[pygame] Re: question about scrolling the world

[Michael Fiano <michael.fiano@xxxxxxxxx>]

On Thu, 20 Mar 2008 13:29:03 -0400
Michael Fiano <michael.fiano@xxxxxxxxx> wrote:

I got it to scroll finally. The only problem I'm having now is making
the scrolling stop so the player doesn't fall off the world :) The
player stops at the north and west edges...but continues to scroll,
walking off the world in the other 2 directions. Can anyone give me
some pointers? The relevant code is in the update() function (yes, i
know my update function is very inefficient...I'm trying to get it to
work before I rewrite it). Thanks for all the help.



import os, sys, random
import pygame
from pygame.locals import *
import config
from data import *

class Player:

	def __init__(self, screen, background, topx, topy):

		# We need access to the screen
		self.screen = screen

		# We need access to the background surface
		self.background = background

		# Get the screen's dimensions from the config file
		self.SCREENWIDTH = config.screen_size[0]
		self.SCREENHEIGHT = config.screen_size[1]

		# Position the player in the center of the background
		# facing south
		self.x = self.SCREENWIDTH/2
		self.y = self.SCREENHEIGHT/2
		self.rect = pygame.Rect(self.x, self.y, 24, 32)
		self.frame = 3

		# Define some needed variables
		self.topx = topx
		self.topy = topy
		self.move = ""
		self.speed = 1
		self.dirtyrects = []
		self.scrollpos = [ 0, 0 ]

		# Define the graphic containing the player's sprites
		self.sprites_player = SpriteSheet('player.png')

		# Define the various frames within the player's spritesheet
		self.playerimgs = self.sprites_player.imgsat([ \
			(24, 5, 24, 26),		# Frame 0: North1
			(0, 6, 24, 26),			# Frame 1: North2
			(48, 6, 24, 26),		# Frame 2: North3
			(24, 69, 24, 26),		# Frame 3: South1
			(0, 70, 24, 26),		# Frame 4: South2
			(48, 70, 24, 26),		# Frame 5: South3
			(24, 101, 24, 26),		# Frame 6: West1
			(0, 102, 24, 26),		# Frame 7: West2
			(48, 102, 24, 26),		# Frame 8: West3
			(24, 37, 24, 26),		# Frame 9: East1
			(0, 38, 24, 26),		# Frame 10: East2
			(48, 38, 24, 26)],-1)	# Frame 11: East3

	def draw(self):

		# Define the shadow graphic
		shadow,null = load_graphic("shadow.png")

		# Draw the player's shadow
		self.screen.blit(shadow, (self.x, self.y+13))

		# Draw the player to the screen
		self.screen.blit(self.playerimgs[self.frame], (self.x,self.y))
		self.dirtyrects.append(self.rect)

	def update(self, direction):

		# Move the player in the specified direction
		self.dirtyrects = []
		if direction is "north":
			self.frame = 0
			for x in range(24):
				self.screen.fill((0,0,0))
				self.screen.blit(self.background, self.scrollpos)
				self.y = self.y-self.speed
				if self.y < self.SCREENHEIGHT/4:
					self.y = self.SCREENHEIGHT/4
					if self.y > self.scrollpos[1]:
						self.scrollpos[1]+=self.speed
						print self.background.get_height()
				self.rect[1] = self.y
				self.draw()
				if x % 12 == 0:
					self.frame+=1
					if self.frame > 2:
						self.frame = 1
				if x == 23:
					self.frame = 0
				pygame.time.delay(5)
				pygame.display.update()
		if direction is "south":
			self.frame = 3
			for x in range(24):
				self.screen.fill((0,0,0))
				self.screen.blit(self.background, self.scrollpos)
				self.y = self.y+self.speed
				if self.y > self.SCREENHEIGHT - self.SCREENHEIGHT/4:
					self.y = self.SCREENHEIGHT - self.SCREENHEIGHT/4
					if self.y > self.scrollpos[1]:
						self.scrollpos[1]-=self.speed
				self.rect[1] = self.y
				self.draw()
				if x % 12 == 0:
					self.frame+=1
					if self.frame > 5:
						self.frame = 4
				if x == 23:
					self.frame = 3
				pygame.time.delay(5)
				pygame.display.update()
		if direction is "west":
			self.frame = 6
			for x in range(24):
				self.screen.fill((0,0,0))
				self.screen.blit(self.background, self.scrollpos)
				self.x = self.x-self.speed
				if self.x < self.SCREENWIDTH/4:
					self.x = self.SCREENWIDTH/4
					if self.x > self.scrollpos[0]:
						self.scrollpos[0]+=self.speed
				self.rect[0] = self.x+self.speed
				self.draw()
				if x % 12 == 0:
					self.frame+=1
					if self.frame > 8:
						self.frame = 7
				if x == 23:
					self.frame = 6
				pygame.time.delay(5)
				pygame.display.update()
		if direction is "east":
			self.frame = 9
			for x in range(24):
				self.screen.fill((0,0,0))
				self.screen.blit(self.background, self.scrollpos)
				self.x = self.x+self.speed
				if self.x >= self.SCREENWIDTH - self.SCREENWIDTH/4:
					self.x = self.SCREENWIDTH - self.SCREENWIDTH/4
					if self.x > self.scrollpos[0]:
						scroll_temp = self.scrollpos[0]
						self.scrollpos[0]-=self.speed
				self.rect[0] = self.x-self.speed
				self.draw()
				if x % 12 == 0:
					self.frame+=1
					if self.frame > 11:
						self.frame = 10
				if x == 23:
					self.frame = 9
				pygame.time.delay(5)
				pygame.display.update()