--- a/include/SDL_shape.h	Tue Jul 20 12:42:43 2010 -0400
+++ b/include/SDL_shape.h	Thu Jul 22 23:11:01 2010 -0400
@@ -83,12 +83,17 @@
 	/** \brief The default mode, a binarized alpha cutoff of 1. */
 	ShapeModeDefault,
 	/** \brief A binarized alpha cutoff with a given integer value. */
-	ShapeModeBinarizeAlpha
+	ShapeModeBinarizeAlpha,
+	/** \brief A binarized alpha cutoff with a given integer value, but with the opposite comparison. */
+	ShapeModeReverseBinarizeAlpha,
+	/** \brief A color key is applied. */
+	ShapeModeColorKey
 } WindowShapeMode;
 /** \brief A union containing parameters for shaped windows. */
 typedef union {
 	/** \brief a cutoff alpha value for binarization of the window shape's alpha channel. */
 	Uint8 binarizationCutoff;
+	SDL_Color colorKey;
 } SDL_WindowShapeParams;
 
 /** \brief A struct that tags the SDL_WindowShapeParams union with an enum describing the type of its contents. */

--- a/src/video/SDL_shape.c	Tue Jul 20 12:42:43 2010 -0400
+++ b/src/video/SDL_shape.c	Thu Jul 22 23:11:01 2010 -0400
@@ -34,7 +34,8 @@
 		result->shaper = result->display->device->shape_driver.CreateShaper(result);
 		if(result->shaper != NULL) {
 			result->shaper->usershownflag = flags & SDL_WINDOW_SHOWN;
-			result->shaper->alphacutoff = 1;
+			result->shaper->mode.mode = ShapeModeDefault;
+			result->shaper->mode.parameters.binarizationCutoff = 1;
 			result->shaper->hasshape = SDL_FALSE;
 			return result;
 		}
@@ -55,12 +56,13 @@
 }
 
 /* REQUIRES that bitmap point to a w-by-h bitmap with 1bpp. */
-void SDL_CalculateShapeBitmap(Uint8 alphacutoff,SDL_Surface *shape,Uint8* bitmap,Uint8 ppb,Uint8 value) {
+void SDL_CalculateShapeBitmap(SDL_WindowShapeMode mode,SDL_Surface *shape,Uint8* bitmap,Uint8 ppb,Uint8 value) {
 	int x = 0;
 	int y = 0;
 	Uint8 r = 0,g = 0,b = 0,alpha = 0;
 	Uint8* pixel = NULL;
 	Uint32 bitmap_pixel,pixel_value = 0;
+	SDL_Color key;
 	if(SDL_MUSTLOCK(shape))
 		SDL_LockSurface(shape);
 	pixel = (Uint8*)shape->pixels;
@@ -82,7 +84,21 @@
 			}
 			SDL_GetRGBA(pixel_value,shape->format,&r,&g,&b,&alpha);
 			bitmap_pixel = y*shape->w + x;
-			bitmap[bitmap_pixel / ppb] |= (alpha >= alphacutoff ? value : 0) << ((ppb - 1) - (bitmap_pixel % ppb));
+			switch(mode.mode) {
+				case(ShapeModeDefault):
+					bitmap[bitmap_pixel / ppb] |= (alpha >= 1 ? value : 0) << ((ppb - 1) - (bitmap_pixel % ppb));
+					break;
+				case(ShapeModeBinarizeAlpha):
+					bitmap[bitmap_pixel / ppb] |= (alpha >= mode.parameters.binarizationCutoff ? value : 0) << ((ppb - 1) - (bitmap_pixel % ppb));
+					break;
+				case(ShapeModeReverseBinarizeAlpha):
+					bitmap[bitmap_pixel / ppb] |= (alpha <= mode.parameters.binarizationCutoff ? value : 0) << ((ppb - 1) - (bitmap_pixel % ppb));
+					break;
+				case(ShapeModeColorKey):
+					key = mode.parameters.colorKey;
+					bitmap[bitmap_pixel / ppb] |= (key.r == r && key.g == g && key.b == b ? value : 0) << ((ppb - 1) - (bitmap_pixel % ppb));
+					break;
+			}
 		}
 	}
 	if(SDL_MUSTLOCK(shape))
@@ -98,18 +114,8 @@
 		//Invalid shape argument.
 		return SDL_INVALID_SHAPE_ARGUMENT;
 	
