Border radius for pygame.draw.polygon (resolves #1527)

buildconfig/stubs/pygame/draw.pyi

@@ -19,6 +19,7 @@ def polygon(
     color: ColorValue,
     points: Sequence[Coordinate],
     width: int = 0,
+    border_radius: int = 0,
 ) -> Rect: ...
 def circle(
     surface: Surface,

docs/reST/ref/draw.rst

@@ -103,7 +103,7 @@ object around the draw calls (see :func:`pygame.Surface.lock` and
 
    | :sl:`draw a polygon`
    | :sg:`polygon(surface, color, points) -> Rect`
-   | :sg:`polygon(surface, color, points, width=0) -> Rect`
+   | :sg:`polygon(surface, color, points, width=0, border_radius=0) -> Rect`
 
    Draws a polygon on the given surface.
 
@@ -129,14 +129,18 @@ object around the draw calls (see :func:`pygame.Surface.lock` and
             outside the original boundary of the polygon. For more details on
             how the thickness for edge lines grow, refer to the ``width`` notes
             of the :func:`pygame.draw.line` function.
+   :param int border_radius: (optional, default: 0) determines the radius for rounded corners of the polygon.
+      Only active when both ``width > 0`` and ``border_radius > 0``.
 
    :returns: a rect bounding the changed pixels, if nothing is drawn the
       bounding rect's position will be the position of the first point in the
       ``points`` parameter (float values will be truncated) and its width and
       height will be 0
    :rtype: Rect
 
-   :raises ValueError: if ``len(points) < 3`` (must have at least 3 points)
+   :raises ValueError: if ``len(points) < 3`` (must have at least 3 points),
+      or if three of the given points provided in inputs are aligned,
+      or if the radius is very large in relation to the size of the adjacent edges.
    :raises TypeError: if ``points`` is not a sequence or ``points`` does not
       contain number pairs
 

src_c/doc/draw_doc.h

@@ -1,7 +1,7 @@
 /* Auto generated file: with make_docs.py .  Docs go in docs/reST/ref/ . */
 #define DOC_DRAW "pygame module for drawing shapes"
 #define DOC_DRAW_RECT "rect(surface, color, rect) -> Rect\nrect(surface, color, rect, width=0, border_radius=0, border_top_left_radius=-1, border_top_right_radius=-1, border_bottom_left_radius=-1, border_bottom_right_radius=-1) -> Rect\ndraw a rectangle"
-#define DOC_DRAW_POLYGON "polygon(surface, color, points) -> Rect\npolygon(surface, color, points, width=0) -> Rect\ndraw a polygon"
+#define DOC_DRAW_POLYGON "polygon(surface, color, points) -> Rect\npolygon(surface, color, points, width=0, border_radius=0) -> Rect\ndraw a polygon"
 #define DOC_DRAW_CIRCLE "circle(surface, color, center, radius) -> Rect\ncircle(surface, color, center, radius, width=0, draw_top_right=None, draw_top_left=None, draw_bottom_left=None, draw_bottom_right=None) -> Rect\ndraw a circle"
 #define DOC_DRAW_ELLIPSE "ellipse(surface, color, rect) -> Rect\nellipse(surface, color, rect, width=0) -> Rect\ndraw an ellipse"
 #define DOC_DRAW_ARC "arc(surface, color, rect, start_angle, stop_angle) -> Rect\narc(surface, color, rect, start_angle, stop_angle, width=1) -> Rect\ndraw an elliptical arc"