to the photo image.
-     * This seems to be the only way to get Pixmap image data out of an image.
-     * Note we have to account for the OVERDRAW_PIXELS border width.
+     * Copy the Pixmap into an ZPixmap format XImage so we can copy it across
+     * to the photo image. This seems to be the only way to get Pixmap image
+     * data out of an image. Note we have to account for the OVERDRAW_PIXELS
+     * border width.
      */
-    if ((ximagePtr = XGetImage(displayPtr,pixmap,-pixmapX1,-pixmapY1,cWidth,cHeight,AllPlanes,ZPixmap)) == NULL) {
+
+    if ((ximagePtr = XGetImage(displayPtr, pixmap, -pixmapX1, -pixmapY1, cWidth,
+            cHeight, AllPlanes, ZPixmap)) == NULL) {
         Tcl_AppendResult(interp, "failed to copy Pixmap to XImage", NULL);
         result = TCL_ERROR;
         goto done;
@@ -2698,55 +2727,59 @@ DrawCanvas(
     
 #ifdef DEBUG_DRAWCANVAS
     Tcl_AppendResult(interp, "ximagePtr {", NULL);
-    sprintf(buffer,"%d",ximagePtr->width);              Tcl_AppendResult(interp, " width ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->height);             Tcl_AppendResult(interp, " height ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->xoffset);            Tcl_AppendResult(interp, " xoffset ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->format);             Tcl_AppendResult(interp, " format ", buffer, NULL);
-                                                        Tcl_AppendResult(interp, " ximagePtr->data", NULL);
+    sprintf(buffer,"%d",ximagePtr->width);   Tcl_AppendResult(interp, " width ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->height);  Tcl_AppendResult(interp, " height ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->xoffset); Tcl_AppendResult(interp, " xoffset ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->format);  Tcl_AppendResult(interp, " format ", buffer, NULL);
+                                             Tcl_AppendResult(interp, " ximagePtr->data", NULL);
     if (ximagePtr->data != NULL) {
-		int ix, iy;
-		Tcl_AppendResult(interp, " {", NULL);
-		for (iy = 0; iy < ximagePtr->height; ++ iy) {
-			Tcl_AppendResult(interp, " {", NULL);
-			for (ix = 0; ix < ximagePtr->bytes_per_line; ++ ix) {
-				if (ix > 0) {
+	int ix, iy;
+
+        Tcl_AppendResult(interp, " {", NULL);
+	for (iy = 0; iy < ximagePtr->height; ++ iy) {
+	    Tcl_AppendResult(interp, " {", NULL);
+	    for (ix = 0; ix < ximagePtr->bytes_per_line; ++ ix) {
+	        if (ix > 0) {
                     if (ix % 4 == 0)
                         Tcl_AppendResult(interp, "-", NULL);
                     else
                         Tcl_AppendResult(interp, " ", NULL);
                 }
-				sprintf(buffer,"%2.2x",ximagePtr->data[ximagePtr->bytes_per_line * iy + ix]&0xFF);
-				Tcl_AppendResult(interp, buffer, NULL);
-			}
-			Tcl_AppendResult(interp, " }", NULL);
-		}
-		Tcl_AppendResult(interp, " }", NULL);
-	} else
-		sprintf(buffer," NULL");
-    sprintf(buffer,"%d",ximagePtr->byte_order);         Tcl_AppendResult(interp, " byte_order ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->bitmap_unit);        Tcl_AppendResult(interp, " bitmap_unit ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->bitmap_bit_order);   Tcl_AppendResult(interp, " bitmap_bit_order ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->bitmap_pad);         Tcl_AppendResult(interp, " bitmap_pad ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->depth);              Tcl_AppendResult(interp, " depth ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->bytes_per_line);     Tcl_AppendResult(interp, " bytes_per_line ", buffer, NULL);
-    sprintf(buffer,"%d",ximagePtr->bits_per_pixel);     Tcl_AppendResult(interp, " bits_per_pixel ", buffer, NULL);
-    sprintf(buffer,"0x%8.8lx",ximagePtr->red_mask);      Tcl_AppendResult(interp, " red_mask ", buffer, NULL);
-    sprintf(buffer,"0x%8.8lx",ximagePtr->green_mask);    Tcl_AppendResult(interp, " green_mask ", buffer, NULL);
-    sprintf(buffer,"0x%8.8lx",ximagePtr->blue_mask);     Tcl_AppendResult(interp, " blue_mask ", buffer, NULL);
+	        sprintf(buffer,"%2.2x",ximagePtr->data[ximagePtr->bytes_per_line * iy + ix]&0xFF);
+	        Tcl_AppendResult(interp, buffer, NULL);
+	    }
+	    Tcl_AppendResult(interp, " }", NULL);
+	}
+	Tcl_AppendResult(interp, " }", NULL);
+    } else
+	sprintf(buffer," NULL");
+    sprintf(buffer,"%d",ximagePtr->byte_order);       Tcl_AppendResult(interp, " byte_order ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->bitmap_unit);      Tcl_AppendResult(interp, " bitmap_unit ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->bitmap_bit_order); Tcl_AppendResult(interp, " bitmap_bit_order ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->bitmap_pad);       Tcl_AppendResult(interp, " bitmap_pad ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->depth);            Tcl_AppendResult(interp, " depth ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->bytes_per_line);   Tcl_AppendResult(interp, " bytes_per_line ", buffer, NULL);
+    sprintf(buffer,"%d",ximagePtr->bits_per_pixel);   Tcl_AppendResult(interp, " bits_per_pixel ", buffer, NULL);
+    sprintf(buffer,"0x%8.8lx",ximagePtr->red_mask);   Tcl_AppendResult(interp, " red_mask ", buffer, NULL);
+    sprintf(buffer,"0x%8.8lx",ximagePtr->green_mask); Tcl_AppendResult(interp, " green_mask ", buffer, NULL);
+    sprintf(buffer,"0x%8.8lx",ximagePtr->blue_mask);  Tcl_AppendResult(interp, " blue_mask ", buffer, NULL);
     Tcl_AppendResult(interp, " }", NULL);
     
