qglwidget

I wrote and tested some code in a Windows XP (Qt 4.7.2) using Visual Studio 2010 and then I tried on another machine with Windows 7 installed. The program opens a QDialog and creates a QGLWidget where I show webcam images (with some processing). While in Windows XP the images are shown correctly, at the moment that I test the program in a Windows 7 machine, the QGLWidget turns black and no image is shown. It is strange, though, that when I move around the window and it gets out of the borders of the screen, the image is shown for an instant and pitch black when I stop moving again, which makes

I am using a 3 layer hierarchy of QGLWidgets to share shaders and vertex data between 5 OpenGL viewports in my CAD-like app. The root context is used for compiling application-wide shaders, the per document context is used to share model vertex data, and the viewport contexts are the ones that actually do the rendering (and also contain grid vertex data and other per viewport stuff). The shader sharing seems to work fine, and so does the grid drawing, but when it comes to sharing vertex data it fails and to be honest - I cannot see how it is supposed to work... I built a 3D icon for an item

I need to scale the result of glDrawPixels image. I'm drawing a 640x480 pixels image buffer with glDrawPixels in a Qt QGLWidget. I tryed to do the following in PaintGL: glScalef(windowWidth/640, windowHeight/480, 0); glDrawPixels(640,480,GL_RGB,GL_UNSIGNED_BYTE,frame); But it doesn't work. I am setting the OpenGL viewport and glOrtho with the size of the widget as: void WdtRGB::paintGL() { glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Setup the OpenGL viewpoint glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(0, windowWidth, windowHeight, 0, -1.0, 1.0); glDepthMask(0); /

In my application I take snapshots of a QGLWidget's contents for two purposes: Not redraw the scene all the time when only an overlay changes, using a cached pixmap instead Lat the user take screenshots of the particular plots (3D scene) The first thing I tried is grabFrameBuffer() . It is natural to use this function as for the first application, what is currently visible in the widget is exactly what I want to cache. PROBLEM: On some hardware (e.g. Intel integrade graphics, Mac OS X with GeForce graphics), the image obtained does not contain the current screen content, but the content before

I'm creating a CAD-like app (Qt-based), it will be a multiple document interface and each document will contain about 5 viewports (derived from QGLWidget). As such I need my flat shader to be shared across the entire application, and then the 3D assets (models stored as VBOs) to be shared across each document i.e. the 5 viewports. I thought as long as I shared around the shader program and VBO GLuint addresses all will automagickly work - it doesn't. I think because each viewport/context has it's own address space on the graphics card, if anyone knows better please inform! I would like to have

I am having trouble with rendering a OpenGL scene. The background is I want to display the frames from a video capture device in a preview window. I am using OpenCV and Qt. And to test I am capturing from my MacBook webcam. The preview window is 200x200 and the frame captured is 640x480. I am not worried about maintaining aspect ratios. Other info from the IplImage struct: Debug: channels: 3 Debug: depth: 8 Debug: dataOrder: 0 Debug: align: 4. Alignment of image rows 4 or 8 Debug: origin: 0. 0=top left, 1=bottom left Debug: widthStep: 2560. Debug: colorModel: RGB So this image shows the