Re-added a simplified version of SDL_SetWindowShape()

In order to handle mouse click transparency this needs to be implemented inside SDL

VisualC-GDK/SDL/SDL.vcxproj

@@ -565,6 +565,7 @@
     <ClInclude Include="..\..\src\video\windows\SDL_windowsmouse.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengl.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengles.h" />
+    <ClInclude Include="..\..\src\video\windows\SDL_windowsshape.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvideo.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvulkan.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowswindow.h" />
@@ -822,6 +823,7 @@
     <ClCompile Include="..\..\src\video\windows\SDL_windowsmouse.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengl.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengles.c" />
+    <ClCompile Include="..\..\src\video\windows\SDL_windowsshape.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvideo.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvulkan.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowswindow.c" />

VisualC-GDK/SDL/SDL.vcxproj.filters

@@ -198,6 +198,7 @@
     <ClCompile Include="..\..\src\video\windows\SDL_windowsmouse.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengl.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengles.c" />
+    <ClCompile Include="..\..\src\video\windows\SDL_windowsshape.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvideo.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvulkan.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowswindow.c" />
@@ -423,6 +424,7 @@
     <ClInclude Include="..\..\src\video\windows\SDL_windowsmouse.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengl.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengles.h" />
+    <ClInclude Include="..\..\src\video\windows\SDL_windowsshape.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvideo.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvulkan.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowswindow.h" />

VisualC/SDL/SDL.vcxproj

@@ -459,6 +459,7 @@
     <ClInclude Include="..\..\src\video\windows\SDL_windowsmouse.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengl.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengles.h" />
+    <ClInclude Include="..\..\src\video\windows\SDL_windowsshape.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvideo.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvulkan.h" />
     <ClInclude Include="..\..\src\video\windows\SDL_windowswindow.h" />
@@ -668,6 +669,7 @@
     <ClCompile Include="..\..\src\video\windows\SDL_windowsmouse.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengl.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengles.c" />
+    <ClCompile Include="..\..\src\video\windows\SDL_windowsshape.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvideo.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvulkan.c" />
     <ClCompile Include="..\..\src\video\windows\SDL_windowswindow.c" />

VisualC/SDL/SDL.vcxproj.filters

@@ -645,6 +645,9 @@
     <ClInclude Include="..\..\src\video\windows\SDL_windowsopengl.h">
       <Filter>video\windows</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\video\windows\SDL_windowsshape.h">
+      <Filter>video\windows</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\src\video\windows\SDL_windowsvideo.h">
       <Filter>video\windows</Filter>
     </ClInclude>
@@ -1231,6 +1234,9 @@
     <ClCompile Include="..\..\src\video\windows\SDL_windowsopengles.c">
       <Filter>video\windows</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\video\windows\SDL_windowsshape.c">
+      <Filter>video\windows</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\video\windows\SDL_windowsvideo.c">
       <Filter>video\windows</Filter>
     </ClCompile>

docs/README-migration.md

@@ -1305,7 +1305,7 @@ The following functions have been removed:
 
 ## SDL_shape.h
 
-This header has been removed. You can create a window with the SDL_WINDOW_TRANSPARENT flag and then render using the alpha channel to achieve a similar effect. You can see an example of this in test/testshape.c
+This header has been removed and a simplified version of this API has been added as SDL_SetWindowShape() in SDL_video.h. See test/testshape.c for an example.
 
 ## SDL_stdinc.h
 

include/SDL3/SDL_properties.h

@@ -141,6 +141,8 @@ extern DECLSPEC void SDLCALL SDL_UnlockProperties(SDL_PropertiesID props);
  * Set a property on a set of properties with a cleanup function that is
  * called when the property is deleted
  *
+ * The cleanup function is also called if setting the property fails for any reason.
+ *
  * \param props the properties to modify
  * \param name the name of the property to modify
  * \param value the new value of the property, or NULL to delete the property

include/SDL3/SDL_video.h

@@ -1028,6 +1028,8 @@ extern DECLSPEC SDL_Window *SDLCALL SDL_GetWindowParent(SDL_Window *window);
  *
  * The following read-only properties are provided by SDL:
  *
+ * - `SDL_PROP_WINDOW_SHAPE_POINTER`: the surface associated with a shaped window
+ *
  * On Android:
  *
  * - `SDL_PROP_WINDOW_ANDROID_WINDOW_POINTER`: the ANativeWindow associated
@@ -1120,6 +1122,7 @@ extern DECLSPEC SDL_Window *SDLCALL SDL_GetWindowParent(SDL_Window *window);
  */
 extern DECLSPEC SDL_PropertiesID SDLCALL SDL_GetWindowProperties(SDL_Window *window);
 
+#define SDL_PROP_WINDOW_SHAPE_POINTER                   "SDL.window.shape"
 #define SDL_PROP_WINDOW_ANDROID_WINDOW_POINTER          "SDL.window.android.window"
 #define SDL_PROP_WINDOW_ANDROID_SURFACE_POINTER         "SDL.window.android.surface"
 #define SDL_PROP_WINDOW_UIKIT_WINDOW_POINTER            "SDL.window.uikit.window"
@@ -2119,6 +2122,22 @@ typedef SDL_HitTestResult (SDLCALL *SDL_HitTest)(SDL_Window *win,
  */
 extern DECLSPEC int SDLCALL SDL_SetWindowHitTest(SDL_Window *window, SDL_HitTest callback, void *callback_data);
 