-	if(shapeMode != NULL) {
-		switch(shapeMode->mode) {
-			case ShapeModeDefault: {
-				window->shaper->alphacutoff = 1;
-				break;
-			}
-			case ShapeModeBinarizeAlpha: {
-				window->shaper->alphacutoff = shapeMode->parameters.binarizationCutoff;
-				break;
-			}
-		}
-	}
+	if(shapeMode != NULL)
+		window->shaper->mode = *shapeMode;
 	//TODO: Platform-specific implementations of SetWindowShape.  X11 is finished.  Win32 is finished.  Debugging is in progress on both.
 	result = window->display->device->shape_driver.SetWindowShape(window->shaper,shape,shapeMode);
 	window->shaper->hasshape = SDL_TRUE;
@@ -137,12 +143,7 @@
 				return SDL_WINDOW_LACKS_SHAPE;
 		}
 		else {
-			if(window->shaper->alphacutoff != 1) {
-				shapeMode->mode = ShapeModeBinarizeAlpha;
-				shapeMode->parameters.binarizationCutoff = window->shaper->alphacutoff;
-			}
-			else
-				shapeMode->mode = ShapeModeDefault;
+			*shapeMode = window->shaper->mode;
 			return 0;
 		}
 	}

--- a/src/video/SDL_sysvideo.h	Tue Jul 20 12:42:43 2010 -0400
+++ b/src/video/SDL_sysvideo.h	Thu Jul 22 23:11:01 2010 -0400
@@ -144,9 +144,8 @@
     /* The user's specified SDL_WINDOW_SHOWN flag, for use once the user gives the window a shape. */
     Uint32 usershownflag;
     
-    /* The cutoff value for alpha-channel binarization.  When alpha is greater-than-or-equal-to this value in the shape
-       image, the corresponding pixel of the actual window will be considered part of the window's shape. */
-    Uint8 alphacutoff;
+    /* The parameters for shape calculation. */
+    SDL_WindowShapeMode mode;
     
     /* Has this window been assigned a shape? */
     SDL_bool hasshape;

--- a/src/video/win32/SDL_win32shape.c	Tue Jul 20 12:42:43 2010 -0400
+++ b/src/video/win32/SDL_win32shape.c	Thu Jul 22 23:11:01 2010 -0400
@@ -26,7 +26,8 @@
 SDL_WindowShaper* Win32_CreateShaper(SDL_Window * window) {
 	SDL_WindowShaper* result = malloc(sizeof(SDL_WindowShaper));
 	result->window = window;
-	result->alphacutoff = 0;
+	result->mode.mode = ShapeModeDefault;
+	result->mode.parameters.binarizationCutoff = 1;
 	result->usershownflag = 0;
 	//Put some driver-data here.
 	window->shaper = result;
@@ -42,7 +43,6 @@
 	if(shape->w != shaper->window->w || shape->h != shaper->window->h)
 		return -3;
 	
-	/* Assume that shaper->alphacutoff already has a value, because SDL_SetWindowShape() should have given it one. */
 	/*
 	 * Start with empty region 
 	 */
@@ -57,7 +57,7 @@
 	/*
 	 * Transfer binarized mask image into workbuffer 
 	 */
-	SDL_CalculateShapeBitmap(shaper->alphacutoff,shape,data->shapebuffer,1,0xff);
+	SDL_CalculateShapeBitmap(shaper->mode,shape,data->shapebuffer,1,0xff);
 	
 	//Move code over to here from AW_windowShape.c
 	Uint8 *pos1 = data->shapebuffer + width - 1;
@@ -338,6 +338,8 @@
 			return -1;
 		}
 	}
+	else
+		memset(data->shapebuffer,0,data->buffersize);
 	
 	window->shaper->usershownflag |= window->flags & SDL_WINDOW_SHOWN;
 	

--- a/src/video/x11/SDL_x11shape.c	Tue Jul 20 12:42:43 2010 -0400
+++ b/src/video/x11/SDL_x11shape.c	Thu Jul 22 23:11:01 2010 -0400
@@ -32,7 +32,8 @@
 	if (SDL_X11_HAVE_XSHAPE) {  /* Make sure X server supports it. */
 		result = malloc(sizeof(SDL_WindowShaper));
 		result->window = window;
-		result->alphacutoff = 0;
+		result->mode.mode = ShapeModeDefault;
+		result->mode.parameters.binarizationCutoff = 1;
 		result->usershownflag = 0;
 		SDL_ShapeData* data = malloc(sizeof(SDL_ShapeData));
 		result->driverdata = data;
@@ -65,6 +66,8 @@
 			return -1;
 		}
 	}
+	else
+		memset(data->bitmap,0,data->bitmapsize);
 	
 	window->shaper->usershownflag |= window->flags & SDL_WINDOW_SHOWN;
 	
@@ -83,7 +86,7 @@
 	SDL_ShapeData *data = shaper->driverdata;
 	
 	/* Assume that shaper->alphacutoff already has a value, because SDL_SetWindowShape() should have given it one. */
-	SDL_CalculateShapeBitmap(shaper->alphacutoff,shape,data->bitmap,8,1);
+	SDL_CalculateShapeBitmap(shaper->mode,shape,data->bitmap,8,1);
 		
 	SDL_WindowData *windowdata = (SDL_WindowData*)(shaper->window->driverdata);
 	Pixmap shapemask = XCreateBitmapFromData(windowdata->videodata->display,windowdata->xwindow,data->bitmap,shaper->window->w,shaper->window->h);