I have a UIView with a dynamically generated graphic context. Its normal size is 100x100, but it can be scaled up to 200x200, so I want its size to be actually 200x200 in order to appear nicely and not blurred however it is displayed.
How can always draw it 200x200 in drawRect, being it displayed at a size of 100 or at a size of 200? If I'm showing it at 100x100, the rect passed to drawRect is smaller than the area I need to draw into.
My code:
- (void) drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextDrawImage(ctx, CGRectMake(0, 0, rect.size.width, rect.size.height), [UIImage imageNamed:#"actionBg.png"].CGImage);
// generate the overlay
if ([self isActive] == NO && self.fullDelay != 0) { // TODO: remove fullDelay check!
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
CGContextRef overlayCtx = UIGraphicsGetCurrentContext();
int segmentSize = (rect.size.height / [self fullDelay]);
for (int i=0; i<[self fullDelay]; i++) {
float alpha = 0.9 - (([self fullDelay] * 0.1) - (i * 0.1));
[[UIColor colorWithRed:120.0/255.0 green:14.0/255.0 blue:14.0/255.0 alpha:alpha] setFill];
if (currentDelay > i) {
CGRect r = CGRectMake(0, i * segmentSize, rect.size.width, segmentSize);
CGContextFillRect(overlayCtx, r);
}
[[UIColor colorWithRed:1 green:1 blue:1 alpha:0.3] setFill];
CGRect line = CGRectMake(0, (i * segmentSize) + segmentSize - 1 , rect.size.width, 1);
CGContextFillRect(overlayCtx, line);
}
UIImage *overlay = UIGraphicsGetImageFromCurrentImageContext();
UIImage *overlayMasked = [TDUtilities maskImage:overlay withMask:[UIImage imageNamed:#"actionMask.png"]];
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
// put the overlay
CGContextSetBlendMode(ctx, kCGBlendModeMultiply);
CGContextDrawImage(ctx, rect, overlayMasked.CGImage);
CGContextSetBlendMode(ctx, kCGBlendModeNormal);
UIGraphicsEndImageContext();
}
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
// draw the delay symbol
CGContextDrawImage(ctx, rect, [UIImage imageNamed:#"delaySymbol.png"].CGImage);
CGContextSetAlpha(ctx, 0.8);
// draw the symbol
NSString *imgName = [K_ACTION_IMAGES objectAtIndex:[self actionType]];
CGContextDrawImage(ctx, rect, [UIImage imageNamed:imgName].CGImage);
CGContextSetAlpha(ctx, 1);
// draw the delay number
imgName = [NSString stringWithFormat:#"%d.png", [self fullDelay]];
CGContextDrawImage(ctx, rect, [UIImage imageNamed:imgName].CGImage);
// draw the priority number
imgName = [NSString stringWithFormat:#"%d.png", [self actionType]];
CGContextDrawImage(ctx, CGRectMake(32, 0, rect.size.width, rect.size.height), [UIImage imageNamed:imgName].CGImage);
}
Have you called setNeedsDisplay method for you view after setting its frame
In overriding a UIView drawRect, I draw the main image with CGContextDrawImage. Over it I need to draw another image (with a multiply blend mode), so I actually need to draw over it.
This second image needs to be prepares since it's generated dynamically (it has to be masked, may be different size and so), so in the end I need to generate it. How can I get a second context where I can draw and mask this second image before applying it over the main one with? If I draw on the current context, it gets directly drawn no the main one before I can mask it.
- (void) drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextDrawImage(ctx, CGRectMake(0, 0, rect.size.width, rect.size.height), [UIImage imageNamed:#"actionBg.png"].CGImage);
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
// generate the overlay
if ([self isActive] == NO && self.fullDelay != 0) { // TODO: remove fullDelay check!
