OpenGL tex-mapping: Whole object is a single texel's color.

Question

Hi guys, I've been trying to get a HUD texture to display for a simulator for a while now, without success.

First I bind the texture like this:

glGenTextures(1,&hudTexObj);
gHud = getPPM("textures/purplenebula/hud.ppm",&n,&m,&s);
glBindTexture(GL_TEXTURE_2D,hudTexObj);
glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST); 
//glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,n,m,0,GL_RGB,GL_UNSIGNED_INT, gHud);

And then I attempt to map it to a QUAD, which results in the whole quad being a single brown color, and I want it to use all the texels. Here's how I map:

    glBindTexture(GL_TEXTURE_2D,hudTexObj);

glBegin(GL_QUADS);
glTexCoord2f(0.0,0.0);
glVertex2f(0,0);

glTexCoord2f(0.0,1.0);
glVertex2f(0,m);

glTexCoord2f(1.0,1.0);
glVertex2f(n,m);

glTexCoord2f(1.0,0.0);
glVertex2f(n,0);
glEnd();

The weird thing is that I've been able to get the exact above code to display the texture in a program of its own, yet when I put it into my main program it fails. Could it have to do with the texture matrix? I'm dumbfounded at this point.

Answer 1

Stupidly, I had enabled automatic tex coord generation far away in another part of the code. So if you see one texel's color covering a whole image, that is the likely cause.