// Begin License:
// Copyright (C) 2006-2008 Tobias Sargeant (tobias.sargeant@gmail.com).
// All rights reserved.
//
// This file is part of the Carve CSG Library (http://carve-csg.com/)
//
// This file may be used under the terms of the GNU General Public
// License version 2.0 as published by the Free Software Foundation
// and appearing in the file LICENSE.GPL2 included in the packaging of
// this file.
//
// This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
// INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE.
// End:


#if defined(HAVE_CONFIG_H)
#  include <carve_config.h>
#endif

#include <carve/aabb.hpp>
#include <carve/geom.hpp>

#include <iostream>
#include <fstream>
#include <string>
#include <stdexcept>

#include "mersenne_twister.h"

/********************************************************/
/* AABB-triangle overlap test code                      */
/* by Tomas Akenine-Möller                              */
/* Function: int triBoxOverlap(double boxcenter[3],      */
/*          double boxhalfsize[3],double triverts[3][3]); */
/* History:                                             */
/*   2001-03-05: released the code in its first version */
/*   2001-06-18: changed the order of the tests, faster */
/*                                                      */
/* Acknowledgement: Many thanks to Pierre Terdiman for  */
/* suggestions and discussions on how to optimize code. */
/* Thanks to David Hunt for finding a ">="-bug!         */
/********************************************************/
#include <math.h>
#include <stdio.h>

#define X 0
#define Y 1
#define Z 2

#define CROSS(dest,v1,v2) \
          dest[0]=v1[1]*v2[2]-v1[2]*v2[1]; \
          dest[1]=v1[2]*v2[0]-v1[0]*v2[2]; \
          dest[2]=v1[0]*v2[1]-v1[1]*v2[0]; 

#define DOT(v1,v2) (v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2])

#define SUB(dest,v1,v2) \
          dest[0]=v1[0]-v2[0]; \
          dest[1]=v1[1]-v2[1]; \
          dest[2]=v1[2]-v2[2]; 

#define FINDMINMAX(x0,x1,x2,min,max) \
  min = max = x0;   \
  if(x1<min) min=x1;\
  if(x1>max) max=x1;\
  if(x2<min) min=x2;\
  if(x2>max) max=x2;

int planeBoxOverlap(double normal[3], double vert[3], double maxbox[3])	// -NJMP-
{
  int q;
  double vmin[3],vmax[3],v;
  for(q=X;q<=Z;q++)
  {
    v=vert[q];					// -NJMP-
    if(normal[q]>0.0f)
    {
      vmin[q]=-maxbox[q] - v;	// -NJMP-
      vmax[q]= maxbox[q] - v;	// -NJMP-
    }
    else
    {
      vmin[q]= maxbox[q] - v;	// -NJMP-
      vmax[q]=-maxbox[q] - v;	// -NJMP-
    }
  }
  if(DOT(normal,vmin)>0.0f) return 0;	// -NJMP-
  if(DOT(normal,vmax)>=0.0f) return 1;	// -NJMP-
  
  return 0;
}

/*======================== X-tests ========================*/
#define AXISTEST_X01(a, b, fa, fb, on_fail)		   \
	p0 = a*v0[Y] - b*v0[Z];			       	   \
	p2 = a*v2[Y] - b*v2[Z];			       	   \
        if(p0<p2) {min=p0; max=p2;} else {min=p2; max=p0;} \
	rad = fa * boxhalfsize[Y] + fb * boxhalfsize[Z];   \
	if(min>rad || max<-rad) on_fail;
#define AXISTEST_X2(a, b, fa, fb, on_fail)		   \
	p0 = a*v0[Y] - b*v0[Z];			           \
	p1 = a*v1[Y] - b*v1[Z];			       	   \
        if(p0<p1) {min=p0; max=p1;} else {min=p1; max=p0;} \
	rad = fa * boxhalfsize[Y] + fb * boxhalfsize[Z];   \
	if(min>rad || max<-rad) on_fail;

