Originally reported by: René Dudfield (Bitbucket: <a href="https://bitbucket.o

Original comment by René Dudfield (Bitbucket: <a href="https://bitbuc

White lines as called from aaline draw in yellow. about pygame HOT 3 CLOSED

pygame commented on May 22, 2024

White lines as called from aaline draw in yellow.

from pygame.

Comments (3)

illume commented on May 22, 2024

Original comment by René Dudfield (Bitbucket: illume, GitHub: illume):

Seems fixed in the repository.

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illume commented on May 22, 2024

Original comment by René Dudfield (Bitbucket: illume, GitHub: illume):

Here is an easier to run example, that also shows the problem is to do with the screen surface and the draw routine.

import pygame
from pygame.locals import *
pygame.init()
screen = pygame.display.set_mode( (200, 200), 0, 32 )
surf = screen
print "screen info", surf.get_masks(), surf.get_shifts(), surf.get_pitch(), surf.get_losses()
surf = pygame.Surface( (200,200), 0, 32)
print "surface info", surf.get_masks(), surf.get_shifts(), surf.get_pitch(), surf.get_losses()

surf.fill((0,0,0,255))
pygame.draw.line( surf, (255, 255, 255), (0,0), (100, 100) )
pygame.draw.aaline( surf, (255, 255, 255), (0,100), (100, 200) )
screen.blit(surf, (0,0))

going = True
while going:
    events = pygame.event.get()
    if QUIT in [e.type for e in events]:
        going = False
    pygame.display.update()

On OSX Lion 64bit python it prints:

screen info (65280, 16711680, 4278190080, 0) (8, 16, 24, 0) 800 (0, 0, 0, 8)
surface info (16711680, 65280, 255, 0) (16, 8, 0, 0) 800 (0, 0, 0, 8)

So we can see that the screen surface, and a normal software surface is laid out differently. So there must be an issue with the draw.aaline method and this type of memory layout.

The example above shows a work around, of blitting to a normal surface and then blitting that surface to the screen. This works as expected and gives a white line, not a yellow one.

from pygame.