#pragma region License
/******************************************************************************
This file is part of the PolyVox library
Copyright (C) 2006  David Williams

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program 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
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
******************************************************************************/
#pragma endregion

#include "IndexedSurfacePatch.h"

#include "progmesh.h"

using namespace std;

namespace PolyVox
{
	IndexedSurfacePatch::IndexedSurfacePatch()
	{
		m_iTimeStamp = -1;
	}

	IndexedSurfacePatch::~IndexedSurfacePatch()	  
	{
	}

	const std::vector<uint32_t>& IndexedSurfacePatch::getIndices(void) const
	{
		return m_vecTriangleIndices;
	}

	uint32_t IndexedSurfacePatch::getNoOfIndices(void) const
	{
		return m_vecTriangleIndices.size();
	}	

	uint32_t IndexedSurfacePatch::getNoOfNonUniformTrianges(void) const
	{
		uint32_t result = 0;
		for(uint32_t i = 0; i < m_vecTriangleIndices.size() - 2; i += 3)
		{
			if((m_vecVertices[m_vecTriangleIndices[i]].getMaterial() == m_vecVertices[m_vecTriangleIndices[i+1]].getMaterial())
			&& (m_vecVertices[m_vecTriangleIndices[i]].getMaterial() == m_vecVertices[m_vecTriangleIndices[i+2]].getMaterial()))
			{
			}
			else
			{
				result++;
			}
		}
		return result;
	}

	uint32_t IndexedSurfacePatch::getNoOfUniformTrianges(void) const
	{
		uint32_t result = 0;
		for(uint32_t i = 0; i < m_vecTriangleIndices.size() - 2; i += 3)
		{
			if((m_vecVertices[m_vecTriangleIndices[i]].getMaterial() == m_vecVertices[m_vecTriangleIndices[i+1]].getMaterial())
			&& (m_vecVertices[m_vecTriangleIndices[i]].getMaterial() == m_vecVertices[m_vecTriangleIndices[i+2]].getMaterial()))
			{
				result++;
			}
		}
		return result;
	}

	uint32_t IndexedSurfacePatch::getNoOfVertices(void) const
	{
		return m_vecVertices.size();
	}

	std::vector<SurfaceVertex>& IndexedSurfacePatch::getRawVertexData(void)
	{
		return m_vecVertices;
	}

	const std::vector<SurfaceVertex>& IndexedSurfacePatch::getVertices(void) const
	{
		return m_vecVertices;
	}		

	void IndexedSurfacePatch::addTriangle(uint32_t index0, uint32_t index1, uint32_t index2)
	{
		m_vecTriangleIndices.push_back(index0);
		m_vecTriangleIndices.push_back(index1);
		m_vecTriangleIndices.push_back(index2);

		if((m_vecVertices[index0].material == m_vecVertices[index1].material) && (m_vecVertices[index0].material == m_vecVertices[index2].material))
		{
			m_mapUsedMaterials.insert(m_vecVertices[index0].material);			
		}
		else
		{
			m_vecVertices[index0].m_bIsMaterialEdgeVertex = true;
			m_vecVertices[index1].m_bIsMaterialEdgeVertex = true;
			m_vecVertices[index2].m_bIsMaterialEdgeVertex = true;
		}
	}

	uint32_t IndexedSurfacePatch::addVertex(const SurfaceVertex& vertex)
	{
		m_vecVertices.push_back(vertex);
		return m_vecVertices.size() - 1;
	}

	void IndexedSurfacePatch::clear(void)
	{
		m_vecVertices.clear();
		m_vecTriangleIndices.clear();
	}

	const bool IndexedSurfacePatch::isEmpty(void) const
	{
		return (getNoOfVertices() == 0) || (getNoOfIndices() == 0);
	}

	////////////////////////////////////////////////////////////////////////////////
	/// The function works on a per triangle basis without any need for connectivity
	/// information. It determines whether a triangle is lying on a flat or curved
	/// section of the surface patch by examining the normals - therefore these
	/// normals must hve been set to something sensible before this functions is called.
	/// \param fAmount A factor controlling how much the vertices move by. Find a good
	/// value by experimentation, starting with something small such as 0.1f.
	/// \param bIncludeEdgeVertices Indicates whether vertices on the edge of an
	/// IndexedSurfacePatch should be smoothed. This can cause dicontinuities between
	/// neighbouring patches.
	////////////////////////////////////////////////////////////////////////////////
	void IndexedSurfacePatch::smoothPositions(float fAmount, bool bIncludeEdgeVertices)
	{
		if(m_vecVertices.size() == 0) //FIXME - I don't think we should need this test, but I have seen crashes otherwise...
		{
			return;
		}

