Hello Everyone,

This is my first post here, but I plan on spending a lot of time here trying to learn (and help others).

I've dabbled in c++ off and on for the last few years, but I found myself struggling to find a project that wasn't too challenging (or too easy) and I stepped away for a bit.

Recently, I started teaching myself a bit about Python. Apparently, it's a simpler language (that can do a lot) and I figure I'll give it a shot, maybe I can accomplish something. So I set out the other day and now I'm here...

I've attempted to render a background image (or terrain) with another image on top that can move to the location of a mouse click. I'm having trouble understanding why the image won't move precisely when I click, every time. For instance, if I click in quick succession, the image may only change locations once every second or more.

I have a feeling like it has something to do with constantly having to redraw the images, perhaps slowing it down? If that's the case, I wouldn't understand why because I thought that the game loop would iterate many times a second.... Or maybe my loop isn't working right? Can I just "move" an image instead of the constant "blit-ing"? If not, then this kind of concerns me with what I plan on doing in the future. (When I click a point on the terrain, I want to move, or walk, the image to that point).

Obviously, this is a very simple task, especially for some of you, but I can't really tell if it's a problem with the way I'm coding it or if it's really how slow python/pygame is?

Here is the code:

import sys, pygame

pygame.init()

SCREEN_WIDTH = 1200
SCREEN_HEIGHT = 800
BLACK = (0, 0, 0)

screen = pygame.display.set_mode([SCREEN_WIDTH, SCREEN_HEIGHT])
pygame.display.set_caption("TTB")
screen.fill(BLACK)

#set cursor here somewhere

terrain = pygame.image.load("terrain.jpg")
terrainRect = terrain.get_rect()
terrain = pygame.transform.scale(terrain, (SCREEN_WIDTH, SCREEN_HEIGHT))
screen.blit(terrain, terrainRect)

oPC = pygame.image.load("amishdude.png")
oPC = pygame.transform.scale(oPC, (75, 75))                                     
oPCrect = oPC.get_rect()
screen.blit(oPC, oPCrect)

pygame.display.flip()

running = True #initialize the main game loop

while running == True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False #break loop and close 
        

    for event in pygame.event.get():
        if event.type == pygame.MOUSEBUTTONDOWN:
                mouseRect = pygame.mouse.get_pos()              
                screen.fill(BLACK)
                screen.blit(terrain, terrainRect)
                screen.blit(oPC, mouseRect)
                pygame.display.update()
                
                
  

pygame.quit()
#sys.exit()

Wow. That was exactly it. I'm not even sure what I was thinking now... Thank you for pointing that out though. Apologies.

That is good news! For clarity purposes though, do we constantly have to blit images (including the terrain) every time something changes? If that's the case, won't it eventually slow down with thousands of image objects moving (and terrain reloading)? Or...say for instance, we have a multiplayer game where we're having to blit all of these images for everyone....Wouldn't that really slow it down?

I realize I have much to learn if I ever choose to go the multiplayer route, but I suppose I'm asking out of curiousity...

That is good news! For clarity purposes though, do we constantly have to blit images (including the terrain) every time something changes? If that's the case, won't it eventually slow down with thousands of image objects moving (and terrain reloading)? Or...say for instance, we have a multiplayer game where we're having to blit all of these images for everyone....Wouldn't that really slow it down?

I realize I have much to learn if I ever choose to go the multiplayer route, but I suppose I'm asking out of curiousity...

I'm not intimately familiar with pygame, but couldn't you just toggle a flag if you've hit an event that will require a redraw, and then wait til all events have been iterated over, then do one set of blits of everything.

Excuse my pseudocode

       UpdateDisplay=FALSE
       for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False #break loop and close
        elif event.type == pygame.MOUSEBUTTONDOWN: #is it elif?
                UpdateMouseRect
                UpdateDisplay=TRUE
        elisf event.type == pygame.WHATEVER
                UpdateWhatever
                UpdateDisplay=TRUE


       if(UpdateDisplay)  # Note this is OUTSIDE the loop
       {         
                screen.fill(BLACK)
                screen.blit(terrain, terrainRect)
                screen.blit(oPC, mouseRect)
                pygame.display.update()
       }