Python script using pygame, illustrating how to use coordinates and create a relative draw function based on alignment with parts of the screen

drawRelative.py

# Libraries to use. Pygame and the system library.
import pygame, sys
from pygame.locals import *

# Set up pygame
pygame.init()

#Set up the window size and title text
SCREEN_WIDTH = 1000
SCREEN_HEIGHT = 500
PAD = 10
window = pygame.display.set_mode((SCREEN_WIDTH,SCREEN_HEIGHT))
pygame.display.set_caption("UI Example")

#load images
gemCount = pygame.image.load("GemCount.png")
keyCount = pygame.image.load("KeyCount.png")
crosshair = pygame.image.load("Crosshair.png")
doomGuy = pygame.image.load("DoomGuy.png")
healthBar = pygame.image.load("HealthBar.png")

def draw_relative(image, offset, align):
    pos = (0,0)
    if align == "TL":
        pos = offset
    elif align == "T":
        pos = (SCREEN_WIDTH/2 - image.get_width()/2 + offset[0], offset[1])
    elif align == "TR":
        pos = (SCREEN_WIDTH - image.get_width() + offset[0], offset[1])
    if align == "L":
        pos = (offset[0], SCREEN_HEIGHT/2 - image.get_height()/2 + offset[1])
    elif align == "C":
        pos = (SCREEN_WIDTH/2 - image.get_width()/2 + offset[0], SCREEN_HEIGHT/2 - image.get_height()/2 + offset[1])
    elif align == "R":
        pos = (SCREEN_WIDTH - image.get_width() + offset[0], SCREEN_HEIGHT/2 - image.get_height()/2 + offset[1])
    if align == "BL":
        pos = (offset[0], SCREEN_HEIGHT - image.get_height() + offset[1])
    elif align == "B":
        pos = (SCREEN_WIDTH/2 - image.get_width()/2 + offset[0], SCREEN_HEIGHT - image.get_height() + offset[1])
    elif align == "BR":
        pos = (SCREEN_WIDTH - image.get_width() + offset[0], SCREEN_HEIGHT - image.get_height() + offset[1])
    
    window.blit(image, pos)


# The game loop
while True:

    #Draw the background
    window.fill((255,255,255))

    #draw the stuff in the scene
    draw_relative(gemCount, (PAD,PAD), "TL")
    draw_relative(crosshair, (0,0), "T")
    draw_relative(keyCount, (-PAD,PAD), "TR")
    draw_relative(crosshair, (0,0), "L")
    draw_relative(crosshair, (0,0), "C")
    draw_relative(crosshair, (0,0), "R")
    draw_relative(crosshair, (0,0), "BL")
    draw_relative(doomGuy, (0,0), "B")
    draw_relative(crosshair, (0,0), "BR")

    #put it all on the screen
    pygame.display.update()

    #check for events (user input)
    for event in pygame.event.get():
        
        #if they closed the window...
        if event.type == QUIT:
            
            #quit!
            pygame.quit()
            sys.exit()