path: root/engine/src/tools/jme3tools/converters/model/strip/Stripifier.java

/*
 * Copyright (c) 2009-2010 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use 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 'jMonkeyEngine' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * 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
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package jme3tools.converters.model.strip;

import java.util.HashSet;
import java.util.logging.Logger;

/**
 *  
 */
class Stripifier {
    private static final Logger logger = Logger.getLogger(Stripifier.class
            .getName());

	public static int CACHE_INEFFICIENCY = 6;

	IntVec indices = new IntVec();

	int cacheSize;

	int minStripLength;

	float meshJump;

	boolean bFirstTimeResetPoint;

	Stripifier() {
		super();
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// FindEdgeInfo()
	//
	// find the edge info for these two indices
	//
	static EdgeInfo findEdgeInfo(EdgeInfoVec edgeInfos, int v0, int v1) {

		// we can get to it through either array
		// because the edge infos have a v0 and v1
		// and there is no order except how it was
		// first created.
		EdgeInfo infoIter = edgeInfos.at(v0);
		while (infoIter != null) {
			if (infoIter.m_v0 == v0) {
				if (infoIter.m_v1 == v1)
					return infoIter;
				
				infoIter = infoIter.m_nextV0;
			} else {
				if (infoIter.m_v0 == v1)
					return infoIter;
				
				infoIter = infoIter.m_nextV1;
			}
		}
		return null;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// FindOtherFace
	//
	// find the other face sharing these vertices
	// exactly like the edge info above
	//
	static FaceInfo findOtherFace(EdgeInfoVec edgeInfos, int v0, int v1,
			FaceInfo faceInfo) {
		EdgeInfo edgeInfo = findEdgeInfo(edgeInfos, v0, v1);

		if ((edgeInfo == null) || (v0 == v1)) {
			//we've hit a degenerate
			return null;
		}

		return (edgeInfo.m_face0 == faceInfo ? edgeInfo.m_face1
				: edgeInfo.m_face0);
	}

	static boolean alreadyExists(FaceInfo faceInfo, FaceInfoVec faceInfos) {
		for (int i = 0; i < faceInfos.size(); ++i) {
			FaceInfo o = faceInfos.at(i);
			if ((o.m_v0 == faceInfo.m_v0) && (o.m_v1 == faceInfo.m_v1)
					&& (o.m_v2 == faceInfo.m_v2))
				return true;
		}
		return false;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// BuildStripifyInfo()
	//
	// Builds the list of all face and edge infos
	//
	void buildStripifyInfo(FaceInfoVec faceInfos, EdgeInfoVec edgeInfos,
			int maxIndex) {
		// reserve space for the face infos, but do not resize them.
		int numIndices = indices.size();
		faceInfos.reserve(numIndices / 3);

		// we actually resize the edge infos, so we must initialize to null
		for (int i = 0; i < maxIndex + 1; i++)
			edgeInfos.add(null);

		// iterate through the triangles of the triangle list
		int numTriangles = numIndices / 3;
		int index = 0;
		boolean[] bFaceUpdated = new boolean[3];

		for (int i = 0; i < numTriangles; i++) {
			boolean bMightAlreadyExist = true;
			bFaceUpdated[0] = false;
			bFaceUpdated[1] = false;
			bFaceUpdated[2] = false;

			// grab the indices
			int v0 = indices.get(index++);
			int v1 = indices.get(index++);
			int v2 = indices.get(index++);

			//we disregard degenerates
			if (isDegenerate(v0, v1, v2))
				continue;

			// create the face info and add it to the list of faces, but only
			// if this exact face doesn't already
			//  exist in the list
			FaceInfo faceInfo = new FaceInfo(v0, v1, v2);

			// grab the edge infos, creating them if they do not already exist
			EdgeInfo edgeInfo01 = findEdgeInfo(edgeInfos, v0, v1);
			if (edgeInfo01 == null) {
				//since one of it's edges isn't in the edge data structure, it
				// can't already exist in the face structure
				bMightAlreadyExist = false;

				// create the info
				edgeInfo01 = new EdgeInfo(v0, v1);

				// update the linked list on both
				edgeInfo01.m_nextV0 = edgeInfos.at(v0);
				edgeInfo01.m_nextV1 = edgeInfos.at(v1);
				edgeInfos.set(v0, edgeInfo01);
				edgeInfos.set(v1, edgeInfo01);

				// set face 0
				edgeInfo01.m_face0 = faceInfo;
			} else {
				if (edgeInfo01.m_face1 != null) {
					logger.info("BuildStripifyInfo: > 2 triangles on an edge"
                            + v0 + "," + v1 + "... uncertain consequences\n");
				} else {
					edgeInfo01.m_face1 = faceInfo;
					bFaceUpdated[0] = true;
				}
			}

			// grab the edge infos, creating them if they do not already exist
			EdgeInfo edgeInfo12 = findEdgeInfo(edgeInfos, v1, v2);
			if (edgeInfo12 == null) {
				bMightAlreadyExist = false;

				// create the info
				edgeInfo12 = new EdgeInfo(v1, v2);

				// update the linked list on both
				edgeInfo12.m_nextV0 = edgeInfos.at(v1);
				edgeInfo12.m_nextV1 = edgeInfos.at(v2);
				edgeInfos.set(v1, edgeInfo12);
				edgeInfos.set(v2, edgeInfo12);