int segmentSize = (ACTION_SIZE / [self fullDelay]);
for (int i=0; i<[self fullDelay]; i++) {
float alpha = 0.9 - (([self fullDelay] * 0.1) - (i * 0.1));
[[UIColor colorWithRed:120.0/255.0 green:14.0/255.0 blue:14.0/255.0 alpha:alpha] setFill];
if (currentDelay > i) {
CGRect r = CGRectMake(0, i * segmentSize, ACTION_SIZE, segmentSize);
CGContextFillRect(ctx, r);
}
[[UIColor colorWithRed:1 green:1 blue:1 alpha:0.3] setFill];
CGRect line = CGRectMake(0, (i * segmentSize) + segmentSize - 1 , ACTION_SIZE, 1);
CGContextFillRect(ctx, line);
}
UIImage *overlay = UIGraphicsGetImageFromCurrentImageContext();
UIImage *overlayMasked = [TDUtilities maskImage:overlay withMask:[UIImage imageNamed:#"actionMask.png"]];
}
}
Here overlayMasked now contains the correct image, but since I've prepared it using the main context, its is not all messed. Thanks
Thanks
You can create a bitmap context using either UIGraphicsBeginImageContextWithOptions or CGBitmapContextCreate. After you're finished drawing in the bitmap context, you can get an image using UIGraphicsGetImageFromCurrentImageContext or CGBitmapContextCreateImage (as appropriate), and then release the context using either UIGraphicsEndImageContext or CGContextRelease.
I want to rotate an UIImage (not UIImageView) in custom degree
I followed this post but it didn't work for me.
Anyone can help? Thanks.
UPDATE:
The code below does some of the job, but I lose some of the image after rotating it:
What should I change to get it right? (btw the yellow color in the screenshots is my UIImageView bg)
- (UIImage *) rotate: (UIImage *) image
{
double angle = 20;
CGSize s = {image.size.width, image.size.height};
UIGraphicsBeginImageContext(s);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, 0,image.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextRotateCTM(ctx, 2*M_PI*angle/360);
CGContextDrawImage(ctx,CGRectMake(0,0,image.size.width, image.size.height),image.CGImage);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
This method return you image on your angle of rotate
#pragma mark -
#pragma mark Rotate Image
- (UIImage *)scaleAndRotateImage:(UIImage *)image {
CGImageRef imgRef = image.CGImage;
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGAffineTransform transform = CGAffineTransformIdentity;
CGRect bounds = CGRectMake(0, 0, width, height);
CGFloat boundHeight;
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0); //use angle/360 *MPI
UIGraphicsBeginImageContext(bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextConcatCTM(context, transform);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imgRef);
UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return imageCopy;
}
- (UIImage *)rotate:(UIImage *)image radians:(float)rads
{
float newSide = MAX([image size].width, [image size].height);
CGSize size = CGSizeMake(newSide, newSide);
UIGraphicsBeginImageContext(size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, newSide/2, newSide/2);
CGContextRotateCTM(ctx, rads);
CGContextDrawImage(UIGraphicsGetCurrentContext(),CGRectMake(-[image size].width/2,-[image size].height/2,size.width, size.height),image.CGImage);
//CGContextTranslateCTM(ctx, [image size].width/2, [image size].height/2);
UIImage *i = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return i;
}
this function rotates any image on its center, but the image becomes a square so I would suggest referencing the image center when drawing it after this function.
You need to address two things to make this work.
You are rotating about the bottom corner of the image instead of the centre
The bounding rectangle of the resulting image needs to be larger now the image is rotated for it to fit in.
To solve the rotation about the centre, first perform a translate to the centre, then rotate, then translate back.
