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  • Image animation over CGContextDrawPDFPage

    - by BittenApple
    I'm modifying the QuartzDemo sample app from Apple. In QuartzViewController.m I have modifications (by DyingCactus) which replac the back button and add a method to handle the back button press as follows: -(void)viewDidLoad { // Add the QuartzView [scrollView addSubview:self.quartzView]; //add custom back button if this is the PDF view... if ([self.quartzView isKindOfClass:[QuartzPDFView class]]) { self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"QuartzDemo" style:UIBarButtonItemStyleBordered target:self action:@selector(myBackButtonHandler:)]; } } - (void)myBackButtonHandler:(id)sender { [self.quartzView setFrame:CGRectMake(150, -200, 100, 200)]; [UIView beginAnimations:nil context:nil]; [UIView setAnimationDelegate:self]; [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)]; [UIView setAnimationDuration:1.0]; [self.quartzView setFrame:CGRectMake(150, 0, 100, 200)]; [UIView commitAnimations]; } - (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context { [self.navigationController popViewControllerAnimated:YES]; } I have a PNG image in resources folder called "bookmark.png" and would like to have that image animate as in animation in the example above. The image can be loaded in an UImageview or something and lets say that I have one called bookmark. How do I call that instead of self.quartzview in this part of code: [self.quartzView setFrame:CGRectMake(150, -200, 100, 200)]; [UIView beginAnimations:nil context:nil]; [UIView setAnimationDelegate:self]; [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)]; [UIView setAnimationDuration:1.0]; [self.quartzView setFrame:CGRectMake(150, 0, 100, 200)]; [UIView commitAnimations];

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  • iphone: how to do Page turning

    - by srnm12
    hi frnds, I am facing the problem from a month and didn't find anything from google.. I am using UIView for pdf display. there is no problem with pdf but problem is with transition. I have to turn each page of pdf with realistic page turn exp. I search, dig a lot about that but i didn't get anything that how to do that. I don't want to use any API'S like codeflake or any other. all i want to do this by my own programming. First i read that this can be done using cocos2d or CAAnimation but i want to know how? b'coz realistic page i think so is completely 3d concept. Let me know guys how to do thay?? here's the example video: http://www.youtube.com/watch?v=oknMWvRO2XE I want animation just like in video....

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  • Algorithm for Text Wrapping Within a Shape

    - by devongovett
    I am looking for an algorithm to wrap text within a non-rectangular shape, preferably based on the Knuth and Plass algorithm. The hardest part of this is that the lines may have different heights due to differing font sizes in the text. The image below is an example of what the algorithm should be able to generate. Thanks for any help!

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  • How to create a "Clustergram" plot ? (in R)

    - by Tal Galili
    Hi all, I came across this interesting website, with an idea of a way to visualize a clustering algorithm called "Clustergram": I am not sure how useful this really is, but in order to play with it I would like to reproduce it with R, but am not sure how to go about doing it. How would you create a line for each item so it would stay consistent throughout the different number of clusters? Here is an example code/data to play with for potential answer: hc <- hclust(dist(USArrests), "ave") plot(hc)

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  • SVG to Android Shape

    - by Buggieboy
    I have started learning about vector drawing in Android with the Shape class. Since Shape is a Drawable, and Drawables are usually defined as XML, it sounds a lot like the vector drawing commands in SVG. My question is this: Has anybody created an XSLT transformation, or other mechanism, for converting an SVG drawing description into Android Shapes?

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  • Millions of 3D points: How to find the 10 of them closest to a given point?

    - by Kazoom
    A point in 3-d is defined by (x,y,z). Distance d between any two points (X,Y,Z) and (x,y,z) is d= Sqrt[(X-x)^2 + (Y-y)^2 + (Z-z)^2]. Now there are a million entries in a file, each entry is some point in space, in no specific order. Given any point (a,b,c) find the nearest 10 points to it. How would you store the million points and how would you retrieve those 10 points from that data structure.

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  • efficient algorithm for drawing circle arcs?

    - by banister
    I am using the mid-point circle algorithm (bresenham circle) to efficiently draw whole circles. Is there something similar to draw circle arcs? I would like to specify a start angle and end angle and have only that portion of the circle drawn. Thanks in advance! EDIT: I would like to draw filled circle arcs too, i.e pie-slices. :)

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  • Quartz 2D: draw from a CGContext to another CGContext

    - by alexey
    I have a CGBitmapContext (bitmapContext) and I would like to draw some rectangle part (rect) of it to the current CGContext (context). Right now I do that way: CGContextRef context = UIGraphicsGetCurrentContext(); CGImageRef cgImage = CGBitmapContextCreateImage(bitmapContext); CGContextClipToRect(context, rect); CGContextDrawImage(context, CGRectMake(0, 0, width, height), cgImage); CGImageRelease(cgImage); Is it optimal? What is the best way to do it?

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  • Encode complex number as RGB pixel

    - by Vi
    How is it better to encode a complex number into RGB pixel and vice versa? Probably (logarithm of) an absolute value goes to brightness and an argument goes to hue. Desaturated pixes should receive randomized argument in reverse transformation. Something like: 0 - (0,0,0) 1 - (255,0,0) -1 - (0,255,255) 0.5 - (128,0,0) i - (255,255,0) -i - (255,0,255) (0,0,0) - 0 (255,255,255) - e^(i * random) (128,128,128) - 0.5 * e^(i *random) (0,128,128) - -0.5 Are there ready-made formulas for that?

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  • trying to draw scaled UIImage in custom view, but nothing's rendering

    - by Ben Collins
    I've created a custom view class and right now just want to draw an image scaled to fit the view, given a UIImage. I tried just drawing the UIImage.CGImage, but as others have attested to on this site (and in the docs), that renders the image upside down. So, at the suggestion of an answer I found to another question, I'm trying to draw it directly, but nothing is rendering in the view and I'm not sure why. Here's my drawing code: - (void)drawRect:(CGRect)rect { // Drawing code [super drawRect:rect]; if (self.originalImage) { [self drawImage]; } } - (void) drawImage { if (CGSizeEqualToSize(originalImage.size, self.frame.size) == NO) { CGFloat scaleFactor = 1.0; CGFloat scaledWidth = 0.0; CGFloat scaledHeight = 0.0; CGPoint thumbPoint = CGPointMake(0.0, 0.0); CGFloat widthFactor = self.frame.size.width / originalImage.size.width; CGFloat heightFactor = self.frame.size.height / originalImage.size.height; if (widthFactor < heightFactor) { scaleFactor = widthFactor; } else { scaleFactor = heightFactor; } scaledWidth = originalImage.size.width * scaleFactor; scaledHeight = originalImage.size.height * scaleFactor; if (widthFactor < heightFactor) { thumbPoint.y = (self.frame.size.height - scaledHeight) * 0.5; } else if (widthFactor > heightFactor) { thumbPoint.x = (self.frame.size.width - scaledWidth) * 0.5; } UIGraphicsBeginImageContext(self.frame.size); CGRect thumbRect = CGRectZero; thumbRect.origin = thumbPoint; thumbRect.size.width = scaledWidth; thumbRect.size.height = scaledHeight; [originalImage drawInRect:thumbRect]; self.scaledImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); } else { self.scaledImage = originalImage; } } My understanding (after studying this a bit) is that the UIGraphicsBeginImageContext function creates an offscreen for me to draw into, so now how do I render that context on top of the original one?

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  • millions of 3d points how to 10 closest to origin

    - by Kazoom
    A point in 3-d is defined by (x,y,z). Distance d between any two points (X,Y,Z) and (x,y,z) is d= Sqrt[(X-x)^2 + (Y-y)^2 + (Z-z)^2]. Now there are a million entries in a file, each entry is some point in space, in no specific order. Given any point (a,b,c) find the nearest 10 points to it. How would you store the million points and how would you retrieve those 10 points from that data structure.

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  • In OpenGL vertex shader, gl_Position doesn't get homogenized..

    - by KJ
    Hi everyone, I was expecting gl_Position to automatically get homogenized (divided by w), but it seems not working.. Why do the followings make different results? 1) void main() { vec4 p; ... omitted ... gl_Position = projectionMatrix * p; } 2) ... same as above ... p = projectionMatrix * p; gl_Position = p / p.w; I think the two are supposed to generate the same results, but it seems it's not the case. 1 doesn't work while 2 is working as expected.. Could it possibly be a precision problem? Am I missing something? This is driving me almost crazy.. helps needed. Many thanks in advance!

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  • Super wide, but not so tall, bitmap?

    - by Erik Karlsson
    Howdy folks. Is there any way to create a more space/resource efficient bitmap? Currently i try to render a file, approx 800 px high but around 720000px wide. It crashes my application, presumebly because of the share memory-size of the bitmap. Can i do it more efficient, like creating it as an gif directly and not later when i save it? I try to save a series of lines/rectangles from a real world reading, and i want it to be 1px per 1/100th of a second. Any input? And btw, i never manage to ogon using google open id : /

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  • How do I prevent jagged edges alongside the surfaces of my 3d model?

    - by badcodenotreat
    Lets say I've implemented in openGL a crude model viewer with shading which renders a series of blocks, such that I have something that looks like this. http://i.imgur.com/TsF7K.jpg Whenever I rotate my model to the side, it causes an unwanted jagged effect along any surface with a steep viewing angle. http://i.imgur.com/Bgl9o.jpg I'm pretty sure this is due to the polygon offset I used to prevent z-fighting between the model and the wireframe, however I'm not able to find the factor/unit parameters in openGL which prevent this unwanted effect. what are the best values of factor and unit for glPolygonOffset to prevent this? would implementing anti-aliasing alleviate the problem? is the trade off in performance trivial/significant? is this perhaps a shading issue? should i try a solution along this line of thought?

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  • How well are SVG filter elements defined?

    - by Peter Becker
    We are considering using SVG filters as part of our toolchain, serving the SVG to browsers capable of supporting it, while serving pre-rendered PNGs to other. One problem we noticed is that the rendering of the filter chains seems to be very inconsistent across renderers. When looking at the "filters01" example from the SVG specification, the rendering looks very different across the tools we tried. Chrome (5.0.307.11) failed to render the image, while other tools (Firefox 3.6, Opera 10.10, Inkscape 0.47, GIMP 2.6.7) render something vaguely similar in style to the picture in the specification, but no two are truly the same. Is that an issue of under-specification or are the tools just not there? If we would use SVG with filter effects: is there a reference tool that can give us a rendering the way it is intended by the spec?

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  • Easy Flood Fill

    - by Jimmy
    Some advice, please. I'm just starting out in C#. I've managed to get some shapes created on a Windows form, and now I'd like to fill them with color. In the old C++ I studied years ago, there was a floodfill function that was really easy. It has been an unpleasant realization to find there's not a similar method available in regular old C#. Does anyone have advice for me, or some code, so I can implement filling without understanding GDI+, DirectX, or rest of the avalanche of acronyms that I've run into by researching this on the web? I need to fill irregular shapes, bounded by a certain color. Gradient and transparency control would be nice, but I'd settle for plain old solid fill right now, just to get a modicom of control over this. Any help, code or advice would be really appreciated.

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  • How do I draw a proper parallelogram that can be animated on iPhone?

    - by Robert Kosara
    I'm trying to do something very simple: I need some parallelograms in my program. These are attached to other objects, all of which are UIViews. It's important that I be able to animate these, since the objects they are attached to can also be animated. I've figured out how to use the transform in UIView/CALayer to do this, but the problem is that these sheared UIViews don't look very nice: there is no anti-aliasing of the edges. Is there some other way to do this? I would like to use UIViews, since I also use them for user interaction and animation is so much easier than drawing by hand. I don't want to use OpenGL for this.

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  • Optimizing drawing on UITableViewCell

    - by Brian
    I am drawing content to a UITableViewCell and it is working well, but I'm trying to understand if there is a better way of doing this. Each cell has the following components: Thumbnail on the left side - could come from server so it is loaded async Title String - variable length so each cell could be different height Timestamp String Gradient background - the gradient goes from the top of the cell to the bottom and is semi-transparent so that background colors shine through with a gloss It currently works well. The drawing occurs as follows: UITableViewController inits/reuses a cell, sets needed data, and calls [cell setNeedsDisplay] The cell has a CALayer for the thumbnail - thumbnailLayer In the cell's drawRect it draws the gradient background and the two strings The cell's drawRect it then calls setIcon - which gets the thumbnail and sets the image as the contents of the thumbnailLayer. If the image is not found locally, it sets a loading image as the contents of the thumbnailLayer and asynchronously gets the thumbnail. Once the thumbnail is received, it is reset by calling setIcon again & resets the thumbnailLayer.contents This all currently works, but using Instruments I see that the thumbnail is compositing with the gradient. I have tried the following to fix this: setting the cell's backgroundView to a view whose drawRect would draw the gradient so that the cell's drawRect could draw the thumbnail and using setNeedsDisplayInRect would allow me to only redraw the thumbnail after it loaded --- but this resulted in the backgroundView's drawing (gradient) covering the cell's drawing (text). I would just draw the thumbnail in the cell's drawRect, but when setNeedsDisplay is called, drawRect will just overlap another image and the loading image may show through. I would clear the rect, but then I would have to redraw the gradient. I would try to draw the gradient in a CAGradientLayer and store a reference to it, so I can quickly redraw it, but I figured I'd have to redraw the gradient if the cell's height changes. Any ideas? I'm sure I'm missing something so any help would be great.

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  • How to access pixels of an NSBitmapImageRep?

    - by Paperflyer
    I have an NSBitmapImageRep that is created like this: NSBitmapImageRep *imageRep = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:NULL pixelsWide:waveformSize.width pixelsHigh:waveformSize.height bitsPerSample:8 samplesPerPixel:4 hasAlpha:YES isPlanar:YES colorSpaceName:NSCalibratedRGBColorSpace bytesPerRow:0 bitsPerPixel:0]; Now I want to access the pixel data so I get a pointer to the pixel planes using unsigned char *bitmapData; [imageRep getBitmapDataPlanes:&bitmapData]; According to the Documentation this returns a C array of five character pointers. But how can it do that? since the type of the argument is unsigned char **, it can only return an array of chars, but not an array of char pointers. So, this leaves me wondering how to access the individual pixels. Do you have an idea how to do that? (I know there is the method – setColor:atX:y:, but it seems to be pretty slow if invoked for every single pixel of a big bitmap.)

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  • Auto scrolling or shifting a bitmap in .NET

    - by mikej
    I have a .NET GDI+ bitmap object (or if it makes the problem easier a WPF bitmap object) and what I want to to is shift the whole lot by dx,dy (whole pixels) and I would ideally like to do it using .NET but API calls are ok. It has to be efficient bacause its going to be called 10,000 times say with moderately large bitmaps. I have implemented a solution using DrawImage - but its slow and it halts the application for minutes while the GC cleans up the temp objects that have been used. I have also started to work on a version using ScrollDC but so far have had no luck getting it to work on the DC of the bitmap (I can make it work buy creating an API bitmap with bitmap handle, then creating a compatible DC asnd calling ScrollDC but then I have to put it back into the bitmap object). There has to be an "inplace" way of shifting a bitmap. mikej

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  • drawing images and lines over UIScrollView

    - by Jorge
    I'm programming an app in which one of the ViewControllers is showing an UIScrollView that shows an image. I'd like to load an image (pushpin in png format) and draw it (and delete it) in some points of the UIScrollView image. I'd also would like to draw bezier paths in that image (and deleting them). I've programmed several apps but this is the first time I face graphic programming and don't know where to start from. Any suggestions? Thanks!