+/**
+ * Set the shape of a transparent window.
+ *
+ * This sets the alpha channel of a transparent window and any fully transparent areas are also transparent to mouse clicks. If you are using something besides the SDL render API, then you are responsible for setting the alpha channel of the window yourself.
+ *
+ * The window must have been created with the SDL_WINDOW_TRANSPARENT flag.
+ *
+ * \param window the window
+ * \param shape the surface representing the shape of the window, or NULL to remove any current shape
+ * \returns 0 on success or a negative error code on failure; call
+ *          SDL_GetError() for more information.
+ *
+ * \since This function is available since SDL 3.0.0.
+ */
+extern DECLSPEC int SDLCALL SDL_SetWindowShape(SDL_Window *window, SDL_Surface *shape);
+
 /**
  * Request a window to demand attention from the user.
  *

src/SDL_properties.c

@@ -348,6 +348,7 @@ int SDL_SetPropertyWithCleanup(SDL_PropertiesID props, const char *name, void *v
 
     property = (SDL_Property *)SDL_calloc(1, sizeof(*property));
     if (!property) {
+        SDL_FreePropertyWithCleanup(NULL, property, NULL, SDL_FALSE);
         return -1;
     }
     property->type = SDL_PROPERTY_TYPE_POINTER;
@@ -374,6 +375,17 @@ int SDL_SetProperty(SDL_PropertiesID props, const char *name, void *value)
     return SDL_PrivateSetProperty(props, name, property);
 }
 
+static void CleanupSurface(void *userdata, void *value)
+{
+    SDL_Surface *surface = (SDL_Surface *)value;
+
+    SDL_DestroySurface(surface);
+}
+
+int SDL_SetSurfaceProperty(SDL_PropertiesID props, const char *name, SDL_Surface *surface)
+{
+    return SDL_SetPropertyWithCleanup(props, name, surface, CleanupSurface, NULL);
+}
 
 int SDL_SetStringProperty(SDL_PropertiesID props, const char *name, const char *value)
 {

src/SDL_properties_c.h

@@ -20,4 +20,5 @@
 */
 
 extern int SDL_InitProperties(void);
+extern int SDL_SetSurfaceProperty(SDL_PropertiesID props, const char *name, SDL_Surface *surface);
 extern void SDL_QuitProperties(void);

src/dynapi/SDL_dynapi.sym

@@ -970,6 +970,7 @@ SDL3_0.0.0 {
     SDL_SetRenderColorScale;
     SDL_GetRenderColorScale;
     SDL_RenderGeometryRawFloat;
+    SDL_SetWindowShape;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -995,3 +995,4 @@
 #define SDL_SetRenderColorScale SDL_SetRenderColorScale_REAL
 #define SDL_GetRenderColorScale SDL_GetRenderColorScale_REAL
 #define SDL_RenderGeometryRawFloat SDL_RenderGeometryRawFloat_REAL
+#define SDL_SetWindowShape SDL_SetWindowShape_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -1020,3 +1020,4 @@ SDL_DYNAPI_PROC(int,SDL_CopyProperties,(SDL_PropertiesID a, SDL_PropertiesID b),
 SDL_DYNAPI_PROC(int,SDL_SetRenderColorScale,(SDL_Renderer *a, float b),(a,b),return)
 SDL_DYNAPI_PROC(int,SDL_GetRenderColorScale,(SDL_Renderer *a, float *b),(a,b),return)
 SDL_DYNAPI_PROC(int,SDL_RenderGeometryRawFloat,(SDL_Renderer *a, SDL_Texture *b, const float *c, int d, const SDL_FColor *e, int f, const float *g, int h, int i, const void *j, int k, int l),(a,b,c,d,e,f,g,h,i,j,k,l),return)
+SDL_DYNAPI_PROC(int,SDL_SetWindowShape,(SDL_Window *a, SDL_Surface *b),(a,b),return)

src/render/SDL_render.c

@@ -989,10 +989,14 @@ SDL_Renderer *SDL_CreateRendererWithProperties(SDL_PropertiesID props)
 
     renderer->color_scale = 1.0f;
 
-    if (SDL_GetWindowFlags(window) & (SDL_WINDOW_HIDDEN | SDL_WINDOW_MINIMIZED)) {
-        renderer->hidden = SDL_TRUE;
-    } else {
-        renderer->hidden = SDL_FALSE;
+    if (window) {
+        if (SDL_GetWindowFlags(window) & SDL_WINDOW_TRANSPARENT) {
+            renderer->transparent_window = SDL_TRUE;
+        }
+
+        if (SDL_GetWindowFlags(window) & (SDL_WINDOW_HIDDEN | SDL_WINDOW_MINIMIZED)) {
+            renderer->hidden = SDL_TRUE;
+        }
     }
 
     new_props = SDL_GetRendererProperties(renderer);
@@ -4247,6 +4251,32 @@ SDL_Surface *SDL_RenderReadPixels(SDL_Renderer *renderer, const SDL_Rect *rect)
     return renderer->RenderReadPixels(renderer, &real_rect);
 }
 
