I'm currently using [UIImage animatedImageNamed:#"..." duration:1.0f] to animate a series of PNG images in my iOS 7 app.
When the image is still, I use UIGraphicsGetImageFromCurrentImageContext() as follows:
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, [UIScreen mainScreen].scale);
{
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIBezierPath* path = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
[color setFill];
[path fillWithBlendMode:kCGBlendModeSourceAtop alpha:1.0];
image = UIGraphicsGetImageFromCurrentImageContext();
} UIGraphicsEndImageContext();
...and then CAAnimation to glow/tint/shade the image mask. For the animated image, though, is there a way to animate the mask so that it follows the animated PNG? (By "mask" I mean shape or silhouette of the image content that I'm animating.)
Related
I currently have the following image on which I am trying to set a border. It consists of an UIImageView with an image inside (a transparent.png)
When I try to set the border for my image (see code), it gives a border to the UIImage, but it doesn't 'snap' around my image. Is it possible to achieve that effect?
See image current implementation here.
- (UIImage*)imageWithBorderFromImage:(UIImage*)source;
{
CGSize size = [source size];
UIGraphicsBeginImageContext(size);
CGRect rect = CGRectMake(0, 0, size.width, size.height);
[source drawInRect:rect blendMode:kCGBlendModeNormal alpha:1.0];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetRGBStrokeColor(context, 1.0, 0.5, 1.0, 1.0);
CGContextStrokeRect(context, rect);
UIImage *testImg = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return testImg;
}
Try Adding a layer behind UIImageView and add a border to it that will do the trick
#define kBorderWidth 3.0.
#define kCornerRadius 8.0
CALayer *borderLayer = [CALayer layer];
CGRect borderFrame = CGRectMake(0, 0, (imageView.frame.size.width), (imageView.frame.size.height));
[borderLayer setBackgroundColor:[[UIColor clearColor] CGColor]];
[borderLayer setFrame:borderFrame];
[borderLayer setCornerRadius:kCornerRadius];
[borderLayer setBorderWidth:kBorderWidth];
[borderLayer setBorderColor:[[UIColor redColor] CGColor]];
[imageView.layer addSublayer:borderLayer];
And don't forget to import QuartzCore/QuartzCore.h
This example will draw a boarder on the layer, but change it's frame slightly to make the border around the layer.
Depending on your needs, if you don't want it to be as accurate as possible, a quick and dirty solution could be something like this:
- (UIImage *)borderedImageFromImage:(UIImage *)source andColor:(UIColor *)borderColor{
CGFloat scale = 0.95;//this determines how big the border will be, the smaller it is the bigger the border
UIImage *borderImage = [source imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
UIGraphicsBeginImageContextWithOptions(source.size, NO, source.scale);
[borderColor set];
[borderImage drawInRect:CGRectMake(0, 0, source.size.width, source.size.height)];
[source drawInRect:CGRectMake(source.size.width*(1-scale)/2,
source.size.height*(1-scale)/2,
source.size.width * scale,
source.size.height * scale)];
borderImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return borderImage;
}
and here is how to use it:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.heartImageView.image = [self borderedImageFromImage:[UIImage imageNamed:#"heart"] andColor:[UIColor blackColor]];
}
What this essentially does is draw the image you want twice, once in the colour of the border (slightly scaled) and once with the normal colour. Your mileage may vary depending on the image.
I am trying to create a custom view to draw a music CD with the album artwork on the CD.
Currently I use core graphics to draw two circular disks inside the drawRect method. The inner disk's colour is set to the background colour of the view to make it look like the inner circle is a hollow circle.
My problem is that I can't draw the UIImage inside the the circular bezier path to get the result that I need.
Here's my drawRect code:
// Draw a CD like view using three drawing operations:
// 1st draw the main disk
// 2nd draw the image if it is set
// 3rd draw the inner disk over the image so that it looks like it is a hollow disk with the image painted on the disk.
