How To Bounce Ball In Paddle Game On Another Shape Using Collisions?

Trying to get the ball to bounce on the platform, but the collision can't be detected? How can we detect collision or make it bounce from the platform? We have made the ball and it

Solution 1:

You can use canvas.find_overlapping(*ball_pos) to check if ball overlaps other objects. It returns IDs of all objects in rectangle ball_pos - event ball - so it is never empty.

It is not ideal because it doesn't check if ball collide below/above/left/right so you don't know how to change direction.

import tkinter as tk

# --- constants ---

WIDTH = 800
HEIGHT = 1000# --- functions ---# for smooth move of platformdefleft_press(event):
    global platform_left
    platform_left = Truedefleft_release(event):
    global platform_left
    platform_left = Falsedefright_press(event):
    global platform_right
    platform_right = Truedefright_release(event):
    global platform_right
    platform_right = Falsedefeventloop():
    global xspeed
    global yspeed

    # move ball
    canvas.move(ball, xspeed, yspeed)
    ball_pos = canvas.coords(ball)

    # move platformif platform_left:
        # move
        canvas.move(platform, -20, 0)
        platform_pos = canvas.coords(platform)
        # check if not leave canvasif platform_pos[0] < 0:
            # move back
            canvas.move(platform, 0-platform_pos[0], 0)
    if platform_right:
        # move
        canvas.move(platform, 20, 0)
        # check if not leave canvas
        platform_pos = canvas.coords(platform)
        if platform_pos[2] > 1200:
            # move back
            canvas.move(platform, -(platform_pos[2]-1200), 0)

    # - collisions -# check collision with borderif ball_pos[3] >= 900or ball_pos[1] <= 0: # y range
        yspeed = -yspeed
    if ball_pos[2] >= 1200or ball_pos[0] <= 0: # x range
        xspeed = -xspeed

    # check collisions with objects 

    collide = canvas.find_overlapping(*ball_pos)

    if platform in collide:
        yspeed = -yspeed

    remove = []

    # check collision with bricksfor brick in bricks:
        if brick in collide:
            remove.append(brick)
            yspeed = -yspeed

    # remove bricksfor brick in remove:
        bricks.remove(brick)
        canvas.delete(brick)

    root.after(10, eventloop)

# --- main ---# - init -

root = tk.Tk()
root.title("Brick Breaker")

canvas = tk.Canvas(root, width=1200, height=900)
canvas.pack()

# - objects -

ball = canvas.create_oval(5, 5, 30, 30, fill="black")
xspeed = 1# gravity
yspeed = 4

platform = canvas.create_rectangle(5, 40, 250, 30, fill="black")
platform_left = False
platform_right = False
root.bind('<Left>', left_press)
root.bind('<KeyRelease-Left>', left_release)
root.bind('<Right>', right_press)
root.bind('<KeyRelease-Right>', right_release)

bricks = []

for i inrange(10):
    x = i*100
    y = 700
    brick = canvas.create_rectangle(x, y, x+50, y+30, fill="red")
    bricks.append(brick)

# - mainloop -

root.after(100, eventloop)
root.mainloop()

BTW: to control speed better change xspeed, yspeed instead of after()