1 files changed, 133 insertions, 0 deletions
diff --git a/engine/src/jbullet/com/jme3/bullet/collision/shapes/HeightfieldCollisionShape.java b/engine/src/jbullet/com/jme3/bullet/collision/shapes/HeightfieldCollisionShape.java
new file mode 100644
index 0000000..7f0611e
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+++ b/engine/src/jbullet/com/jme3/bullet/collision/shapes/HeightfieldCollisionShape.java
@@ -0,0 +1,133 @@
+/*
+ * To change this template, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+package com.jme3.bullet.collision.shapes;
+
+import com.bulletphysics.dom.HeightfieldTerrainShape;
+import com.jme3.bullet.util.Converter;
+import com.jme3.export.InputCapsule;
+import com.jme3.export.JmeExporter;
+import com.jme3.export.JmeImporter;
+import com.jme3.export.OutputCapsule;
+import com.jme3.math.FastMath;
+import com.jme3.math.Vector3f;
+import com.jme3.scene.Mesh;
+import java.io.IOException;
+
+/**
+ * Uses Bullet Physics Heightfield terrain collision system. This is MUCH faster
+ * than using a regular mesh.
+ * There are a couple tricks though:
+ *	-No rotation or translation is supported.
+ *	-The collision bbox must be centered around 0,0,0 with the height above and below the y-axis being
+ *	equal on either side. If not, the whole collision box is shifted vertically and things don't collide
+ *	as they should.
+ * 
+ * @author Brent Owens
+ */
+public class HeightfieldCollisionShape extends CollisionShape {
+
+	//protected HeightfieldTerrainShape heightfieldShape;
+	protected int heightStickWidth;
+	protected int heightStickLength;
+	protected float[] heightfieldData;
+	protected float heightScale;
+	protected float minHeight;
+	protected float maxHeight;
+	protected int upAxis;
+	protected boolean flipQuadEdges;
+
+	public HeightfieldCollisionShape() {
+
+	}
+
+	public HeightfieldCollisionShape(float[] heightmap) {
+		createCollisionHeightfield(heightmap, Vector3f.UNIT_XYZ);
+	}
+
+	public HeightfieldCollisionShape(float[] heightmap, Vector3f scale) {
+		createCollisionHeightfield(heightmap, scale);
+	}
+
+	protected void createCollisionHeightfield(float[] heightmap, Vector3f worldScale) {
+		this.scale = worldScale;
+		this.heightScale = 1;//don't change away from 1, we use worldScale instead to scale
+		
+		this.heightfieldData = heightmap;
+
+		float min = heightfieldData[0];
+		float max = heightfieldData[0];
+		// calculate min and max height
+		for (int i=0; i<heightfieldData.length; i++) {
+			if (heightfieldData[i] < min)
+				min = heightfieldData[i];
+			if (heightfieldData[i] > max)
+				max = heightfieldData[i];
+		}
+		// we need to center the terrain collision box at 0,0,0 for BulletPhysics. And to do that we need to set the
+		// min and max height to be equal on either side of the y axis, otherwise it gets shifted and collision is incorrect.
+		if (max < 0)
+			max = -min;
+		else {
+			if (Math.abs(max) > Math.abs(min))
+				min = -max;
+			else
+				max = -min;
+		}
+		this.minHeight = min;
+		this.maxHeight = max;
+
+		this.upAxis = HeightfieldTerrainShape.YAXIS;
+		this.flipQuadEdges = false;
+
+		heightStickWidth = (int) FastMath.sqrt(heightfieldData.length);
+		heightStickLength = heightStickWidth;
+
+
+		createShape();
+	}
+	
+	protected void createShape() {
+
+		HeightfieldTerrainShape shape = new HeightfieldTerrainShape(heightStickWidth, heightStickLength, heightfieldData, heightScale, minHeight, maxHeight, upAxis, flipQuadEdges);
+		shape.setLocalScaling(new javax.vecmath.Vector3f(scale.x, scale.y, scale.z));
+		cShape = shape;
+		cShape.setLocalScaling(Converter.convert(getScale()));
+                cShape.setMargin(margin);
+	}
+
+	public Mesh createJmeMesh(){
+        //TODO return Converter.convert(bulletMesh);
+		return null;
+    }
+
+    public void write(JmeExporter ex) throws IOException {
+        super.write(ex);
+        OutputCapsule capsule = ex.getCapsule(this);
+        capsule.write(heightStickWidth, "heightStickWidth", 0);
+        capsule.write(heightStickLength, "heightStickLength", 0);
+        capsule.write(heightScale, "heightScale", 0);
+        capsule.write(minHeight, "minHeight", 0);
+        capsule.write(maxHeight, "maxHeight", 0);
+        capsule.write(upAxis, "upAxis", 1);
+        capsule.write(heightfieldData, "heightfieldData", new float[0]);
+        capsule.write(flipQuadEdges, "flipQuadEdges", false);
+    }
+
+    public void read(JmeImporter im) throws IOException {
+        super.read(im);
+        InputCapsule capsule = im.getCapsule(this);
+        heightStickWidth = capsule.readInt("heightStickWidth", 0);
+        heightStickLength = capsule.readInt("heightStickLength", 0);
+        heightScale = capsule.readFloat("heightScale", 0);
+        minHeight = capsule.readFloat("minHeight", 0);
+        maxHeight = capsule.readFloat("maxHeight", 0);
+        upAxis = capsule.readInt("upAxis", 1);
+        heightfieldData = capsule.readFloatArray("heightfieldData", new float[0]);
+        flipQuadEdges = capsule.readBoolean("flipQuadEdges", false);
+        createShape();
+    }
+
+}