pygame中的负坐标

Question

What would be the best way to use negative coordinates in pygame?

At the moment I have a surface that is 1.5 times the original surface then everything that needs to be drawn is shifted up by a certain amount (to ensure the negative coordinates become positive) and drawn.

Is there an easier/alternate way of doing this?

Answer 1

A simple solution is to write a linear mapping function from world coordinates to pygame screen coordinates

def coord(x,y):
    "Convert world coordinates to pixel coordinates."
    return 320+170*x, 400-170*y

and use it when drawing all world objects. Have a look here for a complete example.

Answer 2

There is no way to move the origin of a surface from 0,0.

Implement your own drawing class which transforms all the coordinates passed in into the space of the surface.

Answer 3

If it's similar to an RPG map situation, where you have world coordinates and screen coordinates: use a function that translates world to local, and vice versa.

But I wasn't sure I'd you were looking for Rect's properties?

rect.bottomright = (width, height) # bottom right at window corner

If you want to use center coordinates to blit, vs top left being (0,0)

ship.rect.center = (20, 30) # don't need to translate by adding w/2 to topleft

See also: Rect.move_ip()