/*
	QGLView
	Copyright (C) 2019  Ivan Pelipenko peri4ko@yandex.ru

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef GLMESH_H
#define GLMESH_H

#include <chunkstream.h>
#include "glbuffer.h"
#include "glshaders_types.h"


class Mesh
{
	friend class ObjectBase;
	friend class Scene;
	friend class Renderer;
	friend QDataStream & operator <<(QDataStream & s, const Mesh * m);
	friend QDataStream & operator >>(QDataStream & s, Mesh *& m);
public:
	Mesh();
	~Mesh();

	Mesh * clone();

	//GLVBO & operator =(const GLVBO & o) {return *this;}

	void init    (QOpenGLExtraFunctions * f);
	void destroy (QOpenGLExtraFunctions * f);
	bool rebuffer(QOpenGLExtraFunctions * f);
	void draw    (QOpenGLExtraFunctions * f, int count);
	void clear();
	void loadObject    (QOpenGLExtraFunctions * f, const QGLEngineShaders::Object & object);
	void loadObjects   (QOpenGLExtraFunctions * f, const QVector<QGLEngineShaders::Object> & objects);
	void loadSelections(QOpenGLExtraFunctions * f, const QVector<uchar> & sels);

	int verticesCount() const {return vertices_.size();}
	int trianglesCount() const {return triangles_.size();}
	bool isInit() const {return vao != 0;}
	bool isEmpty() const {return vertices_.isEmpty();}
	uint hash() const;

	QVector<QVector3D> & vertices () {changed = hash_changed = true; return vertices_;}
	QVector<QVector3D> & normals  () {changed = hash_changed = true; return normals_;}
	QVector<QVector2D> & texcoords() {changed = hash_changed = true; return texcoords_;}
	QVector< Vector3i> & indices  () {changed = hash_changed = true; return triangles_;}

	void translatePoints(const QVector3D & dp);
	void scalePoints    (const QVector3D & dp);
	void append(const Mesh * m);

	bool saveToFile(const QString & filename);
	bool loadFromFile(const QString & filename);

	Box3D boundingBox() const;

	static void prepareDrawGeom(QOpenGLExtraFunctions * f);
	static void prepareDrawObj (QOpenGLExtraFunctions * f);
	static void prepareDrawSel (QOpenGLExtraFunctions * f);

private:
	void calculateNormals();
	void calculateTangents();
	void loadBuffer(QOpenGLExtraFunctions * f, Buffer & buf, const void * data, int size);

	QVector<QVector3D> vertices_, normals_, tangents_, bitangents_;
	QVector<QVector2D> texcoords_;
	QVector< Vector3i> triangles_;

	QVector<QGLEngineShaders::Vertex> data_;
	GLenum vao;
	Buffer buffer_geom, buffer_ind, buffer_obj, buffer_sel;
	mutable uint hash_;
	mutable bool hash_changed;
	int vert_count;
	bool changed, objects_changed, selected_changed;

};


QDataStream & operator <<(QDataStream & s, const Mesh * m);
QDataStream & operator >>(QDataStream & s, Mesh *& m);

#endif // GLMESH_H