splitplane.cpp

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <float.h>
#include <math.h>

#include "splitplane.h"
#include "ConvexDecomposition.h"
#include "cd_vector.h"
#include "cd_hull.h"
#include "cd_wavefront.h"
#include "bestfit.h"
#include "planetri.h"
#include "vlookup.h"
#include "meshvolume.h"
#include "bestfitobb.h"
#include "float_math.h"

namespace ConvexDecomposition
{

static void computePlane(const double *A,const double *B,const double *C,double *plane)
{

        double vx = (B[0] - C[0]);
        double vy = (B[1] - C[1]);
        double vz = (B[2] - C[2]);

        double wx = (A[0] - B[0]);
        double wy = (A[1] - B[1]);
        double wz = (A[2] - B[2]);

        double vw_x = vy * wz - vz * wy;
        double vw_y = vz * wx - vx * wz;
        double vw_z = vx * wy - vy * wx;

        double mag = sqrt((vw_x * vw_x) + (vw_y * vw_y) + (vw_z * vw_z));

        if ( mag < 0.000001f )
        {
                mag = 0;
        }
        else
        {
                mag = 1.0f/mag;
        }

        double x = vw_x * mag;
        double y = vw_y * mag;
        double z = vw_z * mag;


        double D = 0.0f - ((x*A[0])+(y*A[1])+(z*A[2]));

  plane[0] = x;
  plane[1] = y;
  plane[2] = z;
  plane[3] = D;

}

class Rect3d
{
public:
  Rect3d(void) { };

  Rect3d(const double *bmin,const double *bmax)
  {

    mMin[0] = bmin[0];
    mMin[1] = bmin[1];
    mMin[2] = bmin[2];

    mMax[0] = bmax[0];
    mMax[1] = bmax[1];
    mMax[2] = bmax[2];

  }

  void SetMin(const double *bmin)
  {
    mMin[0] = bmin[0];
    mMin[1] = bmin[1];
    mMin[2] = bmin[2];
  }

  void SetMax(const double *bmax)
  {
    mMax[0] = bmax[0];
    mMax[1] = bmax[1];
    mMax[2] = bmax[2];
  }

        void SetMin(double x,double y,double z)
        {
                mMin[0] = x;
                mMin[1] = y;
                mMin[2] = z;
        }

        void SetMax(double x,double y,double z)
        {
                mMax[0] = x;
                mMax[1] = y;
                mMax[2] = z;
        }

  double mMin[3];
  double mMax[3];
};

void splitRect(unsigned int axis,
                                                   const Rect3d &source,
                                                         Rect3d &b1,
                                                         Rect3d &b2,
                                                         const double *midpoint)
{
        switch ( axis )
        {
                case 0:
                        b1.SetMin(source.mMin);
                        b1.SetMax( midpoint[0], source.mMax[1], source.mMax[2] );

                        b2.SetMin( midpoint[0], source.mMin[1], source.mMin[2] );
                        b2.SetMax(source.mMax);

                        break;
                case 1:
                        b1.SetMin(source.mMin);
                        b1.SetMax( source.mMax[0], midpoint[1], source.mMax[2] );

                        b2.SetMin( source.mMin[0], midpoint[1], source.mMin[2] );
                        b2.SetMax(source.mMax);

                        break;
                case 2:
                        b1.SetMin(source.mMin);
                        b1.SetMax( source.mMax[0], source.mMax[1], midpoint[2] );

                        b2.SetMin( source.mMin[0], source.mMin[1], midpoint[2] );
                        b2.SetMax(source.mMax);

                        break;
        }
}

bool computeSplitPlane(unsigned int vcount,
                       const double *vertices,
                       unsigned int tcount,
                       const unsigned int *indices,
                       ConvexDecompInterface *callback,
                       double *plane)
{
  bool cret = false;


  double sides[3];
  double matrix[16];

  computeBestFitOBB( vcount, vertices, sizeof(double)*3, sides, matrix );

  double bmax[3];
  double bmin[3];

  bmax[0] = sides[0]*0.5f;
  bmax[1] = sides[1]*0.5f;
  bmax[2] = sides[2]*0.5f;

  bmin[0] = -bmax[0];
  bmin[1] = -bmax[1];
  bmin[2] = -bmax[2];


  double dx = sides[0];
  double dy = sides[1];
  double dz = sides[2];


        double laxis = dx;

        unsigned int axis = 0;

        if ( dy > dx )
        {
                axis = 1;
                laxis = dy;
        }

        if ( dz > dx && dz > dy )
        {
                axis = 2;
                laxis = dz;
        }

  double p1[3];
  double p2[3];
  double p3[3];

  p3[0] = p2[0] = p1[0] = bmin[0] + dx*0.5f;
  p3[1] = p2[1] = p1[1] = bmin[1] + dy*0.5f;
  p3[2] = p2[2] = p1[2] = bmin[2] + dz*0.5f;

  Rect3d b(bmin,bmax);

  Rect3d b1,b2;

  splitRect(axis,b,b1,b2,p1);


//  callback->ConvexDebugBound(b1.mMin,b1.mMax,0x00FF00);
//  callback->ConvexDebugBound(b2.mMin,b2.mMax,0xFFFF00);

  switch ( axis )
  {
    case 0:
      p2[1] = bmin[1];
      p2[2] = bmin[2];

      if ( dz > dy )
      {
        p3[1] = bmax[1];
        p3[2] = bmin[2];
      }
      else
      {
        p3[1] = bmin[1];
        p3[2] = bmax[2];
      }

      break;
    case 1:
      p2[0] = bmin[0];
      p2[2] = bmin[2];

      if ( dx > dz )
      {
        p3[0] = bmax[0];
        p3[2] = bmin[2];
      }
      else
      {
        p3[0] = bmin[0];
        p3[2] = bmax[2];
      }

      break;
    case 2:
      p2[0] = bmin[0];
      p2[1] = bmin[1];

      if ( dx > dy )
      {
        p3[0] = bmax[0];
        p3[1] = bmin[1];
      }
      else
      {
        p3[0] = bmin[0];
        p3[1] = bmax[1];
      }

      break;
  }

  double tp1[3];
  double tp2[3];
  double tp3[3];

  fm_transform(matrix,p1,tp1);
  fm_transform(matrix,p2,tp2);
  fm_transform(matrix,p3,tp3);

//  callback->ConvexDebugTri(p1,p2,p3,0xFF0000);

        computePlane(tp1,tp2,tp3,plane);

  return true;

}


};