Compiling for cocoa now works. Does it run? We'll see.

src/video/SDL_shape.c

@@ -196,7 +196,7 @@ SDL_ShapeTree* SDL_CalculateShapeTree(SDL_WindowShapeMode mode,SDL_Surface* shap
 	return result;
 }
 
-void SDL_TraverseShapeTree(SDL_ShapeTree *tree,void(*function)(SDL_ShapeTree*,void*),void* closure) {
+void SDL_TraverseShapeTree(SDL_ShapeTree *tree,SDL_TraversalFunction function,void* closure) {
 	if(tree->kind == QuadShape) {
 		SDL_TraverseShapeTree((SDL_ShapeTree *)tree->data.children.upleft,function,closure);
 		SDL_TraverseShapeTree((SDL_ShapeTree *)tree->data.children.upright,function,closure);

src/video/SDL_shape_internals.h

@@ -51,10 +51,12 @@ typedef struct {
 	SDL_ShapeKind kind;
 	SDL_ShapeUnion data;
 } SDL_ShapeTree;
+	
+typedef void(*SDL_TraversalFunction)(SDL_ShapeTree*,void*);
 
 extern void SDL_CalculateShapeBitmap(SDL_WindowShapeMode mode,SDL_Surface *shape,Uint8* bitmap,Uint8 ppb);
 extern SDL_ShapeTree* SDL_CalculateShapeTree(SDL_WindowShapeMode mode,SDL_Surface* shape,SDL_bool invert);
-extern void SDL_TraverseShapeTree(SDL_ShapeTree *tree,void(*function)(SDL_ShapeTree*,void*),void* closure);
+extern void SDL_TraverseShapeTree(SDL_ShapeTree *tree,SDL_TraversalFunction function,void* closure);
 extern void SDL_FreeShapeTree(SDL_ShapeTree** shapeTree);
 
 /* Ends C function definitions when using C++ */

src/video/cocoa/SDL_cocoashape.m

@@ -59,7 +59,7 @@ NSRect convert_rect(SDL_Rect rect,SDL_Window* window) {
 	return [[((SDL_WindowData*)window->driverdata)->nswindow contentView] convertRectFromBase:nsrect];
 }
 
-void ConglomerateShapeTree(SDL_ShapeTree* tree,SDL_PathConglomeration cong) {
+void ConglomerateShapeTree(SDL_ShapeTree* tree,SDL_PathConglomeration* cong) {
 	if(tree->kind == OpaqueShape) {
 		NSRect rect = convert_rect(tree->data.shape,cong->window);
 		[cong->clipPath appendBezierPathWithRect:rect];
@@ -84,7 +84,7 @@ int Cocoa_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowS
 	
 	SDL_PathConglomeration cong = {clipPath,shaper->window};
 	
-	SDL_TraverseShapeTree(data->shape,&ConglomerateShapeTree,cong);
+	SDL_TraverseShapeTree(data->shape,(SDL_TraversalFunction)&ConglomerateShapeTree,(void*)&cong);
 	
 	[clipPath addClip];
 }