Pygame Button with rounded Corners, border_radius argument does not work

Question

I am currently learning pygame. When programming rectangles with rounded corners I encountered a problem.

pygame.draw.rect() draw a rectangle rect

Answer 1

I ran into this and had to do it myself already, I might as well share.

Try these, one draws rectangles with rounded corners and the other draws bordered rounded rectangles. They use anti-aliased circles to draw the corners because otherwise they look pretty jagged:

import pygame.gfxdraw

def draw_rounded_rect(surface, rect, color, corner_radius):
    ''' Draw a rectangle with rounded corners.
    Would prefer this: 
        pygame.draw.rect(surface, color, rect, border_radius=corner_radius)
    but this option is not yet supported in my version of pygame so do it ourselves.

    We use anti-aliased circles to make the corners smoother
    '''
    if rect.width < 2 * corner_radius or rect.height < 2 * corner_radius:
        raise ValueError(f"Both height (rect.height) and width (rect.width) must be > 2 * corner radius ({corner_radius})")

    # need to use anti aliasing circle drawing routines to smooth the corners
    pygame.gfxdraw.aacircle(surface, rect.left+corner_radius, rect.top+corner_radius, corner_radius, color)
    pygame.gfxdraw.aacircle(surface, rect.right-corner_radius-1, rect.top+corner_radius, corner_radius, color)
    pygame.gfxdraw.aacircle(surface, rect.left+corner_radius, rect.bottom-corner_radius-1, corner_radius, color)
    pygame.gfxdraw.aacircle(surface, rect.right-corner_radius-1, rect.bottom-corner_radius-1, corner_radius, color)

    pygame.gfxdraw.filled_circle(surface, rect.left+corner_radius, rect.top+corner_radius, corner_radius, color)
    pygame.gfxdraw.filled_circle(surface, rect.right-corner_radius-1, rect.top+corner_radius, corner_radius, color)
    pygame.gfxdraw.filled_circle(surface, rect.left+corner_radius, rect.bottom-corner_radius-1, corner_radius, color)
    pygame.gfxdraw.filled_circle(surface, rect.right-corner_radius-1, rect.bottom-corner_radius-1, corner_radius, color)

    rect_tmp = pygame.Rect(rect)

    rect_tmp.width -= 2 * corner_radius
    rect_tmp.center = rect.center
    pygame.draw.rect(surface, color, rect_tmp)

    rect_tmp.width = rect.width
    rect_tmp.height -= 2 * corner_radius
    rect_tmp.center = rect.center
    pygame.draw.rect(surface, color, rect_tmp)


def draw_bordered_rounded_rect(surface, rect, color, border_color, corner_radius, border_thickness):
    if corner_radius < 0:
        raise ValueError(f"border radius ({corner_radius}) must be >= 0")

    rect_tmp = pygame.Rect(rect)
    center = rect_tmp.center

    if border_thickness:
        if corner_radius <= 0:
            pygame.draw.rect(surface, border_color, rect_tmp)
        else:
            draw_rounded_rect(surface, rect_tmp, border_color, corner_radius)

        rect_tmp.inflate_ip(-2*border_thickness, -2*border_thickness)
        inner_radius = corner_radius - border_thickness + 1
    else:
        inner_radius = corner_radius

    if inner_radius <= 0:
        pygame.draw.rect(surface, color, rect_tmp)
    else:
        draw_rounded_rect(surface, rect_tmp, color, inner_radius)

Answer 2

The documentation is for 2.0.0.dev7, and according to this PR, border_radius was added after 2.0.0.dev6, GitHub reference, was released. So you're trying to use something that hasn't come out yet. You could try building from source and using the keyword (though stability is not a promise). Or you could try using a combination of rectangles and circles to achieve the effect.