From 5a079a2d114f96d4847d1ee305d5b7c16eeec50e Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Sat, 27 Dec 2025 12:03:39 -0800
Subject: Initial commit

---
 .../SDL-3.2.8/src/video/windows/SDL_windowsshape.c | 125 +++++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 contrib/SDL-3.2.8/src/video/windows/SDL_windowsshape.c

(limited to 'contrib/SDL-3.2.8/src/video/windows/SDL_windowsshape.c')

diff --git a/contrib/SDL-3.2.8/src/video/windows/SDL_windowsshape.c b/contrib/SDL-3.2.8/src/video/windows/SDL_windowsshape.c
new file mode 100644
index 0000000..db4e4a0
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/video/windows/SDL_windowsshape.c
@@ -0,0 +1,125 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 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"
+
+#if defined(SDL_VIDEO_DRIVER_WINDOWS) && !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
+
+#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;
+}
+
+bool WIN_UpdateWindowShape(SDL_VideoDevice *_this, SDL_Window *window, SDL_Surface *shape)
+{
+    SDL_WindowData *data = window->internal;
+    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 false;
+            }
+            if (!SDL_StretchSurface(shape, NULL, stretched, NULL, SDL_SCALEMODE_LINEAR)) {
+                SDL_DestroySurface(stretched);
+                return false;
+            }
+            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)) {
+        DeleteObject(mask);
+        return WIN_SetError("SetWindowRgn failed");
+    }
+    return true;
+}
+
+#endif // defined(SDL_VIDEO_DRIVER_WINDOWS) && !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
-- 
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