I follow a youtube video 'https://www.youtube.com/watch?v=cCiXqK9c18g' and in the video he make a class that represent a ball and he used pymunk to make a body and added it to the space and after that he created a method inside the ball class that will use pygame to draw the ball and I did almost like him
import pygame
import pymunk
pygame.init()
fps = 60
dt = 1/fps
dsX = 800 # screen width
dsY = 500 # screen height
display = pygame.display.set_mode((dsX, dsY))
space = pymunk.Space()
clock = pygame.time.Clock()
def convert_cor(point): # convet the coordinates from pymunk to pygame coordinates
return point[0], dsY - point[1]
class Particle: # v: velocity, pos: position[x, y], r: radius of particle(Circle)
def __init__(self, pos = [0, 0], v = [0, 0], r = 10, color = (255, 0, 0)):
self.pos = pos
self.v = v
self.r = r
self.color = color
self.body = pymunk.Body()
self.body.position = self.pos
self.body.velocity = self.v # this is the veclocity
self.shape = pymunk.Circle(self.body, self.r)
self.shape.dencity = 1
self.shape.elasticity = 1
space.add(self.body, self.shape)
def draw(self):
pygame.draw.circle(display, self.color, convert_cor(self.pos), self.r)
class Box: # thickness of the sides of the box and L1, L2, L3, L4 are the sides of the box
def __init__(self, thickness, color):
self.thickness = thickness
self.color = color
L1 = pymunk.Body(body_type = pymunk.Body.STATIC)
L2 = pymunk.Body(body_type = pymunk.Body.STATIC)
L3 = pymunk.Body(body_type = pymunk.Body.STATIC)
L4 = pymunk.Body(body_type = pymunk.Body.STATIC)
L1_shape = pymunk.Segment(L1, (0, 0), (dsX, 0), self.thickness)
L2_shape = pymunk.Segment(L2, (dsX, 0), (dsX, dsY), self.thickness)
L3_shape = pymunk.Segment(L3, (dsX, dsY), (0, dsY), self.thickness)
L4_shape = pymunk.Segment(L4, (0, dsY), (0, 0), self.thickness)
space.add(L1, L1_shape)
space.add(L2, L2_shape)
space.add(L3, L3_shape)
space.add(L4, L4_shape)
def draw(self):
pygame.draw.line(display, self.color, convert_cor((0, 0)), convert_cor((dsX, 0)), self.thickness * 2)
pygame.draw.line(display, self.color, convert_cor((dsX, 0)), convert_cor((dsX, dsY)), self.thickness * 2)
pygame.draw.line(display, self.color, convert_cor((dsX, dsY)), convert_cor((0, dsY)), self.thickness * 2)
pygame.draw.line(display, self.color, convert_cor((0, dsY)), convert_cor((0, 0)), self.thickness * 2)
def Sim(): # the infinite while loop as a function
box = Box(2, (0, 255, 255))
particle = Particle(pos =[dsX/2, dsY/2], v = [-200, 500]) # here i gave the position and the velocity
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
return
display.fill((255, 255, 255))
box.draw()
particle.draw()
clock.tick(fps)
space.step(dt)
pygame.display.update()
Sim()
pygame.quit()
The thing is, I did also a class that will add a rigid sides for the display and i drew the sides from the Box class using the method 'draw' The problem is in the time 5:58 in the video he gave the ball velocity and it start moving and in my code it does not move. any idea why it doen't move? note: I called the ball particle in my code
You error is both a typo and using the wrong variable.
Inside your particles draw function...
# OLD
def draw(self):
pygame.draw.circle(display, self.color, convert_cor(self.pos), self.r)
# New
def draw(self):
pygame.draw.circle(display, self.color, convert_cor(self.body.position), self.r)
You have to use the body's position cause that is the position of the physics body in pymunk's space.
Secondly...
class Particle: # v: velocity, pos: position[x, y], r: radius of particle(Circle)
def __init__(self, pos, v, r=10, color=(255, 0, 0)):
...
# Old
self.shape.dencity = 1
# New
self.shape.density = 1
Since density was not set to anything Pymunk was having a divide by zero error so it wouldn't update the body's position.