				// set face 0
				edgeInfo12.m_face0 = faceInfo;
			} else {
				if (edgeInfo12.m_face1 != null) {
					logger.info("BuildStripifyInfo: > 2 triangles on an edge"
									+ v1
									+ ","
									+ v2
									+ "... uncertain consequences\n");
				} else {
					edgeInfo12.m_face1 = faceInfo;
					bFaceUpdated[1] = true;
				}
			}

			// grab the edge infos, creating them if they do not already exist
			EdgeInfo edgeInfo20 = findEdgeInfo(edgeInfos, v2, v0);
			if (edgeInfo20 == null) {
				bMightAlreadyExist = false;

				// create the info
				edgeInfo20 = new EdgeInfo(v2, v0);

				// update the linked list on both
				edgeInfo20.m_nextV0 = edgeInfos.at(v2);
				edgeInfo20.m_nextV1 = edgeInfos.at(v0);
				edgeInfos.set(v2, edgeInfo20);
				edgeInfos.set(v0, edgeInfo20);

				// set face 0
				edgeInfo20.m_face0 = faceInfo;
			} else {
				if (edgeInfo20.m_face1 != null) {
					logger.info("BuildStripifyInfo: > 2 triangles on an edge"
									+ v2
									+ ","
									+ v0
									+ "... uncertain consequences\n");
				} else {
					edgeInfo20.m_face1 = faceInfo;
					bFaceUpdated[2] = true;
				}
			}

			if (bMightAlreadyExist) {
				if (!alreadyExists(faceInfo, faceInfos))
					faceInfos.add(faceInfo);
				else {

					//cleanup pointers that point to this deleted face
					if (bFaceUpdated[0])
						edgeInfo01.m_face1 = null;
					if (bFaceUpdated[1])
						edgeInfo12.m_face1 = null;
					if (bFaceUpdated[2])
						edgeInfo20.m_face1 = null;
				}
			} else {
				faceInfos.add(faceInfo);
			}

		}
	}

	static boolean isDegenerate(FaceInfo face) {
		if (face.m_v0 == face.m_v1)
			return true;
		else if (face.m_v0 == face.m_v2)
			return true;
		else if (face.m_v1 == face.m_v2)
			return true;
		else
			return false;
	}

	static boolean isDegenerate(int v0, int v1, int v2) {
		if (v0 == v1)
			return true;
		else if (v0 == v2)
			return true;
		else if (v1 == v2)
			return true;
		else
			return false;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// GetNextIndex()
	//
	// Returns vertex of the input face which is "next" in the input index list
	//
	static int getNextIndex(IntVec indices, FaceInfo face) {

		int numIndices = indices.size();
		
		int v0 = indices.get(numIndices - 2);
		int v1 = indices.get(numIndices - 1);

		int fv0 = face.m_v0;
		int fv1 = face.m_v1;
		int fv2 = face.m_v2;

		if (fv0 != v0 && fv0 != v1) {
			if ((fv1 != v0 && fv1 != v1) || (fv2 != v0 && fv2 != v1)) {
                logger.info("GetNextIndex: Triangle doesn't have all of its vertices\n");
                logger.info("GetNextIndex: Duplicate triangle probably got us derailed\n");
			}
			return fv0;
		}
		if (fv1 != v0 && fv1 != v1) {
			if ((fv0 != v0 && fv0 != v1) || (fv2 != v0 && fv2 != v1)) {
                logger.info("GetNextIndex: Triangle doesn't have all of its vertices\n");
                logger.info("GetNextIndex: Duplicate triangle probably got us derailed\n");
			}
			return fv1;
		}
		if (fv2 != v0 && fv2 != v1) {
			if ((fv0 != v0 && fv0 != v1) || (fv1 != v0 && fv1 != v1)) {
                logger.info("GetNextIndex: Triangle doesn't have all of its vertices\n");
                logger.info("GetNextIndex: Duplicate triangle probably got us derailed\n");
			}
			return fv2;
		}

		// shouldn't get here, but let's try and fail gracefully
		if ((fv0 == fv1) || (fv0 == fv2))
			return fv0;
		else if ((fv1 == fv0) || (fv1 == fv2))
			return fv1;
		else if ((fv2 == fv0) || (fv2 == fv1))
			return fv2;
		else
			return -1;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// FindStartPoint()
	//
	// Finds a good starting point, namely one which has only one neighbor
	//
	static int findStartPoint(FaceInfoVec faceInfos, EdgeInfoVec edgeInfos) {
		int bestCtr = -1;
		int bestIndex = -1;

		for (int i = 0; i < faceInfos.size(); i++) {
			int ctr = 0;

			if (findOtherFace(edgeInfos, faceInfos.at(i).m_v0,
					faceInfos.at(i).m_v1, faceInfos.at(i)) == null)
				ctr++;
			if (findOtherFace(edgeInfos, faceInfos.at(i).m_v1,
					faceInfos.at(i).m_v2, faceInfos.at(i)) == null)
				ctr++;
			if (findOtherFace(edgeInfos, faceInfos.at(i).m_v2,
					faceInfos.at(i).m_v0, faceInfos.at(i)) == null)
				ctr++;
			if (ctr > bestCtr) {
				bestCtr = ctr;
				bestIndex = i;
				//return i;
			}
		}
		//return -1;

		if (bestCtr == 0)
			return -1;
		
		return bestIndex;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// FindGoodResetPoint()
	//  
	// A good reset point is one near other commited areas so that
	// we know that when we've made the longest strips its because
	// we're stripifying in the same general orientation.
	//
	FaceInfo findGoodResetPoint(FaceInfoVec faceInfos, EdgeInfoVec edgeInfos) {
		// we hop into different areas of the mesh to try to get
		// other large open spans done. Areas of small strips can
		// just be left to triangle lists added at the end.
		FaceInfo result = null;

		if (result == null) {
			int numFaces = faceInfos.size();
			int startPoint;
			if (bFirstTimeResetPoint) {
				//first time, find a face with few neighbors (look for an edge
				// of the mesh)
				startPoint = findStartPoint(faceInfos, edgeInfos);
				bFirstTimeResetPoint = false;
			} else
				startPoint = (int) (((float) numFaces - 1) * meshJump);

			if (startPoint == -1) {
				startPoint = (int) (((float) numFaces - 1) * meshJump);

