Search Results

Search found 6029 results on 242 pages for 'discrete graphics'.

Page 78/242 | < Previous Page | 74 75 76 77 78 79 80 81 82 83 84 85  | Next Page >

  • C# Drawing Arc with 3 Points

    - by Keeper
    Hi, I need to draw an arc using GraphicsPath and having initial, median and final points. The arc has to pass on them. I tried .DrawCurve and .DrawBezier but the result isn't exactly an arc. What can I do?

    Read the article

  • CGGradient Not Displaying Correctly on iPad 1 and 2

    - by daveMac
    I have been experimenting with creating my own gradients for the UI in my iOS app. I first used a CAGradientLayer but I was disappointed with the "stepped" look so I have been trying out CGGradient. enter code here I am having an issue with the Gradient displaying correctly. I have three iPads—one for each generation. The gradient looks right on the iPad 3 but not on the iPad 1 or 2. This is really strange. I was going to take a screenshot and post the two differences but even more strange, the screenshot look the same (and yes, the brightness is the same on both). The colors seem really washed out on the older iPads. I know the iPad 3 is a retina display, but I think it must be something more than that. Here is the code I am using: - (void)drawRect:(CGRect)rect { CGContextRef currentContext = UIGraphicsGetCurrentContext(); CGGradientRef skyGradient; CGColorSpaceRef rgbColorspace; size_t num_locations = 3; CGFloat locations[3] = { 0.0, .5, 1.0 }; CGFloat components[12] = { .106, .73, .93333, 1., 0.0, 0.0 , 1.0, 1., .106, .73, .93333, 1. }; rgbColorspace = CGColorSpaceCreateDeviceRGB(); skyGradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, num_locations); CGRect currentBounds = self.bounds; CGPoint topLeft = CGPointMake(0.0f, 0.0f); CGPoint bottomRight = CGPointMake(CGRectGetMaxX(currentBounds), CGRectGetMaxY(currentBounds)); CGContextDrawLinearGradient(currentContext, skyGradient, topLeft, bottomRight, 0); CGGradientRelease(skyGradient); CGColorSpaceRelease(rgbColorspace); }

    Read the article

  • Rotate rectangle around center

    - by ESoft
    I am playing with Brad Larsen's adaption of the trackball app. I have two views at a 60 degree angle to each other and was wondering how I get the rotation to be in the center of this (non-closed) rectangle? In the images below I would have liked the rotation to take place all within the blue lines. Code (modified to only rotate around x axis): #import "MyView.h" //===================================================== // Defines //===================================================== #define DEGREES_TO_RADIANS(degrees) \ (degrees * (M_PI / 180.0f)) //===================================================== // Public Interface //===================================================== @implementation MyView - (void)awakeFromNib { transformed = [CALayer layer]; transformed.anchorPoint = CGPointMake(0.5f, 0.5f); transformed.frame = self.bounds; [self.layer addSublayer:transformed]; CALayer *imageLayer = [CALayer layer]; imageLayer.frame = CGRectMake(10.0f, 4.0f, self.bounds.size.width / 2.0f, self.bounds.size.height / 2.0f); imageLayer.transform = CATransform3DMakeRotation(DEGREES_TO_RADIANS(60.0f), 1.0f, 0.0f, 0.0f); imageLayer.contents = (id)[[UIImage imageNamed:@"IMG_0051.png"] CGImage]; imageLayer.borderColor = [UIColor yellowColor].CGColor; imageLayer.borderWidth = 2.0f; [transformed addSublayer:imageLayer]; imageLayer = [CALayer layer]; imageLayer.frame = CGRectMake(10.0f, 120.0f, self.bounds.size.width / 2.0f, self.bounds.size.height / 2.0f); imageLayer.transform = CATransform3DMakeRotation(DEGREES_TO_RADIANS(-60.0f), 1.0f, 0.0f, 0.0f); imageLayer.contents = (id)[[UIImage imageNamed:@"IMG_0089.png"] CGImage]; imageLayer.borderColor = [UIColor greenColor].CGColor; imageLayer.borderWidth = 2.0f; transformed.borderColor = [UIColor whiteColor].CGColor; transformed.borderWidth = 2.0f; [transformed addSublayer:imageLayer]; UIView *line = [[UIView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height / 2.0f, self.bounds.size.width, 2)]; [line setBackgroundColor:[UIColor redColor]]; [self addSubview:line]; line = [[UIView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height * (1.0f / 4.0f), self.bounds.size.width, 2)]; [line setBackgroundColor:[UIColor blueColor]]; [self addSubview:line]; line = [[UIView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height * (3.0f / 4.0f), self.bounds.size.width, 2)]; [line setBackgroundColor:[UIColor blueColor]]; [self addSubview:line]; } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { previousLocation = [[touches anyObject] locationInView:self]; } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { CGPoint location = [[touches anyObject] locationInView:self]; //location = CGPointMake(previousLocation.x, location.y); CATransform3D currentTransform = transformed.sublayerTransform; //CGFloat displacementInX = location.x - previousLocation.x; CGFloat displacementInX = previousLocation.x - location.x; CGFloat displacementInY = previousLocation.y - location.y; CGFloat totalRotation = sqrt((displacementInX * displacementInX) + (displacementInY * displacementInY)); CGFloat angle = DEGREES_TO_RADIANS(totalRotation); CGFloat x = ((displacementInX / totalRotation) * currentTransform.m12 + (displacementInY/totalRotation) * currentTransform.m11); CATransform3D rotationalTransform = CATransform3DRotate(currentTransform, angle, x, 0, 0); previousLocation = location; transformed.sublayerTransform = rotationalTransform; } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { } - (void)dealloc { [super dealloc]; } @end

