MeshBuffer.h

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/***************************************************************************
               MeshBuffer.h  -  K Desktop Planetarium
                             -------------------
    begin                : 2007-07-13
    copyright            : (C) 2007 James B. Bowlin
    email                : bowlin@mindspring.com
***************************************************************************/

#ifndef MESH_BUFFER_H
#define MESH_BUFFER_H

#include "typedef.h"

class HTMesh;

/* @class MeshBuffer the sole purpose of a MeshBuffer is to hold storage space
 * for the results of an HTM inetersection and then allow multiple
 * MeshIterator's to walk through the result set.  The buffer space is allocated
 * when the MeshBuffer is created.  Mesh buffers will usually hang around for
 * the life of an HTMesh.  Each mesh buffer is re-usable.  Simply reset() it and
 * then fill it by append()'ing trixels.  A MeshIterator grabs the size() and
 * the buffer() so it can iterate over the results.
 */

class MeshBuffer {

    public:
        MeshBuffer(HTMesh *mesh);

        ~MeshBuffer();

        /* @short prepare the buffer for a new result set
         */
        void reset() { m_size = m_error = 0; }

        /* @short add trixels to the buffer
         */
        int append(Trixel trixel);

        /* @short the location of the buffer for reading
         */
        const Trixel* buffer() const { return m_buffer; }

        /* @short the number of trixels in the result set
         */
        int size() const { return m_size; }

        /* @short returns the number of trixels that would have overflowed the
         * buffer.
         */
        int error() const { return m_error; }

        /* @short fills the buffer with consecutive integers
         */
        void fill();

    private:
        Trixel *m_buffer;
        int    m_size;
        int    maxSize;
        int    m_error;

};

#endif