+static void SDL_RenderApplyWindowShape(SDL_Renderer *renderer)
+{
+    SDL_Surface *shape = (SDL_Surface *)SDL_GetProperty(SDL_GetWindowProperties(renderer->window), SDL_PROP_WINDOW_SHAPE_POINTER, NULL);
+    if (shape != renderer->shape_surface) {
+        if (renderer->shape_texture) {
+            SDL_DestroyTexture(renderer->shape_texture);
+            renderer->shape_texture = NULL;
+        }
+
+        if (shape) {
+            /* There's nothing we can do if this fails, so just keep on going */
+            renderer->shape_texture = SDL_CreateTextureFromSurface(renderer, shape);
+
+            SDL_SetTextureBlendMode(renderer->shape_texture,
+                SDL_ComposeCustomBlendMode(
+                    SDL_BLENDFACTOR_ZERO, SDL_BLENDFACTOR_SRC_ALPHA, SDL_BLENDOPERATION_ADD,
+                    SDL_BLENDFACTOR_ZERO, SDL_BLENDFACTOR_SRC_ALPHA, SDL_BLENDOPERATION_ADD));
+        }
+        renderer->shape_surface = shape;
+    }
+
+    if (renderer->shape_texture) {
+        SDL_RenderTexture(renderer, renderer->shape_texture, NULL, NULL);
+    }
+}
+
 static void SDL_SimulateRenderVSync(SDL_Renderer *renderer)
 {
     Uint64 now, elapsed;
@@ -4285,6 +4315,10 @@ int SDL_RenderPresent(SDL_Renderer *renderer)
         SDL_RenderLogicalPresentation(renderer);
     }
 
+    if (renderer->transparent_window) {
+        SDL_RenderApplyWindowShape(renderer);
+    }
+
     FlushRenderCommands(renderer); /* time to send everything to the GPU! */
 
 #if DONT_DRAW_WHILE_HIDDEN

src/render/SDL_sysrender.h

@@ -277,6 +277,11 @@ struct SDL_Renderer
     size_t vertex_data_used;
     size_t vertex_data_allocation;
 
+    /* Shaped window support */
+    SDL_bool transparent_window;
+    SDL_Surface *shape_surface;
+    SDL_Texture *shape_texture;
+
     SDL_PropertiesID props;
 
     void *driverdata;

src/video/SDL_sysvideo.h

@@ -253,6 +253,7 @@ struct SDL_VideoDevice
     int (*UpdateWindowFramebuffer)(SDL_VideoDevice *_this, SDL_Window *window, const SDL_Rect *rects, int numrects);
     void (*DestroyWindowFramebuffer)(SDL_VideoDevice *_this, SDL_Window *window);
     void (*OnWindowEnter)(SDL_VideoDevice *_this, SDL_Window *window);
+    int (*UpdateWindowShape)(SDL_VideoDevice *_this, SDL_Window *window, SDL_Surface *shape);
     int (*FlashWindow)(SDL_VideoDevice *_this, SDL_Window *window, SDL_FlashOperation operation);
     int (*SetWindowFocusable)(SDL_VideoDevice *_this, SDL_Window *window, SDL_bool focusable);
     int (*SyncWindow)(SDL_VideoDevice *_this, SDL_Window *window);

src/video/SDL_video.c

@@ -31,6 +31,7 @@
 #include "SDL_video_c.h"
 #include "../events/SDL_events_c.h"
 #include "../SDL_hints_c.h"
+#include "../SDL_properties_c.h"
 #include "../timer/SDL_timer_c.h"
 #include "SDL_video_capture_c.h"
 
@@ -3485,6 +3486,13 @@ void SDL_OnWindowResized(SDL_Window *window)
 {
     SDL_CheckWindowDisplayChanged(window);
     SDL_CheckWindowPixelSizeChanged(window);
+
+    if ((window->flags & SDL_WINDOW_TRANSPARENT) && _this->UpdateWindowShape) {
+        SDL_Surface *surface = (SDL_Surface *)SDL_GetProperty(window->props, SDL_PROP_WINDOW_SHAPE_POINTER, NULL);
+        if (surface) {
+            _this->UpdateWindowShape(_this, window, surface);
+        }
+    }
 }
 
 void SDL_CheckWindowPixelSizeChanged(SDL_Window *window)
@@ -5054,6 +5062,39 @@ int SDL_SetWindowHitTest(SDL_Window *window, SDL_HitTest callback, void *callbac
     return 0;
 }
 