    Read the article

  • Resizing an image with alpha channel

    - by Hafthor
    I am writing some code to generate images - essentially I have a source image that is large and includes transparent regions. I use GDI+ to open that image and add additional objects. What I want to do next is to save this new image much smaller, so I used the Bitmap constructor that takes a source Image object and a height and width, then saved that. I was expecting the alpha channel to be smoothed like the color channels, but this did not happen -- it did result in a couple of semitransparent pixels, but overall it is very blocky. What gives? Using img As New Bitmap("source100x100.png") ''// Drawing stuff Using simg As New Bitmap(img, 20, 20) simg.Save("target20x20.png") End Using End Using Edit: I think what I want is SuperSampling, like what Paint.NET does when set to "Best Quality"

    Read the article

  • Merging photo textures - (from calibrated cameras) - projected onto geometry

    - by freakTheMighty
    I am looking for papers/algorithms for merging projected textures onto geometry. To be more specific, given a set of fully calibrated cameras/photographs and geometry, how can we define a metric for choosing which photograph should be used to texture a given patch of the geometry. I can think of a few attributes one may seek minimize including the angle between the surface normal and the camera, the distance of the camera from the surface, as well as minimizing some parameterization of sharpness. The question is how do these things get combined and are there well established existing solutions?

    Read the article

  • How to write an intersects for Shapes in android

    - by Rafael T
    I have an written an Object called Shape which has a Point representing the topLeftCorner and a Dimension with represents its width and height. To get the topRightCorner I can simply add the width to the topLeftPoint.x. I use to rotate them on a certain degree around their center. The problem after the rotation is, that my intersects(Shape) method fails, because it does not honor the rotation of the Shapes. The rotation will be the same for each Shape. My current implementation looks like this inside my Shape Object: public boolean intersects(Shape s){ // functions returning a Point of shape s return intersects(s.topLeft()) || intersects(s.topRight()) || intersects(s.bottomLeft()) || intersects(s.bottomRight()) || intersects(s.leftCenter()) || intersects(s.rightCenter()) || intersects(s.center()); } public boolean intersects(Point p){ return p.x >= leftX() && p.x <= rightX() && p.y >= topY() && p.y <= bottomY(); } Basically I need functions like rotatedLeftX() or rotatedTopRight() to work properly. Also for that calculation I think it doesn't matter when the topLeft point before a rotation of ie 90 will turn into topRight... I already read this and this Question here, but do not understand it fully.

    Read the article

  • When not to do maximum compression in png?

    - by user1444680
    Intro When saving png images through GIMP, I've always used level 9 (maximum) compression, as I knew that it's lossless. Now I've to specify compression level when saving png format image through GD extension of PHP. Question Is there any case when I shouldn't compress PNG to maximum level? Like any compatibility issues? If there's no problem then why to ask user; why not automatically compress to max?

    Read the article

  • Finding the centroid of a polygon?

    - by user146780
    I have tried: for each vertex, add to total, divide by number of verities to get center. I'v also tried: Find the topmost, bottommost - get midpoint... find leftmost, rightmost, find midpoint. Both of these did not return the perfect center because I'm relying on the center to scale a polygon. I want to scale my polygons so I may put a border around them. What is the best way to find the centroid of a polygon given that the polygon may be concave, convex and have many many sides of various lengths. Thanks

    Read the article

  • Getting invalid context errors

    - by Andrew
    I don't have much code thus far, only this to start: UIGraphicsBeginImageContextWithOptions(bounds.size, NO, 0); CGContextRef context = UIGraphicsGetCurrentContext(); CGMutablePathRef outerPath; CGMutablePathRef highlightPath; CGRect outerRect = rectForRectWithInset(bounds, 1); CGRect highlightRect = CGRectMake(outerRect.origin.x, outerRect.origin.y + 1, outerRect.size.width, outerRect.size.height); And then the problematic bit, which when commented out, the error goes away: CGContextSaveGState(context); CGContextAddPath(context, highlightPath); CGContextSetFillColorWithColor(context, [[UIColor colorWithWhite:1.0 alpha:0.05]CGColor]); CGContextFillPath(context); CGContextRestoreGState(context); Below that is simply: UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();

    Read the article

  • Codebase for making a Flash-based interactive map with SVG vector data?