/*======================== Y-tests ========================*/
#define AXISTEST_Y02(a, b, fa, fb, on_fail)		   \
	p0 = -a*v0[X] + b*v0[Z];		      	   \
	p2 = -a*v2[X] + b*v2[Z];	       	       	   \
        if(p0<p2) {min=p0; max=p2;} else {min=p2; max=p0;} \
	rad = fa * boxhalfsize[X] + fb * boxhalfsize[Z];   \
	if(min>rad || max<-rad) on_fail;
#define AXISTEST_Y1(a, b, fa, fb, on_fail)		   \
	p0 = -a*v0[X] + b*v0[Z];		      	   \
	p1 = -a*v1[X] + b*v1[Z];	     	       	   \
        if(p0<p1) {min=p0; max=p1;} else {min=p1; max=p0;} \
	rad = fa * boxhalfsize[X] + fb * boxhalfsize[Z];   \
	if(min>rad || max<-rad) on_fail;

/*======================== Z-tests ========================*/
#define AXISTEST_Z12(a, b, fa, fb, on_fail)		   \
	p1 = a*v1[X] - b*v1[Y];			           \
	p2 = a*v2[X] - b*v2[Y];			       	   \
        if(p2<p1) {min=p2; max=p1;} else {min=p1; max=p2;} \
	rad = fa * boxhalfsize[X] + fb * boxhalfsize[Y];   \
	if(min>rad || max<-rad) on_fail;
#define AXISTEST_Z0(a, b, fa, fb, on_fail)		   \
	p0 = a*v0[X] - b*v0[Y];				   \
	p1 = a*v1[X] - b*v1[Y];			           \
        if(p0<p1) {min=p0; max=p1;} else {min=p1; max=p0;} \
	rad = fa * boxhalfsize[X] + fb * boxhalfsize[Y];   \
	if(min>rad || max<-rad) on_fail;

int triBoxOverlap_test(double boxcenter[3],double boxhalfsize[3],double triverts[3][3])
{
  /*    use separating axis theorem to test overlap between triangle and box */
  /*    need to test for overlap in these directions: */
  /*    1) the {x,y,z}-directions (actually, since we use the AABB of the triangle */
  /*       we do not even need to test these) */
  /*    2) normal of the triangle */
  /*    3) crossproduct(edge from tri, {x,y,z}-directin) */
  /*       this gives 3x3=9 more tests */
   double v0[3],v1[3],v2[3];
//   double axis[3];
   double min,max,p0,p1,p2,rad,fex,fey,fez;		// -NJMP- "d" local variable removed
   double normal[3],e0[3],e1[3],e2[3];
   /* This is the fastest branch on Sun */
   /* move everything so that the boxcenter is in (0,0,0) */
   SUB(v0,triverts[0],boxcenter);
   SUB(v1,triverts[1],boxcenter);
   SUB(v2,triverts[2],boxcenter);
   /* compute triangle edges */
   SUB(e0,v1,v0);      /* tri edge 0 */
   SUB(e1,v2,v1);      /* tri edge 1 */
   SUB(e2,v0,v2);      /* tri edge 2 */
   /* Bullet 3:  */
   /*  test the 9 tests first (this was faster) */
   fex = fabsf(e0[X]);
   fey = fabsf(e0[Y]);
   fez = fabsf(e0[Z]);
   unsigned test_result = 0;
#define TEST(x) test_result |= x
   AXISTEST_X01(e0[Z], e0[Y], fez, fey, TEST(0x0001));
   AXISTEST_Y02(e0[Z], e0[X], fez, fex, TEST(0x0002));
   AXISTEST_Z12(e0[Y], e0[X], fey, fex, TEST(0x0004));
   fex = fabsf(e1[X]);
   fey = fabsf(e1[Y]);
   fez = fabsf(e1[Z]);
   AXISTEST_X01(e1[Z], e1[Y], fez, fey, TEST(0x0008));
   AXISTEST_Y02(e1[Z], e1[X], fez, fex, TEST(0x0010));
   AXISTEST_Z0( e1[Y], e1[X], fey, fex, TEST(0x0020));
   fex = fabsf(e2[X]);
   fey = fabsf(e2[Y]);
   fez = fabsf(e2[Z]);
   AXISTEST_X2( e2[Z], e2[Y], fez, fey, TEST(0x0040));
   AXISTEST_Y1( e2[Z], e2[X], fez, fex, TEST(0x0080));
   AXISTEST_Z12(e2[Y], e2[X], fey, fex, TEST(0x0100));
   /* Bullet 1: */
   /*  first test overlap in the {x,y,z}-directions */
   /*  find min, max of the triangle each direction, and test for overlap in */
   /*  that direction -- this is equivalent to testing a minimal AABB around */
   /*  the triangle against the AABB */
   /* test in X-direction */
   FINDMINMAX(v0[X],v1[X],v2[X],min,max);
   if(min>boxhalfsize[X] || max<-boxhalfsize[X]) TEST(0x0200);
   /* test in Y-direction */
   FINDMINMAX(v0[Y],v1[Y],v2[Y],min,max);
   if(min>boxhalfsize[Y] || max<-boxhalfsize[Y]) TEST(0x0400);
   /* test in Z-direction */
   FINDMINMAX(v0[Z],v1[Z],v2[Z],min,max);
   if(min>boxhalfsize[Z] || max<-boxhalfsize[Z]) TEST(0x0800);
   /* Bullet 2: */
   /*  test if the box intersects the plane of the triangle */
   /*  compute plane equation of triangle: normal*x+d=0 */
   CROSS(normal,e0,e1);
   // -NJMP- (line removed here)
   if(!planeBoxOverlap(normal,v0,boxhalfsize)) TEST(0x1000);	// -NJMP-
   return test_result;   /* box and triangle overlaps */
}