CGAffineTransform transform = CGAffineTransformIdentity;
transform = CGAffineTransformTranslate(transform, boundingRect.size.width/2, boundingRect.size.height/2);
transform = CGAffineTransformRotate(transform, angle);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
CGContextConcatCTM(context, transform);
// Draw the image into the context
CGContextDrawImage(context, CGRectMake(-imageView.image.size.width/2, -imageView.image.size.height/2, imageView.image.size.width, imageView.image.size.height), imageView.image.CGImage);
// Get an image from the context
rotatedImage = [UIImage imageWithCGImage: CGBitmapContextCreateImage(context)];
To calculate the size of the bounding rectangle you'd need to fit the new rotated image into use this:
- (CGRect) getBoundingRectAfterRotation: (CGRect) rectangle byAngle: (CGFloat) angleOfRotation {
// Calculate the width and height of the bounding rectangle using basic trig
CGFloat newWidth = rectangle.size.width * fabs(cosf(angleOfRotation)) + rectangle.size.height * fabs(sinf(angleOfRotation));
CGFloat newHeight = rectangle.size.height * fabs(cosf(angleOfRotation)) + rectangle.size.width * fabs(sinf(angleOfRotation));
// Calculate the position of the origin
CGFloat newX = rectangle.origin.x + ((rectangle.size.width - newWidth) / 2);
CGFloat newY = rectangle.origin.y + ((rectangle.size.height - newHeight) / 2);
// Return the rectangle
return CGRectMake(newX, newY, newWidth, newHeight);
}
You can find these techniques in my previous posts and answers here:
Creating a UIImage from a rotated UIImageView
and here:
Saving 2 UIImages
Hope this helps,
Dave
for rotate image.. you can use this IBAction ... for each and every button click, the image will be rotate by 90 degree...
-(IBAction)rotateImageClick:(id)sender{
UIImage *image2=[[UIImage alloc]init];
image2 = [self imageRotatedByDegrees:self.roateImageView.image deg:(90)]; //Angle by 90 degree
self.roateImageView.image = image2;
imgData= UIImageJPEGRepresentation(image2,0.9f);
}
for rotating image u only have to pass UIimage and rotating degrees for the following method
- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees
//------------------------------------------------------------------------
#pragma mark - imageRotatedByDegrees Method
- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,oldImage.size.width, oldImage.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, (degrees * M_PI / 180));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-oldImage.size.width / 2, -oldImage.size.height / 2, oldImage.size.width, oldImage.size.height), [oldImage CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
I think this link will be help.......! Rotate Original Image by clicking button in Objective C
http://adrianmobileapplication.blogspot.com/2015/03/rotate-original-image-by-clicking.html
You have to do some thing like this
YourContainer.transform = CGAffineTransformMakeRotation( 270.0/180*M_PI );
I think rest of the thing you can figured out..
I'm using following code to add rounded corners to my UIImage, but the problem is that the rounded corners are showing "white" area instead of transparent or "clear". What am i doing wrong here:
- (UIImage *)makeRoundCornerImageWithCornerWidth:(int)cornerWidth cornerHeight:(int)cornerHeight {
UIImage * newImage = nil;
if (self != nil) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
int w = self.size.width;
int h = self.size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
CGContextBeginPath(context);
CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
[self addRoundedRectToPath:context rect:rect width:cornerWidth height:cornerHeight];
CGContextClosePath(context);
CGContextClip(context);
CGContextDrawImage(context, CGRectMake(0, 0, w, h), self.CGImage);
CGImageRef imageMasked = CGBitmapContextCreateImage(context);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
newImage = [[UIImage imageWithCGImage:imageMasked] retain];
CGImageRelease(imageMasked);
[pool release];
}
return [newImage autorelease];
}
- (void)addRoundedRectToPath:(CGContextRef)context rect:(CGRect)rect width:(float)ovalWidth height:(float)ovalHeight {
float fw, fh;
// If the width or height of the corner oval is zero, then it reduces to a right angle,
// so instead of a rounded rectangle we have an ordinary one.
if (ovalWidth == 0 || ovalHeight == 0) {
CGContextAddRect(context, rect);
return;
}
// Save the context's state so that the translate and scale can be undone with a call
// to CGContextRestoreGState.
CGContextSaveGState(context);
// Translate the origin of the contex to the lower left corner of the rectangle.
CGContextTranslateCTM (context, CGRectGetMinX(rect), CGRectGetMinY(rect));
//Normalize the scale of the context so that the width and height of the arcs are 1.0
CGContextScaleCTM (context, ovalWidth, ovalHeight);
// Calculate the width and height of the rectangle in the new coordinate system.
fw = CGRectGetWidth (rect) / ovalWidth;
fh = CGRectGetHeight (rect) / ovalHeight;
// CGContextAddArcToPoint adds an arc of a circle to the context's path (creating the rounded
// corners). It also adds a line from the path's last point to the begining of the arc, making
// the sides of the rectangle.