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  • A dynamic array of class "landmark", inside another single class "landmarks"

    - by pinnacler
    I'm working on a robot localization simulator and I created a class called "landmark". The end result is going to be a robot that is always centered and always faces the top of the screen. As it turns, the birds eye view map will rotate around the robot. To accomplish this, I'm assuming I can rotate one class and have all elements inside rotate as well. So, the landmark class has properties x,y, label, and radius. This is suppose to simulate a tree location in a forest. To test everything, I need "forest data," and I wrote a script to generate 100 trees in a 100m x 100m area. The script automatically generates values within an acceptable range for x,y, radius. The generated data is stored in an object called tempForest and is 100x3. Ideally, I want to create a class called "landmarks" (plural) that has 100 landmark instances inside. How would I instantiate 100 instances of landmark in one instance of landmarks using that randomly generated data? Ideally, I'd just type treeBeacons = landmarks(); and it would randomly populate 100 (user definable, set in config file) instances with x, y, radius data. I'm not sure how to deal with a dynamic array of class "Landmark", inside another single class "landmarks." Any ideas?

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  • imageWithCGImage and memory

    - by Adam Ernst
    If I use [UIImage imageWithCGImage:], passing in a CGImageRef, do I then release the CGImageRef or does UIImage take care of this itself when it is deallocated? The documentation isn't entirely clear. It says "This method does not cache the image object." Originally I called CGImageRelease on the CGImageRef after passing it to imageWithCGImage:, but that caused a malloc_error_break warning in the Simulator claiming a double-free was occurring.

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  • QPainter paints garbage

    - by DSblizzard
    Fragment of program code: def add_link(Item0Num, Item1Num): global Mw, View # Mw - MainWindow if Item0Num != Item1Num and not link_exists(Item0Num, Item1Num): append( links_to(Item1Num), Item0Num ) append( links_from(Item0Num), Item1Num ) LinkGi = TLinkGi() Mw.Scene.addItem(LinkGi) LinkGi.setZValue(200) LinkGi.scale(1 / View.Scale, 1 / View.Scale) LinkGi.Item0Num = Item0Num LinkGi.Item1Num = Item1Num class TLinkGi(QGraphicsItem): def paint(self, Painter, StyleOptionGraphicsItem, Widget): global Mw, View Pen = QPen(Qt.black, 1) Painter.setPen(Pen) X0, Y0 = task_center(self.Item0Num) self.setPos(X0, Y0) X1, Y1 = task_center(self.Item1Num) X, Y = int( (X1 - X0) * View.Scale ), int( (Y1 - Y0) * View.Scale ) Painter.drawLine(0, 0, X, Y) #Mw.Scene.update(0, 0, Plan.Size, Plan.Size) # (1) #Mw.gvMain.repaint() # (2) def boundingRect(self): global View Rect = QRectF(0, 0, Plan.Size, Plan.Size) return Rect This paints such garbage: http://img697.imageshack.us/content_round.php?page=done&l=img697/5395/qpaintergarbage1.jpg When lines (1) and (2) are uncommented things doesn't become much better: http://img63.imageshack.us/content_round.php?page=done&l=img63/9693/qpaintergarbage0.jpg Please help me to solve this problem.

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  • Are we DELPHI, VCL or Pascal programmers?

    - by José Eduardo
    i´ve been a delphi database programmer since D2. Now i´m facing some digital imaging and 3D challenges that make me to start study OpenGL, DirectX, Color Spaces and so on. I´m really trying but nobody seems to use Delphi for this kind of stuff, just the good-old-paycheck Database programming. ok, i know that we have some very smart guys behind some clever components, some of this open-source. Is there any PhotoShop, Blender, Maya, Office, Sonar, StarCraft, Call of Dutty written in Delphi? Do i have to learn C++ to have access to zillions of books about that kind of stuff? What is the fuzz/hype behind this: int *varName = &anhoterThing? Why pointers seems to be the holy graal to this apps? I´ve downloaded MSVC++ Express and start to learn some WPF and QT integration, and i think: "Man, Delphi does this kind of stuff, with less code, less headaches, since the wheels were invented" This lead my mind to the following... Do you ever tried to write a simple notepad program using just notepad and dcc32 in Pascal/Delphi? if so embarcadero could make our beloved pascal compiler free, and sell just the ide, the vcl, the customer support ... and back to the question: Are we DELPHI, VCL or Pascal programmers?

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