What I m trying to do in order to implement the Frustum Culling algorithm is to start the nested for loop in the render() function from a position that will depend on the player x and y position, such that the code will only loop through a small portion of the .tmx file the portion that has to render. Now the question is, How do I start the loop from a position that will depend from my Player coordinates? Thanks in advance for the help.
import pygame
import pytmx
pygame.init()
class Map():
def __init__(self,filename):
tm=pytmx.load_pygame(filename,pixelalpha=True)
self.width=tm.width * tm.tilewidth
self.height=tm.height*tm.tileheight
self.tmxdata=tm
def render(self,surface):
ti=self.tmxdata.get_tile_image_by_gid
for layer in self.tmxdata.visible_layers:
if isinstance(layer,pytmx.TiledTileLayer):
for x,y,gid in layer:
tile = ti(gid)
if tile
surface.blit(tile,(x*self.tmxdata.tilewidth,y*self.tmxdata.tileheight))
def make_map(self):
temp_surface=pygame.Surface((self.width,self.height))
self.render(temp_surface)
return temp_surface
You can calculate the current tilemap coordinate at a point in the world if the tilemap sizes are constant (i.e every tile has the same width and height).
Say that we have tiles that are 20 pixels wide and 20 pixels high, and your player is at position (432, 36). Then we can find which tile he/she is at by doing integer division (divide and truncate/"remove the decimals").
tile_x = player_x // tile_width
tile_y = player_y // tile_height
In our case, the player will stand on the tile 21 on the x-axis (432 // 20 = 21), and tile 1 on the y-axis (36 // 20 = 1).
From there you can define how big of an area around the player you want to be visible. If you want to render 1 tile in each direction (including the one the player is standing on), you'll have to iterate through x = 20 to 22 and y = 0 to 2.