raycaster.py

import math
import pygame

def distances(objects, entity,screen):

    s = [10000, 2.4142, 1, 0.4142, 0.000000001, -0.4142, -1, -2.4142, -10000, 2.4142, 1, 0.4142, -0.000000001, -0.4142, -1, -2.4142]

    touching = [10000] * 16

    for o in objects:
        for i in range (0,len(s)):

            visRadPoint = (math.cos(math.atan(s[i]))*entity.visRad+entity.x,math.sin(math.atan(s[i]))*entity.visRad+entity.y)

            #visradPoint is b, entity is a

            d = visRadPoint[1] - entity.y
            e = entity.x - visRadPoint[0]
            f = d*entity.x + e*entity.y

            #startpoint is C, endpoint is D
            a = o[1][1] - o[0][1]
            b = o[0][0] - o[1][0]
            c = a*o[0][0] + b*o[0][1]

            determinant = d*b - a*e

            if determinant == 0:
                continue

            x = (b*f - e*c)/determinant
            y = (d*c - a*f)/determinant
            intersect = (x,y)

            if o[0][0] < o[1][0]:
                if intersect[0] < o[0][0] or intersect[0] > o[1][0]:
                    continue

            elif o[0][0] > o[1][0]:
                if intersect[0] > o[0][0] or intersect[0] < o[1][0]:
                    continue
            if o[0][1] < o[1][1]:
                if intersect[1] < o[0][1] or intersect[1] > o[1][1]:
                    continue
            else:
                if intersect[1] > o[0][1] or intersect[1] < o[1][1]:
                    continue

            distance = math.sqrt((intersect[0]-entity.x)**2 + (intersect[1]-entity.y)**2)

            if distance <= entity.visRad and distance < touching[i]:
                if i <= 8 and intersect[0] - entity.x > 0:
                    touching[i] = distance
                elif i > 8 and intersect[0] - entity.x < 0:
                    touching[i] = distance









    for i in range(len(touching)):

        m = 1

        if i > 8:
            m = -1

        a = math.atan(s[i])

        pygame.draw.line(screen, (237, 122, 255), (entity.x, entity.y),(entity.x+m*int(math.cos(a)*entity.visRad),entity.y+m*int(math.sin(a)*entity.visRad)),1)

        pygame.draw.circle(screen,(0, 53, 176),(int(m*math.cos(a)*touching[i]+entity.x), int(m*math.sin(a)*touching[i]+entity.y)),4)


    return touching