int triBoxOverlap_optimized(double boxcenter[3],double boxhalfsize[3],double triverts[3][3])
{
  /*    use separating axis theorem to test overlap between triangle and box */
  /*    need to test for overlap in these directions: */
  /*    1) the {x,y,z}-directions (actually, since we use the AABB of the triangle */
  /*       we do not even need to test these) */
  /*    2) normal of the triangle */
  /*    3) crossproduct(edge from tri, {x,y,z}-directin) */
  /*       this gives 3x3=9 more tests */
   double v0[3],v1[3],v2[3];
//   double axis[3];
   double min,max,p0,p1,p2,rad,fex,fey,fez;		// -NJMP- "d" local variable removed
   double normal[3],e0[3],e1[3],e2[3];
   /* This is the fastest branch on Sun */
   /* move everything so that the boxcenter is in (0,0,0) */
   SUB(v0,triverts[0],boxcenter);
   SUB(v1,triverts[1],boxcenter);
   SUB(v2,triverts[2],boxcenter);
   /* compute triangle edges */
   SUB(e0,v1,v0);      /* tri edge 0 */
   SUB(e1,v2,v1);      /* tri edge 1 */
   SUB(e2,v0,v2);      /* tri edge 2 */
   /* Bullet 3:  */
   /*  test the 9 tests first (this was faster) */
   fex = fabsf(e0[X]);
   fey = fabsf(e0[Y]);
   fez = fabsf(e0[Z]);
   AXISTEST_X01(e0[Z], e0[Y], fez, fey, return 1);
   AXISTEST_Y02(e0[Z], e0[X], fez, fex, return 1);
   AXISTEST_Z12(e0[Y], e0[X], fey, fex, return 1);
   fex = fabsf(e1[X]);
   fey = fabsf(e1[Y]);
   fez = fabsf(e1[Z]);
   AXISTEST_X01(e1[Z], e1[Y], fez, fey, return 1);
   AXISTEST_Y02(e1[Z], e1[X], fez, fex, return 1);
   AXISTEST_Z0( e1[Y], e1[X], fey, fex, return 1);
   fex = fabsf(e2[X]);
   fey = fabsf(e2[Y]);
   fez = fabsf(e2[Z]);
   AXISTEST_X2( e2[Z], e2[Y], fez, fey, return 1);
   AXISTEST_Y1( e2[Z], e2[X], fez, fex, return 1);
   AXISTEST_Z12(e2[Y], e2[X], fey, fex, return 1);
   /* Bullet 1: */
   /*  first test overlap in the {x,y,z}-directions */
   /*  find min, max of the triangle each direction, and test for overlap in */
   /*  that direction -- this is equivalent to testing a minimal AABB around */
   /*  the triangle against the AABB */
   /* test in X-direction */
   FINDMINMAX(v0[X],v1[X],v2[X],min,max);
   if(min>boxhalfsize[X] || max<-boxhalfsize[X]) return 1;
   /* test in Y-direction */
   FINDMINMAX(v0[Y],v1[Y],v2[Y],min,max);
   if(min>boxhalfsize[Y] || max<-boxhalfsize[Y]) return 1;
   /* test in Z-direction */
   FINDMINMAX(v0[Z],v1[Z],v2[Z],min,max);
   if(min>boxhalfsize[Z] || max<-boxhalfsize[Z]) return 1;
   /* Bullet 2: */
   /*  test if the box intersects the plane of the triangle */
   /*  compute plane equation of triangle: normal*x+d=0 */
   CROSS(normal,e0,e1);
   // -NJMP- (line removed here)
   if(!planeBoxOverlap(normal,v0,boxhalfsize)) return 1;	// -NJMP-
   return 0;   /* box and triangle overlaps */
}

