Adding a curve to my rectangle
I am trying to bring Yin-Yang into Objective-c and am having a hard time figuring out how to do it. I created two rectangles that are connected. I am having a hard time figuring out how to draw the lines of my curved rectangle so that I can make a circle out of them. Here is my code so far.
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextAddRect(context, CGRectMake(60, 150, 80, 10));
CGContextStrokePath(context);
CGContextAddRect(context, CGRectMake(60, 150, 190, 10));
CGContextStrokePath(context);
Is there an easier way to create yin-yang in Objective-c or am I in the right direction? I am new to Objective-c and programming in general.
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I would suggest doing this with arcs (in fact, a series of semicircles) instead of rounded rectangles. For example, consider one piece as three separate semicircles:
Then you can draw those arcs like this:
CGContextAddArc(context, center.x, center.y - side / 4.0, side / 4.0, M_PI_2, -M_PI_2, TRUE); // red part
CGContextAddArc(context, center.x, center.y + side / 4.0, side / 4.0, M_PI_2, -M_PI_2, NO); // blue part
CGContextAddArc(context, center.x, center.y, side / 2.0, -M_PI_2, M_PI_2, YES); // dark grey stroke
But obviously, you probably wouldn't be drawing these strokes, but simply filling them in, and then repeat this process for the bottom of the symbol:
- (void)drawRect:(CGRect)rect {
CGFloat side = MIN(rect.size.width, rect.size.height); // length of the side of the square in which the symbol will rest
CGPoint center = CGPointMake(rect.size.width / 2.0, rect.size.height / 2.0); // the center of that square
CGContextRef context = UIGraphicsGetCurrentContext();
// draw white part
CGContextAddArc(context, center.x, center.y - side / 4.0, side / 4.0, M_PI_2, -M_PI_2, TRUE);
CGContextAddArc(context, center.x, center.y + side / 4.0, side / 4.0, M_PI_2, -M_PI_2, NO);
CGContextAddArc(context, center.x, center.y, side / 2.0, -M_PI_2, M_PI_2, YES);
CGContextClosePath(context);
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextFillPath(context);
// draw black part
CGContextAddArc(context, center.x, center.y - side / 4.0, side / 4.0, M_PI_2, -M_PI_2, TRUE);
CGContextAddArc(context, center.x, center.y + side / 4.0, side / 4.0, M_PI_2, -M_PI_2, NO);
CGContextAddArc(context, center.x, center.y, side / 2.0, -M_PI_2, M_PI_2, NO);
CGContextClosePath(context);
CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
CGContextFillPath(context);
// draw black dot
CGContextAddArc(context, center.x, center.y - side / 4.0, side / 12.0, 0, M_PI * 2.0, YES);
CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
CGContextFillPath(context);
// draw white dot
CGContextAddArc(context, center.x, center.y + side / 4.0, side / 12.0, 0, M_PI * 2.0, YES);
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextFillPath(context);
}
This gives:
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