Pygame sin,cos,tan caculating circular movement path - pygame

Question

I have been struggling for few days know trying to figure out how to make for example a image move in circular path. I have looked other posts here but i just can't get it.
So how do i move image in circular path. My code only moves my image 45 degrees and stops then. I would need it to go full circle and continue doing it.
Current Code:
import pygame
pygame.init()
screen = pygame.display.set_mode((400, 400))
CENTER = (200, 200)
RADIUS = 100
x = 0
y = 0
satelliteCenter = (CENTER[0]+RADIUS, CENTER[1])
run = 1
while run == 1:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = 0
pygame.quit()
mouse = pygame.mouse.get_pos()
vector = x-CENTER[0], y-CENTER[1]
x +=1
distance = (vector[0]**2 + vector[1]**2)**0.5
if distance > 0:
scalar = RADIUS / distance
satelliteCenter = (
int(round( CENTER[0] + vector[0]*scalar )),
int(round( CENTER[1] + vector[1]*scalar )) )
screen.fill((255,255,255))
pygame.draw.circle(screen, (71,153,192), CENTER, RADIUS)
pygame.draw.circle(screen, (243,79,79), satelliteCenter, 16)
pygame.display.update()

Answer 1

You can just use a pygame.math.Vector2 and rotate it each frame, scale it by the radius and add it to the CENTER position to get the current center of the small circle.
import sys
import pygame
pygame.init()
screen = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()
CENTER = (200, 200)
RADIUS = 100
# A unit vector pointing to the right.
direction = pygame.math.Vector2(1, 0)
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
pygame.quit()
sys.exit()
direction.rotate_ip(4) # By 4 degrees.
# Normalize it, so that the length doesn't change because
# of floating point inaccuracies.
direction.normalize_ip()
# Scale direction vector, add it to CENTER and convert to ints.
ball_pos = [int(i) for i in CENTER+direction*RADIUS]
screen.fill((255,255,255))
pygame.draw.circle(screen, (71,153,192), CENTER, RADIUS)
pygame.draw.circle(screen, (243,79,79), ball_pos, 16)
pygame.display.update()
clock.tick(30)
Edit: If you want the red ball to follow the mouse, then your example actually works if you set x and y to the mouse pos x, y = pygame.mouse.get_pos().
import sys
import pygame
pygame.init()
screen = pygame.display.set_mode((400, 400))
CENTER = (200, 200)
RADIUS = 100
x = 0
y = 0
satelliteCenter = (CENTER[0]+RADIUS, CENTER[1])
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
pygame.quit()
sys.exit()
x, y = pygame.mouse.get_pos()
vector = x-CENTER[0], y-CENTER[1]
distance = (vector[0]**2 + vector[1]**2)**0.5
if distance > 0:
scalar = RADIUS / distance
satelliteCenter = (
int(round( CENTER[0] + vector[0]*scalar )),
int(round( CENTER[1] + vector[1]*scalar ))
)
screen.fill((255,255,255))
pygame.draw.circle(screen, (71,153,192), CENTER, RADIUS)
pygame.draw.circle(screen, (243,79,79), satelliteCenter, 16)
pygame.display.update()