raycasterino

import pygame
from pygame.locals import *

from math import sqrt,fabs,cos,sin

mapSize=24

worldMap=[
  [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,2,2,2,2,2,0,0,0,0,3,0,3,0,3,0,0,0,1],
  [1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,3,0,0,0,3,0,0,0,1],
  [1,0,0,0,0,0,2,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,2,2,0,2,2,0,0,0,0,3,0,3,0,3,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,4,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,0,4,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,0,0,0,0,5,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,0,4,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,0,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,4,4,4,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1],
  [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1]
];

posX = 22;posY = 12; #x and y start position
dirX = -1;dirY = 0; #initial direction vector
planeX = 0;planeY = 0.66; #the 2d raycaster version of camera plane

time = 0; #time of current frame
oldTime = 0; #time of previous frame

DISP=pygame.display.set_mode((512,384))

go = True
w=512
h=384
rotSpeed=0.01
moveSpeed=0.01
while go:
    #Black Fill
    DISP.fill((0,0,0))

    #RAYCASTING
    for x in range(w):
        #calculate ray position and direction
        cameraX = 2 * x / w - 1; #x-coordinate in camera space
        rayPosX = posX;
        rayPosY = posY;
        rayDirX = dirX + planeX * cameraX;
        rayDirY = dirY + planeY * cameraX;



        #which box of the map we're in
        mapX = int(rayPosX);
        mapY = int(rayPosY);

        #length of ray from current position to next x or y-side
        sideDistX=0;
        sideDistY=0;

        #length of ray from one x or y-side to next x or y-side
        try:
            deltaDistX = sqrt(1 + (rayDirY * rayDirY) / (rayDirX * rayDirX));
            deltaDistY = sqrt(1 + (rayDirX * rayDirX) / (rayDirY * rayDirY));
        except ZeroDivisionError:
            pass
        perpWallDist=0;

        #what direction to step in x or y-direction (either +1 or -1)
        stepX=0;
        stepY=0;

        hit = 0; #was there a wall hit?
        side=0; #was a NS or a EW wall hit?

        #calculate step and initial sideDist
        if rayDirX < 0:
            stepX = -1;
            sideDistX = (rayPosX - mapX) * deltaDistX;
        else:
            stepX = 1;
            sideDistX = (mapX + 1.0 - rayPosX) * deltaDistX;
        if rayDirY < 0:
            stepY = -1;
            sideDistY = (rayPosY - mapY) * deltaDistY;
        else:
            stepY = 1;
            sideDistY = (mapY + 1.0 - rayPosY) * deltaDistY;

        #perform DDA
        while hit == 0:
            #jump to next map square, OR in x-direction, OR in y-direction
            if sideDistX < sideDistY:
              sideDistX += deltaDistX;
              mapX += stepX;
              side = 0;
            else:
              sideDistY += deltaDistY;
              mapY += stepY;
              side = 1;
            #Check if ray has hit a wall
            if worldMap[mapX][mapY] > 0:
                hit = 1;



        #Calculate distance projected on camera direction (oblique distance will give fisheye effect!)
        if side == 0:
            perpWallDist = fabs((mapX - rayPosX + (1 - stepX) / 2) / rayDirX);
        else:
            perpWallDist = fabs((mapY - rayPosY + (1 - stepY) / 2) / rayDirY);



        #Calculate height of line to draw on screen
        lineHeight = abs(int(h / perpWallDist));

        #calculate lowest and highest pixel to fill in current stripe
        drawStart = -lineHeight / 2 + h / 2;
        if drawStart < 0:
            drawStart = 0;
        drawEnd = lineHeight / 2 + h / 2;
        if drawEnd >= h:
            drawEnd = h - 1;


        #choose wall color
        if worldMap[mapX][mapY] == 1:
          color = [255,1,1]
        elif worldMap[mapX][mapY] == 2:
          color = [1,255,1]
        elif worldMap[mapX][mapY] == 3:
          color = [1,1,255]
        elif worldMap[mapX][mapY] == 4:
          color = [255,255,255]
        else:
          color = [1,255,255]

        #give x and y sides different brightness
        color = (color[0],color[1],color[2])
        if side == 1:
          color = (color[0]/2,color[1]/2,color[2]/2)

        #draw the pixels of the stripe as a vertical line
        pygame.draw.line(DISP, color, (x,drawStart), (x,drawEnd), 1)


    #Update Screen
    pygame.display.flip()

    #Event Loop

    keys = pygame.key.get_pressed()
    if keys[K_UP]:
        if worldMap[int(posX + dirX * moveSpeed)][int(posY)] == False:
            posX += dirX * moveSpeed;
        if worldMap[int(posX)][int(posY + dirY * moveSpeed)] == False:
            posY += dirY * moveSpeed;
    if keys[K_LEFT]:
        #both camera direction and camera plane must be rotated
        oldDirX = dirX;
        dirX = dirX * cos(rotSpeed) - dirY * sin(rotSpeed);
        dirY = oldDirX * sin(rotSpeed) + dirY * cos(rotSpeed);
        oldPlaneX = planeX;
        planeX = planeX * cos(rotSpeed) - planeY * sin(rotSpeed);
        planeY = oldPlaneX * sin(rotSpeed) + planeY * cos(rotSpeed);

    for e in pygame.event.get():
        if e.type==QUIT:
            pygame.display.quit()
            go=False