/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2013 CERN
 * @author Maciej Suminski <maciej.suminski@cern.ch>
 *
 * 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 2
 * 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, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

/**
 * @file vbo_item.h
 * @brief Class to handle an item held in a Vertex Buffer Object.
 */

// TODO comments

#ifndef VBO_ITEM_H_
#define VBO_ITEM_H_

#include <GL/gl.h>

namespace KiGfx
{

class VBO_ITEM
{
public:
    VBO_ITEM();
    ~VBO_ITEM();

    // TODO comments
    void PushVertex( const GLfloat* aVertex );
    void PushVertices( const GLfloat* aVertex, GLuint aSize );

    /**
     * Function GetVertices()
     * Returns a pointer to the array containing all vertices.
     * @return Pointer to vertices packed in format {X, Y, Z, R, G, B, A}.
     */
    GLfloat* GetVertices() const;

    GLuint* GetIndices() const;

    /**
     * Function GetSize()
     * Returns information about number of vertices stored.
     * @param Amount of vertices.
     */
    int  GetSize() const;

    /**
     * Function SetOffset()
     * Sets data offset in the VBO.
     * @param aOffset is the offset expressed as a number of vertices.
     */
    void SetOffset( int aOffset );

    /**
     * Function GetOffset()
     * Returns data offset in the VBO.
     * @return Data offset expressed as a number of vertices.
     */
    int  GetOffset() const;

    ///< Functions for getting VBO ids.
    //void SetVbo( int aVboId );
    //int  GetVbo();

    ///< Data organization information for vertices.
    static const int VertStride  = 7;
    static const int VertSize    = VertStride * sizeof(GLfloat);
    static const int IndStride   = 1;
    static const int IndSize     = IndStride * sizeof(GLuint);
    static const int ColorOffset = 3 * sizeof(GLfloat);

private:
    ///< VBO ids in which the item is stored.
    //int      m_vboId; // not used yet

    ///< Contains vertices coordinates and colors.
    ///< Packed by 7 floats for each vertex: {X, Y, Z, R, G, B, A}
    GLfloat* m_vertices;

    ///< Indices of vertices
    GLuint*  m_indices;

    ///< Offset and size of data in VBO.
    int      m_offset;
    int      m_size;

    ///< Shader data used for rendering.
    int      m_shader;
    int      m_shaderAttrib;

    ///< Flag telling if the item should be recached in VBO or not.
    bool     m_isDirty;
};
} // namespace KiGfx

#endif /* VBO_ITEM_H_ */