Merge pull request #2575 from yunline/convert-fix

Set default convert format when `Window.get_surface()` is called

Author: MyreMylar

src_c/_pygame.h

@@ -485,7 +485,7 @@ typedef enum {
 #define PYGAMEAPI_PIXELARRAY_NUMSLOTS 2
 #define PYGAMEAPI_COLOR_NUMSLOTS 5
 #define PYGAMEAPI_MATH_NUMSLOTS 2
-#define PYGAMEAPI_BASE_NUMSLOTS 27
+#define PYGAMEAPI_BASE_NUMSLOTS 29
 #define PYGAMEAPI_EVENT_NUMSLOTS 8
 #define PYGAMEAPI_WINDOW_NUMSLOTS 1
 #define PYGAMEAPI_GEOMETRY_NUMSLOTS 1

src_c/base.c

@@ -2057,6 +2057,27 @@ pg_SetDefaultWindowSurface(pgSurfaceObject *screen)
     pg_default_screen = screen;
 }
 
+SDL_PixelFormat *pg_default_convert_format = NULL;
+
+static SDL_PixelFormat *
+pg_GetDefaultConvertFormat(void)
+{
+    if (pg_default_screen) {
+        return pg_default_screen->surf->format;
+    }
+    return pg_default_convert_format;
+}
+
+static SDL_PixelFormat *
+pg_SetDefaultConvertFormat(Uint32 format)
+{
+    if (pg_default_convert_format != NULL) {
+        SDL_FreeFormat(pg_default_convert_format);
+    }
+    pg_default_convert_format = SDL_AllocFormat(format);
+    return pg_default_convert_format;  // returns for NULL error checking
+}
+
 static char *
 pg_EnvShouldBlendAlphaSDL2(void)
 {
@@ -2273,8 +2294,10 @@ MODINIT_DEFINE(base)
     c_api[24] = pg_DoubleFromObj;
     c_api[25] = pg_TwoDoublesFromObj;
     c_api[26] = pg_TwoDoublesFromFastcallArgs;
+    c_api[27] = pg_GetDefaultConvertFormat;
+    c_api[28] = pg_SetDefaultConvertFormat;
 
-#define FILLED_SLOTS 27
+#define FILLED_SLOTS 29
 
 #if PYGAMEAPI_BASE_NUMSLOTS != FILLED_SLOTS
 #error export slot count mismatch

src_c/include/_pygame.h

@@ -173,6 +173,12 @@ typedef struct pg_bufferinfo_s {
 #define pg_EnvShouldBlendAlphaSDL2 \
     (*(char *(*)(void))PYGAMEAPI_GET_SLOT(base, 23))
 
+#define pg_GetDefaultConvertFormat \
+    (*(SDL_PixelFormat * (*)(void)) PYGAMEAPI_GET_SLOT(base, 27))
+
+#define pg_SetDefaultConvertFormat \
+    (*(SDL_PixelFormat * (*)(Uint32)) PYGAMEAPI_GET_SLOT(base, 28))
+
 #define import_pygame_base() IMPORT_PYGAME_MODULE(base)
 #endif /* ~PYGAMEAPI_BASE_INTERNAL */
 

src_c/surface.c

@@ -1590,32 +1590,33 @@ surf_convert(pgSurfaceObject *self, PyObject *args)
 static SDL_Surface *
 pg_DisplayFormat(SDL_Surface *surface)
 {
-    SDL_Surface *displaysurf;
-    if (!pg_GetDefaultWindowSurface()) {
-        SDL_SetError("No video mode has been set");
+    SDL_PixelFormat *default_format = pg_GetDefaultConvertFormat();
+    if (!default_format) {
+        SDL_SetError(
+            "No convert format has been set, try display.set_mode()"
+            " or Window.get_surface().");
         return NULL;
     }
-    displaysurf = pgSurface_AsSurface(pg_GetDefaultWindowSurface());
-    return PG_ConvertSurface(surface, displaysurf->format);
+    return PG_ConvertSurface(surface, default_format);
 }
 
 static SDL_Surface *
 pg_DisplayFormatAlpha(SDL_Surface *surface)
 {
-    SDL_Surface *displaysurf;
     SDL_PixelFormat *dformat;
     Uint32 pfe;
     Uint32 amask = 0xff000000;
     Uint32 rmask = 0x00ff0000;
     Uint32 gmask = 0x0000ff00;
     Uint32 bmask = 0x000000ff;
 
-    if (!pg_GetDefaultWindowSurface()) {
-        SDL_SetError("No video mode has been set");
+    dformat = pg_GetDefaultConvertFormat();
+    if (!dformat) {
+        SDL_SetError(
+            "No convert format has been set, try display.set_mode()"
+            " or Window.get_surface().");
         return NULL;
     }
-    displaysurf = pgSurface_AsSurface(pg_GetDefaultWindowSurface());
-    dformat = displaysurf->format;
 
     switch (dformat->BytesPerPixel) {
         case 2:

src_c/window.c

@@ -157,12 +157,22 @@ window_get_surface(pgWindowObject *self)
     if (!_surf) {
         return RAISE(pgExc_SDLError, SDL_GetError());
     }
+
+    if (pg_GetDefaultConvertFormat() == NULL) {
+        if (pg_SetDefaultConvertFormat(_surf->format->format) == NULL) {
+            /* This is very unlikely, I think only would happen if SDL runs
+             * out of memory when allocating the format. */
+            return RAISE(pgExc_SDLError, SDL_GetError());
+        }
+    }
+
     if (self->surf == NULL) {
         self->surf = pgSurface_New2(_surf, SDL_FALSE);
         if (!self->surf)
             return NULL;
     }
     self->surf->surf = _surf;
+
     Py_INCREF(self->surf);
     return (PyObject *)self->surf;
 }

test/surface_test.py

@@ -1245,8 +1245,8 @@ def test_convert_init(self):
                 except pygame.error:
                     self.fail("convert() should not raise an exception here.")
 
-            self.assertRaisesRegex(pygame.error, "No video mode", surf.convert)
-            self.assertRaisesRegex(pygame.error, "No video mode", surf8bit.convert)
+            self.assertRaisesRegex(pygame.error, "No convert format", surf.convert)
+            self.assertRaisesRegex(pygame.error, "No convert format", surf8bit.convert)
 
             pygame.display.set_mode((640, 480))
             try:
@@ -1266,7 +1266,9 @@ def test_convert_alpha_init(self):
 
         pygame.display.init()
         try:
-            self.assertRaisesRegex(pygame.error, "No video mode", surf.convert_alpha)
+            self.assertRaisesRegex(
+                pygame.error, "No convert format", surf.convert_alpha
+            )
 
             pygame.display.set_mode((640, 480))
             try: