Prevent Opacity from multiplying with every new objects created

Question

I have this class that call a transparency function to create a transparent inner circle behind my outer circle, the issue is that this circle opacity multiply with each objects created leading to this issue:

This isn't something i want and i don't have much ideas on how to call this function only once per circle, i've tried to place the functions calls in the init def itself before but it don't remember it doing what i wanted.

at the end, all circles should look like

Here is my class and opacity function called transparency (i know it should be called opacity instead i'm just pepega), as well as my function that call that class via another file

import pygame

def transparency(self,surface, inner_surface, size, x, y):
        self.circle = pygame.draw.circle(inner_surface, (255, 255, 255, 10), (x,y), int(size[0]/2)-5)
        surface.blit(inner_surface, (0,0))
        surface.blit(self.image,(x-((size[0])/2),y-((size[1])/2)))

class circles(pygame.sprite.Sprite): # Initalise a new circle with set position and size (defined by cs)

    def __init__(self,surface, inner_surface, x, y, cs, font):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("./assets/circle.png").convert_alpha()
        size = (int(round(2.25*(109-(9*cs)))),int(round(2.25*(109-(9*cs)))))
        self.image = pygame.transform.scale(self.image, size)
        transparency(self, surface, inner_surface, size, x, y)
        pygame.display.update()

def Place_circles(screen, curve, circle_space, font):
    inner = inner_init([GetSystemMetrics(0), GetSystemMetrics(1)])
    Circle_list = []
    idx = [0,0]
    for c in reversed(range(0,len(curve))):
        for p in reversed(range(0,len(curve[c]))):
            dist = math.sqrt(math.pow(curve[c][p][0] - curve[idx[0]][idx[1]][0],2)+math.pow(curve [c][p][1] - curve[idx[0]][idx[1]][1],2))
            if dist > circle_space:
                print(dist)
                print(idx)
                idx = [c,p]
                Circle_list.append(circles.circles(screen, inner, curve[c][p][0], curve[c][p][1], 4, font))

user_5577765 · Answer

import pygame

def transparency(self,surface, inner_surface, size, x, y): self.circle = pygame.draw.circle(inner_surface, (255, 255, 255, 10), (x,y), int(size[0]/2)-5) surface.blit(inner_surface, (0,0)) surface.blit(self.image,(x-((size[0])/2),y-((size[1])/2)))

inner_surface is the same size as the screen. All transparent circles are drawn on inner_surface. Each time you blit the inner_surface onto the screen, any circles drawn on the inner_surface become more opaque. You don't need inner_surface at all. Create a temporary Surface. Draw the circle on the temporary Surface and blit it on the screen:

def transparency(self,surface, size, x, y):
    temp_surface = pygame.Surface(size, pygame.SRCALPHA)
    self.circle = pygame.draw.circle(temp_surface, (255, 255, 255, 10), (size[0]//2, size[1]//2), int(size[0]/2)-5)
    topleft = x - size[0] // 2, y - size[1] // 2
    surface.blit(inner_surface, topleft)
    surface.blit(self.image, topleft)

See also Draw a transparent rectangle in pygame
and How to make transparent pygame.draw.circle.

Prevent Opacity from multiplying with every new objects created

1 Answers