// Note:) This view expects its aspect ratio to be set as 1:1
- (void)drawRect:(CGRect)rect
{
// Draw the main Circular CD disk
UIBezierPath* outerRing = [UIBezierPath bezierPathWithOvalInRect:self.bounds];
[self.mainColor setFill];
[outerRing fill];
[self.outerRingColor setStroke];
[outerRing stroke];
// Draw the album image if it is set
if(self.artwork){
[self.artwork drawInRect:self.bounds blendMode:kCGBlendModeNormal alpha:1.0];
}
// now draw another smaller disk inside
// this will be a percentage smaller than the whole disk's bounds and will be centered inside it
CGFloat sidePaddingCoord = ((1.0f - INNER_DISK_SIZE_PERCENTAGE) / 2) * self.bounds.size.height;
CGFloat side = INNER_DISK_SIZE_PERCENTAGE * self.bounds.size.width;
UIBezierPath* innerRing = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(sidePaddingCoord, sidePaddingCoord, side, side)];
[self.innerRingColor setFill];
[innerRing fill];
[innerRing stroke];
}
This fills the image as a square. I want the image to be clipped inside the outerRing bezier path so that it looks like a music CD.
I'm sure there is a way to use core graphics to achieve something else besides using the image's drawInRect method. Is there any way to 'clip' the image inside the circular bezier path or only draw inside the bezier path?
I've read really great posts by rob mayoff, UIBezierPath Subtract Path, iOS UIImage clip to paths, many thanks.
Here is an adoption of his code. Keep your creation code of outerRing and innerRing, add them to an array named paths.
[self.paths addObject:outerRing];
[self.paths addObject:innerRing];
Then use this help method.
- (UIImage *)maskedImage
{
CGRect rect = CGRectZero;
rect.size = self.originalImage.size;
UIGraphicsBeginImageContextWithOptions(rect.size, YES, 0.0);
UIBezierPath *clipPath = [UIBezierPath bezierPathWithRect:CGRectInfinite];
[clipPath appendPath:self.paths[1]];
clipPath.usesEvenOddFillRule = YES;
CGContextSaveGState(UIGraphicsGetCurrentContext()); {
[clipPath addClip];
[[UIColor orangeColor] setFill];
[self.paths[0] fill];
} CGContextRestoreGState(UIGraphicsGetCurrentContext());
UIImage *mask = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0); {
CGContextClipToMask(UIGraphicsGetCurrentContext(), rect, mask.CGImage);
[self.originalImage drawAtPoint:CGPointZero];
}
UIImage *maskedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return maskedImage;
}
In drawRect,
UIImage *maskedImage = [self maskedImage];
[maskedImage drawInRect:self.bounds blendMode:kCGBlendModeNormal alpha:1.0];
Try below code:
UIImageView *userImageView= [[UIImageView alloc] initWithFrame:CGRectMake(85, 55.0, 90, 90)];
userImageView.layer.cornerRadius = 90/2;
userImageView.clipsToBounds = YES;
userImageView.layer.borderWidth = 1.0f;
userImageView.layer.borderColor = [UIColor blueColor];
[self.view addSubview:userImageView]; //or add it to the view you want
UIImage *userImage = [UIImage imageNamed:#"<image you want to set>"];
userImageView= [[UIImageView alloc] initWithFrame:CGRectMake(90, 60.0, 80, 80)];
userImageView.image = userImage;
userImageView.layer.cornerRadius = 80/2;
userImageView.clipsToBounds = YES;
userImageView.layer.borderWidth = 1.0f;
userImageView.layer.borderColor = [UIColor blueColor;
[self.view addSubview:userImageView]; //or add it to the view you want
I'm currently coloring an existing image using a mask. For example, I have a white image with a black border and a circular mask (like the first two images). Then, I can create a third image with a color (i.e. green) which has green on the center of the original image (because the mask is present there).
The code I'm using is this (suggestions welcomed):
-(UIImage *)paintWithMask:(UIImage *)mask color:(UIColor *)color andSize:(CGSize)size{
UIImage *image = self;
UIImage *rotatedMask = [self rotateImage:mask]; //For some reason this is needed.
UIGraphicsBeginImageContextWithOptions(size, NO, image.scale);
CGRect rect = CGRectMake(0.0f, 0.0f, size.width, size.height);
[image drawInRect:rect];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetBlendMode(context, kCGBlendModeSourceIn);
CGContextSetFillColorWithColor(context, color.CGColor);
CGContextClipToMask(context, rect, [rotatedMask CGImage]);
CGContextFillRect(context, rect);
UIImage *coloredImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return coloredImage;
}
What I need to do now is paint the green circle using only the mask (without the black border obviously), like this:
Any ideas? Thanks a lot!!