     Tcl_AppendResult(interp, "\nvisualPtr {", NULL);
-    sprintf(buffer,"0x%8.8lx",visualPtr->red_mask);      Tcl_AppendResult(interp, " red_mask ", buffer, NULL);
-    sprintf(buffer,"0x%8.8lx",visualPtr->green_mask);    Tcl_AppendResult(interp, " green_mask ", buffer, NULL);
-    sprintf(buffer,"0x%8.8lx",visualPtr->blue_mask);     Tcl_AppendResult(interp, " blue_mask ", buffer, NULL);
+    sprintf(buffer,"0x%8.8lx",visualPtr->red_mask);   Tcl_AppendResult(interp, " red_mask ", buffer, NULL);
+    sprintf(buffer,"0x%8.8lx",visualPtr->green_mask); Tcl_AppendResult(interp, " green_mask ", buffer, NULL);
+    sprintf(buffer,"0x%8.8lx",visualPtr->blue_mask);  Tcl_AppendResult(interp, " blue_mask ", buffer, NULL);
     Tcl_AppendResult(interp, " }", NULL);
     
 #endif
+
     /*
-     * Fill in the PhotoImageBlock structure abd allocate a block of memory for the converted image data.
-     * Note we allocate an alpha channel even though we don't use one, because this layout helps Tk_PhotoPutBlock()
+     * Fill in the PhotoImageBlock structure abd allocate a block of memory
+     * for the converted image data. Note we allocate an alpha channel even
+     * though we don't use one, because this layout helps Tk_PhotoPutBlock()
      * use memcpy() instead of the slow pixel or line copy.
      */
+
     blockPtr.width = cWidth;
     blockPtr.height = cHeight;
     blockPtr.pixelSize = 4;
@@ -2758,64 +2791,91 @@ DrawCanvas(
     blockPtr.pixelPtr = ckalloc(blockPtr.pixelSize * blockPtr.height * blockPtr.width);
 
