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Tessellator: support GeometryBuffer (#466)

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Gustl22 2018-01-03 18:36:44 +01:00 committed by Emux
parent 9de76897bc
commit baa924c697
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1 changed files with 68 additions and 2 deletions
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70
vtm/src/org/oscim/utils/Tessellator.java
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@ -1,5 +1,6 @@
/*
* Copyright 2013 Hannes Janetzek
* Copyright 2018 Gustl22
*
* This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
*
@ -16,6 +17,7 @@
*/
package org.oscim.utils;
import org.oscim.core.GeometryBuffer;
import org.oscim.renderer.bucket.VertexData;
import org.oscim.utils.math.MathUtils;
import org.slf4j.Logger;
@ -27,8 +29,18 @@ public class Tessellator {
static final Logger log = LoggerFactory.getLogger(Tessellator.class);
/**
* Special version for ExtrusionLayer to match indices with vertex
* positions.
* Special version for ExtrusionLayer to match indices with vertex positions.
* Tessellates polygon in tris elements.
*
* @param points the {@link org.oscim.core.GeometryBuffer#points}
* @param ppos the {@link org.oscim.core.GeometryBuffer#pointNextPos} (not needed)
* @param numPoints equals ppos?
* @param index the {@link org.oscim.core.GeometryBuffer#index}
* @param ipos the {@link org.oscim.core.GeometryBuffer#indexCurrentPos}
* @param numRings the number of ring polygons
* @param vertexOffset shift outTris index with offset
* @param outTris the tessellated polygon as triangular {@link org.oscim.renderer.bucket.VertexData}
* @return number of indices of outTris
*/
public static int tessellate(float[] points, int ppos, int numPoints, int[] index,
int ipos, int numRings, int vertexOffset, VertexData outTris) {
@ -119,6 +131,60 @@ public class Tessellator {
return sumIndices;
}
/**
* Tessellates a {@link org.oscim.core.GeometryBuffer} to a triangular/mesh GeometryBuffer.
* The points array remains the same.
*
* @param geom the input GeometryBuffer as POLY or LINE
* @param outMesh the out GeometryBuffer as MESH, but has 2D point coordinates.
* @return number of indices of out3D (0 if tessellation failed)
*/
public static int tessellate(GeometryBuffer geom, GeometryBuffer outMesh) {
int[] index = geom.index;
float[] points = geom.points;
int ipos = 0;
int numRings = 0;
int numPoints = 0;
for (int i = 0; i < index.length && index[i] >= 0; i++) {
numPoints += index[i];
numRings++;
}
int buckets = FastMath.log2(MathUtils.nextPowerOfTwo(numPoints));
buckets -= 2;
//log.debug("tess use {}", buckets);
TessJNI tess = new TessJNI(buckets);
tess.addContour2D(index, points, ipos, numRings);
if (!tess.tesselate())
return 0;
int nverts = tess.getVertexCount() * 2;
int nelems = tess.getElementCount() * 3;
if (numPoints != nverts) {
log.debug("tess ----- skip poly: " + nverts + " " + numPoints);
tess.dispose();
return 0;
}
outMesh.index = new int[nelems];
short[] ids = new short[nelems];
tess.getElementsWithInputVertexIds(ids, 0, 0, nelems);
tess.dispose();
for (int k = 0; k < ids.length; k++) {
if (ids[k] < 0) return 0; // FIXME why sometimes negative indices are produced?
outMesh.index[k] = ids[k];
}
return nelems;
}
// private static final int RESULT_VERTICES = 0;
// private static final int RESULT_TRIANGLES = 1;
//