Added area kwarg to mask.to_surface

Author: Matiiss

buildconfig/stubs/pygame/mask.pyi

@@ -52,6 +52,7 @@ class Mask:
         setcolor: Optional[ColorValue] = (255, 255, 255, 255),
         unsetcolor: Optional[ColorValue] = (0, 0, 0, 255),
         dest: Union[RectValue, Coordinate] = (0, 0),
+        area: Optional[RectValue] = None,
     ) -> Surface: ...
 
 MaskType = Mask

docs/reST/ref/mask.rst

@@ -570,7 +570,7 @@ to store which parts collide.
 
       | :sl:`Returns a surface with the mask drawn on it`
       | :sg:`to_surface() -> Surface`
-      | :sg:`to_surface(surface=None, setsurface=None, unsetsurface=None, setcolor=(255, 255, 255, 255), unsetcolor=(0, 0, 0, 255), dest=(0, 0)) -> Surface`
+      | :sg:`to_surface(surface=None, setsurface=None, unsetsurface=None, setcolor=(255, 255, 255, 255), unsetcolor=(0, 0, 0, 255), dest=(0, 0), area=None) -> Surface`
 
       Draws this mask on the given surface. Set bits (bits set to 1) and unset
       bits (bits set to 0) can be drawn onto a surface.
@@ -612,6 +612,12 @@ to store which parts collide.
          mask (i.e. position ``(0, 0)`` on the mask always corresponds to
          position ``(0, 0)`` on the ``setsurface`` and ``unsetsurface``)
       :type dest: Rect or tuple(int, int) or list(int, int) or Vector2(int, int)
+      :param area: (optional) rectangular portion of the mask to draw. It can be a
+         rect-like object (a Rect, a tuple or a list with 4 numbers or an object with a
+         rect attribute, etc) or it can be None (the default) in which case it will use the
+         entire mask. Just like with Surface.blit, if the rect's topleft is negative
+         the final destination will be ``dest - rect.topleft``.
+      :type area: Rect or rect-like object
 
       :returns: the ``surface`` parameter (or a newly created surface if no
          ``surface`` parameter was provided) with this mask drawn on it

src_c/doc/mask_doc.h

@@ -25,4 +25,4 @@
 #define DOC_MASK_MASK_CONNECTEDCOMPONENT "connected_component() -> Mask\nconnected_component(pos) -> Mask\nReturns a mask containing a connected component"
 #define DOC_MASK_MASK_CONNECTEDCOMPONENTS "connected_components() -> [Mask, ...]\nconnected_components(minimum=0) -> [Mask, ...]\nReturns a list of masks of connected components"
 #define DOC_MASK_MASK_GETBOUNDINGRECTS "get_bounding_rects() -> [Rect, ...]\nReturns a list of bounding rects of connected components"
-#define DOC_MASK_MASK_TOSURFACE "to_surface() -> Surface\nto_surface(surface=None, setsurface=None, unsetsurface=None, setcolor=(255, 255, 255, 255), unsetcolor=(0, 0, 0, 255), dest=(0, 0)) -> Surface\nReturns a surface with the mask drawn on it"
+#define DOC_MASK_MASK_TOSURFACE "to_surface() -> Surface\nto_surface(surface=None, setsurface=None, unsetsurface=None, setcolor=(255, 255, 255, 255), unsetcolor=(0, 0, 0, 255), dest=(0, 0), area=None) -> Surface\nReturns a surface with the mask drawn on it"

src_c/mask.c

@@ -1895,8 +1895,9 @@ extract_color(SDL_Surface *surf, PyObject *color_obj, Uint8 rgba_color[],
  */
 static void
 draw_to_surface(SDL_Surface *surf, bitmask_t *bitmask, int x_dest, int y_dest,
-                int draw_setbits, int draw_unsetbits, SDL_Surface *setsurf,
-                SDL_Surface *unsetsurf, Uint32 *setcolor, Uint32 *unsetcolor)
+                SDL_Rect *area_rect, int draw_setbits, int draw_unsetbits,
+                SDL_Surface *setsurf, SDL_Surface *unsetsurf, Uint32 *setcolor,
+                Uint32 *unsetcolor)
 {
     Uint8 *pixel = NULL;
     Uint8 bpp;
@@ -1912,6 +1913,15 @@ draw_to_surface(SDL_Surface *surf, bitmask_t *bitmask, int x_dest, int y_dest,
         return;
     }
 