CGContextMoveToPoint(context, fw, fh/2); // Start at lower right corner
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1); // Top right corner
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right
// Close the path
CGContextClosePath(context);
// Restore the context's state. This removes the translation and scaling
// but leaves the path, since the path is not part of the graphics state.
CGContextRestoreGState(context);
}
Here's a simpler formulation using UIKit calls:
- (UIImage*) roundCorneredImage: (UIImage*) orig radius:(CGFloat) r {
UIGraphicsBeginImageContextWithOptions(orig.size, NO, 0);
[[UIBezierPath bezierPathWithRoundedRect:(CGRect){CGPointZero, orig.size}
cornerRadius:r] addClip];
[orig drawInRect:(CGRect){CGPointZero, orig.size}];
UIImage* result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
Notice the NO parameter - this makes the image context transparent, so the clipped-out region is transparent.
https://github.com/detroit-labs/AmazeKit
sounds like a job for a library
Right after creating the bitmap context clear it with:
CGContextClearRect (context, CGRectMake(0, 0, w, h));
lukya's comment below your question is what you probably want to do.
Make sure you import QuartzCore:
#import <QuartzCore/QuartzCore.h>
Then, if you have a UIImageView of your image that you want to have rounded corners, just call (assuming imageView is a property and cornerRadius is the desired corner radius):
self.imageView.layer.cornerRadius = cornerRadius;
self.imageView.clipsToBounds = YES;
Since you already have self.CGImage, you could do this to create a UIImageView:
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageWithCGImage:self.CGImage]];
Just make sure to release the imageView after you add it as a subview.
profileImageView.layer.cornerRadius = profileImageView.frame.size.height/2;
profileImageView.clipsToBounds = YES;
I try to get rounded corners on a UIImage, what I read so far, the easiest way is to use a mask images. For this I used code from TheElements iPhone Example and some image resize code I found. My problem is that resizedImage is always nil and I don't find the error...
- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize
{
CGSize imageSize = [self size];
float width = imageSize.width;
float height = imageSize.height;
// scaleFactor will be the fraction that we'll
// use to adjust the size. For example, if we shrink
// an image by half, scaleFactor will be 0.5. the
// scaledWidth and scaledHeight will be the original,
// multiplied by the scaleFactor.
//
// IMPORTANT: the "targetHeight" is the size of the space
// we're drawing into. The "scaledHeight" is the height that
// the image actually is drawn at, once we take into
// account the ideal of maintaining proportions
float scaleFactor = 0.0;
float scaledWidth = targetSize.width;
float scaledHeight = targetSize.height;
CGPoint thumbnailPoint = CGPointMake(0,0);
// since not all images are square, we want to scale
// proportionately. To do this, we find the longest
// edge and use that as a guide.
if ( CGSizeEqualToSize(imageSize, targetSize) == NO )
{
// use the longeset edge as a guide. if the
// image is wider than tall, we'll figure out
// the scale factor by dividing it by the
// intended width. Otherwise, we'll use the
// height.