+int SDL_SetWindowShape(SDL_Window *window, SDL_Surface *shape)
+{
+    SDL_PropertiesID props;
+    SDL_Surface *surface;
+
+    CHECK_WINDOW_MAGIC(window, -1);
+
+    if (!(window->flags & SDL_WINDOW_TRANSPARENT)) {
+        return SDL_SetError("Window must be created with SDL_WINDOW_TRANSPARENT");
+    }
+
+    props = SDL_GetWindowProperties(window);
+    if (!props) {
+        return -1;
+    }
+
+    surface = SDL_ConvertSurfaceFormat(shape, SDL_PIXELFORMAT_ARGB32);
+    if (!surface) {
+        return -1;
+    }
+
+    if (SDL_SetSurfaceProperty(props, SDL_PROP_WINDOW_SHAPE_POINTER, surface) < 0) {
+        return -1;
+    }
+
+    if (_this->UpdateWindowShape) {
+        if (_this->UpdateWindowShape(_this, window, surface) < 0) {
+            return -1;
+        }
+    }
+    return 0;
+}
+
 /*
  * Functions used by iOS application delegates
  */

src/video/cocoa/SDL_cocoawindow.h

@@ -74,6 +74,7 @@ typedef enum
 - (BOOL)isMovingOrFocusClickPending;
 - (void)setFocusClickPending:(NSInteger)button;
 - (void)clearFocusClickPending:(NSInteger)button;
+- (void)updateIgnoreMouseState:(NSEvent *)theEvent;
 - (void)setPendingMoveX:(float)x Y:(float)y;
 - (void)windowDidFinishMoving;
 - (void)onMovingOrFocusClickPendingStateCleared;

src/video/cocoa/SDL_cocoawindow.m

@@ -834,6 +834,28 @@ static SDL_bool Cocoa_IsZoomed(SDL_Window *window)
     }
 }
 
+- (void)updateIgnoreMouseState:(NSEvent *)theEvent
+{
+    SDL_Window *window = _data.window;
+    SDL_Surface *shape = (SDL_Surface *)SDL_GetProperty(SDL_GetWindowProperties(window), SDL_PROP_WINDOW_SHAPE_POINTER, NULL);
+    BOOL ignoresMouseEvents = NO;
+
+    if (shape) {
+        NSPoint point = [theEvent locationInWindow];
+		NSRect windowRect = [[_data.nswindow contentView] frame];
+		if (NSMouseInRect(point, windowRect, NO)) {
+			int x = (int)SDL_roundf((point.x / (window->w - 1)) * (shape->w - 1));
+			int y = (int)SDL_roundf(((window->h - point.y) / (window->h - 1)) * (shape->h - 1));
+			Uint8 a;
+
+			if (SDL_ReadSurfacePixel(shape, x, y, NULL, NULL, NULL, &a) < 0 || a == SDL_ALPHA_TRANSPARENT) {
+				ignoresMouseEvents = YES;
+			}
+		}
+    }
+    _data.nswindow.ignoresMouseEvents = ignoresMouseEvents;
+}
+
 - (void)setPendingMoveX:(float)x Y:(float)y
 {
     pendingWindowWarpX = x;
@@ -1555,6 +1577,10 @@ static int Cocoa_SendMouseButtonClicks(SDL_Mouse *mouse, NSEvent *theEvent, SDL_
     mouseID = mouse->mouseID;
     window = _data.window;
 
+    if (window->flags & SDL_WINDOW_TRANSPARENT) {
+        [self updateIgnoreMouseState:theEvent];
+    }
+
     if ([self processHitTest:theEvent]) {
         SDL_SendWindowEvent(window, SDL_EVENT_WINDOW_HIT_TEST, 0, 0);
         return; /* dragging, drop event. */

src/video/dummy/SDL_nullframebuffer.c

@@ -23,16 +23,11 @@
 #ifdef SDL_VIDEO_DRIVER_DUMMY
 
 #include "../SDL_sysvideo.h"
+#include "../../SDL_properties_c.h"
 #include "SDL_nullframebuffer_c.h"
 
 #define DUMMY_SURFACE "SDL.internal.window.surface"
 
-static void CleanupSurface(void *userdata, void *value)
-{
-    SDL_Surface *surface = (SDL_Surface *)value;
-
-    SDL_DestroySurface(surface);
-}
 
 int SDL_DUMMY_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, Uint32 *format, void **pixels, int *pitch)
 {
@@ -48,7 +43,7 @@ int SDL_DUMMY_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window
     }
 
     /* Save the info and return! */
-    SDL_SetPropertyWithCleanup(SDL_GetWindowProperties(window), DUMMY_SURFACE, surface, CleanupSurface, NULL);
+    SDL_SetSurfaceProperty(SDL_GetWindowProperties(window), DUMMY_SURFACE, surface);
     *format = surface_format;
     *pixels = surface->pixels;
     *pitch = surface->pitch;

src/video/n3ds/SDL_n3dsframebuffer.c

@@ -23,6 +23,7 @@
 #ifdef SDL_VIDEO_DRIVER_N3DS
 
 #include "../SDL_sysvideo.h"
+#include "../../SDL_properties_c.h"
 #include "SDL_n3dsframebuffer_c.h"
 #include "SDL_n3dsvideo.h"
 
@@ -38,12 +39,6 @@ static int GetDestOffset(int x, int y, int dest_width);
 static int GetSourceOffset(int x, int y, int source_width);
 static void FlushN3DSBuffer(const void *buffer, u32 bufsize, gfxScreen_t screen);
 
-static void CleanupSurface(void *userdata, void *value)
-{
-    SDL_Surface *surface = (SDL_Surface *)value;
-
-    SDL_DestroySurface(surface);
-}
 
 int SDL_N3DS_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, Uint32 *format, void **pixels, int *pitch)
 {
@@ -57,7 +52,7 @@ int SDL_N3DS_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window,
         return -1;
     }
 