MTRand rnd;

double randrange(double min, double max) {
  return rnd.rand(max - min) + min;
}

carve::geom::vector<3> randomVector() {
  return carve::geom::VECTOR(randrange(-4.0, +4.0), randrange(-4.0, +4.0), randrange(-4.0, +4.0));
}

carve::geom::tri<3> randomTriangle() {
  return carve::geom::tri<3>(randomVector(), randomVector(), randomVector());
}

int main(int argc, char **argv) {
  carve::geom::aabb<3> aabb(carve::geom::VECTOR(0,0,0), carve::geom::VECTOR(1,1,1));

  for (unsigned i = 0; i < 1000000; ++i) {
    carve::geom::tri<3> tri(randomTriangle());
    double triverts[3][3];
    for (unsigned x = 0; x < 3; ++x) {
      for (unsigned y = 0; y < 3; ++y) {
        triverts[x][y] = tri.v[x][y];
      }
    }
    bool a = aabb.intersects(tri);
    unsigned b = triBoxOverlap_test(aabb.pos.v, aabb.extent.v, triverts);
    if (a != !(bool)b) {
      std::cerr << "i=" << i << " disagreement (" << a << ":" << std::hex << b << std::dec << ") over aabb=" << aabb << " tri=" << tri << std::endl;
      std::cout << 
"ply\n"
"format ascii 1.0\n"
"element vertex 11\n"
"property double x\n"
"property double y\n"
"property double z\n"
"element face 7\n"
"property list uchar ushort vertex_indices\n"
"end_header\n";
      carve::geom::vector<3> amin = aabb.min(), amax = aabb.max();
      std::cout << amax.x << " " << amin.y << " " << amin.z << std::endl;
      std::cout << amin.x << " " << amin.y << " " << amin.z << std::endl;
      std::cout << amin.x << " " << amax.y << " " << amin.z << std::endl;
      std::cout << amax.x << " " << amax.y << " " << amin.z << std::endl;

      std::cout << amax.x << " " << amin.y << " " << amax.z << std::endl;
      std::cout << amin.x << " " << amin.y << " " << amax.z << std::endl;
      std::cout << amin.x << " " << amax.y << " " << amax.z << std::endl;
      std::cout << amax.x << " " << amax.y << " " << amax.z << std::endl;
      std::cout << tri.v[0].x << " " << tri.v[0].y << " " << tri.v[0].z << std::endl;
      std::cout << tri.v[1].x << " " << tri.v[1].y << " " << tri.v[1].z << std::endl;
      std::cout << tri.v[2].x << " " << tri.v[2].y << " " << tri.v[2].z << std::endl;
      std::cout <<
"4 0 1 2 3\n"
"4 1 0 4 5\n"
"4 2 1 5 6\n"
"4 3 2 6 7\n"
"4 0 3 7 4\n"
"4 7 6 5 4\n"
"3 8 9 10\n";
      throw std::runtime_error("failed");
    }
  }
}