		//This will hold the new positions, and is initialised with the current positions.
		std::vector<Vector3DFloat> newPositions(m_vecVertices.size());
		for(uint32_t uIndex = 0; uIndex < newPositions.size(); uIndex++)
		{
			newPositions[uIndex] = m_vecVertices[uIndex].getPosition();
		}

		//Iterate over each triangle
		for(vector<uint32_t>::iterator iterIndex = m_vecTriangleIndices.begin(); iterIndex != m_vecTriangleIndices.end();)
		{
			//Get the vertex data for the triangle
			SurfaceVertex& v0 = m_vecVertices[*iterIndex];
			Vector3DFloat& v0New = newPositions[*iterIndex];
			iterIndex++;
			SurfaceVertex& v1 = m_vecVertices[*iterIndex];
			Vector3DFloat& v1New = newPositions[*iterIndex];
			iterIndex++;
			SurfaceVertex& v2 = m_vecVertices[*iterIndex];
			Vector3DFloat& v2New = newPositions[*iterIndex];
			iterIndex++;

			//Find the midpoint
			Vector3DFloat v3dMidpoint = (v0.position + v1.position + v2.position) / 3.0f;

			//Vectors from vertex to midpoint
			Vector3DFloat v0ToMidpoint = v3dMidpoint - v0.position;
			Vector3DFloat v1ToMidpoint = v3dMidpoint - v1.position;
			Vector3DFloat v2ToMidpoint = v3dMidpoint - v2.position;
			
			//Get the vertex normals
			Vector3DFloat n0 = v0.getNormal();
			Vector3DFloat n1 = v1.getNormal();			
			Vector3DFloat n2 = v2.getNormal();				

			//I don't think these normalisation are necessary... and could be slow.
			//Normals should be normalised anyway, and as long as all triangles are
			//about the same size the distances to midpoint should be similar too.
			//v0ToMidpoint.normalise();
			//v1ToMidpoint.normalise();
			//v2ToMidpoint.normalise();
			//n0.normalise();
			//n1.normalise();
			//n2.normalise();
			
			//If the dot product is zero the the normals are perpendicular
			//to the triangle, hence the positions do not move.
			v0New += (n0 * (n0.dot(v0ToMidpoint)) * fAmount);
			v1New += (n1 * (n1.dot(v1ToMidpoint)) * fAmount);
			v2New += (n2 * (n2.dot(v2ToMidpoint)) * fAmount);
		}

		//Update with the new positions
		for(uint32_t uIndex = 0; uIndex < newPositions.size(); uIndex++)
		{
			if((bIncludeEdgeVertices) || (m_vecVertices[uIndex].isEdgeVertex() == false))
			{
				m_vecVertices[uIndex].setPosition(newPositions[uIndex]);
			}
		}
	}	

	////////////////////////////////////////////////////////////////////////////////
	/// This function can help improve the visual appearance of a surface patch by
	/// smoothing normals with other nearby normals. It iterates over each triangle
	/// in the surface patch and determines the sum of its corners normals. For any
	/// given vertex, these sums are in turn summed for any triangles which use the
	/// vertex. Usually, the resulting normals should be renormalised afterwards.
	/// Note: This function can cause lighting discontinuities accross region boundaries.
	////////////////////////////////////////////////////////////////////////////////
	void IndexedSurfacePatch::sumNearbyNormals(bool bNormaliseResult)
	{
		if(m_vecVertices.size() == 0) //FIXME - I don't think we should need this test, but I have seen crashes otherwise...
		{
			return;
		}

		std::vector<Vector3DFloat> summedNormals(m_vecVertices.size());

		//Initialise all normals to zero. Should be ok as the vector should store all elements contiguously.
		memset(&summedNormals[0], 0, summedNormals.size() * sizeof(Vector3DFloat));

		for(vector<uint32_t>::iterator iterIndex = m_vecTriangleIndices.begin(); iterIndex != m_vecTriangleIndices.end();)
		{
			SurfaceVertex& v0 = m_vecVertices[*iterIndex];
			Vector3DFloat& v0New = summedNormals[*iterIndex];
			iterIndex++;
			SurfaceVertex& v1 = m_vecVertices[*iterIndex];
			Vector3DFloat& v1New = summedNormals[*iterIndex];
			iterIndex++;
			SurfaceVertex& v2 = m_vecVertices[*iterIndex];
			Vector3DFloat& v2New = summedNormals[*iterIndex];
			iterIndex++;

