pygame

In this article you will learn how to implement jump and run logic in Pygame. To do so, we will implement the player logic.

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Movement
Moving left and right is similar to the previous tutorial and simply mean changing the (x,y) position of the player. For jumping, we use a formula from classical mechanics:

F = 1/2 * m * v^2

Where F is the force up/down, m is the mass of your object and v is the velocity. The velocity goes down over time because when the player jumps the velocity will not increase more in this simulation. If the player reaches the ground, the jump ends. In Python, we set a variable isjump to indicate if the player is jumping or not. If the player is, its position will be updated according to the above formula.

Full Code:

from pygame.locals import *
import pygame
import math
from time import sleep
 
class Player:
    x = 10
    y = 500
    speed = 10

    # Stores if player is jumping or not.
    isjump = 0     
    
    # Force (v) up and mass m.
    v = 8 
    m = 2
            
    def moveRight(self):
        self.x = self.x + self.speed
 
    def moveLeft(self):
        self.x = self.x - self.speed
 
    def jump(self):
        self.isjump = 1

    def update(self):
        if self.isjump:
            # Calculate force (F). F = 0.5 * mass * velocity^2.
            if self.v > 0:
                F = ( 0.5 * self.m * (self.v*self.v) )
            else:
                F = -( 0.5 * self.m * (self.v*self.v) )
    
            # Change position
            self.y = self.y - F

            # Change velocity
            self.v = self.v - 1

            # If ground is reached, reset variables.
            if self.y >= 500:
                self.y = 500
                self.isjump = 0
                self.v = 8              
          

class App:
 
    windowWidth = 800
    windowHeight = 600
    player = 0
 
    def __init__(self):
        self._running = True
        self._display_surf = None
        self._image_surf = None
        self.player = Player() 
 
    def on_init(self):
        pygame.init()
        self._display_surf = pygame.display.set_mode((self.windowWidth,self.windowHeight), pygame.HWSURFACE)
        
        pygame.display.set_caption('Pygame pythonspot.com example')
        self._running = True
        self._image_surf = pygame.image.load("pygame.png").convert()
 
    def on_event(self, event):
        if event.type == QUIT:
            self._running = False
 
    def on_loop(self):
        pass
    
    def on_render(self):
        self._display_surf.fill((0,0,0))
        self._display_surf.blit(self._image_surf,(self.player.x,self.player.y))
        self.player.update()
        pygame.display.flip()
        sleep(0.03)
 
    def on_cleanup(self):
        pygame.quit()
 
    def on_execute(self):
        if self.on_init() == False:
            self._running = False
 
        while( self._running ):
            pygame.event.pump()
            keys = pygame.key.get_pressed() 
            
            if (keys[K_RIGHT]):
                self.player.moveRight()
 
            if (keys[K_LEFT]):
                self.player.moveLeft()
 
            if (keys[K_UP]):
                self.player.jump()
 
            if (keys[K_ESCAPE]):
                self._running = False
 
            self.on_loop()
            self.on_render()
        self.on_cleanup()
 
if __name__ == "__main__" :
    theApp = App()
    theApp.on_execute()

If you want to jump on objects, simply add them to the screen, do collision detection and reset the jump variables if collision is true.

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