kc3-lang/SDL

2020-12-08T22:00:06

Fixed bug 5329 - SDL_SetWindowGrab(SDL_FALSE) fails to unlock cursor if window is partially offscreen Ivan Mogilko With SDL 2.0.12 under MS Windows, if the window is partially offscreen calling SDL_SetWindowGrab(w, SDL_TRUE) works, but subsequent call to SDL_SetWindowGrab(w, SDL_FALSE) does not work. I tested this in both real program, and a small test app, where unlocking cursor worked perfectly while window is fully in desktop bounds, but did not work if it was at least few pixels outside. For the reference, following code is enough to reproduce the issue: #include <windows.h> #include <SDL.h> int WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) { SDL_Init(SDL_INIT_VIDEO); SDL_Window* w = SDL_CreateWindow("", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 400, 0); bool grabbed = false; bool want_quit = false; while (!want_quit) { SDL_Event event; while (SDL_PollEvent(&event)) { switch (event.type) { case SDL_QUIT: want_quit = true; break; case SDL_KEYDOWN: if (event.key.keysym.scancode == SDL_SCANCODE_SPACE) { SDL_SetWindowGrab(w, static_cast<SDL_bool>(!grabbed)); grabbed = !grabbed; } } } } SDL_DestroyWindow(w); SDL_Quit(); return 0; }

diff --git a/src/video/windows/SDL_windowswindow.c b/src/video/windows/SDL_windowswindow.c
index ae3a9f6..dd21315 100644
--- a/src/video/windows/SDL_windowswindow.c
+++ b/src/video/windows/SDL_windowswindow.c
@@ -954,9 +954,18 @@ WIN_UpdateClipCursor(SDL_Window *window)
                 }
             }
         }
-    } else if (SDL_memcmp(&clipped_rect, &data->cursor_clipped_rect, sizeof(clipped_rect)) == 0) {
-        ClipCursor(NULL);
-        SDL_zero(data->cursor_clipped_rect);
+    } else {
+        POINT first, second;
+
+        first.x = clipped_rect.left;
+        first.y = clipped_rect.top;
+        second.x = clipped_rect.right - 1;
+        second.y = clipped_rect.bottom - 1;
+        if (PtInRect(&data->cursor_clipped_rect, first) &&
+            PtInRect(&data->cursor_clipped_rect, second)) {
+            ClipCursor(NULL);
+            SDL_zero(data->cursor_clipped_rect);
+        }
     }
     data->last_updated_clipcursor = SDL_GetTicks();
 }