1 files changed, 182 insertions, 0 deletions
diff --git a/engine/src/terrain/com/jme3/terrain/geomipmap/lodcalc/DistanceLodCalculator.java b/engine/src/terrain/com/jme3/terrain/geomipmap/lodcalc/DistanceLodCalculator.java
new file mode 100644
index 0000000..3ab34c9
--- /dev/null
+++ b/engine/src/terrain/com/jme3/terrain/geomipmap/lodcalc/DistanceLodCalculator.java
@@ -0,0 +1,182 @@
+/*
+ * 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.InputCapsule;
+import com.jme3.export.JmeExporter;
+import com.jme3.export.JmeImporter;
+import com.jme3.export.OutputCapsule;
+import com.jme3.math.Vector3f;
+import com.jme3.terrain.geomipmap.TerrainPatch;
+import com.jme3.terrain.geomipmap.UpdatedTerrainPatch;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * Calculates the LOD of the terrain based on its distance from the
+ * cameras. Taking the minimum distance from all cameras.
+ *
+ * @author bowens
+ */
+public class DistanceLodCalculator implements LodCalculator {
+
+    private int size; // size of a terrain patch
+    private float lodMultiplier = 2;
+    private boolean turnOffLod = false;
+    
+    public DistanceLodCalculator() {
+    }
+    
+    public DistanceLodCalculator(int patchSize, float multiplier) {
+        this.size = patchSize;
+        this.lodMultiplier = multiplier;
+    }
+    
+    public boolean calculateLod(TerrainPatch terrainPatch, List<Vector3f> locations, HashMap<String, UpdatedTerrainPatch> updates) {
+        float distance = getCenterLocation(terrainPatch).distance(locations.get(0));
+
+        
+        if (turnOffLod) {
+            // set to full detail
+            int prevLOD = terrainPatch.getLod();
+            UpdatedTerrainPatch utp = updates.get(terrainPatch.getName());
+            if (utp == null) {
+                utp = new UpdatedTerrainPatch(terrainPatch, 0);
+                updates.put(utp.getName(), utp);
+            }
+            utp.setNewLod(0);
+            utp.setPreviousLod(prevLOD);
+            utp.setReIndexNeeded(true);
+            return true;
+        }
+        
+        // go through each lod level to find the one we are in
+        for (int i = 0; i <= terrainPatch.getMaxLod(); i++) {
+            if (distance < getLodDistanceThreshold() * (i + 1)*terrainPatch.getWorldScale().x || i == terrainPatch.getMaxLod()) {
+                boolean reIndexNeeded = false;
+                if (i != terrainPatch.getLod()) {
+                    reIndexNeeded = true;
+                    //System.out.println("lod change: "+lod+" > "+i+"    dist: "+distance);
+                }
+                int prevLOD = terrainPatch.getLod();
+                //previousLod = lod;
+                //lod = i;
+                UpdatedTerrainPatch utp = updates.get(terrainPatch.getName());
+                if (utp == null) {
+                    utp = new UpdatedTerrainPatch(terrainPatch, i);//save in here, do not update actual variables
+                    updates.put(utp.getName(), utp);
+                }
+                utp.setPreviousLod(prevLOD);
+                utp.setReIndexNeeded(reIndexNeeded);
+
+                return reIndexNeeded;
+            }
+        }
+
+        return false;
+    }
+
+    protected Vector3f getCenterLocation(TerrainPatch terrainPatch) {
+        Vector3f loc = terrainPatch.getWorldTranslation().clone();
+        loc.x += terrainPatch.getSize()*terrainPatch.getWorldScale().x / 2;
+        loc.z += terrainPatch.getSize()*terrainPatch.getWorldScale().z / 2;
+        return loc;
+    }
+
+    public void write(JmeExporter ex) throws IOException {
+        OutputCapsule oc = ex.getCapsule(this);
+        oc.write(size, "patchSize", 32);
+        oc.write(lodMultiplier, "lodMultiplier", 32);
+    }
+
+    public void read(JmeImporter im) throws IOException {
+        InputCapsule ic = im.getCapsule(this);
+        size = ic.readInt("patchSize", 32);
+        lodMultiplier = ic.readFloat("lodMultiplier", 2.7f);
+    }
+
+    @Override
+    public LodCalculator clone() {
+        DistanceLodCalculator clone = new DistanceLodCalculator(size, lodMultiplier);
+        return clone;
+    }
+
+    @Override
+    public String toString() {
+        return "DistanceLodCalculator "+size+"*"+lodMultiplier;
+    }
+
+    /**
+     * Gets the camera distance where the LOD level will change
+     */
+    protected float getLodDistanceThreshold() {
+        return size*lodMultiplier;
+    }
+    
+    /**
+     * Does this calculator require the terrain to have the difference of 
+     * LOD levels of neighbours to be more than 1.
+     */
+    public boolean usesVariableLod() {
+        return false;
+    }
+
+    public float getLodMultiplier() {
+        return lodMultiplier;
+    }
+
+    public void setLodMultiplier(float lodMultiplier) {
+        this.lodMultiplier = lodMultiplier;
+    }
+
+    public int getSize() {
+        return size;
+    }
+
+    public void setSize(int size) {
+        this.size = size;
+    }
+
+    public void turnOffLod() {
+        turnOffLod = true;
+    }
+    
+    public boolean isLodOff() {
+        return turnOffLod;
+    }
+    
+    public void turnOnLod() {
+        turnOffLod = false;
+    }
+    
+}