    - by Mike
    I'm looking for a way to take SVG path info (basically a string of coordinates) and dynamically draw it with Actionscript. Icing on the cake would be if those shapes could detect mouse events to trigger JS and dynamically change their appearance (fill, stroke, etc...). I'm currently trying something similar to this (http://raphaeljs.com/australia.html) using SVG but it's just too slow in IE. I've also tried Google's SVG Web (http://code.google.com/p/svgweb/) which basically does exactly what I'm looking for (it converts SVG to Flash in IE) but again, it's sloooooow - which is why I'm considering doing the whole shebang in Flash. Anyone know of some links to point me in the right direction?

    Read the article

  • Border in DrawRectangle

    - by undsoft
    Well, I'm coding the OnPaint event for my own control and it is very nescessary for me to make it pixel-accurate. I've got a little problem with borders of rectangles. See picture: These two rectangles were drawn with the same location and size parameters, but using different size of the pen. See what happend? When border became larger it has eaten the free space before the rectangle (on the left). I wonder if there is some kind of property which makes border be drawn inside of the rectangle, so that the distance to rectangle will always be the same. Thanks.

    Read the article

  • Monochrome BitMap Library

    - by Asad Jibran Ahmed
    I am trying to create a piece of software that can be used to create VERY large (10000x10000) sized bitmaps. All I need is something that can work in monochrome, since the required output is a matrix containing details of black and white pixels in the bitmap. The closest thing I can think of is a font editor, but the size is a problem. Is there any library out there that I can use to create the software, or will I have to write the whole thing from the start?

    Read the article

  • Is there a table of OpenGL extensions, versions, and hardware support somewhere?

    - by Thomas
    I'm looking for some resource that can help me decide what OpenGL version my game needs at minimum, and what features to support through extensions. Ideally, a table of the following format: 1.0 1.1 1.2 1.2.1 1.3 ... multitexture - ARB ARB core core texture_float - EXT EXT ARB ARB ... (Not sure about the values I put in, but you get the idea.) The extension specs themselves, at opengl.org, list the minimum OpenGL version they need, so that part is easy. However, many extensions have been accepted and became core standard in subsequent OpenGL versions, but it is very hard to find when that happened. The only way I could find is to compare the full OpenGL standards document for each version. On a related note, I would also very much like to know which extensions/features are supported by which hardware, to help me decide what features I can safely use in my game, and which ones I need to make optional. For example, a big honkin' table like this: MAX_TEXTURE_IMAGE_UNITS MAX_VERTEX_TEXTURE_IMAGE_UNITS ... GeForce 6xxx 8 4 GeForce 7xxx 16 8 ATi x300 8 4 ... (Again, I'm making the values up.) The table could list hardware limitations from glGet but also support for particular extensions, and limitations of such extension support (e.g. what floating-point texture formats are supported in hardware). Any pointers to these or similar resources would be hugely appreciated!

