opengl

Intersection of line with cube and knowing the point of intersection.

Hello everyone, description lines are originating from origin(0,0,0). lines are at some random angle to the Normal of Top face of the cube. if the lines are intersecting cube, calculate the intersection point. mainly I want to know how much distance the line traveled inside the cube. I don't know exactly which approach I should tak...

matrix image processing in OpenGL CE

im trying to create an image filter in OpenGL CE. currently I am trying to create a series of 4x4 matrices and multiply them together. then use glColorMask and glColor4f to adjust the image accordingly. I've been able to integrate hue rotation, saturation, and brightness. but i am having trouble adding contrast. thus far google hasn't be...

Using GCC (MinGW) to compile OpenGL on Windows

I've searched on google and haven't been able to come up with a solution. I would like to compile some OpenGL programming using GCC. In the GL folder in GCC I have the following headers: gl.h glext.h glu.h Then in my system32 file I have the following .dll opengl32.dll glu32.dll glut32.dll If I wanted to write a simple OpenGL "He...

How to run OpenGL code with out compiling?

So I have some openGL code (such code for example) /* FUNCTION: YCamera :: CalculateWorldCoordinates ARGUMENTS: x mouse x coordinate y mouse y coordinate vec where to store coordinates RETURN: n/a DESCRIPTION: Convert mouse coor...

Using a framebuffer as a vertex buffer without moving the data to the CPU

In OpenGL, is there a way to use framebuffer data as vertex data without moving the data through the CPU? Ideally, a framebuffer object could be recast as a vertex buffer object directly on the GPU. I'd like to use the fragment shader to generate a mesh and then render that mesh. ...

OpenGL: small black pixel on top right corner of texture

I wrote an uncompressed TGA texture loader and it works nearly perfect, except for the fact that there's just one TINY little black patch on the upper right and it's driving me mad. I can get rid of it by using a texture border, but somehow I think that's not the practical solution. Has anyone encountered this kind of problem before ...

c++ opengl: glOrtho() - please explain the usage of this command

Hiya. I started learning OpenGL and I can't understand the usage of glOrtho. can someone please explain what is it used for ? thanks update is it used to set the range of x y and z coordinates limit ? glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); it means that the x, y and z range are from -1 to 1? thanks! ...

scale random 3d model to fit in a viewport

How can I scale a random 3d model to fit in an opengl viewport? I am able to center the model in the middle of the view port. How do I scale it to fit it in the viewport. The model could be an airplane, a cone, an 3d object or any other random model. Appreciate any help. ...

opengl color quadrangle

hello i try out opengl. i have a programm that creates a black border an white corner (quadrangle). now i want to make the corner of the quadrangle in an different color. i don't know where exactly to write the code, and i don't know much a but color4f, i searcherd on google, but didn't get it. (is there a good description somewhere?)...

OpenGL bitmap text fails after drawing polygon

Hi, I'm using Win32 and OpenGL to to draw text onto a window. I'm using the bitmap font method, with wglUseFontBitmaps. Here is my main rendering function: glClear(GL_COLOR_BUFFER_BIT); glPushMatrix(); glColor3f(1.0f, 0.0f, 1.0f); glBegin(GL_QUADS); glVertex2f(0.0f, 0.0f); glVertex2f(128.0f, 0.0f); glVer...

c++: how can i use sdl to load a bitmap into a cube in opengl ?

Hiya. I'm learning OpenGL and SDL and so far I've been able to properly draw and rotate 3d polygons ( yay for me! :) ) how can I load an image file using SDL and load that texture on the 3d shapes that i draw on screen using OpenGL. thanks!!! update I tried the following code that draw a cube, rotates it and adds a bitmap, but I don...

Problem with glaux.h locating

Hello, I try to compile code, that beggins with: #include<stdlib.h> #include<GL/gl.h> #include<glaux.h> with command: cc -o test test.c -I/usr/local/include -L/usr/local/lib -lMesaaux -lMesatk -lMesaGL -lXext -lX11 -lm But one of errors I got is: test.c:3:18: error: glaux.h: No such file or directory Then I try: yum provides ...

gluLookAt doesn't work

hi, i'm programming with opengl and i want to change the camera view: ... void RenderScene() //Zeichenfunktion { glClearColor( 1.0, 0.5, 0.0, 0 ); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); glLoadIdentity (); //1.Form: glBegin( GL_POLYGON ); //polygone glColor3f( 1.0f, 0.0f, 0.0f ); //rot glVe...

YUV Textures and Shaders

I've always used RGB textures. Now comes up the need of use of YUV textures (a set of three texture, specifying 1 luminance and 2 chrominance channels). Of course the YUV texture could be converted on CPU, getting the RGB texture usable as usual... but I need to get RGB pixel directly on GPU, to avoid unnecessary processor load... The pr...

OpenGL billboard interpolation issue

I have a billboard quad with a texture mapped onto it. This is basically some text with transparency. The billboard floats forwards and backwards from the camera's perspective. As the billboard moves away (and appears smaller) there is an flickering effect around the edges of the text where there is a stroke border on the actual textu...

c++ sdl: can i have an sdl-opengl window inside a menu and buttons i created with glade?

Hiya. I used glade to create some gtk buttons. is it possible to add an sdl-opengl window to a glade application ? if so, how ? how can I interact between the gtk events and the sdl events inside the gtk window ? thanks ...

Vertex Buffers in opengl

I'm making a small 3d graphics game/demo for personal learning. I know d3d9 and quite a bit about d3d11 but little about opengl at the moment so I'm intending to abstract out the actual rendering of the graphics so that my scene graph and everything "above" it needs to know little about how to actually draw the graphics. I intend to make...

Where are run the Opengl commands?

Hi, i'm programming a simple OpenGL program on a multi-core computer that has a GPU. The GPU is a simple GeForce with PhysX, CUDA and OpenGL 2.1 support. When i run this program, is the host CPU that executes OpenGL specific commands or the ones are directly transferred to the GPU ??? ...

From a Maya scene to a WebGL animation, where to start?

Hi, I've got some time, and I really would like to learn to get my Maya animated scenes into WebGL. I'm not sure where to start really. It would be amazing if I could make a Canvas element and place a Maya scene into it so that it's animating. Does anyone got a tutorial or some hints? PS. Answers about 3ds Max are also welcome! ...

c++ opengl: how to find normalized vectors for a quad ?

Hiya. can anyone assist me in finding the proper formula for quad normalization ? using c++ with opengl. thank you! ...