#ifndef _SHADER_H_
#define _SHADER_H_

#include <iostream>
#include <string>
#define GL_GLEXT_PROTOTYPES
#ifndef __APPLE__
#include <GL/gl.h>
#include <GL/glu.h>
#else
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#endif

class GLBaseShader {
	friend class GLShaderProgram;

	protected:
		bool shader_source(const char *filename);
		bool shader_source(std::string& filename);
		unsigned int shader;
	public:
		GLBaseShader(GLenum);
};

class GLVertexShader : public GLBaseShader {
	public:
		GLVertexShader() : GLBaseShader(GL_VERTEX_SHADER) {};
		GLVertexShader(const char *s) : GLBaseShader(GL_VERTEX_SHADER) { shader_source(s); };
		GLVertexShader(std::string& s) : GLBaseShader(GL_VERTEX_SHADER) { shader_source(s); };
};

class GLFragmentShader : public GLBaseShader {
	public:
		GLFragmentShader() : GLBaseShader(GL_FRAGMENT_SHADER) {};
		GLFragmentShader(const char *s) : GLBaseShader(GL_FRAGMENT_SHADER) { shader_source(s); };
		GLFragmentShader(std::string& s) : GLBaseShader(GL_FRAGMENT_SHADER) { shader_source(s); };
};

class GLShaderProgram {
	protected:
		unsigned int program;
	public:
		GLShaderProgram();

		bool attach(GLBaseShader&);
		bool detach(GLBaseShader&);
		bool link();
		bool use();
		void remove();
};

void print_ogl_error(GLenum);
bool print_check_ogl_error();

#endif