			Vector3DFloat sumOfNormals = v0.getNormal() + v1.getNormal() + v2.getNormal();

			v0New += sumOfNormals;
			v1New += sumOfNormals;
			v2New += sumOfNormals;
		}

		for(uint32_t uIndex = 0; uIndex < summedNormals.size(); uIndex++)
		{
			if(bNormaliseResult)
			{
				summedNormals[uIndex].normalise();
			}
			m_vecVertices[uIndex].setNormal(summedNormals[uIndex]);
		}
	}

	void IndexedSurfacePatch::generateAveragedFaceNormals(bool bNormalise, bool bIncludeEdgeVertices)
	{
		Vector3DFloat offset = static_cast<Vector3DFloat>(m_Region.getLowerCorner());

		//Initially zero the normals
		for(vector<SurfaceVertex>::iterator iterVertex = m_vecVertices.begin(); iterVertex != m_vecVertices.end(); iterVertex++)
		{
			if(m_Region.containsPoint(iterVertex->getPosition() + offset, 0.001))
			{
				iterVertex->setNormal(Vector3DFloat(0.0f,0.0f,0.0f));
			}
		}

		for(vector<uint32_t>::iterator iterIndex = m_vecTriangleIndices.begin(); iterIndex != m_vecTriangleIndices.end();)
		{
			SurfaceVertex& v0 = m_vecVertices[*iterIndex];
			iterIndex++;
			SurfaceVertex& v1 = m_vecVertices[*iterIndex];
			iterIndex++;
			SurfaceVertex& v2 = m_vecVertices[*iterIndex];
			iterIndex++;

			Vector3DFloat triangleNormal = (v1.getPosition()-v0.getPosition()).cross(v2.getPosition()-v0.getPosition());

			if(m_Region.containsPoint(v0.getPosition() + offset, 0.001))
			{
				v0.setNormal(v0.getNormal() + triangleNormal);
			}
			if(m_Region.containsPoint(v1.getPosition() + offset, 0.001))
			{
				v1.setNormal(v1.getNormal() + triangleNormal);
			}
			if(m_Region.containsPoint(v2.getPosition() + offset, 0.001))
			{
				v2.setNormal(v2.getNormal() + triangleNormal);
			}
		}

		if(bNormalise)
		{
			for(vector<SurfaceVertex>::iterator iterVertex = m_vecVertices.begin(); iterVertex != m_vecVertices.end(); iterVertex++)
			{
				Vector3DFloat normal = iterVertex->getNormal();
				normal.normalise();
				iterVertex->setNormal(normal);
			}
		}
	}

	POLYVOX_SHARED_PTR<IndexedSurfacePatch> IndexedSurfacePatch::extractSubset(std::set<uint8_t> setMaterials)
	{
		POLYVOX_SHARED_PTR<IndexedSurfacePatch> result(new IndexedSurfacePatch);

		if(m_vecVertices.size() == 0) //FIXME - I don't think we should need this test, but I have seen crashes otherwise...
		{
			return result;
		}

		for(vector<uint32_t>::iterator iterIndex = m_vecTriangleIndices.begin(); iterIndex != m_vecTriangleIndices.end();)
		{
			SurfaceVertex& v0 = m_vecVertices[*iterIndex];
			iterIndex++;
			SurfaceVertex& v1 = m_vecVertices[*iterIndex];
			iterIndex++;
			SurfaceVertex& v2 = m_vecVertices[*iterIndex];
			iterIndex++;

			if(
				(setMaterials.find(v0.getMaterial()) != setMaterials.end()) || 
				(setMaterials.find(v1.getMaterial()) != setMaterials.end()) || 
				(setMaterials.find(v2.getMaterial()) != setMaterials.end()))
			{
				uint32_t i0 = result->addVertex(v0);
				uint32_t i1 = result->addVertex(v1);
				uint32_t i2 = result->addVertex(v2);

				result->addTriangle(i0,i1,i2);
			}
		}

		return result;
	}

	/*int IndexedSurfacePatch::countMaterialBoundary(void)
	{
		int count = 0;
		for(int ct = 0; ct < m_vecVertices.size(); ct++)
		{
			if(m_vecVertices[ct].m_bIsMaterialEdgeVertex)
			{
				count++;
			}
		}
		return count;
	}

	void IndexedSurfacePatch::growMaterialBoundary(void)
	{
		std::vector<SurfaceVertex> vecNewVertices = m_vecVertices;

