Implement pygame.image.load_sized_svg (#2620)

Author: ankith26

buildconfig/stubs/pygame/image.pyi

@@ -3,7 +3,7 @@ from typing import Optional, Tuple, Union
 from pygame.bufferproxy import BufferProxy
 from pygame.surface import Surface
 
-from ._common import FileArg, Literal, IntCoordinate
+from ._common import FileArg, Literal, IntCoordinate, Coordinate
 
 _BufferStyle = Union[BufferProxy, bytes, bytearray, memoryview]
 _to_string_format = Literal[
@@ -13,6 +13,7 @@ _from_buffer_format = Literal["P", "RGB", "BGR", "BGRA", "RGBX", "RGBA", "ARGB"]
 _from_string_format = Literal["P", "RGB", "RGBX", "RGBA", "ARGB", "BGRA"]
 
 def load(file: FileArg, namehint: str = "") -> Surface: ...
+def load_sized_svg(file: FileArg, size: Coordinate) -> Surface: ...
 def save(surface: Surface, file: FileArg, namehint: str = "") -> None: ...
 def get_sdl_image_version(linked: bool = True) -> Optional[Tuple[int, int, int]]: ...
 def get_extended() -> bool: ...

docs/reST/ref/image.rst

@@ -109,6 +109,32 @@ following formats.
 
    .. ## pygame.image.load ##
 
+.. function:: load_sized_svg
+
+   | :sl:`load an SVG image from a file (or file-like object) with the given size`
+   | :sg:`load_sized_svg(file, size) -> Surface`
+
+   This function rasterizes the input SVG at the size specified by the ``size``
+   argument. The ``file`` argument can be either a filename, a Python file-like
+   object, or a pathlib.Path.
+
+   The usage of this function for handling SVGs is recommended, as calling the
+   regular ``load`` function and then scaling the returned surface would not
+   preserve the quality that an SVG can provide.
+
+   It is to be noted that this function does not return a surface whose
+   dimensions exactly match the ``size`` argument. This function preserves
+   aspect ratio, so the returned surface could be smaller along at most one
+   dimension.
+
+   This function requires SDL_image 2.6.0 or above. If pygame was compiled with
+   an older version, ``pygame.error`` will be raised when this function is
+   called.
+
+   .. versionadded:: 2.4.0
+
+   .. ## pygame.image.load_sized_svg ##
+
 .. function:: save
 
    | :sl:`save an image to file (or file-like object)`

src_c/doc/image_doc.h

@@ -1,6 +1,7 @@
 /* Auto generated file: with makeref.py .  Docs go in docs/reST/ref/ . */
 #define DOC_IMAGE "pygame module for image transfer"
 #define DOC_IMAGE_LOAD "load(file) -> Surface\nload(file, namehint="") -> Surface\nload new image from a file (or file-like object)"
+#define DOC_IMAGE_LOADSIZEDSVG "load_sized_svg(file, size) -> Surface\nload an SVG image from a file (or file-like object) with the given size"
 #define DOC_IMAGE_SAVE "save(Surface, file) -> None\nsave(Surface, file, namehint="") -> None\nsave an image to file (or file-like object)"
 #define DOC_IMAGE_GETSDLIMAGEVERSION "get_sdl_image_version(linked=True) -> None\nget_sdl_image_version(linked=True) -> (major, minor, patch)\nget version number of the SDL_Image library being used"
 #define DOC_IMAGE_GETEXTENDED "get_extended() -> bool\ntest if extended image formats can be loaded"

src_c/image.c

@@ -48,6 +48,7 @@ SaveTGA_RW(SDL_Surface *surface, SDL_RWops *out, int rle);
 static PyObject *extloadobj = NULL;
 static PyObject *extsaveobj = NULL;
 static PyObject *extverobj = NULL;
+static PyObject *ext_load_sized_svg = NULL;
 
 static const char *
 find_extension(const char *fullname)
@@ -1653,12 +1654,25 @@ SaveTGA(SDL_Surface *surface, const char *file, int rle)
     return ret;
 }
 