float widthFactor = targetSize.width / width;
float heightFactor = targetSize.height / height;
if ( widthFactor < heightFactor )
scaleFactor = widthFactor;
else
scaleFactor = heightFactor;
// ex: 500 * 0.5 = 250 (newWidth)
scaledWidth = width * scaleFactor;
scaledHeight = height * scaleFactor;
// center the thumbnail in the frame. if
// wider than tall, we need to adjust the
// vertical drawing point (y axis)
if ( widthFactor < heightFactor )
thumbnailPoint.y = (targetSize.height - scaledHeight) * 0.5;
else if ( widthFactor > heightFactor )
thumbnailPoint.x = (targetSize.width - scaledWidth) * 0.5;
}
CGContextRef mainViewContentContext;
CGColorSpaceRef colorSpace;
colorSpace = CGColorSpaceCreateDeviceRGB();
// create a bitmap graphics context the size of the image
mainViewContentContext = CGBitmapContextCreate (NULL, targetSize.width, targetSize.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
// free the rgb colorspace
CGColorSpaceRelease(colorSpace);
if (mainViewContentContext==NULL)
return NULL;
//CGContextSetFillColorWithColor(mainViewContentContext, [[UIColor whiteColor] CGColor]);
//CGContextFillRect(mainViewContentContext, CGRectMake(0, 0, targetSize.width, targetSize.height));
CGContextDrawImage(mainViewContentContext, CGRectMake(thumbnailPoint.x, thumbnailPoint.y, scaledWidth, scaledHeight), self.CGImage);
// Create CGImageRef of the main view bitmap content, and then
// release that bitmap context
CGImageRef mainViewContentBitmapContext = CGBitmapContextCreateImage(mainViewContentContext);
CGContextRelease(mainViewContentContext);
CGImageRef maskImage = [[UIImage imageNamed:#"Mask.png"] CGImage];
CGImageRef resizedImage = CGImageCreateWithMask(mainViewContentBitmapContext, maskImage);
CGImageRelease(mainViewContentBitmapContext);
// convert the finished resized image to a UIImage
UIImage *theImage = [UIImage imageWithCGImage:resizedImage];
// image is retained by the property setting above, so we can
// release the original
CGImageRelease(resizedImage);
// return the image
return theImage;
}
If you are using a UIImageView to display the image you can simply do the following:
imageView.layer.cornerRadius = 5.0;
imageView.layer.masksToBounds = YES;
And to add a border:
imageView.layer.borderColor = [UIColor lightGrayColor].CGColor;
imageView.layer.borderWidth = 1.0;
I believe that you'll have to import <QuartzCore/QuartzCore.h> and link against it for the above code to work.
How about these lines...
// Get your image somehow
UIImage *image = [UIImage imageNamed:#"image.jpg"];
// Begin a new image that will be the new image with the rounded corners
// (here with the size of an UIImageView)
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, NO, 1.0);
// Add a clip before drawing anything, in the shape of an rounded rect
[[UIBezierPath bezierPathWithRoundedRect:imageView.bounds
cornerRadius:10.0] addClip];
// Draw your image
[image drawInRect:imageView.bounds];
// Get the image, here setting the UIImageView image
imageView.image = UIGraphicsGetImageFromCurrentImageContext();
// Lets forget about that we were drawing
UIGraphicsEndImageContext();
I created an UIImage-extension in swift, based on #epatel's great answer:
extension UIImage{
var roundedImage: UIImage {
let rect = CGRect(origin:CGPoint(x: 0, y: 0), size: self.size)
UIGraphicsBeginImageContextWithOptions(self.size, false, 1)
defer {
// End context after returning to avoid memory leak
UIGraphicsEndImageContext()
}
UIBezierPath(
roundedRect: rect,
cornerRadius: self.size.height
).addClip()
self.drawInRect(rect)
return UIGraphicsGetImageFromCurrentImageContext()
}
}
Tested in a storyboard:
The problem was the use of CGImageCreateWithMask which returned an all black image. The solution I found was to use CGContextClipToMask instead:
CGContextRef mainViewContentContext;
CGColorSpaceRef colorSpace;
colorSpace = CGColorSpaceCreateDeviceRGB();
// create a bitmap graphics context the size of the image
mainViewContentContext = CGBitmapContextCreate (NULL, targetSize.width, targetSize.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
// free the rgb colorspace
CGColorSpaceRelease(colorSpace);
if (mainViewContentContext==NULL)
return NULL;
CGImageRef maskImage = [[UIImage imageNamed:#"mask.png"] CGImage];
CGContextClipToMask(mainViewContentContext, CGRectMake(0, 0, targetSize.width, targetSize.height), maskImage);
CGContextDrawImage(mainViewContentContext, CGRectMake(thumbnailPoint.x, thumbnailPoint.y, scaledWidth, scaledHeight), self.CGImage);
// Create CGImageRef of the main view bitmap content, and then
// release that bitmap context
CGImageRef mainViewContentBitmapContext = CGBitmapContextCreateImage(mainViewContentContext);
CGContextRelease(mainViewContentContext);
// convert the finished resized image to a UIImage
UIImage *theImage = [UIImage imageWithCGImage:mainViewContentBitmapContext];
// image is retained by the property setting above, so we can
// release the original
CGImageRelease(mainViewContentBitmapContext);
// return the image
return theImage;
Extending Besi's excellent answer, with correct scale, in Swift 4:
extension UIImage {
public func rounded(radius: CGFloat) -> UIImage {
let rect = CGRect(origin: .zero, size: size)
UIGraphicsBeginImageContextWithOptions(size, false, 0)
UIBezierPath(roundedRect: rect, cornerRadius: radius).addClip()
draw(in: rect)
return UIGraphicsGetImageFromCurrentImageContext()!
