Added a billboard model controller.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@137 ed5b42cb-e716-0410-a449-f6a68f950b19
2007-02-01 19:31:55 +00:00
parent 420140a3bc
commit 7cdebe1912
1 changed files with 180 additions and 0 deletions
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+//
+// $Id: EmissionController.java 119 2007-01-24 00:22:12Z dhoover $
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2005 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.jme.model;
+
+import java.io.IOException;
+
+import java.util.Properties;
+
+import com.jme.math.FastMath;
+import com.jme.math.Quaternion;
+import com.jme.math.Vector3f;
+import com.jme.renderer.Camera;
+import com.jme.scene.Controller;
+import com.jme.scene.Spatial;
+import com.jme.system.DisplaySystem;
+import com.jme.util.export.JMEExporter;
+import com.jme.util.export.JMEImporter;
+import com.jme.util.export.InputCapsule;
+import com.jme.util.export.OutputCapsule;
+
+import com.threerings.jme.sprite.PathUtil;
+import com.threerings.jme.util.JmeUtil;
+
+/**
+ * Orients its target towards the camera plane.
+ */
+public class BillboardController extends ModelController
+{
+    /** Determines how the billboard is rotated. */
+    public enum Alignment {
+        DIR_X_POS_Z(false, true),
+        DIR_X_DIR_Z(false, false),
+        POS_X_POS_Z(true, true),
+        DIR_Z(false),
+        POS_Z(true);
+        
+        /** Determines whether rotation is limited to the Z axis. */
+        public boolean isAxial () {
+            return _axial;
+        }
+        
+        /** Determines whether to tilt in the direction of the vector from the eyepoint to the
+         * target's origin (the eye vector) as opposed to the camera direction. */
+        public boolean isEyeRelativeX () {
+            return _eyeRelativeX;
+        }
+        
+        /** Determines whether to swivel in the direction of the eye vector as opposed to the
+         * camera direction. */
+        public boolean isEyeRelativeZ () {
+            return _eyeRelativeZ;
+        }
+        
+        Alignment (boolean eyeRelativeX, boolean eyeRelativeZ) {
+            _eyeRelativeX = eyeRelativeX;
+            _eyeRelativeZ = eyeRelativeZ;
+        }
+        
+        Alignment (boolean eyeRelativeZ) {
+            _axial = true;
+            _eyeRelativeZ = eyeRelativeZ;
+        }
+        
+        protected boolean _axial, _eyeRelativeX, _eyeRelativeZ;
+    };
+    
+    @Override // documentation inherited
+    public void configure (Properties props, Spatial target)
+    {
+        super.configure(props, target);
+        _alignment = Enum.valueOf(Alignment.class,
+            props.getProperty("alignment", "dir_x_pos_z").toUpperCase());
+    }
+    
+    // documentation inherited
+    public void update (float time)
+    {
+        if (!isActive()) {
+            return;
+        }
+        Camera cam = DisplaySystem.getDisplaySystem().getRenderer().getCamera();
+        if (_alignment.isEyeRelativeZ()) {
+            _target.getWorldTranslation().subtract(cam.getLocation(), _yvec);
+        } else {
+            _yvec.set(cam.getDirection());
+        }
+        _zvec.set(_alignment.isAxial() ? Vector3f.UNIT_Z : cam.getUp());
+        if (_alignment.isEyeRelativeX()) {
+            // use the forward vector as-is
+            _yvec.normalizeLocal().cross(_zvec, _xvec);
+            if (_xvec.length() < FastMath.FLT_EPSILON) {
+                return;
+            }
+            _xvec.normalizeLocal().cross(_yvec, _zvec);
+            
+        } else {
+            // project the forward vector onto the up plane
+            _yvec.scaleAdd(-_zvec.dot(_yvec), _zvec, _yvec);
+            if (_yvec.length() < FastMath.FLT_EPSILON) {
+                return;
+            }
+            _yvec.normalizeLocal().cross(_zvec, _xvec);
+        }
+        // compute the world rotation with the axes and rotate into
+        // parent's coordinate system
+        Quaternion lrot = _target.getLocalRotation();
+        lrot.fromAxes(_xvec, _yvec, _zvec);
+        Spatial parent = _target.getParent();
+        if (parent == null) {
+            _rot.loadIdentity();
+        } else {
+            _rot.set(parent.getWorldRotation()).inverseLocal();
+        }
+        _rot.mult(lrot, lrot);
+    }
+    
+    @Override // documentation inherited
+    public Controller putClone (
+        Controller store, Model.CloneCreator properties)
+    {
+        BillboardController bstore;
+        if (store == null) {
+            bstore = new BillboardController();
+        } else {
+            bstore = (BillboardController)store;
+        }
+        super.putClone(bstore, properties);
+        bstore._alignment = _alignment;
+        return bstore;
+    }
+    
+    @Override // documentation inherited
+    public void read (JMEImporter im)
+        throws IOException
+    {
+        super.read(im);
+        InputCapsule capsule = im.getCapsule(this);
+        _alignment = Enum.valueOf(Alignment.class,
+            capsule.readString("alignment", "DIR_X_POS_Z"));
+    }
+    
+    @Override // documentation inherited
+    public void write (JMEExporter ex)
+        throws IOException
+    {
+        super.write(ex);
+        OutputCapsule capsule = ex.getCapsule(this);
+        capsule.write(_alignment.name(), "alignment", "DIR_X_POS_Z");
+    }
+    
+    /** The alignment mode. */
+    protected Alignment _alignment;
+    
+    /** A temporary quaternion. */
+    protected Quaternion _rot = new Quaternion();
+    
+    /** Temporary axis vectors. */
+    protected Vector3f _xvec = new Vector3f(), _yvec = new Vector3f(), _zvec = new Vector3f();
+    
+    private static final long serialVersionUID = 1;
+}