Worked on Windows implementation and the quad-trees.

VisualC/tests/testshape/testshape.vcxproj.user

 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ShowAllFiles>true</ShowAllFiles>
+    <LocalDebuggerCommandArguments Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">"C:\Users\Eli\My Programs\test\shapes\p16_shape24.bmp"</LocalDebuggerCommandArguments>
+    <DebuggerFlavor Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">WindowsLocalDebugger</DebuggerFlavor>
+  </PropertyGroup>
 </Project>
\ No newline at end of file

src/video/SDL_shape.c

@@ -131,6 +131,9 @@ SDL_ShapeTree* RecursivelyCalculateShapeTree(SDL_WindowShapeMode mode,SDL_Surfac
 				case(2):
 					pixel_value = *(Uint16*)pixel;
 					break;
+				case(3):
+					pixel_value = *(Uint32*)pixel & (~mask->format->Amask);
+					break;
 				case(4):
 					pixel_value = *(Uint32*)pixel;
 					break;

src/video/win32/SDL_win32shape.c

@@ -20,7 +20,7 @@
     eligottlieb@gmail.com
 */
 
-#include "SDL_win32shape.h"
+#include "SDL_win32shape.h"
 #include "SDL_win32video.h"
 
 SDL_WindowShaper* Win32_CreateShaper(SDL_Window * window) {
@@ -30,6 +30,8 @@ SDL_WindowShaper* Win32_CreateShaper(SDL_Window * window) {
 	result->mode.mode = ShapeModeDefault;
 	result->mode.parameters.binarizationCutoff = 1;
 	result->usershownflag = 0;
+	result->driverdata = (SDL_ShapeData*)SDL_malloc(sizeof(SDL_ShapeData));
+	((SDL_ShapeData*)result->driverdata)->mask_tree = NULL;
 	//Put some driver-data here.
 	window->shaper = result;
 	resized_properly = Win32_ResizeWindowShape(window);
@@ -51,15 +53,17 @@ void CombineRectRegions(SDL_ShapeTree* node, void* closure) {
 int Win32_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowShapeMode *shapeMode) {
 	SDL_ShapeData *data;
 	HRGN mask_region;
-    SDL_WindowData *windowdata;
+    SDL_WindowData *windowdata;
     HWND hwnd;
 
 	if (shaper == NULL || shape == NULL)
 		return SDL_INVALID_SHAPE_ARGUMENT;
-	if(!SDL_ISPIXELFORMAT_ALPHA(SDL_MasksToPixelFormatEnum(shape->format->BitsPerPixel,shape->format->Rmask,shape->format->Gmask,shape->format->Bmask,shape->format->Amask)) && shapeMode->mode != ShapeModeColorKey || shape->w != shaper->window->w || shape->h != shaper->window->h)
+	if(shape->format->Amask == 0 && shapeMode->mode != ShapeModeColorKey || shape->w != shaper->window->w || shape->h != shaper->window->h)
 		return SDL_INVALID_SHAPE_ARGUMENT;
 	
 	data = (SDL_ShapeData*)shaper->driverdata;
+	if(data->mask_tree != NULL)
+		SDL_FreeShapeTree(&data->mask_tree);
 	data->mask_tree = SDL_CalculateShapeTree(*shapeMode,shape,SDL_FALSE);
 	
 	/*
@@ -72,7 +76,7 @@ int Win32_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowS
 	/*
 	 * Set the new region mask for the window 
 	 */
-	windowdata=(SDL_WindowData *)(shaper->window->driverdata);
+	windowdata=(SDL_WindowData *)(shaper->window->driverdata);
 	hwnd = windowdata->hwnd;
 	SetWindowRgn(hwnd, mask_region, TRUE);