Fix #513 by getting window size with SDL2

When under XMonad, game window size using XGetGeometry() is 2 pixels
shorter (width and height) than using SDL_GetWindowSize(). As a
result, calling SDL_RenderReadPixels() to copy the screen pixels
resulted in a crash (__memmove_sse2_unaligned_erms), probably something
about accelerated rendering and not having width/height multiple of 4.

CHANGELOG.md

@@ -13,6 +13,7 @@
 
 * Fix OSD SDL2 renderer memory leak
 * Fix SDL_GameController functions as they raised the maximum number of buttons
+* Get game window size from SDL2 when possible (#513)
 
 ## [1.4.4] - 2022-10-25
 ### Added

src/library/ScreenCapture.cpp

@@ -227,6 +227,8 @@ int ScreenCapture::init()
     } else
 #endif
     if ((game_info.video & GameInfo::SDL2_RENDERER) || (game_info.video & GameInfo::SDL2_SURFACE)) {
+        LINK_NAMESPACE_SDL2(SDL_GetWindowSize);
+        orig::SDL_GetWindowSize(sdl::gameSDLWindow, &width, &height);
         LINK_NAMESPACE_SDL2(SDL_GetWindowPixelFormat);
         Uint32 sdlpixfmt = orig::SDL_GetWindowPixelFormat(sdl::gameSDLWindow);
         pixelSize = sdlpixfmt & 0xFF;
@@ -691,8 +693,11 @@ int ScreenCapture::copyScreenToSurface()
          * So copying the screen pixels into the texture. */
         void* tex_pixels;
         int tex_pitch;
-        orig::SDL_LockTexture(screenSDLTex, nullptr, &tex_pixels, &tex_pitch);
-        int ret = orig::SDL_RenderReadPixels(sdl_renderer, NULL, 0, tex_pixels, pitch);
+        int ret = orig::SDL_LockTexture(screenSDLTex, nullptr, &tex_pixels, &tex_pitch);
+        if (ret < 0) {
+            debuglogstdio(LCF_DUMP | LCF_SDL | LCF_ERROR, "SDL_LockTexture failed: %s", orig::SDL_GetError());
+        }
+        ret = orig::SDL_RenderReadPixels(sdl_renderer, NULL, 0, tex_pixels, tex_pitch);
         if (ret < 0) {
             debuglogstdio(LCF_DUMP | LCF_SDL | LCF_ERROR, "SDL_RenderReadPixels failed: %s", orig::SDL_GetError());
         }