+    if (area_rect->x < 0) {
+        x_dest -= area_rect->x;
+        area_rect->w += area_rect->x;
+    }
+    if (area_rect->y < 0) {
+        y_dest -= area_rect->y;
+        area_rect->h += area_rect->y;
+    }
+
     /* There is also nothing to do when the destination position is such that
      * nothing will be drawn on the surface. */
     if ((x_dest >= surf->w) || (y_dest >= surf->h) || (-x_dest > bitmask->w) ||
@@ -1921,13 +1931,23 @@ draw_to_surface(SDL_Surface *surf, bitmask_t *bitmask, int x_dest, int y_dest,
 
     bpp = surf->format->BytesPerPixel;
 
+    // clamp rect width and height to not stick out of the mask
+    area_rect->w = MIN(area_rect->w, bitmask->w - area_rect->x);
+    area_rect->h = MIN(area_rect->h, bitmask->h - area_rect->y);
+
     xm_start = (x_dest < 0) ? -x_dest : 0;
+    if (area_rect->x > 0) {
+        xm_start += area_rect->x;
+    }
     x_start = (x_dest > 0) ? x_dest : 0;
-    x_end = MIN(surf->w, bitmask->w + x_dest);
+    x_end = MIN(MIN(surf->w, bitmask->w + x_dest), x_dest + area_rect->w);
 
     ym_start = (y_dest < 0) ? -y_dest : 0;
+    if (area_rect->y > 0) {
+        ym_start += area_rect->y;
+    }
     y_start = (y_dest > 0) ? y_dest : 0;
-    y_end = MIN(surf->h, bitmask->h + y_dest);
+    y_end = MIN(MIN(surf->h, bitmask->h + y_dest), y_dest + area_rect->h);
 
     if (NULL == setsurf && NULL == unsetsurf) {
         /* Draw just using color values. No surfaces. */
@@ -2074,7 +2094,8 @@ mask_to_surface(PyObject *self, PyObject *args, PyObject *kwargs)
 {
     PyObject *surfobj = Py_None, *setcolorobj = NULL, *unsetcolorobj = NULL;
     PyObject *setsurfobj = Py_None, *unsetsurfobj = Py_None;
-    PyObject *destobj = NULL;
+    PyObject *destobj = NULL, *areaobj = NULL;
+    SDL_Rect *area_rect, temp_rect;
     SDL_Surface *surf = NULL, *setsurf = NULL, *unsetsurf = NULL;
     bitmask_t *bitmask = pgMask_AsBitmap(self);
     Uint32 *setcolor_ptr = NULL, *unsetcolor_ptr = NULL;
@@ -2087,11 +2108,11 @@ mask_to_surface(PyObject *self, PyObject *args, PyObject *kwargs)
 
     static char *keywords[] = {"surface",  "setsurface", "unsetsurface",
                                "setcolor", "unsetcolor", "dest",
-                               NULL};
+                               "area",     NULL};
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|OOOOOO", keywords,
-                                     &surfobj, &setsurfobj, &unsetsurfobj,
-                                     &setcolorobj, &unsetcolorobj, &destobj)) {
+    if (!PyArg_ParseTupleAndKeywords(
+            args, kwargs, "|OOOOOOO", keywords, &surfobj, &setsurfobj,
+            &unsetsurfobj, &setcolorobj, &unsetcolorobj, &destobj, &areaobj)) {
         return NULL; /* Exception already set. */
     }
 
@@ -2207,6 +2228,19 @@ mask_to_surface(PyObject *self, PyObject *args, PyObject *kwargs)
         }
     }
 
+    if (areaobj && areaobj != Py_None) {
+        if (!(area_rect = pgRect_FromObject(areaobj, &temp_rect))) {
+            PyErr_SetString(PyExc_TypeError, "invalid rectstyle argument");
+            goto to_surface_error;
+        }
+    }
+    else {
+        temp_rect.x = temp_rect.y = 0;
+        temp_rect.w = bitmask->w;
+        temp_rect.h = bitmask->h;
+        area_rect = &temp_rect;
+    }
+
     if (!pgSurface_Lock((pgSurfaceObject *)surfobj)) {
         PyErr_SetString(PyExc_RuntimeError, "cannot lock surface");
         goto to_surface_error;
@@ -2229,7 +2263,7 @@ mask_to_surface(PyObject *self, PyObject *args, PyObject *kwargs)
 
