seasick

seasick.py

from __future__ import division
from collections import namedtuple
import pygame
import math
import numpy as np

W,H=640,480#screen resolution
DIST=10#distance of the horizon
Y_SHIFT=200#how much to shift the plane down
Y_UNDU=100#how much to undulate the plane up and down
WOBBLE=math.pi/16#how much to wobble
WAVE=math.pi/16#how much to wobble on the z axis
XLINE_STEP=150#how distant the lines are on the X axis
YLINE_STEP=1#how distant the lines are on the y axis
SPEED=0.1
mult=max(W,H)
HW,HZ=int(W//2),int(H//2)

Point=namedtuple("Point",["x","y","z"])

def unity():
    return np.array([
        [1,0,0,0],
        [0,1,0,0],
        [0,0,1,0],
        [0,0,0,1]
        ])

def rotz(v):
    c=math.cos
    s=math.sin
    return np.array([
        [c(v),-s(v),0,0],
        [s(v),c(v),0,0],
        [0,0,1,0],
        [0,0,0,1]
        ])

def project(oldpoint,matrix=None):
    if matrix==None:
        oldpoint=Point(*oldpoint)
    else:
        arr=np.array([list(oldpoint)+[0]]).transpose()
        op=matrix.dot(arr)
        oldpoint=Point(*op[:-1])
    return Point(oldpoint.x/oldpoint.z+HW,oldpoint.y/oldpoint.z+HZ,oldpoint.z)

def line3d(surface,color,start,end,matrix=None):
    start=project(start,matrix)
    end=project(end,matrix)
    pygame.draw.line(surface,color,start[:-1],end[:-1])

pygame.init()
screen=pygame.display.set_mode((W,H))
clock=pygame.time.Clock()
framecount=0
while True:
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            pygame.display.quit()
            raise SystemExit()
        
    screen.fill((0,0,0))
    matrix=rotz(math.sin(framecount/7)*WOBBLE)
    
    y=Y_SHIFT+math.sin(framecount/11)*Y_UNDU
    line3d(screen,(255,255,255),(-W*DIST,y,DIST),(W*DIST,y,DIST),matrix)
    
    for z in range(DIST*100,1,-YLINE_STEP*100):
        z=(z/100)-(framecount*SPEED)%YLINE_STEP
        line3d(screen,(255,255,255),(-W*DIST,y,z),(W*DIST,y,z),matrix)
        
    for x in range(int(-W*DIST),int(W*DIST),XLINE_STEP):
        line3d(screen,(255,255,255),(x,y,DIST),((x,y,0.1)),matrix)
    
    pygame.display.flip()
    framecount+=1
    clock.tick(30)