				//meshJump += 0.1f;
				//if (meshJump > 1.0f)
				//  meshJump = .05f;
			}

			int i = startPoint;
			do {

				// if this guy isn't visited, try him
				if (faceInfos.at(i).m_stripId < 0) {
					result = faceInfos.at(i);
					break;
				}

				// update the index and clamp to 0-(numFaces-1)
				if (++i >= numFaces)
					i = 0;

			} while (i != startPoint);

			// update the meshJump
			meshJump += 0.1f;
			if (meshJump > 1.0f)
				meshJump = .05f;
		}

		// return the best face we found
		return result;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// GetUniqueVertexInB()
	//
	// Returns the vertex unique to faceB
	//
	static int getUniqueVertexInB(FaceInfo faceA, FaceInfo faceB) {

		int facev0 = faceB.m_v0;
		if (facev0 != faceA.m_v0 && facev0 != faceA.m_v1
				&& facev0 != faceA.m_v2)
			return facev0;

		int facev1 = faceB.m_v1;
		if (facev1 != faceA.m_v0 && facev1 != faceA.m_v1
				&& facev1 != faceA.m_v2)
			return facev1;

		int facev2 = faceB.m_v2;
		if (facev2 != faceA.m_v0 && facev2 != faceA.m_v1
				&& facev2 != faceA.m_v2)
			return facev2;

		// nothing is different
		return -1;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// GetSharedVertices()
	//
	// Returns the (at most) two vertices shared between the two faces
	//
	static void getSharedVertices(FaceInfo faceA, FaceInfo faceB, int[] vertex) {
		vertex[0] = -1;
		vertex[1] = -1;

		int facev0 = faceB.m_v0;
		if (facev0 == faceA.m_v0 || facev0 == faceA.m_v1
				|| facev0 == faceA.m_v2) {
			if (vertex[0] == -1)
				vertex[0] = facev0;
			else {
				vertex[1] = facev0;
				return;
			}
		}

		int facev1 = faceB.m_v1;
		if (facev1 == faceA.m_v0 || facev1 == faceA.m_v1
				|| facev1 == faceA.m_v2) {
			if (vertex[0] == -1)
				vertex[0] = facev1;
			else {
				vertex[1] = facev1;
				return;
			}
		}

		int facev2 = faceB.m_v2;
		if (facev2 == faceA.m_v0 || facev2 == faceA.m_v1
				|| facev2 == faceA.m_v2) {
			if (vertex[0] == -1)
				vertex[0] = facev2;
			else {
				vertex[1] = facev2;
				return;
			}
		}

	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// CommitStrips()
	//
	// "Commits" the input strips by setting their m_experimentId to -1 and
	// adding to the allStrips
	//  vector
	//
	static void commitStrips(StripInfoVec allStrips, StripInfoVec strips) {
		// Iterate through strips
		int numStrips = strips.size();
		for (int i = 0; i < numStrips; i++) {

			// Tell the strip that it is now real
			StripInfo strip = strips.at(i);
			strip.m_experimentId = -1;

			// add to the list of real strips
			allStrips.add(strip);

			// Iterate through the faces of the strip
			// Tell the faces of the strip that they belong to a real strip now
			FaceInfoVec faces = strips.at(i).m_faces;
			int numFaces = faces.size();

			for (int j = 0; j < numFaces; j++) {
				strip.markTriangle(faces.at(j));
			}
		}
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// NextIsCW()
	//
	// Returns true if the next face should be ordered in CW fashion
	//
	static boolean nextIsCW(int numIndices) {
		return ((numIndices % 2) == 0);
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// UpdateCacheFace()
	//
	// Updates the input vertex cache with this face's vertices
	//
	static void updateCacheFace(VertexCache vcache, FaceInfo face) {
		if (!vcache.inCache(face.m_v0))
			vcache.addEntry(face.m_v0);

		if (!vcache.inCache(face.m_v1))
			vcache.addEntry(face.m_v1);

		if (!vcache.inCache(face.m_v2))
			vcache.addEntry(face.m_v2);
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// UpdateCacheStrip()
	//
	// Updates the input vertex cache with this strip's vertices
	//
	static void updateCacheStrip(VertexCache vcache, StripInfo strip) {
		for (int i = 0; i < strip.m_faces.size(); ++i) {
			if (!vcache.inCache(strip.m_faces.at(i).m_v0))
				vcache.addEntry(strip.m_faces.at(i).m_v0);

			if (!vcache.inCache(strip.m_faces.at(i).m_v1))
				vcache.addEntry(strip.m_faces.at(i).m_v1);

