Question

I have this code to draw rounded rectangles:

void ContextAddRoundedRect(CGContextRef ctx, CGRect rect, CGFloat radius) {
    CGFloat minX = CGRectGetMinX(rect);
    CGFloat maxX = CGRectGetMaxX(rect);
    CGFloat minY = CGRectGetMinY(rect);
    CGFloat maxY = CGRectGetMaxY(rect);

    CGContextMoveToPoint(ctx, minX + radius, minY);
    CGContextAddArcToPoint(ctx, maxX, minY, maxX, minY + radius, radius);
    CGContextAddArcToPoint(ctx, maxX, maxY, maxX - radius, maxY, radius);
    CGContextAddArcToPoint(ctx, minX, maxY, minX, maxY - radius, radius);
    CGContextAddArcToPoint(ctx, minX, minY, minX + radius, minY, radius);
}

how can I figure out if a given CGPoint is inside my rect, considering the rounded corners?

Answer 1

Instead of building it directly into the CGContextRef like this, you can build it instead as a UIBezierPath, and then use -[UIBezierPath containsPoint:].

When you’re ready to actually render your path into the context, you can do so via:

CGContextAddPath(ctx, [myBezierPath CGPath]);