Mostly seem to have fixed SDL_CalculateShapeTree. Mostly. There still seem...

Mostly seem to have fixed SDL_CalculateShapeTree.  Mostly.  There still seem to be some rendering artifacts, stepping effects, and such on Windows -- which indicates subtle logic errors in SDL_CalculateShapeTree().

Oh well, back into the salt mine.

src/video/SDL_shape.c

@@ -156,7 +156,7 @@ RecursivelyCalculateShapeTree(SDL_WindowShapeMode mode,SDL_Surface* mask,SDL_Rec
                     break;
                 case(ShapeModeColorKey):
                     key = mode.parameters.colorKey;
-                    pixel_opaque = ((key.r == r && key.g == g && key.b == b) ? SDL_TRUE : SDL_FALSE);
+                    pixel_opaque = ((key.r != r || key.g != g || key.b != b) ? SDL_TRUE : SDL_FALSE);
                     break;
             }
             if(last_opaque == -1)
@@ -170,14 +170,14 @@ RecursivelyCalculateShapeTree(SDL_WindowShapeMode mode,SDL_Surface* mask,SDL_Rec
                 next.x = dimensions.x;
                 next.y = dimensions.y;
                 result->data.children.upleft = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
-                next.x = dimensions.w / 2;
+                next.x += next.w;
                 //Unneeded: next.y = dimensions.y;
                 result->data.children.upright = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
                 next.x = dimensions.x;
-                next.y = dimensions.h / 2;
+                next.y += next.h;
                 result->data.children.downleft = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
-                next.x = dimensions.w / 2;
-                //Unneeded: next.y = dimensions.h / 2 + 1;
+                next.x += next.w;
+                //Unneeded: next.y = dimensions.y + dimensions.h /2;
                 result->data.children.downright = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
                 return result;
             }
@@ -214,15 +214,15 @@ SDL_TraverseShapeTree(SDL_ShapeTree *tree,SDL_TraversalFunction function,void* c
 }
 
 void
-SDL_FreeShapeTree(SDL_ShapeTree** shapeTree) {
-    if((*shapeTree)->kind == QuadShape) {
-        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shapeTree)->data.children.upleft);
-        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shapeTree)->data.children.upright);
-        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shapeTree)->data.children.downleft);
-        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shapeTree)->data.children.downright);
+SDL_FreeShapeTree(SDL_ShapeTree** shape_tree) {
+    if((*shape_tree)->kind == QuadShape) {
+        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shape_tree)->data.children.upleft);
+        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shape_tree)->data.children.upright);
+        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shape_tree)->data.children.downleft);
+        SDL_FreeShapeTree((SDL_ShapeTree **)&(*shape_tree)->data.children.downright);
     }
-    SDL_free(*shapeTree);
-    *shapeTree = NULL;
+    SDL_free(*shape_tree);
+    *shape_tree = NULL;
 }
 
 int
@@ -240,7 +240,6 @@ SDL_SetWindowShape(SDL_Window *window,SDL_Surface *shape,SDL_WindowShapeMode *sh
     result = window->display->device->shape_driver.SetWindowShape(window->shaper,shape,shape_mode);
     window->shaper->hasshape = SDL_TRUE;
     if((window->shaper->usershownflag & SDL_WINDOW_SHOWN) == SDL_WINDOW_SHOWN) {
-        SDL_SetWindowPosition(window,window->x,window->y);
         SDL_ShowWindow(window);
         window->shaper->usershownflag &= !SDL_WINDOW_SHOWN;
     }

src/video/SDL_shape_internals.h

@@ -57,7 +57,7 @@ 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);
 extern void SDL_TraverseShapeTree(SDL_ShapeTree *tree,SDL_TraversalFunction function,void* closure);
-extern void SDL_FreeShapeTree(SDL_ShapeTree** shapeTree);
+extern void SDL_FreeShapeTree(SDL_ShapeTree** shape_tree);
 
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus

src/video/win32/SDL_win32shape.c

@@ -21,6 +21,7 @@
 */
 
 #include <stdio.h>
+#include "SDL_assert.h"
 #include "SDL_win32shape.h"
 #include "SDL_win32video.h"
 
@@ -43,47 +44,31 @@ Win32_CreateShaper(SDL_Window * window) {
     return result;
 }
 