     /*
-     * Now convert the image data pixel by pixel from XImage to 32bit RGBA format suitable for Tk_PhotoPutBlock().
+     * Now convert the image data pixel by pixel from XImage to 32bit RGBA
+     * format suitable for Tk_PhotoPutBlock().
      */
+
     DecomposeMaskToShiftAndBits(visualPtr->red_mask,&rshift,&rbits);
     DecomposeMaskToShiftAndBits(visualPtr->green_mask,&gshift,&gbits);
     DecomposeMaskToShiftAndBits(visualPtr->blue_mask,&bshift,&bbits);
+
 #ifdef DEBUG_DRAWCANVAS
-    sprintf(buffer,"%d",rshift);  Tcl_AppendResult(interp, "\nbits { rshift ", buffer, NULL);
-    sprintf(buffer,"%d",gshift);  Tcl_AppendResult(interp, " gshift ", buffer, NULL);
-    sprintf(buffer,"%d",bshift);  Tcl_AppendResult(interp, " bshift ", buffer, NULL);
-    sprintf(buffer,"%d",rbits);   Tcl_AppendResult(interp, " rbits ", buffer, NULL);
-    sprintf(buffer,"%d",gbits);   Tcl_AppendResult(interp, " gbits ", buffer, NULL);
-    sprintf(buffer,"%d",bbits);   Tcl_AppendResult(interp, " bbits ", buffer, " }", NULL);
+    sprintf(buffer,"%d",rshift); Tcl_AppendResult(interp, "\nbits { rshift ", buffer, NULL);
+    sprintf(buffer,"%d",gshift); Tcl_AppendResult(interp, " gshift ", buffer, NULL);
+    sprintf(buffer,"%d",bshift); Tcl_AppendResult(interp, " bshift ", buffer, NULL);
+    sprintf(buffer,"%d",rbits);  Tcl_AppendResult(interp, " rbits ", buffer, NULL);
+    sprintf(buffer,"%d",gbits);  Tcl_AppendResult(interp, " gbits ", buffer, NULL);
+    sprintf(buffer,"%d",bbits);  Tcl_AppendResult(interp, " bbits ", buffer, " }", NULL);
     Tcl_AppendResult(interp, "\nConverted_image {", NULL);
 #endif
-    /* SVP: Ok I had to use ximagePtr->bits_per_pixel here and in the switch (...) below to get this to work on Windows. X11 correctly
-     * sets the bitmap_pad and bitmap_unit fields to 32, but on Windows they are 0 and 8 respectively! */
+
+    /* Ok, had to use ximagePtr->bits_per_pixel here and in the switch (...)
+     * below to get this to work on Windows. X11 correctly sets the bitmap
+     *_pad and bitmap_unit fields to 32, but on Windows they are 0 and 8
+     * respectively!
+     */
+
     bytesPerPixel = ximagePtr->bits_per_pixel/8;
     for (y = 0; y < blockPtr.height; ++y) {
+
 #ifdef DEBUG_DRAWCANVAS
         Tcl_AppendResult(interp, " {", NULL);
 #endif
+
         for(x = 0; x < blockPtr.width; ++x) {
             unsigned long pixel;
-			switch (ximagePtr->bits_per_pixel) {
+
+            switch (ximagePtr->bits_per_pixel) {
 
                 /*
                  * Get an 8 bit pixel from the XImage.
                  */
+
                 case 8 :
-                   pixel = *((unsigned char *)(ximagePtr->data + bytesPerPixel * x + ximagePtr->bytes_per_line * y));
+                    pixel = *((unsigned char *)(ximagePtr->data + bytesPerPixel * x
+                            + ximagePtr->bytes_per_line * y));
                     break;
 
                 /*
-                 * Get a 16 bit pixel from the XImage, and correct the byte order as necessary.
+                 * Get a 16 bit pixel from the XImage, and correct the
+                 * byte order as necessary.
                  */
+
                 case 16 :
-                    pixel = *((unsigned short *)(ximagePtr->data + bytesPerPixel * x + ximagePtr->bytes_per_line * y));
-                    if ((IS_BIG_ENDIAN && ximagePtr->byte_order == LSBFirst) || (!IS_BIG_ENDIAN && ximagePtr->byte_order == MSBFirst))
+                    pixel = *((unsigned short *)(ximagePtr->data + bytesPerPixel * x
+                            + ximagePtr->bytes_per_line * y));
+                    if ((IS_BIG_ENDIAN && ximagePtr->byte_order == LSBFirst)
+                            || (!IS_BIG_ENDIAN && ximagePtr->byte_order == MSBFirst))
                         pixel = BYTE_SWAP16(pixel);
                     break;
 
                 /*
-                 * Grab a 32 bit pixel from the XImage, and correct the byte order as necessary.
+                 * Grab a 32 bit pixel from the XImage, and correct the
+                 * byte order as necessary.
                  */
+
                 case 32 :
-                    pixel = *((unsigned long *)(ximagePtr->data + bytesPerPixel * x + ximagePtr->bytes_per_line * y));
-                    if ((IS_BIG_ENDIAN && ximagePtr->byte_order == LSBFirst) || (!IS_BIG_ENDIAN && ximagePtr->byte_order == MSBFirst))
+                    pixel = *((unsigned long *)(ximagePtr->data + bytesPerPixel * x
+                            + ximagePtr->bytes_per_line * y));
+                    if ((IS_BIG_ENDIAN && ximagePtr->byte_order == LSBFirst)
+                            || (!IS_BIG_ENDIAN && ximagePtr->byte_order == MSBFirst))
                         pixel = BYTE_SWAP32(pixel);
                     break;
             }
 
