Python turtle 3d soft render (+WASD movement and camera rotation)

turtle3d_grid.py

"""
Черепашка вміє в 3D

Управління:
    - стрілочки -- поворот
    - WASD -- рух
"""

import turtle
import math
from math import sin, cos, pi
import time
import random
from collections import deque

turtle.tracer(0, 0)
turtle.bgcolor('black')

SQ = [(-1, -1), (-1, 1), (1, 1), (1, -1)]
Nlines = 10
size = 200
figure = [(x*size, y*size) for x, y in SQ]

camAngle = 1.3
camAngleSpeed = 0
camX = 131
camY = 472

def cam_left(ang=0.1):
    global camAngle, camAngleSpeed, camSpeed
    camAngleSpeed += ang/1000
    camSpeed = 0
    #camAngle += ang 
    redraw()

def cam_forward(speed=10, ang=math.pi/2):
    global camX, camY, camAngleSpeed
    #camAngleSpeed = 0
    camX -= speed*math.sin(camAngle-ang)
    camY -= speed*math.cos(camAngle-ang)
    print(camX, camY, camAngle)
    redraw()

turtle.onkeypress(lambda: cam_left(-0.1), "Left")
turtle.onkeypress(lambda: cam_left(0.1), "Right")
turtle.onkeypress(lambda: cam_forward(10), "Up")
turtle.onkeypress(lambda: cam_forward(10), "w")
turtle.onkeypress(lambda: cam_forward(-10), "Down")
turtle.onkeypress(lambda: cam_forward(-10), "s")
turtle.onkeypress(lambda: cam_forward(10, 0), "d")
turtle.onkeypress(lambda: cam_forward(10, math.pi), "a")
turtle.listen()

t1 = turtle.Turtle()
t1.penup()
t1.shapesize(3)
t1.color('white')

def rotated(x, y, angle, center=(0, 0)):
    sin_, cos_ = math.sin(angle), math.cos(angle)
    x0, y0 = center
    newx = x0 + (x-x0)*sin_ + (y-y0)*cos_
    newy = y0 + (x-x0)*cos_ - (y-y0)*sin_
    return (newx, newy)

def perspective(x, y, z=0, camera=None, f=500):
    """
    Perspective transformation. XY is horizontal 
    plane. Object Z is zero by default, change it if
    you want to elevate object above the plane
    """
    if camera:
        xc, yc, zc = camera
    else:
        xc, yc, zc = camX, camY, 100
    h = y - yc
    if y == yc:
        # todo: return something better
        return (0, 0)
    r = f/(y - yc)
    return ((xc - x)*r, -(zc - z)*r)

def view(x, y, z=0):
    newx, newy = rotated(x, y, camAngle, 
            center=(camX, camY))
    return perspective(newx, newy, z)

def line(x1, y1, x2, y2, t):
    t.penup()
    t.goto(x1, y1)
    t.pendown()
    t.goto(x2, y2)
    t.penup()

random_fig = deque(maxlen=100)

def redraw():
    t1.clear()
    t1.color('white')
    t1.pensize(1)
    
    for i in range(Nlines+1):
        x1, y1 = view(size*(SQ[0][0] + i*2/Nlines), 
                      SQ[0][1]*size)
        x2, y2 = view(size*(SQ[1][0] + i*2/Nlines),
                      SQ[1][1]*size)
        line(x1,y1,x2,y2,t1)
        x1, y1 = view(size*(SQ[1][0]), 
                      size*(SQ[1][1] - i*2/Nlines))
        x2, y2 = view(size*(SQ[2][0]),
                      size*(SQ[2][1] - i*2/Nlines))
        line(x1,y1,x2,y2,t1)

    t1.penup()
    if random_fig:
        x,y,z,_ = random_fig[0]
        t1.goto(*view(x,y,z))
    t1.pendown()
    t1.pensize(3)
    
    for x, y, z, color in random_fig:
        if not color:
            color = 'white'
        t1.color(color)
        t1.goto(*view(x, y, z))
    t1.penup()


redraw()

tstart = real_start = time.time()
while True:
    camAngle += camAngleSpeed
    if time.time() > tstart + 0.05:
        tstart = time.time()
        dt = tstart - real_start
        random_fig.append((
            size*sin(dt*3), 
            size*cos(dt*5), 
            size/2+size/2*sin(dt),
            (random.random(), random.random(), 0)
            ))
        redraw()
    turtle.update()