simple script to locate sprites in a sprite sheet

sprite_parse.py

import pygame
import pygame.locals as locals

def check_adjacency(rect, px):
    test_rect = pygame.Rect(rect.left-1, rect.top-1, rect.width+2, rect.height+2)
    return test_rect.collidepoint(px[0], px[1])


def find_groups(groups, px):
    return [grp for grp in groups if check_adjacency(grp, px)]


def merge_rects(rect1, rect2):
    if rect1.height == 0 or rect1.width == 0:
        return rect2
    if rect2.height == 0 or rect2.width == 0:
        return rect1

    top = min(rect1.top, rect2.top)
    bottom = max(rect1.bottom, rect2.bottom)
    left = min(rect1.left, rect2.left)
    right = max(rect1.right, rect2.right)

    return pygame.Rect(left, top, right-left, bottom-top)


def extend_rect(rect, px):
    """Extend rect to make it contain px."""
    top = min(rect.top, px[1])
    left = min(rect.left, px[0])

    bottom = rect.bottom if rect.bottom > px[1] else px[1]+1
    right = rect.right if rect.right > px[0] else px[0]+1

    rect.top = top
    rect.left = left
    rect.height = bottom - top
    rect.width = right - left


if __name__ == "__main__":
    time = pygame.time.Clock()

    pygame.font.init()
    font = pygame.font.SysFont("Courier", 15)
    loading_font = pygame.font.SysFont("Courier", 30)

#    image = pygame.image.load("sprite/test2.png")
    image = pygame.image.load("sprite/travis2.png")
    screen = pygame.display.set_mode(image.get_size(), 0, 32)
    image = image.convert()
    colorkey = (39, 83, 83, 255)

    size = image.get_size()
    total_pixels = size[0] * size[1]
    processed_pixels = 0
    last_load = 0
    groups = []

    for y in xrange(size[1]):
        for x in xrange(size[0]):
            for event in pygame.event.get():
                if event.type == locals.QUIT:
                    exit(0)

            processed_pixels += 1
            load = str(int(float(processed_pixels) * 100 / total_pixels)) + "%"
            if load != last_load:
                screen.blit(loading_font.render(load, True, (255, 255, 255), (0, 0, 0)), (0, 0))
                pygame.display.flip()
                last_load = load
            px = (x, y)
            if image.get_at(px) != colorkey:
                grps = find_groups(groups, px)
                if grps:
                    # TODO: maybe extend_rect should change first rect in-place
                    groups.remove(grps[0])
                    extend_rect(grps[0], px)
                    if len(grps) > 1:
                        for grp in grps[1:]:
                            grps[0] = merge_rects(grps[0], grp)
                            groups.remove(grp)
                    groups.append(grps[0])
                else:
                    groups.append(pygame.Rect(px[0], px[1], 1, 1))

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == locals.QUIT:
                running = False

        screen.blit(image, (0, 0))

        for rect in groups:
            pygame.draw.rect(screen, (255, 0, 0), rect, 1)

        mousepos = pygame.mouse.get_pos()
        for rect in groups:
            if rect.collidepoint(mousepos[0], mousepos[1]):
                text = font.render(
                    "%s, %s, %s, %s" % (rect.top, rect.left, rect.width, rect.height),
                    True, (255, 255, 255), (0, 0, 0))
                screen.blit(text, rect)

        pygame.display.flip()

        time.tick(30)