			if (!vcache.inCache(strip.m_faces.at(i).m_v2))
				vcache.addEntry(strip.m_faces.at(i).m_v2);
		}
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// CalcNumHitsStrip()
	//
	// returns the number of cache hits per face in the strip
	//
	static float calcNumHitsStrip(VertexCache vcache, StripInfo strip) {
		int numHits = 0;
		int numFaces = 0;

		for (int i = 0; i < strip.m_faces.size(); i++) {
			if (vcache.inCache(strip.m_faces.at(i).m_v0))
				++numHits;

			if (vcache.inCache(strip.m_faces.at(i).m_v1))
				++numHits;

			if (vcache.inCache(strip.m_faces.at(i).m_v2))
				++numHits;

			numFaces++;
		}

		return ((float) numHits / (float) numFaces);
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// AvgStripSize()
	//
	// Finds the average strip size of the input vector of strips
	//
	static float avgStripSize(StripInfoVec strips) {
		int sizeAccum = 0;
		int numStrips = strips.size();
		for (int i = 0; i < numStrips; i++) {
			StripInfo strip = strips.at(i);
			sizeAccum += strip.m_faces.size();
			sizeAccum -= strip.m_numDegenerates;
		}
		return ((float) sizeAccum) / ((float) numStrips);
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// CalcNumHitsFace()
	//
	// returns the number of cache hits in the face
	//
	static int calcNumHitsFace(VertexCache vcache, FaceInfo face) {
		int numHits = 0;

		if (vcache.inCache(face.m_v0))
			numHits++;

		if (vcache.inCache(face.m_v1))
			numHits++;

		if (vcache.inCache(face.m_v2))
			numHits++;

		return numHits;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// NumNeighbors()
	//
	// Returns the number of neighbors that this face has
	//
	static int numNeighbors(FaceInfo face, EdgeInfoVec edgeInfoVec) {
		int numNeighbors = 0;

		if (findOtherFace(edgeInfoVec, face.m_v0, face.m_v1, face) != null) {
			numNeighbors++;
		}

		if (findOtherFace(edgeInfoVec, face.m_v1, face.m_v2, face) != null) {
			numNeighbors++;
		}

		if (findOtherFace(edgeInfoVec, face.m_v2, face.m_v0, face) != null) {
			numNeighbors++;
		}

		return numNeighbors;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// IsCW()
	//
	// Returns true if the face is ordered in CW fashion
	//
	static boolean isCW(FaceInfo faceInfo, int v0, int v1) {
		if (faceInfo.m_v0 == v0)
			return (faceInfo.m_v1 == v1);
		else if (faceInfo.m_v1 == v0)
			return (faceInfo.m_v2 == v1);
		else
			return (faceInfo.m_v0 == v1);

	}

	static boolean faceContainsIndex(FaceInfo face, int index) {
		return ((face.m_v0 == index) || (face.m_v1 == index) || (face.m_v2 == index));
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// FindTraversal()
	//
	// Finds the next face to start the next strip on.
	//
	static boolean findTraversal(FaceInfoVec faceInfos, EdgeInfoVec edgeInfos,
			StripInfo strip, StripStartInfo startInfo) {

		// if the strip was v0.v1 on the edge, then v1 will be a vertex in the
		// next edge.
		int v = (strip.m_startInfo.m_toV1 ? strip.m_startInfo.m_startEdge.m_v1
				: strip.m_startInfo.m_startEdge.m_v0);

		FaceInfo untouchedFace = null;
		EdgeInfo edgeIter = edgeInfos.at(v);
		while (edgeIter != null) {
			FaceInfo face0 = edgeIter.m_face0;
			FaceInfo face1 = edgeIter.m_face1;
			if ((face0 != null && !strip.isInStrip(face0)) && face1 != null
					&& !strip.isMarked(face1)) {
				untouchedFace = face1;
				break;
			}
			if ((face1 != null && !strip.isInStrip(face1)) && face0 != null
					&& !strip.isMarked(face0)) {
				untouchedFace = face0;
				break;
			}

			// find the next edgeIter
			edgeIter = (edgeIter.m_v0 == v ? edgeIter.m_nextV0
					: edgeIter.m_nextV1);
		}

		startInfo.m_startFace = untouchedFace;
		startInfo.m_startEdge = edgeIter;
		if (edgeIter != null) {
			if (strip.sharesEdge(startInfo.m_startFace, edgeInfos))
				startInfo.m_toV1 = (edgeIter.m_v0 == v); //note! used to be
			// m_v1
			else
				startInfo.m_toV1 = (edgeIter.m_v1 == v);
		}
		return (startInfo.m_startFace != null);
	}

	////////////////////////////////////////////////////////////////////////////////////////
	// RemoveSmallStrips()
	//
	// allStrips is the whole strip vector...all small strips will be deleted
	// from this list, to avoid leaking mem
	// allBigStrips is an out parameter which will contain all strips above
	// minStripLength
	// faceList is an out parameter which will contain all faces which were
	// removed from the striplist
	//
	void removeSmallStrips(StripInfoVec allStrips, StripInfoVec allBigStrips,
			FaceInfoVec faceList) {
		faceList.clear();
		allBigStrips.clear(); //make sure these are empty
		FaceInfoVec tempFaceList = new FaceInfoVec();

		for (int i = 0; i < allStrips.size(); i++) {
			if (allStrips.at(i).m_faces.size() < minStripLength) {
				//strip is too small, add faces to faceList
				for (int j = 0; j < allStrips.at(i).m_faces.size(); j++)
					tempFaceList.add(allStrips.at(i).m_faces.at(j));

