hit testing a shape, adding shapes within another shape

C4WorkSpace.m

#import "C4WorkSpace.h"

@implementation C4WorkSpace {
    C4Shape *t;
}

-(void)setup {
    t = [C4Shape arcWithCenter:CGPointMake(180, 180) radius:180 startAngle:0
                      endAngle:PI clockwise:NO];
    [self.canvas addShape:t];
    t.userInteractionEnabled = NO;
    t.origin = CGPointMake(180,70);
    t.frame = CGRectMake(180, 70, t.width, t.height);
    [self.canvas addShape:t];
    [self runMethod:@"createShapes" afterDelay:0.1];
}

-(void)createShapes {
    for(int i = 0; i < 50;) {
        CGPoint p = CGPointMake([C4Math randomInt:t.width] + t.origin.x,
                                [C4Math randomInt:t.height] + t.origin.y);
        
        if([t pointInside:[t convertPoint:p fromView:self.canvas] withEvent:nil]) {
            C4Shape *s = [C4Shape ellipse:CGRectMake(0, 0, 20, 20)];
            s.center = p;
            [self.canvas addShape:s];
            i++;
        }
    }
}

@end