-    SDL_SetPropertyWithCleanup(SDL_GetWindowProperties(window), N3DS_SURFACE, framebuffer, CleanupSurface, NULL);
+    SDL_SetSurfaceProperty(SDL_GetWindowProperties(window), N3DS_SURFACE, framebuffer);
     *format = FRAMEBUFFER_FORMAT;
     *pixels = framebuffer->pixels;
     *pitch = framebuffer->pitch;

src/video/offscreen/SDL_offscreenframebuffer.c

@@ -23,16 +23,11 @@
 #ifdef SDL_VIDEO_DRIVER_OFFSCREEN
 
 #include "../SDL_sysvideo.h"
+#include "../../SDL_properties_c.h"
 #include "SDL_offscreenframebuffer_c.h"
 
 #define OFFSCREEN_SURFACE "SDL.internal.window.surface"
 
-static void CleanupSurface(void *userdata, void *value)
-{
-    SDL_Surface *surface = (SDL_Surface *)value;
-
-    SDL_DestroySurface(surface);
-}
 
 int SDL_OFFSCREEN_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, Uint32 *format, void **pixels, int *pitch)
 {
@@ -48,7 +43,7 @@ int SDL_OFFSCREEN_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *wi
     }
 
     /* Save the info and return! */
-    SDL_SetPropertyWithCleanup(SDL_GetWindowProperties(window), OFFSCREEN_SURFACE, surface, CleanupSurface, NULL);
+    SDL_SetSurfaceProperty(SDL_GetWindowProperties(window), OFFSCREEN_SURFACE, surface);
     *format = surface_format;
     *pixels = surface->pixels;
     *pitch = surface->pitch;

src/video/windows/SDL_windowsshape.c

@@ -0,0 +1,124 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifdef SDL_VIDEO_DRIVER_WINDOWS
+
+#include "SDL_windowsvideo.h"
+#include "SDL_windowsshape.h"
+
+
+static void AddRegion(HRGN *mask, int x1, int y1, int x2, int y2)
+{
+    HRGN region = CreateRectRgn(x1, y1, x2, y2);
+    if (*mask) {
+        CombineRgn(*mask, *mask, region, RGN_OR);
+        DeleteObject(region);
+    } else {
+        *mask = region;
+    }
+}
+
+static HRGN GenerateSpanListRegion(SDL_Surface *shape, int offset_x, int offset_y)
+{
+    HRGN mask = NULL;
+    int x, y;
+    int span_start = -1;
+
+    for (y = 0; y < shape->h; ++y) {
+        const Uint8 *a = (const Uint8 *)shape->pixels + y * shape->pitch;
+        for (x = 0; x < shape->w; ++x) {
+            if (*a == SDL_ALPHA_TRANSPARENT) {
+                if (span_start != -1) {
+                    AddRegion(&mask, offset_x + span_start, offset_y + y, offset_x + x, offset_y + y + 1);
+                    span_start = -1;
+                }
+            } else {
+                if (span_start == -1) {
+                    span_start = x;
+                }
+            }
+            a += 4;
+        }
+        if (span_start != -1) {
+            /* Add the final span */
+            AddRegion(&mask, offset_x + span_start, offset_y + y, offset_x + x, offset_y + y + 1);
+            span_start = -1;
+        }
+    }
+    return mask;
+}
+
+int WIN_UpdateWindowShape(SDL_VideoDevice *_this, SDL_Window *window, SDL_Surface *shape)
+{
+    SDL_WindowData *data = window->driverdata;
+    HRGN mask = NULL;
+
+    /* Generate a set of spans for the region */
+    if (shape) {
+        SDL_Surface *stretched = NULL;
+        RECT rect;
+
+        if (shape->w != window->w || shape->h != window->h) {
+            stretched = SDL_CreateSurface(window->w, window->h, SDL_PIXELFORMAT_ARGB32);
+            if (!stretched) {
+                return -1;
+            }
+            if (SDL_SoftStretch(shape, NULL, stretched, NULL, SDL_SCALEMODE_LINEAR) < 0) {
+                SDL_DestroySurface(stretched);
+                return -1;
+            }
+            shape = stretched;
+        }
+
+        rect.top = 0;
+        rect.left = 0;
+        rect.bottom = 0;
+        rect.right = 0;
+        if (!(SDL_GetWindowFlags(data->window) & SDL_WINDOW_BORDERLESS)) {
+            WIN_AdjustWindowRectForHWND(data->hwnd, &rect, 0);
+        }
+
+        mask = GenerateSpanListRegion(shape, -rect.left, -rect.top);
+
+        if (!(SDL_GetWindowFlags(data->window) & SDL_WINDOW_BORDERLESS)) {
+            /* Add the window borders */
+            /* top */
+            AddRegion(&mask, 0, 0, -rect.left + shape->w + rect.right + 1, -rect.top + 1);
+            /* left */
+            AddRegion(&mask, 0, -rect.top, -rect.left + 1, -rect.top + shape->h + 1);
+            /* right */
+            AddRegion(&mask, -rect.left + shape->w, -rect.top, -rect.left + shape->w + rect.right + 1, -rect.top + shape->h + 1);
+            /* bottom */
+            AddRegion(&mask, 0, -rect.top + shape->h, -rect.left + shape->w + rect.right + 1, -rect.top + shape->h + rect.bottom + 1);
+        }
+
+        if (stretched) {
+            SDL_DestroySurface(stretched);
+        }
+    }
+    if (!SetWindowRgn(data->hwnd, mask, TRUE)) {
+        return WIN_SetError("SetWindowRgn failed");
+    }
+    return 0;
+}
+
+#endif /* SDL_VIDEO_DRIVER_WINDOWS */

