I need to color a shape on my screen any color I wish. I am currently trying to do this with a UIImage which I want to recolor to my desires. The only way to do this, as far as I know, is to take the individual pixels of the UIImage, which calls for many more lines of code that I would like to write to fix this problem. Is there any way to change the UIImage color other than what I have written? Would it be easier to draw the shape in context and fill it?
TY.
Update: The Hexagon is drawing itself the right way, but it doesn't fill right at all. Here is the code:
self.Hexagon.lineWidth=10;
[self.Hexagon moveToPoint:CGPointMake(hexWidth/2, 0)];
[self.Hexagon addLineToPoint:CGPointMake(hexWidth, hexHeight/4)];
[self.Hexagon addLineToPoint:CGPointMake(hexWidth, hexHeight*0.75)];
[self.Hexagon addLineToPoint:CGPointMake(hexWidth/2, hexHeight)];
[self.Hexagon addLineToPoint:CGPointMake(0, hexHeight*0.75)];
[self.Hexagon addLineToPoint:CGPointMake(0, hexHeight/4)];
[self.Hexagon addLineToPoint:CGPointMake(hexWidth/2, 0)];
[self.Hexagon closePath];
[[UIColor blackColor] setStroke];
[self.Hexagon stroke];
[[UIColor whiteColor] setFill];
[self.Hexagon fill];
I recommend using a CAShapeLayer. You could even animate the fill color. Your performance will be very good and your memory usage will be low.
this function creates a CGPath containing a hexagon: (based on OP question)
CGPathRef CGPathCreateHexagon( CGFloat hexWidth, CGFloat hexHeight )
{
CGMutablePathRef p = CGPathCreateMutable() ;
CGPathMoveToPoint( p, NULL, hexWidth * 0.5, 0.0 ) ;
CGPathAddLineToPoint( p, NULL, hexWidth, hexHeight * 0.75 ) ;
CGPathAddLineToPoint( p, NULL, hexWidth, hexHeight * 0.75 ) ;
CGPathAddLineToPoint( p, NULL, hexWidth * 0.5, hexHeight ) ;
CGPathAddLineToPoint( p, NULL, 0.0, hexHeight * 0.75 ) ;
CGPathAddLineToPoint( p, NULL, hexWidth * 0.5, 0.0 ) ;
CGPathAddLineToPoint( p, NULL, 0.0, hexHeight * 0.25 ) ;
CGPathAddLineToPoint( p, NULL, hexWidth * 0.5, 0.0 ) ;
CGPathCloseSubpath( p ) ;
return p ;
}
method to use when setting up your UIView:
-(void)addHexagonLayer
{
CAShapeLayer * layer = [ CAShapeLayer layer ] ;
layer.lineWidth = 10.0 ;
{
CGPathRef p = CGPathCreateHexagon( 100.0, 100.0 ) ;
layer.path = p ;
CGPathRelease( p ) ;
}
layer.fillColor = [[ UIColor redColor ] CGColor ] ; // put your fill color here
layer.position = (CGPoint){ CGRectGetMidX( self.view.bounds ), CGRectGetMidY( self.view.bounds ) } ; // position your hexagon layer appropriately.
[ self.view.layer addSublayer:layer ] ; // add layer to your view and position appropriately
}
edit I created a complete demo just for fun:
#import "AppDelegate.h"
static CGPathRef CGPathCreateHexagon( CGAffineTransform * t, CGFloat w, CGFloat h )
{
CGFloat w_4 = w * 0.25 ;
CGFloat w_2 = w * 0.5f ;
CGFloat h_2 = h * 0.5f ;
CGMutablePathRef p = CGPathCreateMutable() ;
CGPathAddLines( p, t, (CGPoint[]){
{ -w_4, h_2 }, { w_4, h_2 }, { w_2, 0 }, { w_4, -h_2 }, { -w_4, -h_2 }, { -w_2, 0 }
}, 6 ) ;
CGPathCloseSubpath( p ) ;
return p ;
}
@implementation CALayer (SetPositionPixelAligned)
-(CGPoint)pixelAlignedPositionForPoint:(CGPoint)p
{
CGSize size = self.bounds.size ;
CGPoint anchorPoint = self.anchorPoint ;
CGPoint result = (CGPoint){ roundf( p.x ) + anchorPoint.x * fmodf( size.width, 2.0f ), roundf( p.y ) + anchorPoint.y * fmodf( size.height, 2.0f ) } ;
return result;
}
@end
@interface HexagonsView : UIView
@property ( nonatomic ) CGFloat hexHeight ;
@property ( nonatomic ) CGFloat hexWidth ;
@property ( nonatomic, readonly ) CGPathRef hexagonPath ;
@end
@implementation HexagonsView
@synthesize hexagonPath = _hexagonPath ;
-(void)dealloc
{
CGPathRelease( _hexagonPath ) ;
_hexagonPath = NULL ;
}
-(CGPathRef)hexagonPath
{
if ( !_hexagonPath )
{
_hexagonPath = CGPathCreateHexagon( NULL, self.hexWidth, self.hexHeight ) ;
}
return _hexagonPath ;
}
-(void)setHexWidth:(CGFloat)w
{
_hexWidth = w ;
CGPathRelease( _hexagonPath ) ;
_hexagonPath = NULL ;
}
-(void)setHexHeight:(CGFloat)h
{
_hexHeight = h ;
CGPathRelease( _hexagonPath ) ;
_hexagonPath = NULL ;
}
-(void)layoutSubviews
{
[ super layoutSubviews ] ;
CGRect bounds = self.bounds ;
bounds.size.height += self.hexHeight * 0.5 ; // make sure we cover last row ;
CGPoint p ;
p.x = CGRectGetMinY( bounds ) ;
while( p.y < CGRectGetMaxY( bounds ) )
{
p.x = CGRectGetMinX( bounds ) ;
while( p.x < CGRectGetMaxX( bounds ) )
{
{
CAShapeLayer * layer = [ CAShapeLayer layer ] ;
layer.path = self.hexagonPath ;
layer.fillColor = [[ UIColor colorWithHue:(CGFloat)arc4random_uniform( 100 ) / 256.0 saturation:1.0 brightness:1.0 alpha:1.0 ] CGColor ] ;
layer.position = [ layer pixelAlignedPositionForPoint:p ] ;
[ self.layer addSublayer:layer ] ;
}
CGPoint p2 = { p.x + self.hexWidth * 0.75f, p.y + self.hexHeight * 0.5f } ;
if ( p2.y < CGRectGetMaxY( bounds )) // no unnecessary hexagons
{
CAShapeLayer * layer = [ CAShapeLayer layer ] ;
layer.path = self.hexagonPath ;
layer.fillColor = [[ UIColor colorWithHue:(CGFloat)arc4random_uniform( 256 ) / 256.0 saturation:1.0 brightness:1.0 alpha:1.0 ] CGColor ] ;
layer.position = [ layer pixelAlignedPositionForPoint:p2 ] ;
[ self.layer addSublayer:layer ] ;
}
p.x += self.hexWidth * 1.5 ;
}
p.y += self.hexHeight ;
}
}
@end
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.window.backgroundColor = [UIColor whiteColor];
HexagonsView * view = [[ HexagonsView alloc ] initWithFrame:self.window.bounds ] ;
view.hexHeight = 100.0f ;
view.hexWidth = 100.0f ;
[ self.window addSubview:view ] ;
[self.window makeKeyAndVisible];
return YES;
}
@end