     Py_BEGIN_ALLOW_THREADS; /* Release the GIL. */
 
-    draw_to_surface(surf, bitmask, x_dest, y_dest, draw_setbits,
+    draw_to_surface(surf, bitmask, x_dest, y_dest, area_rect, draw_setbits,
                     draw_unsetbits, setsurf, unsetsurf, setcolor_ptr,
                     unsetcolor_ptr);
 

test/mask_test.py

@@ -2822,7 +2822,6 @@ def test_to_surface__dest_default(self):
         assertSurfaceFilled(self, to_surface, expected_color, mask_rect)
         assertSurfaceFilledIgnoreArea(self, to_surface, surface_color, mask_rect)
 
-    @unittest.expectedFailure
     def test_to_surface__area_param(self):
         """Ensures to_surface accepts an area arg/kwarg."""
         expected_ref_count = 2
@@ -2854,6 +2853,60 @@ def test_to_surface__area_param(self):
             self.assertEqual(to_surface.get_size(), size)
             assertSurfaceFilled(self, to_surface, expected_color)
 
+    def test_to_surface__area_output(self):
+        dst = pygame.Surface((2, 2))
+        mask = pygame.mask.Mask((2, 2), fill=True)
+
+        white = (255, 255, 255, 255)
+        black = (0, 0, 0, 255)
+
+        # make sure the surface is black, this is to make sure the test surface and mask are different colors
+        self.assertEqual(dst.get_at((0, 0)), black)
+        # make sure the mask is set and the default color after conversion is white
+        self.assertEqual(mask.to_surface().get_at((0, 0)), white)
+
+        test_areas_plus_destinations_and_expected_pattern = [
+            [{"dest": (0, 0), "area": None}, [[white, white], [white, white]]],
+            [{"dest": (0, 0), "area": (0, 0, 1, 1)}, [[white, black], [black, black]]],
+            [{"dest": (0, 0), "area": (0, 0, 2, 2)}, [[white, white], [white, white]]],
+            [{"dest": (1, 0), "area": (0, 0, 1, 2)}, [[black, white], [black, white]]],
+            [{"dest": (0, 0), "area": (0, 0, 0, 0)}, [[black, black], [black, black]]],
+            [{"dest": (1, 0), "area": (-1, 0, 1, 1)}, [[black, black], [black, black]]],
+            [{"dest": (0, 0), "area": (-1, 0, 2, 1)}, [[black, white], [black, black]]],
+            [
+                {"dest": (1, 1), "area": (-2, -2, 1, 1)},
+                [[black, black], [black, black]],
+            ],
+            [
+                {"dest": (0, 1), "area": (0, 0, 50, 50)},
+                [[black, black], [white, white]],
+            ],
+            [
+                {"dest": (-1, 0), "area": (-1, 0, 2, 2)},
+                [[white, black], [white, black]],
+            ],
+            [
+                {"dest": (0, -1), "area": (-1, 0, 3, 2)},
+                [[black, white], [black, black]],
+            ],
+            [{"dest": (0, 0), "area": (2, 2, 2, 2)}, [[black, black], [black, black]]],
+            [
+                {"dest": (-5, -5), "area": (-5, -5, 6, 6)},
+                [[white, black], [black, black]],
+            ],
+            [
+                {"dest": (-5, -5), "area": (-5, -5, 1, 1)},
+                [[black, black], [black, black]],
+            ],
+        ]
+
+        for kwargs, pattern in test_areas_plus_destinations_and_expected_pattern:
+            surface = dst.copy()
+            mask.to_surface(surface=surface, **kwargs)
+            for y, row in enumerate(pattern):
+                for x, value in enumerate(row):
+                    self.assertEqual(surface.get_at((x, y)), value)
+
     def test_to_surface__area_default(self):
         """Ensures the default area is correct."""
         expected_color = pygame.Color("white")