pygame._render: Changing/getting the line rendering methods used by the SDL2 render API

buildconfig/stubs/pygame/_render.pyi

@@ -146,3 +146,6 @@ class Texture:
 @final
 class Image:
     pass
+
+def get_line_render_method() -> int: ...
+def set_line_render_method(method: int) -> bool: ...

src_c/constants.c

@@ -671,6 +671,11 @@ MODINIT_DEFINE(constants)
     DEC_CONSTS(FLASH_UNTIL_FOCUSED, -1);
 #endif
 
+    DEC_CONSTS(LINE_RENDER_DEFAULT, 0)
+    DEC_CONSTS(LINE_RENDER_POINT, 1)
+    DEC_CONSTS(LINE_RENDER_LINE, 2)
+    DEC_CONSTS(LINE_RENDER_GEOMETRY, 3)
+
     if (PyModule_AddObject(module, "__all__", all_list)) {
         Py_DECREF(all_list);
         Py_DECREF(module);

src_c/render.c

@@ -1183,6 +1183,38 @@ image_renderer_draw(pgImageObject *self, PyObject *area, PyObject *dest)
     return 1;
 }
 
+#if SDL_VERSION_ATLEAST(2, 0, 20)
+static PyObject *
+get_line_render_method(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    const char *hint = SDL_GetHint(SDL_HINT_RENDER_LINE_METHOD);
+    return PyLong_FromLong(hint == NULL ? 0 : hint[0] - '0'); // hint is a char between 0-3
+}
+
+static PyObject *
+set_line_render_method(PyObject *self, PyObject *args)
+{
+    int method;
+    if (!PyArg_ParseTuple(args, "i", &method)) {
+        return RAISE(PyExc_ValueError, "Invalid line render method: must be an int"
+            " (use LINE_RENDER_* constants)");
+    }
+    if (method < 0 || 3 < method) {
+        return RAISE(PyExc_ValueError, "Invalid line render method: must be between"
+            " 0 and 3 (use LINE_RENDER_* constants)");
+    }
+
+    // SDL_SetHint expects the method as a string
+    char hint[2];
+    hint[0] = method + '0'; // ascii char manipulation
+    hint[1] = '\0';
+
+    if (SDL_SetHint(SDL_HINT_RENDER_LINE_METHOD, hint))
+        Py_RETURN_TRUE;
+    Py_RETURN_FALSE;
+}
+#endif
+
 /* Module definition */
 static PyMethodDef renderer_methods[] = {
     {"draw_point", (PyCFunction)renderer_draw_point,
@@ -1307,7 +1339,15 @@ static PyTypeObject pgImage_Type = {
     //.tp_init = (initproc)image_init,
     .tp_new = PyType_GenericNew, .tp_getset = image_getset};
 
-static PyMethodDef _render_methods[] = {{NULL, NULL, 0, NULL}};
+static PyMethodDef _render_methods[] = {
+#if SDL_VERSION_ATLEAST(2, 0, 20)
+    {"get_line_render_method", (PyCFunction)get_line_render_method,
+     METH_NOARGS, NULL},
+    {"set_line_render_method", (PyCFunction)set_line_render_method,
+     METH_VARARGS, NULL},
+#endif
+
+    {NULL, NULL, 0, NULL}};
 
 MODINIT_DEFINE(_render)
 {

test.py

@@ -0,0 +1,7 @@
+from pygame import _render
+
+import pygame
+
+
+pygame.init()
+_render.set_line_render_method("test")

test/render_test.py

@@ -482,3 +482,25 @@ def test_update(self):
         result = self.renderer.to_surface()
         for x in range(25, 75):
             self.assertEqual(pygame.Color(80, 120, 160, 255), result.get_at((x, 50)))
+
+
+class LineRenderMethodTest(unittest.TestCase):
+    def test_correct_argument(self):
+        with self.assertRaises(ValueError):
+            _render.set_line_render_method(-1)
+        with self.assertRaises(ValueError):
+            _render.set_line_render_method(10)
+        with self.assertRaises(ValueError):
+            _render.set_line_render_method("foo")
+        with self.assertRaises(ValueError):
+            _render.set_line_render_method(None)
+
+    def test_get_set_line_render_method(self):
+        if _render.set_line_render_method(pygame.LINE_RENDER_DEFAULT):
+            self.assertEqual(pygame.LINE_RENDER_DEFAULT, _render.get_line_render_method())
+        if _render.set_line_render_method(pygame.LINE_RENDER_POINT):
+            self.assertEqual(pygame.LINE_RENDER_POINT, _render.get_line_render_method())
+        if _render.set_line_render_method(pygame.LINE_RENDER_LINE):
+            self.assertEqual(pygame.LINE_RENDER_LINE, _render.get_line_render_method())
+        if _render.set_line_render_method(pygame.LINE_RENDER_GEOMETRY):
+            self.assertEqual(pygame.LINE_RENDER_GEOMETRY, _render.get_line_render_method())