Hello, in my class I have an attribute IBOutlet UIImageView *imageView; And if I want to draw an image in this view I do : imageView.image = [UIImage imageNamed:@"foo.png"]; But how can I do to draw some points with coordinate x, y (in pixel) directly in the view ? Thanks ! ...
Hello! I'm running into an issue when I try to create a CGContextRef while attempting to resize some images: There are the errors Sun May 16 20:07:18 new-host.home app [7406] <Error>: Unable to create bitmap delegate device Sun May 16 20:07:18 new-host.home app [7406] <Error>: createBitmapContext: failed to create delegate. My code ...
In Mac OS X, every display gets a unique CGDirectDisplayID number assigned to it. You can use CGGetActiveDisplayList() or [NSScreen screens] to access them, among others. Per Apple's docs: A display ID can persist across processes and system reboot, and typically remains constant as long as certain display parameters do not ...
I have three CGGradientRef's that I need to be able to dynamically recolor. When I Initialise the CGGradientRef's the first time I get the expected result, but every time I attempt to change the colors nothing happens. Why? gradient is an instance variable ins a subclass of CALayer: @interface GradientLayer : CALayer { CGGradientR...
Hi, I'm trying to rotate a button that I've connected to the controller from the Interface Builder. I've set it's image right from Interface Builder. I'm using this code on the method that runs when I click it: [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:2.0]; [UIView setAnimationRepeatCount:5]; updateButton...
I'm trying to repeat an animation until a certain condition is met. Something like this: - (void) animateUpdate { if (inUpdate) { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:2.0]; [UIView setAnimationDelegate: self]; [UIView setAnimationDidStopSelector: @selector(animateUpd...
In my drawRect method, I am drawing a PNG image. On top of that, I want to draw a rect with a 20% alpha color, like this: [[UIColor colorWithWhite:0.0 alpha:0.2] set]; UIRectFill(rect); The problem is, that the alpha property seems to get ignored. No alpha is applied at all, just a black rectangle is drawn. How can I fix this? Thanks ...
Hello, I'm trying to implement "hand draw tool". At the moment algorythm looks like that (I don't insert any code because methods are quite big, will try to explain an idea): Drawing In touchesStarted: method I create NSMutableArray *pointsArray and add point into it. Call setNeedsDisplay: method. In touchesMoved: method I calculate ...
I have a method where I draw a PDF to a bitmap. Once in a while I see this error in the log when running it on an actual device (not simulator): <Error>: FT_Select_Charmap failed: error 6 The error is occurring at the marked line (#11): NSURL *url = [NSURL fileURLWithPath:pdfFilePath]; CGPDFDocumentRef documentRef = CGPDFDocumentCrea...
Hello. I have a task - draw smooth curve input: set of points (they added in realtime) current solution: I use each 4 points to draw qubic Bezier curve (1 - strart, 2 and 3rd - control points, 4- end). End point of each curve is start point for the next one. problem: at the curves connection I often have "fracture" (angle) Can you t...
Hello, me and my friend develop iPad application (a lot of CoreGraphics stuff). But we can't find an agreement. I tell him that testing on device is essential, he tells me that testing on iPhone 3G/3GS will be enough (I have both devices). Can you tell me, probably we really can test our app on 3GS? The main thing is that interface will...
I have a PDF file that I want to draw in outline form. I want to draw the first several pages on the document each in their own UIImage to use on a button so that when clicked, the main display will navigate to the clicked page. However, CGContextDrawPDFPage seems to be using copious amounts of memory when attempting to draw the page. ...
When I call CGPDFPageGetDrawingTransform() with a rotation argument, the application crashes. If I specify no rotation, there is no crash. Here is my drawLayer:inContext: method: - (void)drawLayer:(CALayer*)layer inContext:(CGContextRef)context { CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0); CGRect boundingBox = CGContextG...
filling a path with a solid color is easy enough: CGPoint aPoint; for (id pointValue in points) { aPoint = [pointValue CGPointValue]; CGContextAddLineToPoint(context, aPoint.x, aPoint.y); } [[UIColor redColor] setFill]; [[UIColor blackColor] setStroke]; CGContextDrawPath(context, kCGPathFillStroke); I'd like to draw a gradient...
Take a look of this image: http://imagebin.ca/img/b-W91wDU.png I have some CGPath like the image 1 and I would like to know how I can create an inner shadow effect like the image 2 I'm working with objective-c and Core Graphics iPhone SDK: 3.2 ...
Hi all, I have an application in which I'm doing some custom drawing, a bunch of lines on a gradient background, like so (ignore the text, they're just UILabels): http://prehensile.co.uk/outgoing/Screenshot2010-06-09at12.22.32.png At the moment, that's all done by starting a new CGContext, drawing stuff into it with CGContextDrawLinea...
Hi guys; I am trying to draw individual pixels in xcode to be outputted to the iphone. I do not know any OpenGL or Quartz coding but I do know a bit about Core Graphics. I was thinking about drawing small rectangles with width and height of one, but do not know how to implement this into code and how to get this to show in the view. Any...
UIGraphicsBeginImageContext(targetSize); //instruments show here a leak 128bytes CGRect thumbnailRect = CGRectZero; thumbnailRect.origin = thumbnailPoint; thumbnailRect.size.width = scaledWidth; thumbnailRect.size.height = scaledHeight; [sourceImage drawInRect:thumbnailRect]; newImage = UIGraphicsGetImageFromCurrentImageContext(); U...
I have a 100x100 pixel image that I want to draw at various angles rotated around the center of the image. The following code works, but rotates around the original origo of the coordinate system (upper left hand corner) and not the translated location. Thus the image is not rotated around itself but around the upper left corner of the s...
Gentelmen, is there is any possibility to write photos in RAW format? I especially interested in com.cannon.cr2-raw-image UTI type. CGImageDestinationCreateWithData returns <Error>: CGImageDestinationCreate type doesn't support writing for given UTI. Can i install some additional codecs? May be some special library, even not CoreG...