+static PyObject *
+image_load_sized_svg(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    if (ext_load_sized_svg) {
+        return PyObject_Call(ext_load_sized_svg, args, kwargs);
+    }
+
+    return RAISE(PyExc_NotImplementedError,
+                 "Support for sized svg image loading was not compiled in.");
+}
+
 static PyMethodDef _image_methods[] = {
     {"load_basic", (PyCFunction)image_load_basic, METH_O, DOC_IMAGE_LOADBASIC},
     {"load_extended", (PyCFunction)image_load_extended,
      METH_VARARGS | METH_KEYWORDS, DOC_IMAGE_LOADEXTENDED},
     {"load", (PyCFunction)image_load, METH_VARARGS | METH_KEYWORDS,
      DOC_IMAGE_LOAD},
+    {"load_sized_svg", (PyCFunction)image_load_sized_svg,
+     METH_VARARGS | METH_KEYWORDS, DOC_IMAGE_LOADSIZEDSVG},
 
     {"save_extended", (PyCFunction)image_save_extended,
      METH_VARARGS | METH_KEYWORDS, DOC_IMAGE_SAVEEXTENDED},
@@ -1734,6 +1748,11 @@ MODINIT_DEFINE(image)
         if (!extverobj) {
             goto error;
         }
+        ext_load_sized_svg =
+            PyObject_GetAttrString(extmodule, "_load_sized_svg");
+        if (!ext_load_sized_svg) {
+            goto error;
+        }
         Py_DECREF(extmodule);
     }
     else {
@@ -1746,6 +1765,7 @@ MODINIT_DEFINE(image)
     Py_XDECREF(extloadobj);
     Py_XDECREF(extsaveobj);
     Py_XDECREF(extverobj);
+    Py_XDECREF(ext_load_sized_svg);
     Py_DECREF(extmodule);
     Py_DECREF(module);
     return NULL;

src_c/imageext.c

@@ -137,6 +137,53 @@ image_load_ext(PyObject *self, PyObject *arg, PyObject *kwarg)
     return final;
 }
 
+static PyObject *
+imageext_load_sized_svg(PyObject *self, PyObject *arg, PyObject *kwargs)
+{
+#if SDL_IMAGE_VERSION_ATLEAST(2, 6, 0)
+    PyObject *obj, *size, *final;
+    SDL_Surface *surf;
+    SDL_RWops *rw = NULL;
+    int width, height;
+    static char *kwds[] = {"file", "size", NULL};
+
+    if (!PyArg_ParseTupleAndKeywords(arg, kwargs, "OO", kwds, &obj, &size)) {
+        return NULL;
+    }
+
+    if (!pg_TwoIntsFromObj(size, &width, &height)) {
+        return RAISE(PyExc_TypeError, "size must be two numbers");
+    }
+
+    if (width <= 0 || height <= 0) {
+        return RAISE(PyExc_ValueError,
+                     "both components of size must be be positive");
+    }
+
+    rw = pgRWops_FromObject(obj, NULL);
+    if (rw == NULL) {
+        return NULL;
+    }
+
+    Py_BEGIN_ALLOW_THREADS;
+    surf = IMG_LoadSizedSVG_RW(rw, width, height);
+    SDL_RWclose(rw);
+    Py_END_ALLOW_THREADS;
+    if (surf == NULL) {
+        return RAISE(pgExc_SDLError, IMG_GetError());
+    }
+    final = (PyObject *)pgSurface_New(surf);
+    if (final == NULL) {
+        SDL_FreeSurface(surf);
+    }
+    return final;
+#else  /* ~SDL_IMAGE_VERSION_ATLEAST(2, 6, 0) */
+    return RAISE(
+        pgExc_SDLError,
+        "pygame must be compiled with SDL_image 2.6.0+ to use this function");
+#endif /* ~SDL_IMAGE_VERSION_ATLEAST(2, 6, 0) */
+}
+
 static PyObject *
 image_save_ext(PyObject *self, PyObject *arg, PyObject *kwarg)
 {
@@ -265,6 +312,8 @@ static PyMethodDef _imageext_methods[] = {
      METH_VARARGS | METH_KEYWORDS,
      "_get_sdl_image_version() -> (major, minor, patch)\n"
      "Note: Should not be used directly."},
+    {"_load_sized_svg", (PyCFunction)imageext_load_sized_svg,
+     METH_VARARGS | METH_KEYWORDS, "Note: Should not be used directly."},
     {NULL, NULL, 0, NULL}};
 
