Pygame: How to tile subsurfaces on an image - image

Question

I'm completely new to Python/Pygame and I'm trying to slice an image up into subsurfaces and then blit them in order to the screen (so that later on I can modify it to call upon a certain tile and then blit it).
E1: I think I've finally managed to slice it the right way but there's a little hitch with the blitting.
E2: Updated the code and error (been getting this one on most of the code I tried before as well).
import pygame
from pygame.locals import *
pygame.init()
screen = pygame.display.set_mode((640, 480))
screen.fill((255, 255, 255))
def load_tileset(filename, width, height):
image = pygame.image.load(filename).convert()
image_width, image_height = image.get_size()
tileset = []
for tile_x in range(0, image_width//width):
line = []
tileset.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 tileset
def draw_background(screen, tile_img, field_rect):
img_rect = tile_img.get_rect()
for y in range(0,400,32):
for x in range(0,600,32):
screen.blit(tile_img, (x,y))
Field_Rect = Rect(50,50, 300,300)
tileset = load_tileset("platform1.bmp", 17, 17)
bg_tile_img = tileset[0]
draw_background(screen, bg_tile_img, Field_Rect)
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
if event.type == KEYDOWN:
if event.key == K_ESCAPE:
pygame.quit()
pygame.display.flip()
The error it gives atm is:
img_rect = tile_img.get_rect()
AttributeError: 'list' object has no attribute 'get_rect'

Answer 1

In this function here where you create the tileset:
def load_tileset(filename, width, height):
image = pygame.image.load(filename).convert()
image_width, image_height = image.get_size()
tileset = []
for tile_x in range(0, image_width//width):
line = []
tileset.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 tileset
...you will notice that tileset is a list, and each element of tileset (labeled as line), is also a list.
So in this code here:
tileset = load_tileset("platform1.bmp", 17, 17)
bg_tile_img = tileset[0]
draw_background(screen, bg_tile_img, Field_Rect)
...you are passing a list, called bg_tile_img, to the draw_background function.
Your draw_background function should instead look more like this:
def draw_background(screen, tile_img, field_rect):
for img in tile_img:
img_rect = img.get_rect()
for y in range(0,400,32):
for x in range(0,600,32):
screen.blit(img, (x,y))
Alternatively, instead of passing bg_tile_img as a list, pop an element off of it to pass to the draw_background function.

Answer 2

You are not assigning the tileset:
load_tileset("platform1.bmp", 17, 17)
should be:
tileset = load_tileset("platform1.bmp", 17, 17)
Update:
set_mode creates the window, so it should be outside the main loop (load_tileset too):
screen = pygame.display.set_mode((640, 480))
tileset = load_tileset("platform1.bmp", 17, 17)
while True:
for event in pygame.event.get():
...
Also, I can't see any call to draw_background.
Update2:
As Haz said, tileset is a list of lines (a matrix), you could use coordinates to retrieve a specific tile:
bg_tile_img = tileset[0][0]
Or make the tileset a plain list, adding everything directly to the tileset instead of using lines.