#MonthOfCode day 30 - infinity

day_30.py

import pygame
from time import sleep
import random
from math import cos,sin,pi
DISP_WIDTH = 800
DISP_HEIGHT = 600

class Player:
    '''models a moving player representation that can move left or right'''
    BASECOLOR = pygame.Color('darkred')
    BASE_SPEED = 2.
    SIZE = 16

    def __init__(self, x_init, y_init):
        self.vx, self.vy = 0.,0.
        self.x,self.y = float(x_init), float(y_init)
        self.color= Player.BASECOLOR
        self.moving_left = self.moving_right = False

    def markToDisplay(self, surface):
        pygame.draw.circle( surface, self.color, (int(self.x),int(self.y)), Player.SIZE) 

    def startMovingRight(self):
        self.moving_right = True

    def startMovingLeft(self):
        self.moving_left = True

    def stopMoving(self):
        if( self.moving_right):
            self.moving_right= False
        if( self.moving_left):
            self.moving_left= False
        terrain.stopScroll()

    def updatePosition( self ):
        if not (self.moving_right or self.moving_left):
            self.vx = 0.
        else:
            if self.moving_right:
                self.vx = Player.BASE_SPEED
            if self.moving_left:
                self.vx = -Player.BASE_SPEED
    
        #scrolling
        if( self.x+self.vx> (2./3)*DISP_WIDTH ):
            if( not terrain.isScrolling()):
                terrain.startScrollLeft()  # scroll in the inverse direction of player mov. to make it happen
            self.stuck = True
        elif( self.x+self.vx< (1./3)*DISP_WIDTH ):
            if( not terrain.isScrolling()):
                terrain.startScrollRight()
            self.stuck = True
        else:
            self.stuck = False

        if(not self.stuck):
            self.x += self.vx
        self.y = int( DISP_HEIGHT - terrain.l_heights[ int(self.x) ] - Player.SIZE )

class Terrain:
    def __init__(self):
        self.dist = 0
        self.det_h_fct= \
            lambda k:  228. + ( \
                128.0 *cos(0.0002 *k) + 32. * sin(0.01 * k) + 16.* abs( sin(0.02 *k + (pi/2) ) ) + 64.*sin( pi/800 * k )   )

        self.l_heights = list()
        for i in xrange(DISP_WIDTH ):
            self.l_heights.append( self.det_h_fct(i) )
        self.color = pygame.Color('darkgreen')
        self.moving_right = self.moving_left = False

    def isScrolling( self):
        return ( self.moving_right or self.moving_left )

    def startScrollRight(self):
        self.moving_right = True

    def startScrollLeft(self):
        self.moving_left = True

    def stopScroll(self):
        self.moving_left = self.moving_right = False

    def update(self):
        #refresh terrain heights
        if (self.moving_right):
            self.dist-= 1 
            self.l_heights.pop()
            self.l_heights.insert(0, self.det_h_fct( self.dist ) )
            self.dist-= 1 
            self.l_heights.pop()
            self.l_heights.insert(0, self.det_h_fct( self.dist ) )
        if (self.moving_left):
            self.dist+=1
            self.l_heights.pop(0)
            self.l_heights.append(  self.det_h_fct( self.dist+DISP_WIDTH-1 ) )
            self.dist+=1
            self.l_heights.pop(0)
            self.l_heights.append(  self.det_h_fct( self.dist+DISP_WIDTH-1 ) )

    def markToDisplay(self, surface):
        for ind in xrange(len(self.l_heights) ):
            h_val = self.l_heights[ ind]
            pygame.draw.line( surface, self.color,
                (ind, DISP_HEIGHT-1), (ind, DISP_HEIGHT-1-h_val),  )

def refreshScreen():
    window.fill(  pygame.Color('lightblue') )
    terrain.markToDisplay(window)
    pl_obj.markToDisplay(window )
    pygame.display.flip() 

# init. pygame libr; create the screen and diplays a help message in the console
pygame.init() 
window = pygame.display.set_mode( (DISP_WIDTH, DISP_HEIGHT) )
pl_obj = Player( DISP_WIDTH/2, DISP_HEIGHT/2 )
terrain = Terrain()

program_done = False
while not program_done: 
    refreshScreen()
    for event in pygame.event.get(): 
        if event.type == pygame.QUIT: 
            program_done = True
            break 

        if event.type is pygame.KEYDOWN:
            if( pygame.key.get_pressed()[ pygame.K_RIGHT ] ):
                pl_obj.startMovingRight()
            if( pygame.key.get_pressed()[ pygame.K_LEFT ] ):
                pl_obj.startMovingLeft()
        if event.type is pygame.KEYUP:
            if( not pygame.key.get_pressed()[ pygame.K_RIGHT ] ):
                pl_obj.stopMoving()
            if( not pygame.key.get_pressed()[ pygame.K_LEFT ] ):
                pl_obj.stopMoving()
    pl_obj.updatePosition()
    terrain.update()