Module 6 - Section 0 - Repeat!

Printed by:	Guest user
Date:	Thursday, 21 November 2024, 4:07 PM

Description

If we want to animate an object that we are going to draw inside the main loop using the pygame template we should:

First : create an initialization block of commands outside the Main program loop where we define the starting position (x , y) of the object and the starting speed in each axis:

rect_x = 50 # X starting position of rectangle
rect_y = 50 # Y starting position of rectangle
speed_x = 5 # X speed of rectangle
speed_y = 5 # Y speed of rectangle
Second : inside the main loop change the position according to the speed:

rect_x += speed_x
rect_y += speed_y
Third : Change the drawing command using the defined variables:

pygame.draw.rect(screen, WHITE, [rect_x, rect_y, 50,50])

To bounce the object at the edges of the screen we change the direction of the object's speed when it reaches the edges.

if rect_x >= 650 or rect_x <= 0:
        speed_x *= -1
if rect_y >= 450 or rect_y <= 0:
        speed_y *= -1

If the object is larger or smaller or if it is different (circle) we have to change the borders in the previous commands accordingly.

To get the position of the mouse inside a graphics screen created with pygame we use the command,

pos = pygame.mouse.get_pos()

inside the main loop, so depending of the clock.tick() command the position is read constantly.

The variable pos is a tuple of two numbers that we can use to move a shape using the tuples numbers as coordinates. The commands are:

x = pos[0] # assign the x position of the mouse to variable x
y = pos[1] # assign the y position of the mouse to variable y

and to draw a shape at the position x,y :

pygame.draw.circle(screen, RED, [ x, y], 30, 0)