/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/


///
/// Collision Demo shows a degenerate case, where the Simplex solver has to deal with near-affine dependent cases
/// See the define CATCH_DEGENERATE_TETRAHEDRON in Bullet's btVoronoiSimplexSolver.cpp
///


#define CHECK_GENSHER_TRIANGLE_CASE 1


///This low-level internal demo does intentionally NOT use the btBulletCollisionCommon.h header
///It needs internal access
#include "btBulletCollisionCommon.h"
#include "LinearMath/btQuaternion.h"
#include "LinearMath/btTransform.h"
#include "BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.h"
#include "BulletCollision/CollisionShapes/btBoxShape.h"
#include "BulletCollision/NarrowPhaseCollision/btGjkPairDetector.h"
#include "BulletCollision/NarrowPhaseCollision/btPointCollector.h"
#include "BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.h"
#include "BulletCollision/NarrowPhaseCollision/btConvexPenetrationDepthSolver.h"
#include "BulletCollision/NarrowPhaseCollision/btGjkEpaPenetrationDepthSolver.h"
#include "LinearMath/btTransformUtil.h"


#include <ctime>

#include "LinearMath/btIDebugDraw.h"

#include <iostream>
#include <fstream>
int main(int argc,char** argv)
{
	const int numObjects = 2;
	
	btTransform tr[numObjects];
  
	btScalar coneRad(0.584545); // cone radius
	btScalar coneheight(1); //height of the cone
	btScalar sphereRad(0.1); //radius of the sphere
	btConeShapeZ*	coneA = new btConeShapeZ(coneRad,coneheight); //Declaration of conical shape
	btSphereShape*	sphereB = new btSphereShape(sphereRad); //Declaration of spherical shape
	
	coneA->setMargin(btScalar(0));
	sphereB->setMargin(btScalar(0));
	
	
	btVoronoiSimplexSolver sGjkSimplexSolver;
	btGjkEpaPenetrationDepthSolver epaSolver;
	btPointCollector gjkOutput;
	
	btGjkPairDetector convexConvex(coneA,sphereB,&sGjkSimplexSolver,&epaSolver); 
  
	btGjkPairDetector::ClosestPointInput input; 
	btQuaternion q1;
	q1.setValue(0, 0, 0, 1); //Quaternion to represent the orientation of the cone axis 
	tr[0].setRotation(q1);
	tr[0].setOrigin(btVector3(0, 0, -1)); // centre of the base circle of the cone

	tr[1].setIdentity();
	tr[1].setOrigin((btVector3(0.9,  0.9,  0.1))); // centre of the sphere	

	input.m_transformA = tr[0]; 
	input.m_transformB = tr[1]; 
	
	convexConvex.getClosestPoints(input, gjkOutput, 0); // compute the shortest distance between the sphere and the cone 
	btVector3 p1 = gjkOutput.m_pointInWorld; //foot of perpendicular on the sphere
	btVector3 p2 = gjkOutput.m_pointInWorld + gjkOutput.m_normalOnBInWorld*gjkOutput.m_distance; 
	printf("Shortest distance between the cone and sphere from GJK solver = %lf\n",gjkOutput.m_distance );
	
	

}