Is it possible to have openGL in 2 windows? as in 2 different windows (lets say the first is 640x480 and the other is 1024x768) rendering different things (lets say one window is an editor and the other is the main/normal window display) ...
I'm pretty much a newbie with opengl. I imagine glReadPixels is horrible so whats the best way to do this? I was thinking of having a function that locks a texture rect, do something like glTexSubImage2D to copy the pixels to RAM, modify it, then use glTexSubImage2D to copy the ram back into the texture. Is this a good way? I can think o...
I've been programming opengl using glut as my window handler, lately i've been thinking if there are any advantages to switching to an alternate window handler such as wxWidgets or qt. Are there any major differences at all or is it just a matter of taste? Since glut provides some additional functions for opengl-programming beyond the w...
According to ARB_geometry_shader4 it is possible to render a scene onto the 6 faces of a cube map with a geometry shader and the cube map attached to a framebuffer object. I want to create a shadow map using this way. However there seems to be a conflict that I can't resolve: I can only attach a texture with GL_DEPTH_COMPONENT as inter...
I did a lot of VRML+Java work in college and loved it, but I feel like it's not really a marketable skill. Has anyone worked with a high level graphics API like open inventor, coin..etc that is actually in use to a degree that makes investing a lot of time in the API worthwhile for something more than a hobby? ...
Let's say I want to draw a simple quad like this: glBegin(GL_QUADS); glVertex2f(-1.0,-1.0); glVertex2f(1.0,-1.0); glVertex2f(1.0, 1.0); glVertex2f(-1.0, 1.0); glEnd(); Is there a way to draw this such that it appears behind all 3D objects and fills up the whole screen? My camera moves with the mouse, so this quad also has to appear s...
Hi, I have a curious problem about an App which MainView is inherited from NSOpenGlView. I am able to draw many things in it, like a basic OpenGL tutorial.... but when I try to implement a basic trackball, it looks like the app waits until I release the mouse button before it refreshes my view... even if I call directly the "DrawRect" c...
I'm stuck at not being able to map texture to a square in openGLES. I'm trying to display a jpg image on the screen, and in order for me to do that, I draw a square that I want to then map image onto. However all I get as an output is a white square. I don't know what am I doing wrong. And this problem is preventing me from moving forwar...
Hi. I'm learning some OpenGL game programing, and I'm stuck in how to implement so the camera follows the mousepointer. Like in a fps game you want to look where your mouse is pointing, but I can't find a nice solution to this while I'm moving. I was thinking of saving one matrix for the move, like walkking and strafing, while using qua...
I plan to develop a tool for realtime video manipulation using C++, Qt and OpenGL. Video overlay isn't an option since shaders should be used for frame processing. At the moment I imagine a following sequence of steps: Decode video (CPU) Preprocess it (optional, CPU) Transer it to video memory (GPU using DMA) Further process it using v...
I've noticed that a OpenGL app I've been working on has significant performance difference when run on Linux vs WindowsXP. Granted, there are a lot of textures and shadow buffers but I would estimate that the app runs about 10x slower on Windows XP. Any ideas? Any suggestions for porting the code to DirectX? Can that be done easily...
This is something I've been looking into for while, but I have yet to find any concrete information or good examples. I have, say, a bunch of unconnected objects (triangle strips for instance). What is the efficient way to render these? I've heard about putting several objects in one VBO to reduce openGL calls, but have not seen a prope...
Is there someplace I can read about the changes and additions made in GLSL from version 1.1 to 1.2 and from 1.2 to 1.3? Google seem to be at a loss for this and I really don't want to start reading the complete specification. ...
I need to draw an 2d-array of color triplets on the screen, what is the fastest way of doing that? The target language is C/C++ and the program has only to work on Linux, but platform independant solutions are preferred obviously. I run Xorg, XVideo and OpenGL are available. How many FPS can I expect on 1024x768 on an Intel Core 2 Duo ...
I need some hardware for high bandwidth video processing using GLSL. Could anyone recommend me the best GPU for the job? My requirements (most to least important): fits into laptop good fragment shaders support (high instruction limit etc) pixel buffer object extension quality opengl windows driver low price :) ...
If you were writing the next 3d graphics intensive application in C# (like a 3d modelling and animation software), which one would be a better choice? If we consider C# as platform independent, then OpenGL seems tempting, but what about the performance, etc? Since the used language is C#, the performance is pretty crucial to consider. ...
Hi all, I'm looking into iPhone development. Most likely I'd be working on the move, so need a laptop to develop on. What would be the minimum spec laptop I could use to develop for the iPhone? Most likely the development would include OpenGL work. Thanks. ...
Hi all, I have some scientific image data that's coming out of a detector device in a 16 bit range which then gets rendered in an image. In order to display this data, I'm using OpenGL, because it should support ushorts as part of the library. I've managed to get this data into textures rendering on an OpenGL 1.4 platform, a limitatio...
I'm trying to figure out a simple to draw some text in OpenGL. My research has shown its a fairly complex task. It involves creating (or generating at runtime) a font atlas texture, and then creating a quad for each letter with just the right placement and texture coordinates. I've heard some good things about freetype, but have found...
When implementing texture mapping on a standard polygonal mesh using the usual algorithm, you can run into issues related to deformations along the y-axis in that the deformations follow along bands of constant height rows of quads instead of the vertices in this direction being able to stretch independently compared to that along the x-...