I'm creating a CALayer like this:
UIColor *color = [UIColor colorWithPatternImage:[UIImage imageNamed:#"MyPattern.png"]];
backgroundLayer = [[CALayer alloc] init];
[backgroundLayer setBackgroundColor:[color CGColor]];
[[self layer] addSublayer:backgroundLayer];
For some reason, the pattern is drawn upside down. I've already tried setting geometryFlipped and applying sublayer transforms, but it doesn't work.
Using [backgroundLayer setTransform:CATransform3DMakeScale(1.0, -1.0, 1.0)]; actually does work.
I would rather use this method:
CALayer *backgroundLayer = [CALayer layer];
backgroundLayer.frame = CGRectMake(50, 50, 200, 200);
UIImage *img = [UIImage imageNamed:#"MyPattern.png"];
CGImageRef imgRef = CGImageRetain(img.CGImage);
backgroundLayer.contents = (id) imgRef;
[self.layer addSublayer:backgroundLayer];
This will provide image content inside the layer and it fits automatically, so it works great for backgrounds. Im not sure why your method isnt working, sorry about that, but I thought it would be nice to provide you with this method.
Instead of using CATransform3DMakeScale you can flip image yourself:
UIImage* img = [UIImage imageNamed:#"MyPattern.png"];
img = [UIImage imageWithCGImage:img.CGImage
scale:img.scale
orientation:UIImageOrientationDownMirrored];
UIColor* color = [UIColor colorWithPatternImage:img];
…
This works fine for me.
Or you can go further and actually redraw the image.
- (UIImage*)flipImage:(UIImage*)image {
UIGraphicsBeginImageContext(image.size);
CGContextDrawImage(UIGraphicsGetCurrentContext(),CGRectMake(0.,0., image.size.width, image.size.height),image.CGImage);
UIImage* img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Details why it can be useful are in this answer.
Related
I am trying to overlap two local images and trying to show the overlapped one in third image.
I am using this code but simulator shows nothing.
- (void)viewDidLoad
{
[super viewDidLoad];
image1 = [[UIImage alloc]init];
image1 = [UIImage imageNamed:#"iphone.png"];
imageA = [[UIImageView alloc]initWithImage:image1];
[self merge];
}
-(void)merge
{
CGSize size = CGSizeMake(320, 480);
UIGraphicsBeginImageContext(size);
CGPoint thumbPoint = CGPointMake(0,0);
imageview.image = imageA.image;
[imageA.image drawAtPoint:thumbPoint];
imageB = [[UIImage alloc]init];
imageB = [UIImage imageNamed:#"Favorites.png"];
CGPoint starredPoint = CGPointMake(0, 0);
[imageB drawAtPoint:starredPoint];
UIImage *imageC = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
imageview.image = imageC;
[self.view addSubview:imageview];
}
I can't figure out/don't know where i am making mistake.
Any help would be appreciable.
Remove all the code from every where except the below code in Merge.
-(void)merge
{
CGSize size = CGSizeMake(320, 480);
UIGraphicsBeginImageContext(size);
CGPoint point1 = CGPointMake(0,0);
// The second point has to be some where different than the first point, other wise, the second image will be above the first image, and you wont even know that the two images are there.
CGPoint point2 = CGPointMake(100,100);
UIImage *imageOne = [UIImage imageNamed:#"Image1.png"];
[imageOne drawAtPoint:point1];
UIImage *imageTwo = [UIImage imageNamed:#"Image2.png"];
// If you want the above image to have some blending, then you can do some thing like below.
// [imageTwo drawAtPoint:point2 blendMode:kCGBlendModeMultiply alpha:0.5];
[imageTwo drawAtPoint:point2];
UIImage *imageC = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(100,100,200,200)];
iv.image=imageC;
[self.view addSubview:iv];
}
here's a general purpose "merge" function wrote as a UIImage category... allows image overlay/underlay.
http://saveme-dot-txt.blogspot.com/2011/06/merge-image-function.html
I am creating an app that send photo on email,i have created gallery,now i want my app can write text on that photo and send it on email. Any suggestions? tutorials are acceptable.
Simplest but tricky, Add a UIView inside a UIImageView and a UILabel, update with yourimage and text. Now take an UIImage by capture screenshot here. and attach it with your email.
You can create UIImageView with image then place UILabel with clear background on image view, and finally make a UIImage using Core Graphics.
Something like this:
UIImage *bcg = [UIImage imageNamed:#"image.png"];
UIImageView *imgView = [[UIImageView alloc] initWithImage:bcg];
imgView.frame = CGRectZero;//Some frame
[self addSubview:imgView];
[imgView release];
UILabel *text = [[UILabel alloc] initWithFrame:CGRectMake(0, imgView.frame.size.height - 20, imgView.frame.size.width, 20)];
text.backgroundColor = [UIColor clearColor];
text.text = #"Some text";
[imgView addSubview:text];
UIImage *resultImage = nil;
UIGraphicsBeginImageContext(CGSizeMake(self.bounds.size.width,
self.bounds.size.height));
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGSize imageSize = CGSizeMake(self.bounds.size.width,
self.bounds.size.height);
UIGraphicsBeginImageContext(imageSize);
[viewImage drawInRect:CGRectMake(0,
0,
imageSize.width,
imageSize.height)
blendMode:kCGBlendModeNormal alpha:1];
resultImage = UIGraphicsGetImageFromCurrentImageContext();
This method easier to debug than draw image and text in context.
