I've written a small example program using OpenGL and GLUT to display a 2-by-2 grid of four colored squares using the glDrawPixels function. Unfortunately, I've found that: The colors in the grid are not being displayed properly; and When the glPixelZoom function is passed negative arguments to rotate the pixmap, nothing is displayed...
I know how to draw straight lines but could I draw a line which http://img163.imageshack.us/img163/2320/path3003.png (around a straight line i.e.)? Excuse me, I do not speak English very well to describe this more detailed ;-) Edit: Hey sorry for my late answer - you are right, it should be something like a sine wave which "vericulates...
I have an arbitrary tree structure of nodes. I want to draw this tree to provide users a visual representation. I need to recurse over the tree and for each node add a graphic item to a list, and then just draw the list of items once tree recursion has finished. The recursion and drawing of items is of course trivial - what's a bit more ...
Hi. I have a 4-control-point bezier curve that represents some timing stuff. The first control is fixed at (0, 0) and the last control is fixed at (1, 1). The two points in between define a bezier curve that specifies how I get from 0 to 1. Now I need to create a second curve, based off the first one. This second curve also needs to go...
I want to create an application which the user is able to manipulate the line he draw. Something like Deleting the line or Selecting it. How should I do that? Thanks in advance I managed to do it using a hard coded rectangle. But I don't still have an idea how to do it using the drawLine() Can I use drawPath to do the hit test? Here...
I'm working on a Direct3D application and I sometimes need to terminate the application forcefully via the debugger. After the application has been terminated in this way a couple of times, Direct3D reports an "Out of video memory" error when attempting to create a new device. Presently I am working around this by switching my display re...
/* main- frame */ import java.awt.* ; import java.awt.event.* ; import javax.swing.* ; public class Mainframe { public Mainframe() { // TODO Auto-generated constructor stub } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub SimpleThread ST = new SimpleThread(); ST.sta...
In Qt, there is no "QGraphicsPolylineItem", so I have to implement it form QGraphicsItem. I reimplement 'paint' and 'boundingRect' functions.In 'paint()' function, I just simply draw all lines in the polyline. It's OK without any user's interaction. For selection and movable function, I reimplement the 'QPainterPath* shape()' functio...
I am using the GL selection buffer to implement mouse picking. Unfortunately, OpenGL is returning hits in the selection buffer even for objects that are entirely occluded. For example, if there is a man hidden behind a wall, the selection buffer will include a hit record for the man even though he is not visible. Selection is implemente...
I'm fairly certain that it shouldn't matter since the graphics card is still executing the commands given by the CPU and sending the framebuffer to a monitor that is simply not listening. However, I'm not sure if the graphics card doesn't detect this. ...
Is using kCGImageAlphaNone any faster or slower than using kCGImageAlphaPremultipliedFirst as the color format when using CGImageCreate() for fast animation frame rendering from bitmaps. Does double-buffering the bitmaps used between alternating frames help with load-on-write memory paging performance? ...
Do you have to first draw any source images into the canvas before you can obtain the pixel array data? or is there a better way? such as having a second hidden canvas? I am using several images that I will mash together, and draw into the main canvas. What is the best way to obtain to say backgroundData, objectsData, effectsData, from ...
How do I redraw the pixel array after I after I have previously used getImageData? The way that I thought made sense gives me the error: An invalid or illegal string was specified" code: "12 function makeImage(canvasId, background, object) { var canvas = document.getElementById(canvasId); var ctx = canvas.getContext('2d'); ...
hey Guys, well, the title says it all: I have need to make a sort of "Pie Chart"-style circular display. the wedges of the chart have to be touchable, and the whole circle has to be able to spin 360deg.. I'm still an android noob, but I'm guessing that I can't do this with a Layout.. right? preferably, the wedges would be image ...
Simulating Ocean Water: http://www.finelightvisualtechnology.com/docs/coursenotes2004.pdf I'm trying to simulate ocean and I need your help. Please be patient, I'm newbie to computer graphics but I know basics of physics and mathematics. As you can see I need to compute the formula: k is a vector, x is a coordinate (so I suggest that...
Given a triangle vertex defined with three 3D points, how do you calculate the angle between it and a given point. class Point3D { double x, y, z; } class Vertex { Point3D P1, P2, P3; } Point3D LightPoint; Light point in Red. Blue points - triangle with the surface normal shown. I need to calculate the surface normal, an...
I've read some of posts here about png/jpg/gif but still I'm quite confused.. I've got a big header on my website : width:850px height:380px weight:108kb And it's jpg. A woman + gradient + some layers on top and behing her.. Do you think 108kb it's too much? I was thinking about cut it to png pieces..Would that be a bad idea? What's y...
Currently, I can create polygon-based selection box that has only one color on dashed stroke like the following photo. In the other hand, all photo editors has selection box like the following photo. Is it possible to do this in WPF 4.0 without use double border in same place (two polygon objects place in the same location with dif...
I have a .NET Windows.Forms diagram editor that can export its diagrams as bitmaps. It also comes with a command line utility that just converts diagrams to bitmap images. I don't want to scale the diagram to a given bitmap size; instead, I want to size the bitmap based on the diagram's bounding box. I can easily determine it after dra...
http://i51.tinypic.com/15wcw2d.jpg This is an animation I made using Mathematica. As can be seen by highlighting the image, the margins at both the left and right sides are too wide. I don't want to have to submit the image to another program just for the cropping, so what do I do to eliminate the whitespace? Looking at the documentati...