Two Methods of Multitexture In Cg

Method 1: Using OpenGL's native multi-texture support (using semantics)
// In C++ File:
   // Identify the textures to use for the pixel shader...
    cgGLSetTextureParameter( g_CGparam_testTexture, g_testTextureID );
    cgGLSetTextureParameter( g_CGparam_checkerTexture, g_checkerTextureID );
    // STAGE 0
    glActiveTextureARB( GL_TEXTURE0_ARB );
    glBindTexture( GL_TEXTURE_2D, g_testTextureID );
    // STAGE 1
    glActiveTextureARB( GL_TEXTURE1_ARB );
    glBindTexture( GL_TEXTURE_2D, g_checkerTextureID );
   cgGLBindProgram( g_CGprogram_pixel );
   cgGLEnableProfile( g_CGprofile_pixel );
   // Draw primitives
   cgGLDisableProfile( g_CGprofile_pixel );
// In Cg File:
   uniform sampler2D testTexture    : TEXUNIT0,
   uniform sampler2D checkerTexture : TEXUNIT1
Method 2: Using Cg's special texture functions:cgGLSetTextureParameter, cgGLEnableTextureParameter, and cgGLDisableTextureParameter
// In C++ File:
   g_CGparam_testTexture    = cgGetNamedParameter(g_CGprogram_pixel, "testTexture");
    g_CGparam_checkerTexture = cgGetNamedParameter(g_CGprogram_pixel, "checkerTexture");
    // Identify the textures to use for the pixel shader...
    cgGLSetTextureParameter( g_CGparam_testTexture, g_testTextureID );
    cgGLSetTextureParameter( g_CGparam_checkerTexture, g_checkerTextureID );
    cgGLBindProgram( g_CGprogram_pixel );
    cgGLEnableProfile( g_CGprofile_pixel );
    cgGLEnableTextureParameter( g_CGparam_testTexture );
    cgGLEnableTextureParameter( g_CGparam_checkerTexture );
    // Draw primitives
    cgGLDisableTextureParameter( g_CGparam_checkerTexture );
    cgGLDisableTextureParameter( g_CGparam_testTexture );
    cgGLDisableProfile( g_CGprofile_pixel );
// In Cg File:
    uniform sampler2D testTexture,
    uniform sampler2D checkerTexture