Mask SDL3: don't set python error without GIL

Author: Starbuck5

src_c/mask.c

@@ -956,9 +956,11 @@ palette_colors - this only affects surfaces with a palette
 
 */
 
-int
-bitmask_threshold(bitmask_t *m, SDL_Surface *surf, SDL_Surface *surf2,
-                  Uint32 color, Uint32 threshold, int palette_colors)
+void
+bitmask_threshold(bitmask_t *m, SDL_Surface *surf, PG_PixelFormat *format,
+                  SDL_Palette *palette, SDL_Surface *surf2,
+                  PG_PixelFormat *format2, Uint32 color, Uint32 threshold,
+                  int palette_colors)
 {
     int x, y, rshift, gshift, bshift, rshift2, gshift2, bshift2;
     int rloss, gloss, bloss, rloss2, gloss2, bloss2;
@@ -968,13 +970,6 @@ bitmask_threshold(bitmask_t *m, SDL_Surface *surf, SDL_Surface *surf2,
     Uint8 r, g, b, a;
     Uint8 tr, tg, tb, ta;
     int bpp1, bpp2;
-    PG_PixelFormat *format, *format2;
-    SDL_Palette *palette, *palette2;
-
-    if (!PG_GetSurfaceDetails(surf, &format, &palette)) {
-        PyErr_SetString(pgExc_SDLError, SDL_GetError());
-        return -1;
-    }
 
     rmask = format->Rmask;
     gmask = format->Gmask;
@@ -988,10 +983,6 @@ bitmask_threshold(bitmask_t *m, SDL_Surface *surf, SDL_Surface *surf2,
     bpp1 = PG_FORMAT_BytesPerPixel(format);
 
     if (surf2) {
-        if (!PG_GetSurfaceDetails(surf2, &format2, &palette2)) {
-            PyErr_SetString(pgExc_SDLError, SDL_GetError());
-            return -1;
-        }
         rmask2 = format2->Rmask;
         gmask2 = format2->Gmask;
         bmask2 = format2->Bmask;
@@ -1005,12 +996,9 @@ bitmask_threshold(bitmask_t *m, SDL_Surface *surf, SDL_Surface *surf2,
         bpp2 = PG_FORMAT_BytesPerPixel(format2);
     }
     else { /* make gcc stop complaining */
-        format2 = NULL;
-        palette2 = NULL;
         rmask2 = gmask2 = bmask2 = 0;
         rshift2 = gshift2 = bshift2 = 0;
         rloss2 = gloss2 = bloss2 = 0;
-        format2 = NULL;
         pixels2 = NULL;
         bpp2 = 0;
     }
@@ -1120,7 +1108,6 @@ bitmask_threshold(bitmask_t *m, SDL_Surface *surf, SDL_Surface *surf2,
             }
         }
     }
-    return 0;  // No errors!
 }
 
 static PyObject *
@@ -1130,6 +1117,8 @@ mask_from_threshold(PyObject *self, PyObject *args, PyObject *kwargs)
     pgSurfaceObject *surfobj2 = NULL;
     pgMaskObject *maskobj = NULL;
     SDL_Surface *surf = NULL, *surf2 = NULL;
+    PG_PixelFormat *surf_format, *surf2_format = NULL;
+    SDL_Palette *surf_palette;
     PyObject *rgba_obj_color, *rgba_obj_threshold = NULL;
     Uint8 rgba_threshold[4] = {0, 0, 0, 255};
     Uint32 color;
@@ -1150,6 +1139,17 @@ mask_from_threshold(PyObject *self, PyObject *args, PyObject *kwargs)
         surf2 = pgSurface_AsSurface(surfobj2);
     }
 
+    if (!PG_GetSurfaceDetails(surf, &surf_format, &surf_palette)) {
+        return RAISE(pgExc_SDLError, SDL_GetError());
+    }
+
+    if (surf2) {
+        surf2_format = PG_GetSurfaceFormat(surf2);
+        if (!surf2_format) {
+            return RAISE(pgExc_SDLError, SDL_GetError());
+        }
+    }
+
     if (!pg_MappedColorFromObj(rgba_obj_color, surf, &color,
                                PG_COLOR_HANDLE_ALL)) {
         return NULL;
@@ -1162,15 +1162,9 @@ mask_from_threshold(PyObject *self, PyObject *args, PyObject *kwargs)
         }
     }
     else {
-#if SDL_VERSION_ATLEAST(3, 0, 0)
-        color_threshold =
-            SDL_MapSurfaceRGBA(surf, rgba_threshold[0], rgba_threshold[1],
-                               rgba_threshold[2], rgba_threshold[3]);
-#else
-        color_threshold =
-            SDL_MapRGBA(surf->format, rgba_threshold[0], rgba_threshold[1],
-                        rgba_threshold[2], rgba_threshold[3]);
-#endif
+        color_threshold = PG_MapRGBA(surf_format, surf_palette,
+                                     rgba_threshold[0], rgba_threshold[1],
+                                     rgba_threshold[2], rgba_threshold[3]);
     }
 
     maskobj = CREATE_MASK_OBJ(surf->w, surf->h, 0);
@@ -1185,8 +1179,8 @@ mask_from_threshold(PyObject *self, PyObject *args, PyObject *kwargs)
     }
 
     Py_BEGIN_ALLOW_THREADS;
-    threshold_ret = bitmask_threshold(maskobj->mask, surf, surf2, color,
-                                      color_threshold, palette_colors);
+    bitmask_threshold(maskobj->mask, surf, surf_format, surf_palette, surf2,
+                      surf2_format, color, color_threshold, palette_colors);
     Py_END_ALLOW_THREADS;
 
     pgSurface_Unlock(surfobj);