/*
 * Copyright 1998 Hewlett-Packard Company
 *
 * This file may be copied, modified and distributed only in
 * accordance with the terms of the limited licence contained
 * in the accompanying file LICENSE.TXT.
 */

//package hplb.java3d;

import  java.io.*;
import  java.util.*;
import  java.awt.Component;

import  javax.media.j3d.*;
import  javax.vecmath.*;
import  com.sun.j3d.utils.image.TextureLoader;

/**
 *  .3DS format model loader for Java3D.
 *  @author Rycharde Hawkes
 *  @version 1.0
 */

public class Load3DS
{
    static final int        MAX_SURFACES    = 33;
    static final int        verbosity       = 0;

    int                     totalPolygons   = 0;
    int                     totalVertices   = 0;

    //
    // Root of the scene graph for the file.
    //

    BranchGroup             root            = null;

    //
    // Lookup table of instances of SharedObjects held
    // in <objectTable>, indexed by name.
    //

    Hashtable               instanceTable   = null;

    //
    // Lookup table of all SharedObjects created,
    // indexed by name.
    //

    Hashtable               objectTable     = null;

    //
    // Refers to the object currently being constructed.
    //

    SharedGroup             object          = null;

    //
    // Refers to the shape component of the object
    // currently being constructed.
    //

    Shape3D                 shape           = null;

    //
    // <geometry>     == current object's geometry.
    // <noofVertices> == number of vertices in the face list.
    // <vertices>     == vertex array.
    // <noofFaces>    == number of faces in the object.
    // <faces>        == list of all the faces in the object.
    // <sharedFaces>  == list of vertices constructing each face.
    // <surfaces>     == list of surfaces making up geometry.
    // <textureCoords>== list of geometry's texture coordinates.
    //

    TriangleArray           geometry        = null;
    int                     noofVertices    = 0;
    Point3f[]               vertices        = null;
    int                     noofFaces       = 0;
    Face[]                  faces           = null;
    Vector[]                sharedFaces     = null;
    Surface[]               surfaces        = null;
    Point2f[]               textureCoords   = null;

    //
    // Used to indicate whether surfaces were specified
    // and created.
    //

    boolean                 surfacesCreated = true;

    //
    // A lookup table of Appearance objects representing
    // the materials in the file, indexed by material name.
    //

    Hashtable               mats            = null;

    //
    // <mat> refers to 3DS material currently being constructed.
    // <matName> is that name of the 3DS material.
    // <material> refers to the counterpart Java3D Material.
    //

    Appearance              mat             = null;
    String                  matName         = null;
    Material                material        = null;

    //
    // <shininess>    == 3DS shininess percentage.
    //

    float                   shininess       = 0.0f;

    //
    // Provided by the constructor of this object, needed
    // by the TextureLoader class.
    //

    Component               component       = null;

    //
    // <nodeName>     == name of a referenced SharedObject.
    // <instanceName> == name of an instance of a SharedObject.
    //

    String                  nodeName        = null;
    String                  instanceName    = null;

    //
    // <translation>  == positional component of the objects' transform.
    // <orientation>  == rotational component of the objects' transform.
    // <scale>        == scalar component of the objects' transform.
    //

    Vector3f                translation     = null;
    Matrix4f                orientation     = null;
    Vector3f                scale           = null;


	String					path 			= null;

