project-swan/libcygnet/include/cygnet/GlWrappers.h

#pragma once

#include <stdint.h>
#include <stdexcept>

#include "util.h"

namespace Cygnet {

struct GlCompileError: public std::exception {
	GlCompileError(std::string message): message(std::move(message)) {}
	const char *what() const noexcept override { return message.c_str(); }
	std::string message;
};

class GlShader {
public:
	enum class Type {
		VERTEX,
		FRAGMENT,
	};

	GlShader(Type type, const char *source);
	~GlShader();

	GLuint id() const { return id_; }

private:
	GLuint id_;
};

class GlVxShader: public GlShader {
public:
	explicit GlVxShader(const char *source): GlShader(Type::VERTEX, source) {}
};

class GlFrShader: public GlShader {
public:
	explicit GlFrShader(const char *source): GlShader(Type::FRAGMENT, source) {}
};

class GlProgram {
public:
	template <typename... T>
	GlProgram(const T &... shaders): GlProgram() { (addShader(shaders), ...); link(); }
	GlProgram();
	~GlProgram();

	void use();
	GLuint id() const { return id_; }

protected:

	GLint attribLoc(const char *name);
	GLint uniformLoc(const char *name);

private:
	void addShader(const GlShader &shader);
	void link();

	GLuint id_;
};

class GlTexture {
public:
	GlTexture();

	void bind();
	void upload(GLsizei width, GLsizei height, void *data,
			GLenum format, GLenum type);
	GLuint id() { return id_; }
	int width() { return w_; }
	int height() { return h_; }

private:
	GLuint id_;
	int w_;
	int h_;
};

}