 /*DOC*/ static char _imageext_doc[] =

test/image_test.py

@@ -1786,6 +1786,85 @@ def test_load_extended(self):
                 surf = pygame.image.load_extended(example_path("data/" + filename))
                 self.assertEqual(surf.get_at((0, 0)), expected_color)
 
+    @unittest.skipIf(
+        pygame.image.get_sdl_image_version() < (2, 6, 0),
+        "load_sized_svg requires SDL_image 2.6.0+",
+    )
+    def test_load_sized_svg(self):
+        EXPECTED_COLOR = (0, 128, 128, 255)
+        EXPECTED_ASPECT_RATIO = pygame.Vector2(1, 1).normalize()
+        for size in (
+            (10, 10),
+            [100, 100],
+            pygame.Vector2(1, 1),
+            [4, 2],
+            (1000, 30),
+        ):
+            with self.subTest(
+                f"Test loading SVG with size",
+                size=size,
+            ):
+                # test with both keywords and no keywords
+                surf = pygame.image.load_sized_svg(example_path("data/teal.svg"), size)
+                surf_kw = pygame.image.load_sized_svg(
+                    file=example_path("data/teal.svg"), size=size
+                )
+                self.assertEqual(surf.get_at((0, 0)), EXPECTED_COLOR)
+                self.assertEqual(surf_kw.get_at((0, 0)), EXPECTED_COLOR)
+                ret_size = surf.get_size()
+                self.assertEqual(surf_kw.get_size(), ret_size)
+
+                # test the returned surface exactly fits the size box
+                self.assertTrue(
+                    (ret_size[0] == size[0] and ret_size[1] <= size[1])
+                    or (ret_size[1] == size[1] and ret_size[0] <= size[0]),
+                    f"{ret_size = } must exactly fit {size = }",
+                )
+
+                # test that aspect ratio is maintained
+                self.assertEqual(
+                    pygame.Vector2(ret_size).normalize(), EXPECTED_ASPECT_RATIO
+                )
+
+    @unittest.skipIf(
+        pygame.image.get_sdl_image_version() < (2, 6, 0),
+        "load_sized_svg requires SDL_image 2.6.0+",
+    )
+    def test_load_sized_svg_erroring(self):
+        for type_error_size in (
+            [100],
+            (0, 0, 10, 3),
+            "foo",
+            pygame.Vector3(-3, 10, 10),
+        ):
+            with self.subTest(
+                f"Test TypeError",
+                type_error_size=type_error_size,
+            ):
+                self.assertRaises(
+                    TypeError,
+                    pygame.image.load_sized_svg,
+                    example_path("data/teal.svg"),
+                    type_error_size,
+                )
+
+        for value_error_size in (
+            [100, 0],
+            (0, 0),
+            [-2, -1],
+            pygame.Vector2(-3, 10),
+        ):
+            with self.subTest(
+                f"Test ValueError",
+                value_error_size=value_error_size,
+            ):
+                self.assertRaises(
+                    ValueError,
+                    pygame.image.load_sized_svg,
+                    example_path("data/teal.svg"),
+                    value_error_size,
+                )
+
     def test_load_pathlib(self):
         """works loading using a Path argument."""
         path = pathlib.Path(example_path("data/asprite.bmp"))