			} else {
				allBigStrips.add(allStrips.at(i));
			}
		}

		boolean[] bVisitedList = new boolean[tempFaceList.size()];

		VertexCache vcache = new VertexCache(cacheSize);

		int bestNumHits = -1;
		int numHits;
		int bestIndex = -9999;

		while (true) {
			bestNumHits = -1;

			//find best face to add next, given the current cache
			for (int i = 0; i < tempFaceList.size(); i++) {
				if (bVisitedList[i])
					continue;

				numHits = calcNumHitsFace(vcache, tempFaceList.at(i));
				if (numHits > bestNumHits) {
					bestNumHits = numHits;
					bestIndex = i;
				}
			}

			if (bestNumHits == -1.0f)
				break;
			bVisitedList[bestIndex] = true;
			updateCacheFace(vcache, tempFaceList.at(bestIndex));
			faceList.add(tempFaceList.at(bestIndex));
		}
	}

	////////////////////////////////////////////////////////////////////////////////////////
	// CreateStrips()
	//
	// Generates actual strips from the list-in-strip-order.
	//
	int createStrips(StripInfoVec allStrips, IntVec stripIndices,
			boolean bStitchStrips) {
		int numSeparateStrips = 0;

		FaceInfo tLastFace = new FaceInfo(0, 0, 0);
		int nStripCount = allStrips.size();
		
		//we infer the cw/ccw ordering depending on the number of indices
		//this is screwed up by the fact that we insert -1s to denote changing
		// strips
		//this is to account for that
		int accountForNegatives = 0;

		for (int i = 0; i < nStripCount; i++) {
			StripInfo strip = allStrips.at(i);
			int nStripFaceCount = strip.m_faces.size();
			
			// Handle the first face in the strip
			{
				FaceInfo tFirstFace = new FaceInfo(strip.m_faces.at(0).m_v0,
						strip.m_faces.at(0).m_v1, strip.m_faces.at(0).m_v2);

				// If there is a second face, reorder vertices such that the
				// unique vertex is first
				if (nStripFaceCount > 1) {
					int nUnique = getUniqueVertexInB(strip.m_faces.at(1),
							tFirstFace);
					if (nUnique == tFirstFace.m_v1) {
						int tmp = tFirstFace.m_v0;
						tFirstFace.m_v0 = tFirstFace.m_v1;
						tFirstFace.m_v1 = tmp;
					} else if (nUnique == tFirstFace.m_v2) {
						int tmp = tFirstFace.m_v0;
						tFirstFace.m_v0 = tFirstFace.m_v2;
						tFirstFace.m_v2 = tmp;
					}

					// If there is a third face, reorder vertices such that the
					// shared vertex is last
					if (nStripFaceCount > 2) {
						if (isDegenerate(strip.m_faces.at(1))) {
							int pivot = strip.m_faces.at(1).m_v1;
							if (tFirstFace.m_v1 == pivot) {
								int tmp = tFirstFace.m_v1;
								tFirstFace.m_v1 = tFirstFace.m_v2;
								tFirstFace.m_v2 = tmp;
							}
						} else {
							int[] nShared = new int[2];
							getSharedVertices(strip.m_faces.at(2), tFirstFace,
									nShared);
							if ((nShared[0] == tFirstFace.m_v1)
									&& (nShared[1] == -1)) {
								int tmp = tFirstFace.m_v1;
								tFirstFace.m_v1 = tFirstFace.m_v2;
								tFirstFace.m_v2 = tmp;
							}
						}
					}
				}

				if ((i == 0) || !bStitchStrips) {
					if (!isCW(strip.m_faces.at(0), tFirstFace.m_v0,
							tFirstFace.m_v1))
						stripIndices.add(tFirstFace.m_v0);
				} else {
					// Double tap the first in the new strip
					stripIndices.add(tFirstFace.m_v0);

					// Check CW/CCW ordering
					if (nextIsCW(stripIndices.size() - accountForNegatives) != isCW(
							strip.m_faces.at(0), tFirstFace.m_v0,
							tFirstFace.m_v1)) {
						stripIndices.add(tFirstFace.m_v0);
					}
				}

				stripIndices.add(tFirstFace.m_v0);
				stripIndices.add(tFirstFace.m_v1);
				stripIndices.add(tFirstFace.m_v2);

				// Update last face info
				tLastFace.set(tFirstFace);
			}

			for (int j = 1; j < nStripFaceCount; j++) {
				int nUnique = getUniqueVertexInB(tLastFace, strip.m_faces.at(j));
				if (nUnique != -1) {
					stripIndices.add(nUnique);

					// Update last face info
					tLastFace.m_v0 = tLastFace.m_v1;
					tLastFace.m_v1 = tLastFace.m_v2;
					tLastFace.m_v2 = nUnique;
				} else {
					//we've hit a degenerate
					stripIndices.add(strip.m_faces.at(j).m_v2);
					tLastFace.m_v0 = strip.m_faces.at(j).m_v0; //tLastFace.m_v1;
					tLastFace.m_v1 = strip.m_faces.at(j).m_v1; //tLastFace.m_v2;
					tLastFace.m_v2 = strip.m_faces.at(j).m_v2; //tLastFace.m_v1;

