| /* |
| * 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 |
| * 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. |
| */ |
| |
| package com.jme3.terrain.geomipmap.lodcalc; |
| |
| import com.jme3.export.JmeExporter; |
| import com.jme3.export.JmeImporter; |
| import com.jme3.math.FastMath; |
| import com.jme3.math.Vector3f; |
| import com.jme3.renderer.Camera; |
| import com.jme3.terrain.geomipmap.TerrainPatch; |
| import com.jme3.terrain.geomipmap.UpdatedTerrainPatch; |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.List; |
| |
| public class PerspectiveLodCalculator implements LodCalculator { |
| |
| private TerrainPatch patch; |
| private Camera cam; |
| private float[] entropyDistances; |
| private float pixelError; |
| |
| public PerspectiveLodCalculator() {} |
| |
| public PerspectiveLodCalculator(Camera cam, float pixelError){ |
| this.cam = cam; |
| this.pixelError = pixelError; |
| } |
| |
| /** |
| * This computes the "C" value in the geomipmapping paper. |
| * See section "2.3.1.2 Pre-calculating d" |
| * |
| * @param cam |
| * @param pixelLimit |
| * @return |
| */ |
| private float getCameraConstant(Camera cam, float pixelLimit){ |
| float n = cam.getFrustumNear(); |
| float t = FastMath.abs(cam.getFrustumTop()); |
| float A = n / t; |
| float v_res = cam.getHeight(); |
| float T = (2f * pixelLimit) / v_res; |
| return A / T; |
| } |
| |
| public boolean calculateLod(List<Vector3f> locations, HashMap<String, UpdatedTerrainPatch> updates) { |
| return calculateLod(patch, locations, updates); |
| } |
| |
| public boolean calculateLod(TerrainPatch terrainPatch, List<Vector3f> locations, HashMap<String, UpdatedTerrainPatch> updates) { |
| if (entropyDistances == null){ |
| // compute entropy distances |
| float[] lodEntropies = patch.getLodEntropies(); |
| entropyDistances = new float[lodEntropies.length]; |
| float cameraConstant = getCameraConstant(cam, pixelError); |
| for (int i = 0; i < lodEntropies.length; i++){ |
| entropyDistances[i] = lodEntropies[i] * cameraConstant; |
| } |
| } |
| |
| Vector3f patchPos = getCenterLocation(patch); |
| |
| // vector from camera to patch |
| //Vector3f toPatchDir = locations.get(0).subtract(patchPos).normalizeLocal(); |
| //float facing = cam.getDirection().dot(toPatchDir); |
| float distance = patchPos.distance(locations.get(0)); |
| |
| // go through each lod level to find the one we are in |
| for (int i = 0; i <= patch.getMaxLod(); i++) { |
| if (distance < entropyDistances[i] || i == patch.getMaxLod()){ |
| boolean reIndexNeeded = false; |
| if (i != patch.getLod()) { |
| reIndexNeeded = true; |
| // System.out.println("lod change: "+lod+" > "+i+" dist: "+distance); |
| } |
| int prevLOD = patch.getLod(); |
| |
| //previousLod = lod; |
| //lod = i; |
| UpdatedTerrainPatch utp = updates.get(patch.getName()); |
| if (utp == null) { |
| utp = new UpdatedTerrainPatch(patch, i);//save in here, do not update actual variables |
| updates.put(utp.getName(), utp); |
| } |
| utp.setPreviousLod(prevLOD); |
| utp.setReIndexNeeded(reIndexNeeded); |
| return reIndexNeeded; |
| } |
| } |
| |
| return false; |
| } |
| |
| public Vector3f getCenterLocation(TerrainPatch patch) { |
| Vector3f loc = patch.getWorldTranslation().clone(); |
| loc.x += patch.getSize() / 2; |
| loc.z += patch.getSize() / 2; |
| return loc; |
| } |
| |
| @Override |
| public LodCalculator clone() { |
| try { |
| return (LodCalculator) super.clone(); |
| } catch (CloneNotSupportedException ex) { |
| throw new AssertionError(); |
| } |
| } |
| |
| public void write(JmeExporter ex) throws IOException { |
| } |
| |
| public void read(JmeImporter im) throws IOException { |
| } |
| |
| public boolean usesVariableLod() { |
| return true; |
| } |
| |
| public float getPixelError() { |
| return pixelError; |
| } |
| |
| public void setPixelError(float pixelError) { |
| this.pixelError = pixelError; |
| } |
| |
| public void setCam(Camera cam) { |
| this.cam = cam; |
| } |
| |
| public void turnOffLod() { |
| //TODO |
| } |
| |
| public boolean isLodOff() { |
| return false; //TODO |
| } |
| |
| public void turnOnLod() { |
| //TODO |
| } |
| |
| } |