Draw arrow with rounded corners using CoreGraphics

gistfile1.m

@implementation UIImage (Arrow)

+ (UIImage*)arrowImageWithSize:(CGFloat)arrowSize withColor:(UIColor*)arrowColor thickness:(CGFloat)thickness
{
	//
	// Create bezier path for arrow
	//	 
	//	 +---+-------+-+
	//	 |             |
	//	 |             +
	//       |             |
	//	 +     +-----+-+
	//	 |     |
	//	 |     |
	//	 +     +
	//	 |     |
	//	 +--+--+
	//
	
	UIBezierPath *bezierPath = [UIBezierPath bezierPath];
	
	// Setup bezier path line width
	bezierPath.lineWidth = 0.5f;
	
	// Calculate radius
	CGFloat radius = thickness * 0.5f;
	
	// Top left
	[bezierPath moveToPoint:CGPointMake(0, radius)];
	[bezierPath addQuadCurveToPoint:CGPointMake(radius, 0) controlPoint:CGPointMake(0, 0)];
	
	// Top right
	[bezierPath addLineToPoint:CGPointMake(arrowSize - radius, 0)];
	[bezierPath addQuadCurveToPoint:CGPointMake(arrowSize, radius) controlPoint:CGPointMake(arrowSize, 0)];
	[bezierPath addQuadCurveToPoint:CGPointMake(arrowSize - radius, thickness) controlPoint:CGPointMake(arrowSize, thickness)];
	
	// Middle
	[bezierPath addLineToPoint:CGPointMake(thickness + radius, thickness)];
	[bezierPath addQuadCurveToPoint:CGPointMake(thickness, thickness + radius) controlPoint:CGPointMake(thickness, thickness)];
	
	// Bottom right
	[bezierPath addLineToPoint:CGPointMake(thickness, arrowSize - radius)];
	[bezierPath addQuadCurveToPoint:CGPointMake(radius, arrowSize) controlPoint:CGPointMake(thickness, arrowSize)];
	
	// Bottom left
	[bezierPath addQuadCurveToPoint:CGPointMake(0, arrowSize - radius) controlPoint:CGPointMake(0, arrowSize)];
	
	// Close path
	[bezierPath closePath];
	
	// Rotate bezierPath by 45 deg to get arrow to point north
	CGFloat angle = 45 * M_PI/180;
	
	// Create transformation matrix
	CGAffineTransform transform = CGAffineTransformIdentity;
	
	// Translate bezier path origin to its center to rotate around its center
	transform = CGAffineTransformMakeTranslation(arrowSize * 0.5f, arrowSize * 0.5f);
	
	// Rotate bezier path
	transform = CGAffineTransformRotate(transform, angle);
	
	// Apply transformation matrix
	// This will calculated new bounds for bezier path
	[bezierPath applyTransform:transform];
	
	// Undo translation
	[bezierPath applyTransform:CGAffineTransformMakeTranslation(-bezierPath.bounds.origin.x, -bezierPath.bounds.origin.y)];
	
	// Get bounding rect of rotated bezierPath
	CGRect arrowRect = CGRectZero;
	arrowRect.size.width = ceil(CGRectGetWidth(bezierPath.bounds));
	arrowRect.size.height = ceil(CGRectGetHeight(bezierPath.bounds));
	
	// Create image context and draw bezier path
	UIGraphicsBeginImageContextWithOptions(arrowRect.size, NO, 0.0f);
	
	// Fill and stroke bezier path
	[arrowColor setFill];
	[bezierPath fill];
	
	UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
	
	UIGraphicsEndImageContext();
	
	return image;
}

@end