    /**
     * <p>Given a <i>filename</i>, Load3DS will construct an appropriate Java3D scene graph
     * - accessible from Load3DS.root().  It also constructs a table of <i>objects</i>,
     * indexed by their proper name and a table of <instances> of those objects which
     * are refered to by ther instance name.  Currently, only two <properties> are
     * returned, "polygons" and "vertices", the value of which are a java.lang.Integer
     * giving the total number of polygons and vertices in the .3DS file respectively.</p>
     * <p>Limitations of the current version:
     * <li>Lights are not created.</li>
     * <li>Interpretation of 3DS's shininess and shininess strength could be better.</li>
     * <li>Only handles those texture map image formats supported by com.sun.j3d.utils.image.TextureLoader.</li>
     * </p>
     * <p>Java3Disms:
     * <li>3DS wireframe material = PolygonAttributes.POLYGON_LINE</li>
     * <li>3DS metal-shaded material = PolygonAttributes.POLYGON_POINT</li>
     * <li>3DS constant-shaded material = PolygonAttributes.POLYGON_FILL</li>
     * <li>3DS phong-shaded material = PolygonAttributes.POLYGON_PHONG</li>
     * <li>Hidden objects don't seem to be set by 3DSMax.  Load3DS simulates this
     * by hiding objects whose names begin with '$'.</li>
     * <li>Note that only 3DS planar mapping generates correct 2D texture coords.</li>
     * <li>1 generic 3DSMax unit = 1 Java3D unit.  This loader does not handle other 3DSMax units,
     * e.g. metric.</li>
     * </p>
     * <p>Known bugs:
     * <li>Normal calculation fails for certain surfaces.</li>
     * @param filename .3DS file to load.
     * @param component parent java.awt.Component (needed by com.sun.j3d.utils.image.TextureLoader).
     * @param objects table of named objects indexed by object name.  name-value pairs
     * are a string and a SharedGroup respectively.
     * @param instances table of instanced objects indexed by instance name.  name-value
     * pairs are a string and a TransformGroup respectively.
     * @param properties information about the .3DS file.
     * @exception IOException any failure to process .3DS file.
     * @see com.sun.j3d.utils.image.TextureLoader
     */

    public Load3DS( String filename, Component component,
                      Hashtable objects, Hashtable instances,
                      Properties properties )
                throws IOException
    {
    	//System.out.println( "Load3DS: loading '" + filename + "'..." );
		path = (new java.io.File( filename )).getParent();
		if ( path == null )
		{
			path = ".\\";
		}

		System.out.println( "Load3DS: using path = " + path );
        RandomAccessFile    in  = new RandomAccessFile( filename, "r" );

        this.component   = component;
        root        = new BranchGroup();        // Root of scene graph for this file.
        mats        = new Hashtable();

        objectTable     = objects;
        instanceTable   = instances;

        try
        {
            for ( ;; )
            {
                processChunk( in );
            }
        }
        catch ( EOFException e )
        {
        }

        properties.put( "polygons", Integer.toString( totalPolygons ) );
        properties.put( "vertices", Integer.toString( totalVertices ) );
    }


    void prepareForNewObject()
    {
        object          = null;
        shape           = null;
        geometry        = null;
        noofVertices    = 0;
        vertices        = null;
        sharedFaces     = null;
        noofFaces       = 0;
        faces           = null;
        surfaces        = null;
        surfacesCreated = false;
        textureCoords   = null;
        mat             = null;
        matName         = null;
        material        = null;
        shininess       = 0.0f;
        component       = null;
        nodeName        = null;
        instanceName    = null;
        translation     = null;
        orientation     = null;
        scale           = null;
    }


    /**
     *  Returns the root of the scene graph constructed
     *  from the given file.
     *  @return Root of constructed scene graph.
     */

    public BranchGroup root()
    {
        return root;
    }


    //
    // A .3DS file consists of a series of chunks.  Each chunk
    // starts with a tag ID and the chunks' length followed by
    // optional data.  This method handles most of those chunks
    // processed by this loader.  Those chunks that are not
    // recognised are ignored.
    //

    void processChunk( RandomAccessFile in )
            throws IOException
    {
        int tag     = readUnsignedShort( in );
        int length  = readInt( in );

        switch ( tag )
        {
            case S3D_M3DMAGIC:          // 3DS file
            case S3D_MMAGIC:            // Editor chunks
            case S3D_MAT_ENTRY:         // 3DS material
            case S3D_HIERARCHY_NODE:    // Object instance
            case S3D_N_TRI_OBJECT:      // Object definition
                processChunk( in );
                break;

