shader_testing/dumpShader.inl

#include <GL/glew.h>

#include "shader_testing.h"


const char* gl_enum_to_string(GLenum e);


void
dumpShader(GLuint prog_id)
{
	std::cout << "dumping shader info, program id: " << prog_id << "\n";

	GLint active_uniforms;
	GLint active_uniform_blocks;
	GLint active_attribs;

	// NOTE: unused uniforms/attributes get optimized away
	// https://www.khronos.org/opengl/wiki/Program_Introspection#Attributes
	// https://stackoverflow.com/questions/54811319/how-to-get-from-glgetattriblocation-to-glgetactiveattrib-index
	glGetProgramiv(prog_id, GL_ACTIVE_UNIFORMS, &active_uniforms);
	glGetProgramiv(prog_id, GL_ACTIVE_UNIFORM_BLOCKS, &active_uniform_blocks);
	glGetProgramiv(prog_id, GL_ACTIVE_ATTRIBUTES, &active_attribs);

	printf("active uniforms: %d\n", active_uniforms);
	printf("active uniform blocks: %d\n", active_uniform_blocks);
	printf("active attributes: %d\n", active_attribs);

	GLchar uni_name[256];
	GLsizei length;
	GLint size;
	GLenum type;

	for (int i = 0; i < active_uniforms; i++) {
		glGetActiveUniform(prog_id, i, sizeof(uni_name),
							&length, &size, &type, uni_name);
		printf("uniform idx: %d, len: %d, type: %s, name: %s \n",
				i, length, gl_enum_to_string(type), uni_name);
	}

	for (int i = 0; i < active_attribs; i++) {
		glGetActiveAttrib(prog_id, i, sizeof(uni_name),
							&length, &size, &type, uni_name);
		printf("attribute idx: %d, len: %d, type: %s, name: %s \n",
				i, length, gl_enum_to_string(type), uni_name);
	}

}

const char*
gl_enum_to_string(GLenum e)
{
	switch (e) {
		case 0x8b5c: return "GL_FLOAT_MAT4";
		case 0x8b51: return "GL_FLOAT_VEC3";

		default: return "???";
	}
}