				}
			}

			// Double tap between strips.
			if (bStitchStrips) {
				if (i != nStripCount - 1)
					stripIndices.add(tLastFace.m_v2);
			} else {
				//-1 index indicates next strip
				stripIndices.add(-1);
				accountForNegatives++;
				numSeparateStrips++;
			}

			// Update last face info
			tLastFace.m_v0 = tLastFace.m_v1;
			tLastFace.m_v1 = tLastFace.m_v2;
			tLastFace.m_v2 = tLastFace.m_v2;
		}

		if (bStitchStrips)
			numSeparateStrips = 1;
		return numSeparateStrips;
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// FindAllStrips()
	//
	// Does the stripification, puts output strips into vector allStrips
	//
	// Works by setting runnning a number of experiments in different areas of
	// the mesh, and
	//  accepting the one which results in the longest strips. It then accepts
	// this, and moves
	//  on to a different area of the mesh. We try to jump around the mesh some,
	// to ensure that
	//  large open spans of strips get generated.
	//
	void findAllStrips(StripInfoVec allStrips, FaceInfoVec allFaceInfos,
			EdgeInfoVec allEdgeInfos, int numSamples) {
		// the experiments
		int experimentId = 0;
		int stripId = 0;
		boolean done = false;

		int loopCtr = 0;

		while (!done) {
			loopCtr++;

			//
			// PHASE 1: Set up numSamples * numEdges experiments
			//
			StripInfoVec[] experiments = new StripInfoVec[numSamples * 6];
			for (int i = 0; i < experiments.length; i++)
				experiments[i] = new StripInfoVec();

			int experimentIndex = 0;
			HashSet<FaceInfo> resetPoints = new HashSet<FaceInfo>(); /* NvFaceInfo */
			for (int i = 0; i < numSamples; i++) {
				// Try to find another good reset point.
				// If there are none to be found, we are done
				FaceInfo nextFace = findGoodResetPoint(allFaceInfos,
						allEdgeInfos);
				if (nextFace == null) {
					done = true;
					break;
				}
				// If we have already evaluated starting at this face in this
				// slew of experiments, then skip going any further
				else if (resetPoints.contains(nextFace)) {
					continue;
				}

				// trying it now...
				resetPoints.add(nextFace);

				// otherwise, we shall now try experiments for starting on the
				// 01,12, and 20 edges
				
				// build the strip off of this face's 0-1 edge
				EdgeInfo edge01 = findEdgeInfo(allEdgeInfos, nextFace.m_v0,
						nextFace.m_v1);
				StripInfo strip01 = new StripInfo(new StripStartInfo(nextFace,
						edge01, true), stripId++, experimentId++);
				experiments[experimentIndex++].add(strip01);

				// build the strip off of this face's 1-0 edge
				EdgeInfo edge10 = findEdgeInfo(allEdgeInfos, nextFace.m_v0,
						nextFace.m_v1);
				StripInfo strip10 = new StripInfo(new StripStartInfo(nextFace,
						edge10, false), stripId++, experimentId++);
				experiments[experimentIndex++].add(strip10);

				// build the strip off of this face's 1-2 edge
				EdgeInfo edge12 = findEdgeInfo(allEdgeInfos, nextFace.m_v1,
						nextFace.m_v2);
				StripInfo strip12 = new StripInfo(new StripStartInfo(nextFace,
						edge12, true), stripId++, experimentId++);
				experiments[experimentIndex++].add(strip12);

				// build the strip off of this face's 2-1 edge
				EdgeInfo edge21 = findEdgeInfo(allEdgeInfos, nextFace.m_v1,
						nextFace.m_v2);
				StripInfo strip21 = new StripInfo(new StripStartInfo(nextFace,
						edge21, false), stripId++, experimentId++);
				experiments[experimentIndex++].add(strip21);

				// build the strip off of this face's 2-0 edge
				EdgeInfo edge20 = findEdgeInfo(allEdgeInfos, nextFace.m_v2,
						nextFace.m_v0);
				StripInfo strip20 = new StripInfo(new StripStartInfo(nextFace,
						edge20, true), stripId++, experimentId++);
				experiments[experimentIndex++].add(strip20);

				// build the strip off of this face's 0-2 edge
				EdgeInfo edge02 = findEdgeInfo(allEdgeInfos, nextFace.m_v2,
						nextFace.m_v0);
				StripInfo strip02 = new StripInfo(new StripStartInfo(nextFace,
						edge02, false), stripId++, experimentId++);
				experiments[experimentIndex++].add(strip02);
			}

			//
			// PHASE 2: Iterate through that we setup in the last phase
			// and really build each of the strips and strips that follow to
			// see how
			// far we get
			//
			int numExperiments = experimentIndex;
			for (int i = 0; i < numExperiments; i++) {

				// get the strip set

				// build the first strip of the list
				experiments[i].at(0).build(allEdgeInfos, allFaceInfos);
				int experimentId2 = experiments[i].at(0).m_experimentId;

				StripInfo stripIter = experiments[i].at(0);
				StripStartInfo startInfo = new StripStartInfo(null, null, false);
				while (findTraversal(allFaceInfos, allEdgeInfos, stripIter,
						startInfo)) {

					// create the new strip info
					//TODO startInfo clone ?
					stripIter = new StripInfo(startInfo, stripId++,
							experimentId2);

					// build the next strip
					stripIter.build(allEdgeInfos, allFaceInfos);