		for(vector<uint32_t>::iterator iterIndex = m_vecTriangleIndices.begin(); iterIndex != m_vecTriangleIndices.end();)
		{
			SurfaceVertex& v0 = m_vecVertices[*iterIndex];
			SurfaceVertex& v0New = vecNewVertices[*iterIndex];
			iterIndex++;
			SurfaceVertex& v1 = m_vecVertices[*iterIndex];
			SurfaceVertex& v1New = vecNewVertices[*iterIndex];
			iterIndex++;
			SurfaceVertex& v2 = m_vecVertices[*iterIndex];
			SurfaceVertex& v2New = vecNewVertices[*iterIndex];
			iterIndex++;

			if(v0.m_bIsMaterialEdgeVertex || v1.m_bIsMaterialEdgeVertex || v2.m_bIsMaterialEdgeVertex)
			{
				v0New.m_bIsMaterialEdgeVertex = true;
				v1New.m_bIsMaterialEdgeVertex = true;
				v2New.m_bIsMaterialEdgeVertex = true;
			}
		}

		m_vecVertices = vecNewVertices;
	}*/

	void IndexedSurfacePatch::makeProgressiveMesh(void)
	{

		//Build the mesh using Stan Melax's code
		List<VectorM> vecList;
		for(int vertCt = 0; vertCt < m_vecVertices.size(); vertCt++)
		{
			VectorM vec;
			vec.x = m_vecVertices[vertCt].getPosition().getX();
			vec.y = m_vecVertices[vertCt].getPosition().getY();
			vec.z = m_vecVertices[vertCt].getPosition().getZ();

			if(m_vecVertices[vertCt].isEdgeVertex() || m_vecVertices[vertCt].m_bIsMaterialEdgeVertex)
			{
				vec.fBoundaryCost = 1.0f;
			}
			else
			{
				vec.fBoundaryCost = 0.0f;
			}

			vecList.Add(vec);
		}

		List<tridata> triList;
		for(int triCt = 0; triCt < m_vecTriangleIndices.size(); )
		{
			tridata tri;
			tri.v[0] = m_vecTriangleIndices[triCt];
			triCt++;
			tri.v[1] = m_vecTriangleIndices[triCt];
			triCt++;
			tri.v[2] = m_vecTriangleIndices[triCt];
			triCt++;
			triList.Add(tri);
		}

		List<int> map;
		List<int> permutation;

		ProgressiveMesh(vecList, triList, map, permutation);

		//Apply the permutation to our vertices
		std::vector<SurfaceVertex> vecNewVertices(m_vecVertices.size());
		for(int vertCt = 0; vertCt < m_vecVertices.size(); vertCt++)
		{
			vecNewVertices[permutation[vertCt]]= m_vecVertices[vertCt];
		}

		std::vector<uint32_t> vecNewTriangleIndices(m_vecTriangleIndices.size());
		for(int triCt = 0; triCt < m_vecTriangleIndices.size(); triCt++)
		{
			vecNewTriangleIndices[triCt] = permutation[m_vecTriangleIndices[triCt]];
		}

		m_vecVertices = vecNewVertices;
		m_vecTriangleIndices = vecNewTriangleIndices;

		////////////////////////////////////////////////////////////////////////////////
		//Check for unused vertices?
		//int usedVertices = 0;
		//int unusedVertices = 0;
		/*usedVertices = 0;
		unusedVertices = 0;
		for(int vertCt = 0; vertCt < isp->m_vecVertices.size(); vertCt++)
		{
			bool found = false;
			for(int triCt = 0; triCt < isp->m_vecTriangleIndices.size();  triCt++)
			{
				if(vertCt == isp->m_vecTriangleIndices[triCt])
				{
					found = true;
					break;
				}
			}
			if(found)
			{
				usedVertices++;
			}
			else
			{
				unusedVertices++;
			}
		}

		std::cout << "Used   = " << usedVertices << std::endl;
		std::cout << "Unused = " << unusedVertices << std::endl;*/
		////////////////////////////////////////////////////////////////////////////////

		////////////////////////////////////////////////////////////////////////////////

		//switch triangle order?
		/*int noOfTriIndices = isp->m_vecTriangleIndices.size();
		for(int triCt = 0; triCt < noOfTriIndices; triCt++)
		{
			vecNewTriangleIndices[(noOfTriIndices - 1) - triCt] = isp->m_vecTriangleIndices[triCt];
		}
		isp->m_vecTriangleIndices = vecNewTriangleIndices;*/