src/video/windows/SDL_windowsshape.h

@@ -0,0 +1,28 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifndef SDL_windowsshape_h_
+#define SDL_windowsshape_h_
+
+extern int WIN_UpdateWindowShape(SDL_VideoDevice *_this, SDL_Window *window, SDL_Surface *shape);
+
+#endif /* SDL_windowsshape_h_ */

src/video/windows/SDL_windowsvideo.c

@@ -210,6 +210,7 @@ static SDL_VideoDevice *WIN_CreateDevice(void)
     device->ShowWindowSystemMenu = WIN_ShowWindowSystemMenu;
     device->SetWindowFocusable = WIN_SetWindowFocusable;
 #endif
+    device->UpdateWindowShape = WIN_UpdateWindowShape;
 
 #ifdef SDL_VIDEO_OPENGL_WGL
     device->GL_LoadLibrary = WIN_GL_LoadLibrary;

src/video/windows/SDL_windowsvideo.h

@@ -42,6 +42,7 @@
 #include "SDL_windowsclipboard.h"
 #include "SDL_windowsevents.h"
 #include "SDL_windowsopengl.h"
+#include "SDL_windowsshape.h"
 
 #if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
 #include "SDL_windowskeyboard.h"

src/video/x11/SDL_x11shape.c

@@ -0,0 +1,110 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifdef SDL_VIDEO_DRIVER_X11
+
+#include "SDL_x11video.h"
+#include "SDL_x11shape.h"
+
+
+#ifdef SDL_VIDEO_DRIVER_X11_XSHAPE
+static Uint8 *GenerateShapeMask(SDL_Surface *shape)
+{
+    int x, y;
+    const size_t ppb = 8;
+    const size_t bytes_per_scanline = (size_t)(shape->w + (ppb - 1)) / ppb;
+    const Uint8 *a;
+    Uint8 *mask;
+    Uint8 *mask_scanline;
+    Uint8 mask_value;
+
+    mask = (Uint8 *)SDL_calloc(1, shape->h * bytes_per_scanline);
+    if (mask) {
+        for (y = 0; y < shape->h; y++) {
+            a = (const Uint8 *)shape->pixels + y * shape->pitch;
+            mask_scanline = mask + y * bytes_per_scanline;
+            for (x = 0; x < shape->w; x++) {
+                mask_value = (*a == SDL_ALPHA_TRANSPARENT) ? 0 : 1;
+                mask_scanline[x / ppb] |= mask_value << (x % ppb);
+                a += 4;
+            }
+        }
+    }
+    return mask;
+}
+#endif /* SDL_VIDEO_DRIVER_X11_XSHAPE */
+
+int X11_UpdateWindowShape(SDL_VideoDevice *_this, SDL_Window *window, SDL_Surface *shape)
+{
+#ifdef SDL_VIDEO_DRIVER_X11_XSHAPE
+    SDL_WindowData *windowdata = window->driverdata;
+    int result = -1;
+
+    /* Generate a set of spans for the region */
+    if (shape) {
+        SDL_Surface *stretched = NULL;
+        Uint8 *mask;
+        Pixmap pixmap;
+
+        if (shape->w != window->w || shape->h != window->h) {
+            stretched = SDL_CreateSurface(window->w, window->h, SDL_PIXELFORMAT_ARGB32);
+            if (!stretched) {
+                return -1;
+            }
+            if (SDL_SoftStretch(shape, NULL, stretched, NULL, SDL_SCALEMODE_LINEAR) < 0) {
+                SDL_DestroySurface(stretched);
+                return -1;
+            }
+            shape = stretched;
+        }
+
+        mask = GenerateShapeMask(shape);
+        if (mask) {
+            pixmap = X11_XCreateBitmapFromData(windowdata->videodata->display, windowdata->xwindow, (const char *)mask, shape->w, shape->h);
+            X11_XShapeCombineMask(windowdata->videodata->display, windowdata->xwindow, ShapeInput, 0, 0, pixmap, ShapeSet);
+            SDL_free(mask);
+
+            result = 0;
+        }
+
+        if (stretched) {
+            SDL_DestroySurface(stretched);
+        }
+    } else {
+        Region region = X11_XCreateRegion();
+        XRectangle rect;
+
+        rect.x = 0;
+        rect.y = 0;
+        rect.width = window->w;
+        rect.height = window->h;
+        X11_XUnionRectWithRegion(&rect, region, region);
+        X11_XShapeCombineRegion(windowdata->videodata->display, windowdata->xwindow, ShapeInput, 0, 0, region, ShapeSet);
+        X11_XDestroyRegion(region);
+        result = 0;
+    }
+#endif /* SDL_VIDEO_DRIVER_X11_XSHAPE */
+
+    return result;
+}
+
+#endif /* SDL_VIDEO_DRIVER_X11 */

src/video/x11/SDL_x11shape.h

@@ -0,0 +1,28 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifndef SDL_x11shape_h_
+#define SDL_x11shape_h_
+
+extern int X11_UpdateWindowShape(SDL_VideoDevice *_this, SDL_Window *window, SDL_Surface *shape);
+
+#endif /* SDL_x11shape_h_ */

src/video/x11/SDL_x11sym.h

@@ -156,6 +156,7 @@ SDL_X11_SYM(int,XQueryTree,(Display* a,Window b,Window* c,Window* d,Window** e,u
 SDL_X11_SYM(Bool,XSupportsLocale,(void),(),return)
 SDL_X11_SYM(Status,XmbTextListToTextProperty,(Display* a,char** b,int c,XICCEncodingStyle d,XTextProperty* e),(a,b,c,d,e),return)
 SDL_X11_SYM(Region,XCreateRegion,(void),(),return)
+SDL_X11_SYM(int,XUnionRectWithRegion,(XRectangle *a, Region b, Region c),(a,b,c), return)
 SDL_X11_SYM(void,XDestroyRegion,(Region),(a),)
 SDL_X11_SYM(void,XrmInitialize,(),(),)
 SDL_X11_SYM(char*,XResourceManagerString,(Display *display),(display),)

src/video/x11/SDL_x11video.c

@@ -35,6 +35,7 @@
 #include "SDL_x11xfixes.h"
 #include "SDL_x11xinput2.h"
 #include "SDL_x11messagebox.h"
+#include "SDL_x11shape.h"
 
 #ifdef SDL_VIDEO_OPENGL_EGL
 #include "SDL_x11opengles.h"
@@ -208,6 +209,7 @@ static SDL_VideoDevice *X11_CreateDevice(void)
     device->SetWindowHitTest = X11_SetWindowHitTest;
     device->AcceptDragAndDrop = X11_AcceptDragAndDrop;
     device->FlashWindow = X11_FlashWindow;
+    device->UpdateWindowShape = X11_UpdateWindowShape;
     device->ShowWindowSystemMenu = X11_ShowWindowSystemMenu;
     device->SetWindowFocusable = X11_SetWindowFocusable;
     device->SyncWindow = X11_SyncWindow;

test/CMakeLists.txt

@@ -347,6 +347,7 @@ files2headers(gamepad_image_headers
     gamepad_touchpad.bmp
 )
 files2headers(icon_bmp_header icon.bmp)
+files2headers(glass_bmp_header glass.bmp)
 
 add_sdl_test_executable(testaudio MAIN_CALLBACKS NEEDS_RESOURCES TESTUTILS SOURCES testaudio.c)
 add_sdl_test_executable(testcolorspace SOURCES testcolorspace.c)
@@ -386,7 +387,7 @@ add_sdl_test_executable(testscale NEEDS_RESOURCES TESTUTILS SOURCES testscale.c)
 add_sdl_test_executable(testsem NONINTERACTIVE NONINTERACTIVE_ARGS 10 NONINTERACTIVE_TIMEOUT 30 SOURCES testsem.c)
 add_sdl_test_executable(testsensor SOURCES testsensor.c)
 add_sdl_test_executable(testshader NEEDS_RESOURCES TESTUTILS SOURCES testshader.c)
-add_sdl_test_executable(testshape NEEDS_RESOURCES SOURCES testshape.c)
+add_sdl_test_executable(testshape NEEDS_RESOURCES SOURCES testshape.c ${glass_bmp_header})
 add_sdl_test_executable(testsprite MAIN_CALLBACKS NEEDS_RESOURCES TESTUTILS SOURCES testsprite.c)
 add_sdl_test_executable(testspriteminimal SOURCES testspriteminimal.c ${icon_bmp_header})
 add_sdl_test_executable(teststreaming NEEDS_RESOURCES TESTUTILS SOURCES teststreaming.c)

test/testshape.c

@@ -12,24 +12,69 @@
 #include <SDL3/SDL.h>
 #include <SDL3/SDL_main.h>
 
+#include "glass.h"
+
+
+static SDL_HitTestResult SDLCALL ShapeHitTest(SDL_Window *window, const SDL_Point *area, void *userdata)
+{
+    SDL_Surface *shape = (SDL_Surface *)userdata;
+    Uint8 r, g, b, a;
+
+    if (SDL_ReadSurfacePixel(shape, area->x, area->y, &r, &g, &b, &a) == 0) {
+        if (a != SDL_ALPHA_TRANSPARENT) {
+            /* We'll just make everything draggable */
+            return SDL_HITTEST_DRAGGABLE;
+        }
+    }
+    return SDL_HITTEST_NORMAL;
+}
 
 int main(int argc, char *argv[])
 {
+    const char *image_file = NULL;
     SDL_Window *window = NULL;
     SDL_Renderer *renderer = NULL;
     SDL_Surface *shape = NULL;
-    SDL_Texture *shape_texture = NULL;
-    SDL_Event event;
+    SDL_bool resizable = SDL_FALSE;
+    Uint32 flags;
     SDL_bool done = SDL_FALSE;
+    SDL_Event event;
+    int i;
     int return_code = 1;
 