-typedef struct {
-	POINT corners[4];
-	void* next;
-} SDL_ShapeRect;
-
 void
 CombineRectRegions(SDL_ShapeTree* node,void* closure) {
 	char debug_str[200];
-    SDL_ShapeRect* rect_list = *((SDL_ShapeRect**)closure);
+    HRGN mask_region = *((HRGN*)closure),temp_region = NULL;
     if(node->kind == OpaqueShape) {
-        SDL_ShapeRect* rect = SDL_malloc(sizeof(SDL_ShapeRect));
+        //Win32 API regions exclude their outline, so we widen the region by one pixel in each direction to include the real outline.
         sprintf_s(&debug_str[0],200,"x: %u y: %u, x+w: %u, y+h: %u\n",
                   node->data.shape.x,node->data.shape.y,
 				  node->data.shape.x + node->data.shape.w,node->data.shape.y + node->data.shape.h);
         OutputDebugStringA(debug_str);
 		OutputDebugStringA("Converting SDL_ShapeTree opaque node to Windows rectangle.\n");
-        rect->corners[0].x = node->data.shape.x; rect->corners[0].y = node->data.shape.y;
-        rect->corners[1].x = node->data.shape.x + node->data.shape.w; rect->corners[1].y = node->data.shape.y;
-        rect->corners[2].x = node->data.shape.x + node->data.shape.w; rect->corners[2].y = node->data.shape.y + node->data.shape.h;
-        rect->corners[3].x = node->data.shape.x; rect->corners[3].y = node->data.shape.y + node->data.shape.h;
-        rect->next = *((SDL_ShapeRect**)closure);
-        *((SDL_ShapeRect**)closure) = rect;
+        temp_region = CreateRectRgn(node->data.shape.x - 1,node->data.shape.y - 1,node->data.shape.x + node->data.shape.w + 1,node->data.shape.y + node->data.shape.h + 1);
+        if(mask_region != NULL) {
+            CombineRgn(mask_region,mask_region,temp_region,RGN_OR);
+            DeleteObject(temp_region);
 		}
-}
-
-Uint32 num_shape_rects(SDL_ShapeRect* rect) {
-    if(rect == NULL)
-        return 0;
 		else
-		return 1 + num_shape_rects(rect->next);
+            *((HRGN*)closure) = temp_region;
+	}
 }
 
 int
 Win32_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowShapeMode *shape_mode) {
     SDL_ShapeData *data;
-    HRGN mask_region;
-	SDL_ShapeRect* rects = NULL,*old = NULL;
-	Uint16 num_rects = 0,i = 0;
-	int* polygonVertexNumbers = NULL;
-	POINT* polygons = NULL;
-	char debug_str[200];
+    HRGN mask_region = NULL;
 
     if (shaper == NULL || shape == NULL)
         return SDL_INVALID_SHAPE_ARGUMENT;
@@ -95,34 +80,11 @@ Win32_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowShape
         SDL_FreeShapeTree(&data->mask_tree);
     data->mask_tree = SDL_CalculateShapeTree(*shape_mode,shape);
     
-    SDL_TraverseShapeTree(data->mask_tree,&CombineRectRegions,&rects);
-    num_rects = num_shape_rects(rects);
-    polygonVertexNumbers = (int*)SDL_malloc(sizeof(int)*num_rects);
-    for(i=0;i<num_rects;i++)
-        polygonVertexNumbers[i] = 4;
-    polygons = (POINT*)SDL_malloc(sizeof(POINT)*4*num_rects);
-    for(i=0;i<num_rects*4;i++) {
-		polygons[i] = rects->corners[i % 4];
-        if(i % 4 == 3) {
-			sprintf_s(&debug_str[0],200,"x: %u y: %u, x+w: %u, y+h: %u\n",
-                      rects->corners[0].x,rects->corners[0].y,
-                      rects->corners[2].x,rects->corners[2].y);
-            OutputDebugStringA(debug_str);
-            old = rects;
-            rects = rects->next;
-            SDL_free(old);
-		}
-	}
+    SDL_TraverseShapeTree(data->mask_tree,&CombineRectRegions,&mask_region);
+	SDL_assert(mask_region != NULL);
 
-    /*
-     * Set the new region mask for the window 
-     */
-    mask_region = CreatePolyPolygonRgn(polygons,polygonVertexNumbers,num_rects,WINDING);
     SetWindowRgn(((SDL_WindowData *)(shaper->window->driverdata))->hwnd, mask_region, TRUE);
     
-    SDL_free(polygons);
-    SDL_free(polygonVertexNumbers);
-    
     return 0;
 }