            case S3D_HIERARCHY:         // Start of the instance tree
                if ( surfacesCreated == false )
                {
                    createUnsmoothedFaces();
                    prepareForNewObject();
                }

                processChunk( in );
                break;

            case S3D_HIERARCHY_LINK:    // Details of an object instance
                processLink( in );
                break;

            case S3D_NODE_ID:           // Node ID - unused.
                processNodeID( in );
                break;

            case S3D_POS_TRACK_TAG:     // Contains object's initial position
                processPosTrackTag( in );
                break;

            case S3D_ROT_TRACK_TAG:     // Contains object's initial orientation
                processRotTrackTag( in );
                break;

            case S3D_SCL_TRACK_TAG:     // Contains object's initial scale
                processSclTrackTag( in );
                break;

            case S3D_INSTANCE_NAME:     // Name given to object instance
                instanceName = readName( in );
                break;

            case S3D_AMBIENT_LIGHT:     // Ambient light
                processAmbientLight( in );
                break;

            case S3D_MASTER_SCALE:      // Global scaling factor
                processMasterScale( in );
                break;

            case S3D_MAT_NAME:          // Start of a 3DS material
                matName     = readName( in );
                mat         = new Appearance();
                material    = new Material();
                material.setLightingEnable( true );
                mat.setMaterial( material );
                mats.put( matName, mat );

                if ( verbosity > 2 )
                {
                    System.out.println( "Processing material '" + matName + "'" );
                }
                break;

            case S3D_MAT_AMBIENT:       // Ambient colour of material
                Color3f     ambient = readColor( in );
                material.setAmbientColor( ambient );

                if ( verbosity > 2 )
                {
                    System.out.println( "==     Ambient: " + ambient );
                }
                break;

            case S3D_MAT_DIFFUSE:       // Diffuse colour of material
                Color3f     diffuse = readColor( in );
                material.setDiffuseColor( diffuse );

                if ( verbosity > 2 )
                {
                    System.out.println( "==     Diffuse: " + diffuse );
                }
                break;

            case S3D_MAT_SPECULAR:      // Specular colour of material
                material.setSpecularColor( readColor( in ) );
                break;

            case S3D_MAT_SHININESS:     // 3DS shininess percentage
                shininess = readPercentage( in );
                //System.out.println( "== Shininess: " + shininess );
                break;

            case S3D_MAT_SHININESS_STRENGTH:    // 3DS shininess strength
                float   shininessStrength = readPercentage( in );
                //System.out.println( "== Shininess strength: " + shininessStrength );
                material.setShininess( (1.0f - ((shininess + shininessStrength) / 2.0f)) * 128 );
                break;

            case S3D_MAT_TRANSPARENCY:  // Transparency percentage
                float   transparency = readPercentage( in );

                if ( verbosity > 2 )
                {
                    System.out.println( "== Transparency: " + transparency );
                }

                if ( transparency > 0.1f )
                {
                    TransparencyAttributes  ta  = new TransparencyAttributes();

                    ta.setTransparency( transparency );
                    mat.setTransparencyAttributes( ta );

                    //
                    // If we turn transparency on then we should
                    // also turn back face culling off.
                    //

                    PolygonAttributes       pa  = new PolygonAttributes();

                    pa.setCullFace( PolygonAttributes.CULL_NONE );
                    mat.setPolygonAttributes( pa );
                }
                break;

            case S3D_MAT_SHADING:       // Type of rendering
                int                 style;
                int                 mode = readUnsignedShort( in );
                PolygonAttributes   pa = mat.getPolygonAttributes();
                ColoringAttributes  ca = mat.getColoringAttributes();

                if ( pa == null )
                {
                    pa = new PolygonAttributes();
                }