}
}
You aren't actually doing anything other than scaling there. What you need to do is to "mask" the corners of the image by clipping it with a CGPath. For instance -
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextBeginTransparencyLayerWithRect(context, self.frame, NULL);
CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);
CGFloat roundRadius = (radius) ? radius : 12.0;
CGFloat minx = CGRectGetMinX(self.frame), midx = CGRectGetMidX(self.frame), maxx = CGRectGetMaxX(self.frame);
CGFloat miny = CGRectGetMinY(self.frame), midy = CGRectGetMidY(self.frame), maxy = CGRectGetMaxY(self.frame);
// draw the arcs, handle paths
CGContextMoveToPoint(context, minx, midy);
CGContextAddArcToPoint(context, minx, miny, midx, miny, roundRadius);
CGContextAddArcToPoint(context, maxx, miny, maxx, midy, roundRadius);
CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, roundRadius);
CGContextAddArcToPoint(context, minx, maxy, minx, midy, roundRadius);
CGContextClosePath(context);
CGContextDrawPath(context, kCGPathFill);
CGContextEndTransparencyLayer(context);
}
I suggest checking out the Quartz 2D programming guide or some other samples.
static void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth, float ovalHeight)
{
float fw, fh;
if (ovalWidth == 0 || ovalHeight == 0) {
CGContextAddRect(context, rect);
return;
}
CGContextSaveGState(context);
CGContextTranslateCTM (context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextScaleCTM (context, ovalWidth, ovalHeight);
fw = CGRectGetWidth (rect) / ovalWidth;
fh = CGRectGetHeight (rect) / ovalHeight;
CGContextMoveToPoint(context, fw, fh/2);
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1);
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1);
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1);
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1);
CGContextClosePath(context);
CGContextRestoreGState(context);
}
+ (UIImage *)imageWithRoundCorner:(UIImage*)img andCornerSize:(CGSize)size
{
UIImage * newImage = nil;
if( nil != img)
{
#autoreleasepool {
int w = img.size.width;
int h = img.size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
CGContextBeginPath(context);
CGRect rect = CGRectMake(0, 0, img.size.width, img.size.height);
addRoundedRectToPath(context, rect, size.width, size.height);
CGContextClosePath(context);
CGContextClip(context);
CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);
CGImageRef imageMasked = CGBitmapContextCreateImage(context);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
[img release];
newImage = [[UIImage imageWithCGImage:imageMasked] retain];
CGImageRelease(imageMasked);
}
}
return newImage;
}
I think this could be very related:
In iOS 11 there is a very elgant way of rounding each single corner of a (Image)View.
let imageView = UIImageView(image: UIImage(named: "myImage"))
imageView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
imageView.layer.cornerRadius = 10.0
I liked the answer of #samwize, however it caused me nasty memory leaks when used with collectionView.
To fix it I found that UIGraphicsEndImageContext() was missing
extension UIImage {
/**
Rounds corners of UIImage
- Parameter proportion: Proportion to minimum paramter (width or height)
in order to have the same look of corner radius independetly
from aspect ratio and actual size
*/
func roundCorners(proportion: CGFloat) -> UIImage {
let minValue = min(self.size.width, self.size.height)
let radius = minValue/proportion
let rect = CGRect(origin: CGPoint(x: 0, y: 0), size: self.size)
UIGraphicsBeginImageContextWithOptions(self.size, false, 1)
UIBezierPath(roundedRect: rect, cornerRadius: radius).addClip()
self.draw(in: rect)
let image = UIGraphicsGetImageFromCurrentImageContext() ?? self
UIGraphicsEndImageContext()
return image
}
}
Feel free to just pass the radius instead of proportion. proportion is used because I have collectionView scroll and images have different sizes, therefore when using constant radius it actually looks different in terms of proprtions (example: two images, one is 1000x1000 and another 2000x2000, corner radius of 30 will look different on each one of them)
So if you do image.roundCorners(proportion: 20) all the pictures look like the have the same corner radius.
