In OpenGL is there a way to get a list of all uniforms & attribs used by a shader program?

Question

I'd like to get a list of all the uniforms & attribs used by a shader program object. glGetAttribLocation() & glGetUniformLocation() can be used to map a string to a location, but what I would really like is the list of strings without having to parse the glsl code.

Note: In OpenGL 2.0 glGetObjectParameteriv() is replaced by glGetProgramiv(). And the enum is GL_ACTIVE_UNIFORMS & GL_ACTIVE_ATTRIBUTES.

Answer 1

Variables shared between both examples:

GLint i; GLint count;  GLint size; // size of the variable GLenum type; // type of the variable (float, vec3 or mat4, etc)  const GLsizei bufSize = 16; // maximum name length GLchar name[bufSize]; // variable name in GLSL GLsizei length; // name length 

Attributes

glGetProgramiv(program, GL_ACTIVE_ATTRIBUTES, &count); printf("Active Attributes: %d\n", count);  for (i = 0; i < count; i++) {     glGetActiveAttrib(program, (GLuint)i, bufSize, &length, &size, &type, name);      printf("Attribute #%d Type: %u Name: %s\n", i, type, name); } 

Uniforms

glGetProgramiv(program, GL_ACTIVE_UNIFORMS, &count); printf("Active Uniforms: %d\n", count);  for (i = 0; i < count; i++) {     glGetActiveUniform(program, (GLuint)i, bufSize, &length, &size, &type, name);      printf("Uniform #%d Type: %u Name: %s\n", i, type, name); } 

OpenGL Documentation / Variable Types

The various macros representing variable types can be found in the docs. Such as GL_FLOAT, GL_FLOAT_VEC3, GL_FLOAT_MAT4, etc.

• glGetActiveAttrib
• glGetActiveUniform