I seem to be having difficulties adding a mask via CALayers. I'm simply trying to mask a UIImageView. Here's my code:
CALayer *maskLayer = [CALayer layer];
UIImage *mask = [UIImage imageNamed:#"mask.png"];
maskLayer.contents = mask;
UIImageView *viewToMask = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
viewToMask.image = [UIImage imageNamed:#"picture.png"];
viewToMask.layer.mask = maskLayer;
[self.view addSubview:viewToMask];
Mask.png is black with a transparent circle punched through it (is this correct way to mask?). I'm not sure where this is failing, perhaps at maskLayer.contents since its supposed to be a CGImageRef but I get errors when I set it as mask.CGImage, or through a local variable CGImageRef = mask.CGImage. Anyway, the way its set now doesn't give errors, so I hope its fine.
Does anyone know what's going on, or how to properly set masks with CALayers? Thanks
Try
maskLayer.contents = (id)mask.CGImage;
Yes, the cast sucks, but it's necessary.
I think you'll also need to say
maskLayer.bounds = (CGRect){CGPointZero, mask.size};
try this:
CALayer *maskLayer = [CALayer layer];
UIImage *mask = [UIImage imageNamed:#"mask.png"];
maskLayer.contents = (id)mask.CGImage;
// maskLayer.contentsGravity = kCAGravityCenter;
maskLayer.frame = CGRectMake(0.0, 0.0,1024,768);
UIImageView *viewToMask = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
viewToMask.image = [UIImage imageNamed:#"picture.png"];
viewToMask.layer.mask = maskLayer;
[self.view addSubview:viewToMask];
you also need to set mask frame
I have simple View based application. I had taken only UILabel on it.
Following is my code in viewDidLoad:
lblBack.textColor = [UIColor blueColor];
UIImage *img = [UIImage imageNamed:#"cn3.png"];
lblBack.backgroundColor = [UIColor colorWithPatternImage:img];
lblBack.text = #"Hello World!!!...";
// UIImageView *imgView = [[UIImageView alloc] initWithImage:img];
//
// CGRect rect = CGRectMake(0, 0, lblBack.frame.size.width, lblBack.frame.size.height);
// [imgView setFrame:rect];
// NSLog(#"Rect : %#",NSStringFromCGRect(rect));
// [img drawInRect:rect];
// imgView.contentMode = UIViewContentModeScaleAspectFill;
// imgView.contentMode = UIViewContentModeScaleAspectFit;
// imgView.contentMode = UIViewContentModeScaleToFill;
// [lblBack addSubview:imgView];
Comments shows some of the things that i have tried. I am getting following output:
In this one image is repeated 3 times. But I want that image should be stretched to fill the Label width.
I have referred some of the previous links that shows me to add Image in background and use clearColor for UILabel. Also seen example of Adding custom view in Background. But all this I dont want to use unless I dont have other solutions...
I just want to perform all things on UILabel only.... no other control except UIImage or UIImageView i want to use..
Dhiren try this code :
UIImage *img = [UIImage imageNamed:#"cab.png"];
CGSize imgSize = testLabel.frame.size;
UIGraphicsBeginImageContext( imgSize );
[img drawInRect:CGRectMake(0,0,imgSize.width,imgSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
testLabel.backgroundColor = [UIColor colorWithPatternImage:newImage];
I have tested this code.
Porting over Maulik's answer to Swift 2.2, you get the following code:
var img: UIImage = UIImage(named: "cabImage")!
var imgSize: CGSize = testLabel.frame.size
UIGraphicsBeginImageContext(imgSize)
img.drawInRect(CGRectMake(0, 0, imgSize.width, imgSize.height))
var newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
testLabel.backgroundColor = UIColor(patternImage: newImage)
Personally tested to be working!
I am trying to create a drop shadow for an image. I also have an animation between views and this is the backdrop. However, when I use the following code, the image is not drawn. Anyone have any ideas?
self.frontViewBackground = [[[UIView alloc] initWithFrame:frame] autorelease];
//self.frontViewBackground.image = [UIImage imageNamed:#"whitepaper3.png"];
self.frontViewBackground.multipleTouchEnabled = YES;
[self.photoView addSubview:self.frontViewBackground];
UIImage *image = [UIImage imageNamed:#"whitepaper3.png"];
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetShadow(ctx, CGSizeMake(1, -2), 3.0);
[image drawInRect:self.frontViewBackground.frame blendMode:kCGBlendModeNormal alpha:1.0];
CGContextRestoreGState(ctx);
Have you thought about using CALayer's shadow properties? For example you could do the following:
UIView *view = [[UIView alloc] initWithFrame:frame];
view.layer.shadowColor = [[UIColor blackColor] CGColor];
view.layer.shadowRadius = 5.0
Check out more here: http://developer.apple.com/iphone/library/documentation/GraphicsImaging/Reference/CALayer_class/Introduction/Introduction.html#//apple_ref/occ/instp/CALayer/shadowColor