             /*
-             * We have a pixel with the correct byte order, so pull out the colours and place them in the photo block.
-             * Perhaps we could just not bother with the alpha byte because we are using TK_PHOTO_COMPOSITE_SET later?
-             * ***Windows: We have to swap the red and blue values. The XImage storage is B - G - R - A which becomes a
-             * 32bit ARGB quad. However the visual mask is a 32bit ABGR quad. And Tk_PhotoPutBlock() wants R-G-B-A which is
-             * a 32bit ABGR quad. If the visual mask was correct there would be no need to swap anything here.
+             * We have a pixel with the correct byte order, so pull out the
+             * colours and place them in the photo block. Perhaps we could
+             * just not bother with the alpha byte because we are using
+             * TK_PHOTO_COMPOSITE_SET later?
+             * ***Windows: We have to swap the red and blue values. The
+             * XImage storage is B - G - R - A which becomes a 32bit ARGB
+             * quad. However the visual mask is a 32bit ABGR quad. And
+             * Tk_PhotoPutBlock() wants R-G-B-A which is a 32bit ABGR quad.
+             * If the visual mask was correct there would be no need to
+             * swap anything here.
              */
+
 #ifdef _WIN32
 #define   R_OFFSET 2
 #define   B_OFFSET 0
@@ -2823,40 +2883,56 @@ DrawCanvas(
 #define   R_OFFSET 0
 #define   B_OFFSET 2
 #endif
-            blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x + R_OFFSET] = (unsigned char)((pixel & visualPtr->red_mask) >> rshift);
-            blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x +1] = (unsigned char)((pixel & visualPtr->green_mask) >> gshift);
-            blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x + B_OFFSET] = (unsigned char)((pixel & visualPtr->blue_mask) >> bshift);
+            blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x + R_OFFSET] =
+                    (unsigned char)((pixel & visualPtr->red_mask) >> rshift);
+            blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x +1] =
+                    (unsigned char)((pixel & visualPtr->green_mask) >> gshift);
+            blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x + B_OFFSET] =
+                    (unsigned char)((pixel & visualPtr->blue_mask) >> bshift);
             blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x +3] = 0xFF;
+
 #ifdef DEBUG_DRAWCANVAS
             {
-				int ix;
+		int ix;
                 if (x > 0)
                     Tcl_AppendResult(interp, "-", NULL);
-				for (ix = 0; ix < 4; ++ix) {
+	        for (ix = 0; ix < 4; ++ix) {
                     if (ix > 0)
                         Tcl_AppendResult(interp, " ", NULL);
-					sprintf(buffer,"%2.2x",blockPtr.pixelPtr[blockPtr.pitch * y + blockPtr.pixelSize * x + ix]&0xFF); Tcl_AppendResult(interp, buffer, NULL);
+		    sprintf(buffer,"%2.2x",blockPtr.pixelPtr[blockPtr.pitch * y
+                            + blockPtr.pixelSize * x + ix]&0xFF);
+                    Tcl_AppendResult(interp, buffer, NULL);
                 }
             }
 #endif
+
         }
+
 #ifdef DEBUG_DRAWCANVAS
         Tcl_AppendResult(interp, " }", NULL);
 #endif
+
     }
+
 #ifdef DEBUG_DRAWCANVAS
     Tcl_AppendResult(interp, " }", NULL);
 #endif
+
     /*
      * Now put the copied pixmap into the photo.
      * If either zoom or subsample are not 1, we use the zoom function.
      */
+
     if (subsample != 1 || zoom != 1) {
-        if ((result = Tk_PhotoPutZoomedBlock(interp, photohandle, &blockPtr, 0, 0, cWidth * zoom / subsample, cHeight * zoom / subsample, zoom, zoom, subsample, subsample, TK_PHOTO_COMPOSITE_SET)) != TCL_OK) {
+        if ((result = Tk_PhotoPutZoomedBlock(interp, photohandle, &blockPtr,
+                0, 0, cWidth * zoom / subsample, cHeight * zoom / subsample,
+                zoom, zoom, subsample, subsample, TK_PHOTO_COMPOSITE_SET))
+                != TCL_OK) {
             goto done;
         }
     } else {
-        if ((result = Tk_PhotoPutBlock(interp, photohandle, &blockPtr, 0, 0, cWidth, cHeight, TK_PHOTO_COMPOSITE_SET)) != TCL_OK) {
+        if ((result = Tk_PhotoPutBlock(interp, photohandle, &blockPtr, 0, 0,
+            cWidth, cHeight, TK_PHOTO_COMPOSITE_SET)) != TCL_OK) {
             goto done;
         }
     }
@@ -2864,6 +2940,7 @@ DrawCanvas(
     /*
      * Clean up anything we have allocated and exit.
      */
+
 done:
     if (blockPtr.pixelPtr)
         ckfree(blockPtr.pixelPtr);