gim_contact.h

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#ifndef GIM_CONTACT_H_INCLUDED
#define GIM_CONTACT_H_INCLUDED

/*
-----------------------------------------------------------------------------
This source file is part of GIMPACT Library.

For the latest info, see http://gimpact.sourceforge.net/

Copyright (c) 2006 Francisco Leon Najera. C.C. 80087371.
email: projectileman@yahoo.com

 This library is free software; you can redistribute it and/or
 modify it under the terms of EITHER:
   (1) The GNU Lesser General Public License as published by the Free
       Software Foundation; either version 2.1 of the License, or (at
       your option) any later version. The text of the GNU Lesser
       General Public License is included with this library in the
       file GIMPACT-LICENSE-LGPL.TXT.
   (2) The BSD-style license that is included with this library in
       the file GIMPACT-LICENSE-BSD.TXT.
   (3) The zlib/libpng license that is included with this library in
       the file GIMPACT-LICENSE-ZLIB.TXT.

 This library 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 files
 GIMPACT-LICENSE-LGPL.TXT, GIMPACT-LICENSE-ZLIB.TXT and GIMPACT-LICENSE-BSD.TXT for more details.

-----------------------------------------------------------------------------
*/
#include "gim_geometry.h"
#include "gim_radixsort.h"
#include "gim_array.h"


#define NORMAL_CONTACT_AVERAGE 1
#define CONTACT_DIFF_EPSILON 0.00001f

class GIM_CONTACT
{
public:
    btVector3 m_point;
    btVector3 m_normal;
    GREAL m_depth;//Positive value indicates interpenetration
    GREAL m_distance;//Padding not for use
    GUINT m_feature1;//Face number
    GUINT m_feature2;//Face number
public:
    GIM_CONTACT()
    {
    }

    GIM_CONTACT(const GIM_CONTACT & contact):
                m_point(contact.m_point),
                m_normal(contact.m_normal),
                m_depth(contact.m_depth),
                m_feature1(contact.m_feature1),
                m_feature2(contact.m_feature2)
    {
        m_point = contact.m_point;
        m_normal = contact.m_normal;
        m_depth = contact.m_depth;
        m_feature1 = contact.m_feature1;
        m_feature2 = contact.m_feature2;
    }

    GIM_CONTACT(const btVector3 &point,const btVector3 & normal,
                    GREAL depth, GUINT feature1, GUINT feature2):
                m_point(point),
                m_normal(normal),
                m_depth(depth),
                m_feature1(feature1),
                m_feature2(feature2)
    {
    }

    SIMD_FORCE_INLINE GUINT calc_key_contact() const
    {
        GINT _coords[] = {
            (GINT)(m_point[0]*1000.0f+1.0f),
            (GINT)(m_point[1]*1333.0f),
            (GINT)(m_point[2]*2133.0f+3.0f)};
        GUINT _hash=0;
        GUINT *_uitmp = (GUINT *)(&_coords[0]);
        _hash = *_uitmp;
        _uitmp++;
        _hash += (*_uitmp)<<4;
        _uitmp++;
        _hash += (*_uitmp)<<8;
        return _hash;
    }

    SIMD_FORCE_INLINE void interpolate_normals( btVector3 * normals,GUINT normal_count)
    {
        btVector3 vec_sum(m_normal);
        for(GUINT i=0;i<normal_count;i++)
        {
            vec_sum += normals[i];
        }

        GREAL vec_sum_len = vec_sum.length2();
        if(vec_sum_len <CONTACT_DIFF_EPSILON) return;

        GIM_INV_SQRT(vec_sum_len,vec_sum_len); // 1/sqrt(vec_sum_len)

        m_normal = vec_sum*vec_sum_len;
    }

};


class gim_contact_array:public gim_array<GIM_CONTACT>
{
public:
    gim_contact_array():gim_array<GIM_CONTACT>(64)
    {
    }

    SIMD_FORCE_INLINE void push_contact(const btVector3 &point,const btVector3 & normal,
                    GREAL depth, GUINT feature1, GUINT feature2)
    {
        push_back_mem();
        GIM_CONTACT & newele = back();
        newele.m_point = point;
        newele.m_normal = normal;
        newele.m_depth = depth;
        newele.m_feature1 = feature1;
        newele.m_feature2 = feature2;
    }

    SIMD_FORCE_INLINE void push_triangle_contacts(
        const GIM_TRIANGLE_CONTACT_DATA & tricontact,
        GUINT feature1,GUINT feature2)
    {
        for(GUINT i = 0;i<tricontact.m_point_count ;i++ )
        {
            push_back_mem();
            GIM_CONTACT & newele = back();
            newele.m_point = tricontact.m_points[i];
            newele.m_normal = tricontact.m_separating_normal;
            newele.m_depth = tricontact.m_penetration_depth;
            newele.m_feature1 = feature1;
            newele.m_feature2 = feature2;
        }
    }

    void merge_contacts(const gim_contact_array & contacts, bool normal_contact_average = true);
    void merge_contacts_unique(const gim_contact_array & contacts);
};

#endif // GIM_CONTACT_H_INCLUDED