There is a much easier way of doing this without CoreGraphics. Simply do the following:
-(UIImageView *)imageViewWithMask:(UIImage *)mask color:(UIColor *)color andSize:(CGSize)size{
UIImage *tempImage = mask;
tempImage = [tempImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
UIGraphicsBeginImageContextWithOptions(size, NO,0);
[tempImage drawInRect: CGRectMake(0,0,size.width,size.height)];
tempImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageView *iv = [[UIImageView alloc] initWithImage: tempImage];
iv.tintColor = color;
return iv;
}
I'm currently dealing with an iOS app asset generation in code ( creating CAShapeLayer and rendering it as an UIImage ).
I'm having a problem with rounded corners getting distorted when drawing a bezier path for my layer and was wondering if someone has had the same issue?
Screenshot to visualize the problem :
http://i.stack.imgur.com/I8Jre.png
( Generated UIImage is used as a backgroundImage for UIButton )
Code used to create a layer :
CAShapeLayer * layer = [CAShapeLayer new];
[layer setBackgroundColor:[UIColor clearColor].CGColor];
[layer setFrame:CGRectMake(.0, .0, size.width, size.height)];
[layer setFillColor:[UIColor colorForKey:#"colour_1"].CGColor];
[layer setStrokeColor:[UIColor colorForKey:#"colour_4"].CGColor];
[layer setLineWidth:2.0];
[layer setPath:[UIBezierPath bezierPathWithRoundedRect:layer.frame byRoundingCorners:UIRectCornerBottomLeft|UIRectCornerBottomRight cornerRadii:CGSizeMake(10.0, 10.0)].CGPath];
Turn it into an UIImage :
UIImage * imageFromCALayer(CALayer * layer) {
UIGraphicsBeginImageContextWithOptions([layer frame].size, NO, [UIScreen mainScreen].scale);
[layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return outputImage;
}
Why are you taking a CAShapeLayer and rasterizing it to an image? Just draw the path directly! Not only is that the correct way to generate an image, but it will give you more control over the drawing process.
Since your CAShapeLayer and the image have the same dimensions and you apply an outline (which is half inside and half outside the shapes path) the resulting image is cropped. So all you need to do is to add the width of the outline to the width and height of your resulting image.
I have an jpg Image with a round object in a rect and want to make the envoirement of the round object transparent...
(Remove red area in this example)
With the help of this iOS make part of an UIImage transparent and "UIBezierPath bezierPathWithOvalInRect" i've got a little success, but this make a path around my object, and I need to invert it, to make the outside and not the inside of the path transparent..
Im not shure where I have to change my code to get the right result..
Here is my code:
//BezierPath
UIBezierPath *bezierPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 100, 100)];
// Create an image context containing the original UIImage.
UIGraphicsBeginImageContext(_imgTemp.image.size);
[_imgTemp.image drawAtPoint:CGPointZero];
// Clip to the bezier path and clear that portion of the image.
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextAddPath(context,bezierPath.CGPath);
CGContextClip(context);
CGContextClearRect(context,CGRectMake(0,0,self._imgTemp.image.size.width,self._imgTemp.image.size.height));
// Build a new UIImage from the image context.
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self._imgTemp.image = newImage;
Anybody got the resolving?
To only draw within the black circle you should move [_imgTemp.image drawAtPoint:CGPointZero]; to after CGContextClip(context); and then remove the CGContextClearRect( ... ) call entirely:
//BezierPath
UIBezierPath *bezierPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 100, 100)];
// Create an image context containing the original UIImage.
UIGraphicsBeginImageContext(_imgTemp.image.size);
// Clip to the bezier path and clear that portion of the image.
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextAddPath(context,bezierPath.CGPath);
CGContextClip(context);
// Draw here when the context is clipped
[_imgTemp.image drawAtPoint:CGPointZero];
// Build a new UIImage from the image context.
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self._imgTemp.image = newImage;