					// add it to the list
					experiments[i].add(stripIter);
				}
			}

			//
			// Phase 3: Find the experiment that has the most promise
			//
			int bestIndex = 0;
			double bestValue = 0;
			for (int i = 0; i < numExperiments; i++) {
				float avgStripSizeWeight = 1.0f;
				//float numTrisWeight = 0.0f;
				float numStripsWeight = 0.0f;
				float avgStripSize = avgStripSize(experiments[i]);
				float numStrips = experiments[i].size();
				float value = avgStripSize * avgStripSizeWeight
						+ (numStrips * numStripsWeight);
				//float value = 1.f / numStrips;
				//float value = numStrips * avgStripSize;

				if (value > bestValue) {
					bestValue = value;
					bestIndex = i;
				}
			}

			//
			// Phase 4: commit the best experiment of the bunch
			//
			commitStrips(allStrips, experiments[bestIndex]);
		}
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// SplitUpStripsAndOptimize()
	//
	// Splits the input vector of strips (allBigStrips) into smaller, cache
	// friendly pieces, then
	//  reorders these pieces to maximize cache hits
	// The final strips are output through outStrips
	//
	void splitUpStripsAndOptimize(StripInfoVec allStrips,
			StripInfoVec outStrips, EdgeInfoVec edgeInfos,
			FaceInfoVec outFaceList) {
		int threshold = cacheSize;
		StripInfoVec tempStrips = new StripInfoVec();
		int j;

		//split up strips into threshold-sized pieces
		for (int i = 0; i < allStrips.size(); i++) {
			StripInfo currentStrip;
			StripStartInfo startInfo = new StripStartInfo(null, null, false);

			int actualStripSize = 0;
			for (j = 0; j < allStrips.at(i).m_faces.size(); ++j) {
				if (!isDegenerate(allStrips.at(i).m_faces.at(j)))
					actualStripSize++;
			}

			if (actualStripSize /* allStrips.at(i).m_faces.size() */
			> threshold) {

				int numTimes = actualStripSize /* allStrips.at(i).m_faces.size() */
						/ threshold;
				int numLeftover = actualStripSize /* allStrips.at(i).m_faces.size() */
						% threshold;

				int degenerateCount = 0;
				for (j = 0; j < numTimes; j++) {
					currentStrip = new StripInfo(startInfo, 0, -1);

					int faceCtr = j * threshold + degenerateCount;
					boolean bFirstTime = true;
					while (faceCtr < threshold + (j * threshold)
							+ degenerateCount) {
						if (isDegenerate(allStrips.at(i).m_faces.at(faceCtr))) {
							degenerateCount++;

							//last time or first time through, no need for a
							// degenerate
							if ((((faceCtr + 1) != threshold + (j * threshold)
									+ degenerateCount) || ((j == numTimes - 1)
									&& (numLeftover < 4) && (numLeftover > 0)))
									&& !bFirstTime) {
								currentStrip.m_faces
										.add(allStrips.at(i).m_faces
												.at(faceCtr++));
							} else
								++faceCtr;
						} else {
							currentStrip.m_faces.add(allStrips.at(i).m_faces
									.at(faceCtr++));
							bFirstTime = false;
						}
					}
					/*
					 * threshold; faceCtr < threshold+(j*threshold); faceCtr++) {
					 * currentStrip.m_faces.add(allStrips.at(i).m_faces.at(faceCtr]); }
					 */
					///*
					if (j == numTimes - 1) //last time through
					{
						if ((numLeftover < 4) && (numLeftover > 0)) //way too
						// small
						{
							//just add to last strip
							int ctr = 0;
							while (ctr < numLeftover) {
								if (!isDegenerate(allStrips.at(i).m_faces
										.at(faceCtr))) {
									currentStrip.m_faces
											.add(allStrips.at(i).m_faces
													.at(faceCtr++));
									++ctr;
								} else {
									currentStrip.m_faces
											.add(allStrips.at(i).m_faces
													.at(faceCtr++));
									++degenerateCount;
								}
							}
							numLeftover = 0;
						}
					}
					//*/
					tempStrips.add(currentStrip);
				}

				int leftOff = j * threshold + degenerateCount;

				if (numLeftover != 0) {
					currentStrip = new StripInfo(startInfo, 0, -1);

					int ctr = 0;
					boolean bFirstTime = true;
					while (ctr < numLeftover) {
						if (!isDegenerate(allStrips.at(i).m_faces.at(leftOff))) {
							ctr++;
							bFirstTime = false;
							currentStrip.m_faces.add(allStrips.at(i).m_faces
									.at(leftOff++));
						} else if (!bFirstTime)
							currentStrip.m_faces.add(allStrips.at(i).m_faces
									.at(leftOff++));
						else
							leftOff++;
					}
					/*
					 * for(int k = 0; k < numLeftover; k++) {
					 * currentStrip.m_faces.add(allStrips.at(i).m_faces[leftOff++]); }
					 */

					tempStrips.add(currentStrip);
				}
			} else {
				//we're not just doing a tempStrips.add(allBigStrips[i])
				// because
				// this way we can delete allBigStrips later to free the memory
				currentStrip = new StripInfo(startInfo, 0, -1);

				for (j = 0; j < allStrips.at(i).m_faces.size(); j++)
					currentStrip.m_faces.add(allStrips.at(i).m_faces.at(j));

				tempStrips.add(currentStrip);
			}
		}

		//add small strips to face list
		StripInfoVec tempStrips2 = new StripInfoVec();
		removeSmallStrips(tempStrips, tempStrips2, outFaceList);

		outStrips.clear();
		//screw optimization for now
		//  for(i = 0; i < tempStrips.size(); ++i)
		//    outStrips.add(tempStrips[i]);

		if (tempStrips2.size() != 0) {
			//Optimize for the vertex cache
			VertexCache vcache = new VertexCache(cacheSize);

			float bestNumHits = -1.0f;
			float numHits;
			int bestIndex = -99999;

			int firstIndex = 0;
			float minCost = 10000.0f;

			for (int i = 0; i < tempStrips2.size(); i++) {
				int numNeighbors = 0;

