The GLSL API - Graphics Shaders - page 370

Standard OpenGL Function Built-in Atribute Variable

glVertex(...) gl_Vertex

glColor(...) gl_Color

glNormal(...) gl_Normal

glSecondaryColor(...) gl_SecondaryColor

glMultiTexCoord(i, ...) gl_MultiTexCoordi, i=1..N

glFogCoordf(...) gl_FogCoord

Table 14.2. Atribute variables deined by compatibility-mode OpenGL vertex functions.

A C++ Class to Handle Shader Program Creation
Appendix A shows a C++ class that is handy for shader creation and use. As a
preview, here is how such an application would look:

#include “glslprogram.h”

float Ad, Bd, NoiseAmp, NoiseFreq, Tol;
GLSLProgram * Ovals;

During setup:

Ovals = new GLSLProgram( );
Ovals->SetVerbose( true );
Ovals->SetGstap( true );
bool good = Ovals->Create( “ovalnoise.vert”, “ovalnoise.frag” );
if( ! good )
{
fprintf( stderr, “GLSL Program Ovals wasn't created.\n” );
<<handle the fact that the shaders did not compile or link>>
}

In the display callback:

Ovals->Use( );
// we assume the user has interactively changed the uniform
// vars:
Ovals->SetUniform( “uAd”, Ad );
Ovals->SetUniform( “uBd”, Bd );
Ovals->SetUniform( “uNoiseAmp”, NoiseAmp );
Ovals->SetUniform( “uNoiseFreq”, NoiseFreq );
Ovals->SetUniform( “uTol”, Tol );