#MonthOfCode day 30 - infinity

day_30.py

# thema= INFINITY, tested with python3.1 + pygame1.9.1
import pygame
from time import sleep
import random
from math import cos,sin,pi


# constants
DISP_WIDTH = 800
DISP_HEIGHT = 600
MAX_FPS = 65
N_PIX = 8
BG_COLOR_DESC = 'lightblue'


# let's define two classes: Player, and Terrain
class Player:
    '''models a moving player representation that can move left or right'''
    BASECOLOR = pygame.Color('darkred')
    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 push_right(self):
        self.moving_right = True

    def push_left(self):
        self.moving_left = True

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

    def update( self ):
        if not (self.moving_right or self.moving_left):
            self.vx = 0.
        else:
            if self.moving_right:
                self.vx = float(N_PIX)
            if self.moving_left:
                self.vx = -float(N_PIX)
    
        #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)

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


class Terrain:
    def __init__(self):
        self.dist = 0

        # the magic (terrain-gen) is done by this function
        self.height_func = lambda x: 228 + 128*cos(0.0002*x) + 32*sin(0.01*x) + 64*sin(pi/800*x) + 16*abs(sin(0.02 *x + (pi/2)))

        self.l_heights = list()
        for i in range(DISP_WIDTH ):
            self.l_heights.append( self.height_func(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):
            for i in range(N_PIX):
                self.dist -= 1 
                self.l_heights.pop()
                self.l_heights.insert(0, self.height_func( self.dist ) )

        elif (self.moving_left):
            for i in range(N_PIX):
                self.dist += 1 
                self.l_heights.pop(0)
                self.l_heights.append(self.height_func( self.dist+DISP_WIDTH-1 ) )

    def draw(self, surface):
        for ind in range(len(self.l_heights) ):
            h_val = self.l_heights[ ind]
            p1 = (ind, DISP_HEIGHT-1)
            p2 = (ind, DISP_HEIGHT-1-h_val)
            pygame.draw.line(surface, self.color, p1, p2)


# source-code body
# global vars & init. the game
pygame.init() 
window = pygame.display.set_mode( (DISP_WIDTH, DISP_HEIGHT) )
pl_obj = Player( DISP_WIDTH/2, DISP_HEIGHT/2 )
terrain = Terrain()
game_over = False
clock = pygame.time.Clock()
bg_color = pygame.Color(BG_COLOR_DESC)

# - game loop
while not game_over: 
    for event in pygame.event.get(): 
        if event.type == pygame.QUIT: 
            game_over = True
            continue

        if event.type is pygame.KEYDOWN:
            if( pygame.key.get_pressed()[ pygame.K_RIGHT ] ):
                pl_obj.push_right()
            if( pygame.key.get_pressed()[ pygame.K_LEFT ] ):
                pl_obj.push_left()
        if event.type is pygame.KEYUP:
            if( not pygame.key.get_pressed()[ pygame.K_RIGHT ] ):
                pl_obj.freeze()
            if( not pygame.key.get_pressed()[ pygame.K_LEFT ] ):
                pl_obj.freeze()
    
    # logic
    pl_obj.update()
    terrain.update()
    
    # rendering
    window.fill(bg_color)
    terrain.draw(window)
    pl_obj.draw(window)
    
    pygame.display.flip()
    clock.tick(MAX_FPS)

pygame.quit()
print('done.')