Using move_ip in Pygame 1.9.4

Question

I'm trying to move a rectangle that I created in the far top right corner down and to the left. I've commented out the line that's causing the error, which is:

invalid destination position for blit

# render box to display level
displayfont = pygame.font.SysFont(None, 30)
text = displayfont.render('level', True, (red), (white))
textrect = text.get_rect()
textrect.topright = screen.get_rect().topright
# textrect = textrect.move_ip(-50, -50) #keeps getting invalid destination for blit
screen.blit(text, textrect)

Any suggestions? Thanks in advance!

Answer 1

The method pygame.Rect.move_ip doesn't return any value. It modifies the pygame.Rect object itself.

So after

textrect = textrect.move_ip(-50, -50)

the value of textrect is None.

Further note, that the top right coordinate of a Surface is (widht, 0). If you want to move to the center of the surface, then you have to move in the negative x direction, but in the positive y direction rather than the negative y direction.

To solve your issue it has to be:

displayfont = pygame.font.SysFont(None, 30)
text = displayfont.render('level', True, (red), (white))
textrect = text.get_rect()
textrect.topright = screen.get_rect().topright

textrect.move_ip(-50, 50)  

screen.blit(text, textrect)