This answer is also an updated version.
The reason it worked with clipping, not with masking, seems to be the color space.
Apple Documentation's below.
mask
A mask. If the mask is an image, it must be in the DeviceGray color space, must not have an alpha component, and may not itself be masked by an image mask or a masking color. If the mask is not the same size as the image specified by the image parameter, then Quartz scales the mask to fit the image.
Hi guys try this code,
+ (UIImage *)roundedRectImageFromImage:(UIImage *)image withRadious:(CGFloat)radious {
if(radious == 0.0f)
return image;
if( image != nil) {
CGFloat imageWidth = image.size.width;
CGFloat imageHeight = image.size.height;
CGRect rect = CGRectMake(0.0f, 0.0f, imageWidth, imageHeight);
UIWindow *window = [[[UIApplication sharedApplication] windows] objectAtIndex:0];
const CGFloat scale = window.screen.scale;
UIGraphicsBeginImageContextWithOptions(rect.size, NO, scale);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextBeginPath(context);
CGContextSaveGState(context);
CGContextTranslateCTM (context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextScaleCTM (context, radious, radious);
CGFloat rectWidth = CGRectGetWidth (rect)/radious;
CGFloat rectHeight = CGRectGetHeight (rect)/radious;
CGContextMoveToPoint(context, rectWidth, rectHeight/2.0f);
CGContextAddArcToPoint(context, rectWidth, rectHeight, rectWidth/2.0f, rectHeight, radious);
CGContextAddArcToPoint(context, 0.0f, rectHeight, 0.0f, rectHeight/2.0f, radious);
CGContextAddArcToPoint(context, 0.0f, 0.0f, rectWidth/2.0f, 0.0f, radious);
CGContextAddArcToPoint(context, rectWidth, 0.0f, rectWidth, rectHeight/2.0f, radious);
CGContextRestoreGState(context);
CGContextClosePath(context);
CGContextClip(context);
[image drawInRect:CGRectMake(0.0f, 0.0f, imageWidth, imageHeight)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
return nil;
}
Cheers !!!
It's very easy to create a rounded image when you make use of the image dimension.
cell.messageImage.layer.cornerRadius = image.size.width / 2
cell.messageImage.layer.masksToBounds = true
Found out the best and simple way of doing it is as follows (no answer did that):
UIImageView *imageView;
imageView.layer.cornerRadius = imageView.frame.size.width/2.0f;
imageView.layer.masksToBounds = TRUE;
Pretty simple and done this right.
See here...
IMO unless you absolutely need to do it in code, just overlay an image on top.
Something along the lines of...
- (void)drawRect:(CGRect)rect
{
// Drawing code
[backgroundImage drawInRect:rect];
[buttonOverlay drawInRect:rect];
}
For Creating a Round Corner image we can use quartzcore.
First How to add QuartzCore framework?
Click project -Targets
->project
->BuildPhase
->Link Binary with Libraries
->Then click + symbol finally select from list and add it
or else
Click project -Targets
->Targets
->general
->Linked Frameworks and Libraries
->Then click + symbol finally select from list and add the QuartzCore framework
Now import
#import <QuartzCore/QuartzCore.h>
in your ViewController
Then in viewDidLoad method
self.yourImageView.layer.cornerRadius = 5.0;
self.yourImageView.layer.borderWidth = 1.0f;
self.yourImageView.layer.borderColor = [UIColor blackColor].CGColor;
self.yourImageView.layer.masksToBounds = YES;
I was struggling to round the corners of a UIImage box in my storyboard. I had a IBOutlet for my UIImage called image. After reading a bunch of posts on here, I simply added 3 lines and that worked perfectly.
import UIKit
Then in viewDidLoad:
image.layer.cornerRadius = 20.0
image.layer.masksToBounds = true
This is for iOS 11.1 in Xcode 9.