		//Now build the new index buffers
		std::vector<uint32_t> vecNewTriangles;
		std::vector<uint32_t> vecUnaffectedTriangles;
		std::vector<uint32_t> vecCollapsedTriangles;

		vector<bool> vecCanCollapse(m_vecVertices.size());
		for(int ct = 0; ct < vecCanCollapse.size(); ct++)
		{
			vecCanCollapse[ct] = true;
		}

		vector<bool> vecTriangleRemoved(m_vecTriangleIndices.size() / 3);
		for(int ct = 0; ct < vecTriangleRemoved.size(); ct++)
		{
			vecTriangleRemoved[ct] = false;
		}

		int noOfCollapsed = 0;
		m_vecLodRecords.clear();
		

		for(int vertToCollapse = m_vecVertices.size() - 1; vertToCollapse > 0; vertToCollapse--)
		//int vertToCollapse = isp->m_vecVertices.size() - 1;
		{
			int vertCollapseTarget = map[vertToCollapse];

			if((vecCanCollapse[vertToCollapse]) && (vecCanCollapse[vertCollapseTarget]))
			{
				int noOfNew = 0;

				for(int triCt = 0; triCt < m_vecTriangleIndices.size();)
				{
					int v0 = m_vecTriangleIndices[triCt];
					triCt++;
					int v1 = m_vecTriangleIndices[triCt];
					triCt++;
					int v2 = m_vecTriangleIndices[triCt];
					triCt++;

					if(vecTriangleRemoved[(triCt - 3) / 3] == false)
					{
						if( (v0 == vertToCollapse) || (v1 == vertToCollapse) || (v2 == vertToCollapse) )
						{
							vecCollapsedTriangles.push_back(v0);
							vecCollapsedTriangles.push_back(v1);
							vecCollapsedTriangles.push_back(v2);

							vecCanCollapse[v0] = false;
							vecCanCollapse[v1] = false;
							vecCanCollapse[v2] = false;

							noOfCollapsed++;

							int targetV0 = v0;
							int targetV1 = v1;
							int targetV2 = v2;

							if(targetV0 == vertToCollapse) targetV0 = vertCollapseTarget;
							if(targetV1 == vertToCollapse) targetV1 = vertCollapseTarget;
							if(targetV2 == vertToCollapse) targetV2 = vertCollapseTarget;

							if((targetV0 != targetV1) && (targetV1 != targetV2) && (targetV2 != targetV0))
							{
								vecNewTriangles.push_back(targetV0);
								vecNewTriangles.push_back(targetV1);
								vecNewTriangles.push_back(targetV2);

								noOfNew++;

								vecCanCollapse[targetV0] = false;
								vecCanCollapse[targetV1] = false;
								vecCanCollapse[targetV2] = false;
							}										

							vecTriangleRemoved[(triCt - 3) / 3] = true;

							
						}
					}
				}
				LodRecord lodRecord;
				lodRecord.beginIndex = vecNewTriangles.size() - (3 * noOfNew);
				lodRecord.endIndex = vecCollapsedTriangles.size();
				m_vecLodRecords.push_back(lodRecord);
			}
		}

		//Copy triangles into unaffected list
		for(int triCt = 0; triCt < m_vecTriangleIndices.size();)
		{
			int v0 = m_vecTriangleIndices[triCt];
			triCt++;
			int v1 = m_vecTriangleIndices[triCt];
			triCt++;
			int v2 = m_vecTriangleIndices[triCt];
			triCt++;

			if(vecTriangleRemoved[(triCt - 3) / 3] == false)
			{
				vecUnaffectedTriangles.push_back(v0);
				vecUnaffectedTriangles.push_back(v1);
				vecUnaffectedTriangles.push_back(v2);
			}
		}

		//Now copy the three lists of triangles back
		m_vecTriangleIndices.clear();

		for(int ct = 0; ct < vecNewTriangles.size(); ct++)
		{
			m_vecTriangleIndices.push_back(vecNewTriangles[ct]);
		}

		for(int ct = 0; ct < vecUnaffectedTriangles.size(); ct++)
		{
			m_vecTriangleIndices.push_back(vecUnaffectedTriangles[ct]);
		}

		for(int ct = 0; ct < vecCollapsedTriangles.size(); ct++)
		{
			m_vecTriangleIndices.push_back(vecCollapsedTriangles[ct]);
		}

		//Adjust the lod records
		for(int ct = 0; ct < m_vecLodRecords.size(); ct++)
		{
			m_vecLodRecords[ct].endIndex += (vecNewTriangles.size() + vecUnaffectedTriangles.size());
		}
	}
}