Re: [pygame] sprite 'weird' rotation

[Michael George <mdgeorge@xxxxxxxxxxxxxx>]

Actually, after looking more closely, rotate_point wasn't what you 
needed.  The problem was because when you rotate the image, the output 
is still an upright rectangle, and you were placing (the upper left 
corner of) that rectangle in the same place.  If you place the center 
instead, it works out.  See the attached file for the fixed version.

--Mike

Paulo Silva wrote:
> thanks!
>
> but btw, i tried to apply it, and the result got more weird - not only
> i can't move the sprites independently, as the rotations got much more
> weird
>
> http://pastebin.com/f733ebf04
>
> (anyway, i'm still newbie on Pygame, and i still struggle a lot about
> how Python deals with variables, arrays, lists, and methods )
>
> if someone know how to fix it, be welcome on editing that, and sharing
> us the resulting pastebin url - thanks a lot in advance! :)
>
>
>
> On 7/19/09, Michael George <mdgeorge@xxxxxxxxxxxxxx> wrote:
>   
> > You can use a function from my game:
> >
> > http://pen.svn.sourceforge.net/viewvc/pen/data/parts/cannon.py?revision=31&view=markup
> >
> > see the rotate_point function
> >
> > --Mike
> >
> > Paulo Silva wrote:
> >     
> > > hi,
> > >
> > > i confess it seems a bad handle from me about sprite rotation on
> > > Pygame - do someone know better how we can handle it better, making
> > > them rotating its center?
> > >
> > > http://pastebin.com/f53335b66
> > >
> > > thanks!
> > >
> > >       
> >     

#! /usr/bin/python
# using sprites_rgba.png from http://img17.imageshack.us/img17/3166/spritesrgba.png
import sys, pygame, math, os, random
from pygame.locals import *
pygame.init()
size=width,height=960,240;screen=pygame.display.set_mode(size);pygame.display.set_caption("multiplayer sprite test with collisions")

spd=4;amnt=4;ampl=8;xpos=[0]*amnt;ypos=[0]*amnt;rotv=[0]*amnt;sprid=[];spridr=[]   #some arrays and variables
for i in range (0,amnt,1):
  xpos[i]=64+(128*i)+random.randint(0,32);ypos[i]=64+random.randint(0,32);rotv[i]=random.randint(0,359)

sprall=pygame.image.load("sprites_rgba.png")  #loading sprites
for i in range (0,4,1):
  spritetmp=sprall.subsurface(i*64,0,64,64);spriterecttmp=spritetmp.get_rect()
  sprid.append(spritetmp);spridr.append(spriterecttmp)

rotincr=5

while 1:
  key=pygame.key.get_pressed()  #checking pressed keys
  if key[pygame.K_a]:xpos[0]-=spd
  if key[pygame.K_d]:xpos[0]+=spd
  if key[pygame.K_w]:ypos[0]-=spd
  if key[pygame.K_s]:ypos[0]+=spd
  if key[pygame.K_z]:rotv[0]+=rotincr
  if key[pygame.K_x]:rotv[0]-=rotincr

  if key[pygame.K_f]:xpos[1]-=spd
  if key[pygame.K_h]:xpos[1]+=spd
  if key[pygame.K_t]:ypos[1]-=spd
  if key[pygame.K_g]:ypos[1]+=spd
  if key[pygame.K_v]:rotv[1]+=rotincr
  if key[pygame.K_b]:rotv[1]-=rotincr

  if key[pygame.K_j]:xpos[2]-=spd
  if key[pygame.K_l]:xpos[2]+=spd
  if key[pygame.K_i]:ypos[2]-=spd
  if key[pygame.K_k]:ypos[2]+=spd
  if key[pygame.K_m]:rotv[2]+=rotincr
  if key[pygame.K_COMMA]:rotv[2]-=rotincr

  if key[pygame.K_LEFT]: xpos[3]-=spd
  if key[pygame.K_RIGHT]:xpos[3]+=spd
  if key[pygame.K_UP]:   ypos[3]-=spd
  if key[pygame.K_DOWN]: ypos[3]+=spd
  if key[pygame.K_KP0]:  rotv[3]+=rotincr
  if key[pygame.K_KP_PERIOD]:rotv[3]-=rotincr

  bgcolour=0x998877    #checking collisions
  if spridr[0].colliderect(spridr[1]):bgcolour=0xAA5555
  if spridr[0].colliderect(spridr[2]):bgcolour=0x55AA55
  if spridr[0].colliderect(spridr[3]):bgcolour=0x5555AA
  if spridr[1].colliderect(spridr[2]):bgcolour=0x55AAAA
  if spridr[1].colliderect(spridr[3]):bgcolour=0xAA55AA
  if spridr[2].colliderect(spridr[3]):bgcolour=0xAAAA55
  screen.fill(bgcolour)

  for i in range (0,amnt,1):    #displaying sprites
    spridr[i].centerx=xpos[i]
    spridr[i].centery=ypos[i]

    #tmq=pygame.transform.rotate(sprid[i],rotv[i])  # <- rotate behaviour looks weird - center of rotation is not kept (...?)
    #screen.blit(tmq,spridr[i])

    tmq=pygame.transform.rotate(sprid[i],rotv[i])
    rect = tmq.get_rect()
    rect.center =  (xpos[1], ypos[i])
    screen.blit(tmq,rect)

  for event in pygame.event.get():  #praxis stuff
    if event.type==pygame.QUIT:sys.exit()
  pygame.display.flip();pygame.time.delay(1000/50)