Shaders and Programs - Praise for OpenGL ES 30 Programming Guide - page 86

Example 4-3 Querying for Active Uniforms

GLint maxUniformLen;
GLint numUniforms;
char *uniformName;
GLint index;

glGetProgramiv ( progObj, GL_ACTIVE_UNIFORMS, &numUniforms );
glGetProgramiv ( progObj, GL_ACTIVE_UNIFORM_MAX_LENGTH,
&maxUniformLen );

uniformName = malloc ( sizeof ( char ) * maxUniformLen );

for ( index = 0; index < numUniforms; index++ )
{
GLint size;
GLenum type;
GLint location;

// Get the uniform info
glGetActiveUniform ( progObj, index, maxUniformLen, NULL,
&size, &type, uniformName );

// Get the uniform location
location = glGetUniformLocation ( progObj, uniformName );

switch ( type )
{
case GL_FLOAT:
//
break;

case GL_FLOAT_VEC2:
//
break;

case GL_FLOAT_VEC3:
//
break;

case GL_FLOAT_VEC4:
//
break;

case GL_INT:
//
break;

// ... Check for all the types ...