Hi John,
The code that was given is a modified version of PixelPerfect. Please
look into it. :)
I noticed that the code that i posted is probably doing redundant
comparisons for odd pixel width/height collision rectangles (when
reduced to 1 x h ow w x 1 ), which I'll modify.
Regards
John Eriksson wrote:
Hi,
If you're looking for a pixel perfect collision detection algorithm,
there is a project at pygame which contains an even faster one.
PixelPerfect - http://www.pygame.org/projects/9/207/
It also contains some replacements methods for spritecollide,
groupcollide and spritecollideany and an example to show how to use it.
The algorithm was used in one of the Second Pyweek Challenge winners!
Trip on the Funny Boat - http://www.pygame.org/projects/20/235/
Best Regards
/John Eriksson
tis 2007-01-30 klockan 06:30 -0800 skrev Kamilche:
V. Karthik Kumar wrote:
I happened to read the changes list a day ago. I saw the code, I thought
that this change might help detect regular pp cols faster.
This version keeps checking pixels from the outer rectangle of the
colliding area to the inner. It works considerably faster when objects
are regular and convex, which is often the case.
This isn't a patch as such, I'd recommend people try it out and report
the results and then decide.
Regards,
Karthik
------------------------------------------------------------------------
def pp_collide(obj1,obj2):
"""If the function finds a collision it will return True
if not it will return False.
"""
rect1, rect2, hm1, hm2 = obj1.rect, obj2.rect, obj1.hitmask, obj2.hitmask
if not rect1.colliderect(rect2):
return False
rect = rect1.clip(rect2)
w, h, x1, y1, x2, y2 = rect.width, rect.height, rect.x-rect1.x,
rect.y-rect1.y, rect.x-rect2.x, rect.y-rect2.y
while w > 0 and h > 0:
for x in range(w):
if hm1[x1+x][y1] and hm2[x2+x][y2]:
return True
if hm1[x1+x][y1+h-1] and hm2[x2+x][y2+h-1]:
return True
for y in range(1, h-1):
if hm1[x1][y1+y] and hm2[x2][y2+y]:
return True
if hm1[x1+w-1][y1+y] and hm2[x2+w-1][y2+y]:
return True
w, h, x1, y1, x2, y2 = w-2, h-2, x1+1, y1+1, x2+1, y2+1
return False
Is it faster than pygame's builtin rect.collidepoint method?