    Read the article

  • Blit Queue Optimization Algorithm

    - by martona
    I'm looking to implement a module that manages a blit queue. There's a single surface, and portions of this surface (bounded by rectangles) are copied to elsewhere within the surface: add_blt(rect src, point dst); There can be any number of operations posted, in order, to the queue. Eventually the user of the queue will stop posting blits, and ask for an optimal set of operations to actually perform on the surface. The task of the module is to ensure that no pixel is copied unnecessarily. This gets tricky because of overlaps of course. A blit could re-blit a previously copied pixel. Ideally blit operations would be subdivided in the optimization phase in such a way that every block goes to its final place with a single operation. It's tricky but not impossible to put this together. I'm just trying to not reinvent the wheel. I looked around on the 'net, and the only thing I found was the SDL_BlitPool Library which assumes that the source surface differs from the destination. It also does a lot of grunt work, seemingly unnecessarily: regions and similar building blocks are a given. I'm looking for something higher-level. Of course, I'm not going to look a gift horse in the mouth, and I also don't mind doing actual work... If someone can come forward with a basic idea that makes this problem seem less complex than it does right now, that'd be awesome too. EDIT: Thinking about aaronasterling's answer... could this work? Implement customized region handler code that can maintain metadata for every rectangle it contains. When the region handler splits up a rectangle, it will automatically associate the metadata of this rectangle with the resulting sub-rectangles. When the optimization run starts, create an empty region handled by the above customized code, call this the master region Iterate through the blt queue, and for every entry: Let srcrect be the source rectangle for the blt beng examined Get the intersection of srcrect and master region into temp region Remove temp region from master region, so master region no longer covers temp region Promote srcrect to a region (srcrgn) and subtract temp region from it Offset temp region and srcrgn with the vector of the current blt: their union will cover the destination area of the current blt Add to master region all rects in temp region, retaining the original source metadata (step one of adding the current blt to the master region) Add to master region all rects in srcrgn, adding the source information for the current blt (step two of adding the current blt to the master region) Optimize master region by checking if adjacent sub-rectangles that are merge candidates have the same metadata. Two sub-rectangles are merge candidates if (r1.x1 == r2.x1 && r1.x2 == r2.x2) | (r1.y1 == r2.y1 && r1.y2 == r2.y2). If yes, combine them. Enumerate master region's sub-rectangles. Every rectangle returned is an optimized blt operation destination. The associated metadata is the blt operation`s source.

    Read the article

  • How do I integrate a BSDF into a ray caster.

    - by pelb
    I'm trying to implement sub surface scattering at isosurfaces and looked up how a BSDF works mathematically. Implementing the reflective and diffuse part seems to be quite easy as i just have to evaluate phong at the isosurface intersection, but how do you I apply the transmissive part of the BSDF? In what way do i have to modify the ray direction. Any pointers to a practical implementation are welcome. Thanks and So long!

    Read the article

  • Why are all my masked views unmasked in my view snapshot?

    - by mystify
    I'm taking a snapshot of an view. This view has got some subviews which have layer masks applied to them. For some reason, those masks take no effect in the snapshot and the masked parts are completely visible. UIGraphicsBeginImageContext(theView.frame.size); [theView.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); I assume this is a bug in the framework. But maybe it's not? Did I do anything wrong here?

    Read the article

  • How can I tell if a closed path contains a given point?

    - by Tom Seago
    In Android, I have a Path object which I happen to know defines a closed path, and I need to figure out if a given point is contained within the path. What I was hoping for was something along the lines of path.contains(int x, int y) but that doesn't seem to exist. The specific reason I'm looking for this is because I have a collection of shapes on screen defined as paths, and I want to figure out which one the user clicked on. If there is a better way to be approaching this such as using different UI elements rather than doing it "the hard way" myself, I'm open to suggestions. I'm open to writing an algorithm myself if I have to, but that means different research I guess.

    Read the article

  • Simulating brush strokes for painting application

    - by DrRobot
    I'm trying to write an application that can be used to create pictures that look like paintings using simulated brush strokes. Are there any good sources for simple ways of simulating brush strokes? For example, given a list of mouse positions that the user has dragged the mouse through, a brush width and a brush texture, how do I determine what to draw to the canvas? I've tried angling the brush texture in the direction of the mouse movement and dabbing several brush texture images along the path, but it doesn't look great. I think I'm missing something where the brush texture should shrink and grow on corners. Any simple to follow links would be appreciated. I've found complex academic papers on simulating e.g. oil paints but I just want a basic algorithm to use that produces OK results if possible.

    Read the article

  • Optimally place a pie slice in a rectangle.

    - by Lisa
    Given a rectangle (w, h) and a pie slice with start angle and end angle, how can I place the slice optimally in the rectangle so that it fills the room best (from an optical point of view, not mathematically speaking)? I'm currently placing the pie slice's center in the center of the rectangle and use the half of the smaller of both rectangle sides as the radius. This leaves plenty of room for certain configurations. Examples to make clear what I'm after, based on the precondition that the slice is drawn like a unit circle: A start angle of 0 and an end angle of PI would lead to a filled lower half of the rectangle and an empty upper half. A good solution here would be to move the center up by 1/4*h. A start angle of 0 and an end angle of PI/2 would lead to a filled bottom right quarter of the rectangle. A good solution here would be to move the center point to the top left of the rectangle and to set the radius to the smaller of both rectangle sides. This is fairly easy for the cases I've sketched but it becomes complicated when the start and end angles are arbitrary. I am searching for an algorithm which determines center of the slice and radius in a way that fills the rectangle best. Pseudo code would be great since I'm not a big mathematician.

    Read the article

< Previous Page | 74 75 76 77 78 79 80 81 82 83 84 85  | Next Page >