winemac.drv: No Flicker patch

dlls/winemac.drv/macdrv.h

@@ -41,6 +41,7 @@ extern BOOL allow_vsync DECLSPEC_HIDDEN;
 extern BOOL allow_set_gamma DECLSPEC_HIDDEN;
 extern BOOL allow_software_rendering DECLSPEC_HIDDEN;
 extern BOOL disable_window_decorations DECLSPEC_HIDDEN;
+extern BOOL force_backing_store DECLSPEC_HIDDEN;
 
 extern const char* debugstr_cf(CFTypeRef t) DECLSPEC_HIDDEN;
 

dlls/winemac.drv/macdrv_main.c

@@ -66,6 +66,7 @@ int use_precise_scrolling = TRUE;
 int gl_surface_mode = GL_SURFACE_IN_FRONT_OPAQUE;
 int retina_enabled = FALSE;
 int enable_app_nap = FALSE;
+BOOL force_backing_store = FALSE;
 
 CFDictionaryRef localized_strings;
 
@@ -384,6 +385,9 @@ static void setup_options(void)
     if (!get_config_key(hkey, appkey, "EnableAppNap", buffer, sizeof(buffer)))
         enable_app_nap = IS_OPTION_TRUE(buffer[0]);
 
+    if (!get_config_key(hkey, appkey, "ForceOpenGLBackingStore", buffer, sizeof(buffer)))
+        force_backing_store = IS_OPTION_TRUE(buffer[0]);
+
     /* Don't use appkey.  The DPI and monitor sizes should be consistent for all
        processes in the prefix. */
     if (!get_config_key(hkey, NULL, "RetinaMode", buffer, sizeof(buffer)))

dlls/winemac.drv/opengl.c

@@ -1452,7 +1452,7 @@ static BOOL create_context(struct wgl_context *context, CGLContextObj share, uns
         attribs[n++] = pf->samples;
     }
 
-    if (pf->backing_store)
+    if (force_backing_store || pf->backing_store)
         attribs[n++] = kCGLPFABackingStore;
 
     if (core)