/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2022, assimp team

All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/

#include "GeometryUtils.h"

#include <assimp/vector3.h>

namespace Assimp {

// ------------------------------------------------------------------------------------------------
ai_real GeometryUtils::heron( ai_real a, ai_real b, ai_real c ) {
    const ai_real s = (a + b + c) / 2;
    const ai_real area = pow((s * ( s - a ) * ( s - b ) * ( s - c ) ), (ai_real)0.5 );
    return area;
}

// ------------------------------------------------------------------------------------------------
ai_real GeometryUtils::distance3D( const aiVector3D &vA, const aiVector3D &vB ) {
    const ai_real lx = ( vB.x - vA.x );
    const ai_real ly = ( vB.y - vA.y );
    const ai_real lz = ( vB.z - vA.z );
    const ai_real a = lx*lx + ly*ly + lz*lz;
    const ai_real d = pow( a, (ai_real)0.5 );

    return d;
}

// ------------------------------------------------------------------------------------------------
ai_real GeometryUtils::calculateAreaOfTriangle( const aiFace& face, aiMesh* mesh ) {
    ai_real area = 0;

    const aiVector3D vA( mesh->mVertices[ face.mIndices[ 0 ] ] );
    const aiVector3D vB( mesh->mVertices[ face.mIndices[ 1 ] ] );
    const aiVector3D vC( mesh->mVertices[ face.mIndices[ 2 ] ] );

    const ai_real a = distance3D( vA, vB );
    const ai_real b = distance3D( vB, vC );
    const ai_real c = distance3D( vC, vA );
    area = heron( a, b, c );

    return area;
}

// ------------------------------------------------------------------------------------------------
// Check whether a ray intersects a plane and find the intersection point
bool GeometryUtils::PlaneIntersect(const aiRay& ray, const aiVector3D& planePos, 
        const aiVector3D& planeNormal, aiVector3D& pos) {
    const ai_real b = planeNormal * (planePos - ray.pos);
    ai_real h = ray.dir * planeNormal;
    if ((h < 10e-5 && h > -10e-5) || (h = b/h) < 0)
        return false;

    pos = ray.pos + (ray.dir * h);
    return true;
}

// ------------------------------------------------------------------------------------------------
void GeometryUtils::normalizeVectorArray(aiVector3D *vectorArrayIn, aiVector3D *vectorArrayOut, 
        size_t numVectors) {
    for (size_t i=0; i<numVectors; ++i) {
		    vectorArrayOut[i] = vectorArrayIn[i].Normalize();
	  }
}

} // namespace Assimp