				//find strip with least number of neighbors per face
				for (j = 0; j < tempStrips2.at(i).m_faces.size(); j++) {
					numNeighbors += numNeighbors(tempStrips2.at(i).m_faces
							.at(j), edgeInfos);
				}

				float currCost = (float) numNeighbors
						/ (float) tempStrips2.at(i).m_faces.size();
				if (currCost < minCost) {
					minCost = currCost;
					firstIndex = i;
				}
			}

			updateCacheStrip(vcache, tempStrips2.at(firstIndex));
			outStrips.add(tempStrips2.at(firstIndex));

			tempStrips2.at(firstIndex).visited = true;

			boolean bWantsCW = (tempStrips2.at(firstIndex).m_faces.size() % 2) == 0;

			//this n^2 algo is what slows down stripification so much....
			// needs to be improved
			while (true) {
				bestNumHits = -1.0f;

				//find best strip to add next, given the current cache
				for (int i = 0; i < tempStrips2.size(); i++) {
					if (tempStrips2.at(i).visited)
						continue;

					numHits = calcNumHitsStrip(vcache, tempStrips2.at(i));
					if (numHits > bestNumHits) {
						bestNumHits = numHits;
						bestIndex = i;
					} else if (numHits >= bestNumHits) {
						//check previous strip to see if this one requires it
						// to switch polarity
						StripInfo strip = tempStrips2.at(i);
						int nStripFaceCount = strip.m_faces.size();

						FaceInfo tFirstFace = new FaceInfo(
								strip.m_faces.at(0).m_v0,
								strip.m_faces.at(0).m_v1,
								strip.m_faces.at(0).m_v2);

						// If there is a second face, reorder vertices such
						// that the
						// unique vertex is first
						if (nStripFaceCount > 1) {
							int nUnique = getUniqueVertexInB(strip.m_faces
									.at(1), tFirstFace);
							if (nUnique == tFirstFace.m_v1) {
								int tmp = tFirstFace.m_v0;
								tFirstFace.m_v0 = tFirstFace.m_v1;
								tFirstFace.m_v1 = tmp;
							} else if (nUnique == tFirstFace.m_v2) {
								int tmp = tFirstFace.m_v0;
								tFirstFace.m_v0 = tFirstFace.m_v2;
								tFirstFace.m_v2 = tmp;
							}

							// If there is a third face, reorder vertices such
							// that the
							// shared vertex is last
							if (nStripFaceCount > 2) {
								int[] nShared = new int[2];
								getSharedVertices(strip.m_faces.at(2),
										tFirstFace, nShared);
								if ((nShared[0] == tFirstFace.m_v1)
										&& (nShared[1] == -1)) {
									int tmp = tFirstFace.m_v2;
									tFirstFace.m_v2 = tFirstFace.m_v1;
									tFirstFace.m_v1 = tmp;
								}
							}
						}

						// Check CW/CCW ordering
						if (bWantsCW == isCW(strip.m_faces.at(0),
								tFirstFace.m_v0, tFirstFace.m_v1)) {
							//I like this one!
							bestIndex = i;
						}
					}
				}

				if (bestNumHits == -1.0f)
					break;
				tempStrips2.at(bestIndex).visited = true;
				updateCacheStrip(vcache, tempStrips2.at(bestIndex));
				outStrips.add(tempStrips2.at(bestIndex));
				bWantsCW = (tempStrips2.at(bestIndex).m_faces.size() % 2 == 0) ? bWantsCW
						: !bWantsCW;
			}
		}
	}

	///////////////////////////////////////////////////////////////////////////////////////////
	// Stripify()
	//
	//
	// in_indices are the input indices of the mesh to stripify
	// in_cacheSize is the target cache size
	//
	void stripify(IntVec in_indices, int in_cacheSize, int in_minStripLength,
			int maxIndex, StripInfoVec outStrips, FaceInfoVec outFaceList) {
		meshJump = 0.0f;
		bFirstTimeResetPoint = true; //used in FindGoodResetPoint()

		//the number of times to run the experiments
		int numSamples = 10;

		//the cache size, clamped to one
		cacheSize = Math.max(1, in_cacheSize - CACHE_INEFFICIENCY);

		minStripLength = in_minStripLength;
		//this is the strip size threshold below which we dump the strip into
		// a list

		indices = in_indices;

		// build the stripification info
		FaceInfoVec allFaceInfos = new FaceInfoVec();
		EdgeInfoVec allEdgeInfos = new EdgeInfoVec();

		buildStripifyInfo(allFaceInfos, allEdgeInfos, maxIndex);

		StripInfoVec allStrips = new StripInfoVec();

		// stripify
		findAllStrips(allStrips, allFaceInfos, allEdgeInfos, numSamples);

		//split up the strips into cache friendly pieces, optimize them, then
		// dump these into outStrips
		splitUpStripsAndOptimize(allStrips, outStrips, allEdgeInfos,
				outFaceList);

	}

}