2D Tiles Games - More Algorithms to Slice Tilesets

Prior to heading out to go fishing, I came across this nice post on slicing a tileset into rows and columns.  The example uses Surface.subsurface, which I haven't been using effectively.


import pygame import pygame.locals def load_tile_table(filename, width, height): image = pygame.image.load(filename).convert() image_width, image_height = image.get_size() tile_table = [] for tile_x in range(0, image_width/width): line = [] tile_table.append(line) for tile_y in range(0, image_height/height): rect = (tile_x*width, tile_y*height, width, height) line.append(image.subsurface(rect)) return tile_table if __name__=='__main__': pygame.init() screen = pygame.display.set_mode((128, 98)) screen.fill((255, 255, 255)) table = load_tile_table("tileset.png", 24, 16) for x, row in enumerate(table): for y, tile in enumerate(row): screen.blit(tile, (x*32, y*24)) pygame.display.flip() while pygame.event.wait().type != pygame.locals.QUIT: pass 


The author wrote a more elaborate tutorial here.

The author of bitcraft-PyTMX used the code below to handle tilesets.


tmxdata.images = [0] * tmxdata.maxgid for firstgid, t in sorted((t.firstgid, t) for t in tmxdata.tilesets): path = os.path.join(os.path.dirname(tmxdata.filename), t.source) image = pygame.image.load(path) w, h = image.get_size() tile_size = (t.tilewidth, t.tileheight) real_gid = t.firstgid - 1 colorkey = None if t.trans: colorkey = pygame.Color("#{0}".format(t.trans)) # i dont agree with margins and spacing, but i'll support it anyway # such is life. okay.jpg tilewidth = t.tilewidth + t.spacing tileheight = t.tileheight + t.spacing # some tileset images may be slightly larger than the tile area # ie: may include a banner, copyright, ect. this compensates for that width = ((int((w-t.margin*2) + t.spacing) / tilewidth) * tilewidth) - t.spacing height = ((int((h-t.margin*2) + t.spacing) / tileheight) * tileheight) - t.spacing # using product avoids the overhead of nested loops p = product(xrange(t.margin, height+t.margin, tileheight), xrange(t.margin, width+t.margin, tilewidth)) for (y, x) in p: real_gid += 1 gids = tmxdata.mapGID(real_gid) if gids == []: continue original = image.subsurface(((x,y), tile_size)) for gid, flags in gids: tile = handle_transformation(original, flags) tile = pygame_convert(tile, colorkey, force_colorkey, pixelalpha) tmxdata.images[gid] = tile

I plan to review the code snippets above in more detail after the fishing trip.