-    if (argc != 2) {
-        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Usage: %s shape.bmp\n", argv[0]);
-        goto quit;
+    for (i = 1; i < argc; ++i) {
+        if (SDL_strcmp(argv[i], "--resizable") == 0) {
+            resizable = SDL_TRUE;
+        } else if (!image_file) {
+            image_file = argv[i];
+        } else {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Usage: %s [--resizable] [shape.bmp]\n", argv[0]);
+            goto quit;
+        }
     }
 
-    /* Create the window hidden so we can set the window size to match our shape */
-    window = SDL_CreateWindow("Shape test", 1, 1, SDL_WINDOW_HIDDEN | SDL_WINDOW_TRANSPARENT);
+    if (image_file) {
+        shape = SDL_LoadBMP(image_file);
+        if (!shape) {
+            SDL_Log("Couldn't load %s: %s\n", image_file, SDL_GetError());
+            goto quit;
+        }
+    } else {
+        shape = SDL_LoadBMP_RW(SDL_RWFromConstMem(glass_bmp, sizeof(glass_bmp)), SDL_TRUE);
+        if (!shape) {
+            SDL_Log("Couldn't load glass.bmp: %s\n", SDL_GetError());
+            goto quit;
+        }
+    }
+
+    /* Create the window hidden so we can set the shape before it's visible */
+    flags = (SDL_WINDOW_HIDDEN | SDL_WINDOW_TRANSPARENT);
+    if (resizable) {
+        flags |= SDL_WINDOW_RESIZABLE;
+    } else {
+        flags |= SDL_WINDOW_BORDERLESS;
+    }
+    window = SDL_CreateWindow("SDL Shape Test", shape->w, shape->h, flags);
     if (!window) {
         SDL_Log("Couldn't create transparent window: %s\n", SDL_GetError());
         goto quit;
@@ -41,12 +86,6 @@ int main(int argc, char *argv[])
         goto quit;
     }
 
-    shape = SDL_LoadBMP(argv[1]);
-    if (!shape) {
-        SDL_Log("Couldn't load %s: %s\n", argv[1], SDL_GetError());
-        goto quit;
-    }
-
     if (!SDL_ISPIXELFORMAT_ALPHA(shape->format->format)) {
         /* Set the colorkey to the top-left pixel */
         Uint8 r, g, b, a;
@@ -55,24 +94,16 @@ int main(int argc, char *argv[])
         SDL_SetSurfaceColorKey(shape, 1, SDL_MapRGBA(shape->format, r, g, b, a));
     }
 
-    shape_texture = SDL_CreateTextureFromSurface(renderer, shape);
-    if (!shape_texture) {
-        SDL_Log("Couldn't create shape texture: %s\n", SDL_GetError());
-        goto quit;
-    }
-
-    /* Set the blend mode so the alpha channel of the shape is the window transparency */
-    if (SDL_SetTextureBlendMode(shape_texture,
-            SDL_ComposeCustomBlendMode(
-                SDL_BLENDFACTOR_ZERO, SDL_BLENDFACTOR_SRC_ALPHA, SDL_BLENDOPERATION_ADD,
-                SDL_BLENDFACTOR_ZERO, SDL_BLENDFACTOR_SRC_ALPHA, SDL_BLENDOPERATION_ADD)) < 0) {
-        SDL_Log("Couldn't set shape blend mode: %s\n", SDL_GetError());
-        goto quit;
+    if (!resizable) {
+        /* Set the hit test callback so we can drag the window */
+        if (SDL_SetWindowHitTest(window, ShapeHitTest, shape) < 0) {
+            SDL_Log("Couldn't set hit test callback: %s\n", SDL_GetError());
+            goto quit;
+        }
     }
 
     /* Set the window size to the size of our shape and show it */
-    SDL_SetWindowSize(window, shape->w, shape->h);
-    SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+    SDL_SetWindowShape(window, shape);
     SDL_ShowWindow(window);
 
     /* We're ready to go! */
@@ -80,8 +111,11 @@ int main(int argc, char *argv[])
         while (SDL_PollEvent(&event)) {
             switch (event.type) {
             case SDL_EVENT_KEY_DOWN:
+                if (event.key.keysym.sym == SDLK_ESCAPE) {
+                    done = SDL_TRUE;
+                }
+                break;
             case SDL_EVENT_QUIT:
-                /* Quit on keypress and quit event */
                 done = SDL_TRUE;
                 break;
             default:
@@ -93,9 +127,6 @@ int main(int argc, char *argv[])
         SDL_SetRenderDrawColor(renderer, 255, 255, 255, SDL_ALPHA_OPAQUE);
         SDL_RenderClear(renderer);
 
-        /* Apply the shape */
-        SDL_RenderTexture(renderer, shape_texture, NULL, NULL);
-
         /* Show everything on the screen and wait a bit */
         SDL_RenderPresent(renderer);
         SDL_Delay(100);