[pygame] New way for drawing an arc

[Silver <rockachu2@xxxxxxxxx>]

I recently figured out how to draw an arc in pygame without moire holes
and allowing stuff like antialiasing. Just if any of your are interested.

The script is a little slow.
Also: atan issues where the arc starts out from the left instead of top.
I can't seem to fix it.


--Rockachu2

import math

def draw_arc_matrix(matrix, pos, radius, color, width, angle1, angle2):
    #print "Drawing arc at", pos, "with radius of ", radius
    for x in xrange(getmatrixwidth(matrix)):
        for y in xrange(getmatrixheight(matrix)):
            n = ((x-pos[0])**2 )+ ((y-pos[1])**2 )
            if n > (radius-width)**2:
                if n < (radius)**2:
                    ## now to check arc
                    #print x,y
                    #setpoint(matrix, [x,y], color)
                    angle = math.atan2(y-pos[1], x-pos[0])
                    angle = math.degrees(angle)+180
                    #print angle, angle1, angle2
                    if angle1 > angle2:
                        if angle < angle1:
                            if angle > angle2:
                                setpoint(matrix, [x,y], color)
                                #print x,y
                    else:
                        if angle > angle1:
                            if angle < angle2:
                                #print x,y
                                setpoint(matrix, [x,y], color)
def setpoint(matrix, pos, color):
    matrix.set_at(pos, color)
    
    #matrix[pos[0]][pos[1]] = color
    #return matrix
    
def getmatrixwidth(matrix):
    # reurn len(matrix)
    return matrix.get_rect().width
    
def getmatrixheight(matrix):
    # return len(matrix[0])
    return matrix.get_rect().height
    
if __name__ == "__main__":
    import pygame
    pygame.init()
    screen = pygame.display.set_mode((200,200))
    angle = 0
    anglec = 1
    while True:
        anglec += .1
        anglec %= 360
        screen.fill((0,0,0))
        draw_arc_matrix(screen, (100,100), 80, (255,255,255), 10, angle, anglec)
        pygame.display.update()
        pygame.event.get()