Refactored POvRAY export from toxiclibs (as and external library)

POVInterface.java

/*
 * This library adds PovRAY export facility to toxiclibscore
 * Copyright (c) 2012 Martin Prout
 *
 * 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.
 *
 * http://creativecommons.org/licenses/LGPL/2.1/
 *
 * 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
package toxi.geom.mesh;

import java.io.PrintWriter;

/**
 *
 * @author Martin Prout
 */
public interface POVInterface {

    /**
     * 
     * @param name
     */
    void setName(String name);

    /**
     * Saves the mesh as PovRAY mesh2 format to the given {@link PrintWriter}. Currently
     * no texture coordinates are supported or written.
     *
     * @param pw PrintWriter (save to a PovRAY *.inc file)
     */
    void saveAsPOV(PrintWriter pw);

    /**
     * Saves the mesh as PovRAY mesh2 format to the given {@link PrintWriter}. Currently
     * no texture coordinates are supported or written.
     *
     * @param pw PrintWriter (save to a PovRAY *.inc file)
     * @param normals  
     */
    void saveAsPOV(PrintWriter pw, boolean normals);
    
}

POVMesh.java

/*
 * This library adds PovRAY export facility to toxiclibscore
 * Copyright (c) 2012 Martin Prout
 *
 * 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.
 *
 * http://creativecommons.org/licenses/LGPL/2.1/
 *
 * 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
package toxi.geom.mesh;

import java.io.PrintWriter;

/**
 * This class provides access to underlying TriangleMesh parameters
 * to allow export in PovRAY mesh2 format (with or without normals)
 * @author Martin Prout
 */
public class POVMesh implements POVInterface {
    /**
     * private instance of TriangleMesh
     */
    private TriangleMesh mesh;

    /**
     * Default constructor this mesh should not be null
     */
    public POVMesh() {
        mesh = new TriangleMesh();
    }


    /**
     * Constructor gives local access to TriangleMesh parameters
     * @param mesh WETriangleMesh
     */
    public POVMesh(WETriangleMesh mesh) {
        this.mesh = mesh;
    }
    
    /**
     * Constructor gives local access to TriangleMesh parameters
     * @param mesh TriangleMesh
     */
    public POVMesh(TriangleMesh mesh) {
        this.mesh = mesh;
    }

    /**
     * Saves the mesh as PovRAY mesh2 format by appending it to the given mesh
     * {@link POVWriter} instance. Saves normals.
     *     
     * @param obj POVWriter
     */

    protected void saveAsPOV(POVWriter obj) {
        saveAsPOV(obj, true);
    }

    /**
     * Saves the mesh as PovRAY mesh2 format to the given {@link PrintWriter}.
     * Without normals (when saveNormal is false)
     * @param pw PrintWriter
     * @param saveNormals boolean 
     */

    protected void saveAsPOV(POVWriter pw, boolean saveNormals) {
        int vOffset = pw.getCurrVertexOffset();
        pw.beginMesh2(mesh.name);
        // vertices
        pw.total(mesh.vertices.size());
        for (Vertex v : mesh.vertices.values()) {
            pw.vertex(v);
        }
        pw.endSection();
        // faces
        if (saveNormals) {
            // normals
            pw.beginNormals(mesh.vertices.size());
            for (Vertex v : mesh.vertices.values()) {
                pw.normal(v.normal.getNormalized());
            }
            pw.endSection();
        }
        pw.beginIndices(mesh.faces.size());
        for (Face f : mesh.faces) {
            pw.face(f.b.id + vOffset, f.a.id + vOffset, f.c.id + vOffset);

        }
        pw.endSection();
    }

    /**
     * Saves the mesh as PovRAY mesh2 format to the given {@link PrintWriter}.
     * With normals as default (save to a PovRAY *.inc file, where name is
     * used to declare a mesh2 object, for inclusion in  a PovRAY *.pov file)
     *     
     * @param pw PrintWriter 
     */
    @Override
    public void saveAsPOV(PrintWriter pw) {
        POVWriter obj = new POVWriter();
        obj.beginSave(pw);
        saveAsPOV(obj);
        obj.endSave();
    }

    /**
     * Saves the mesh as PovRAY mesh2 format to the given {@link PrintWriter}.
     * Without normals (when saveNormal is false).
     *     
     * @param pw PrintWriter (save to a PovRAY *.inc file)
     * @param normals  
     */
    @Override
    public void saveAsPOV(PrintWriter pw, boolean normals) {
        POVWriter obj = new POVWriter();
        obj.beginSave(pw);
        saveAsPOV(obj, normals);
        obj.endSave();
    }
    
    /**
     * Explicitly set the mesh name rather than use default which can vary
     * from 'aabb' to 'untitled' NB: a mesh name is required in *.pov file
     * @param name 
     */

    @Override
    public void setName(String name) {
        mesh.setName(name);
    }
}

POVWriter.java

/*
 * This library adds PovRAY export facility to toxiclibscore
 * Copyright (c) 2012 Martin Prout
 *
 * 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.
 *
 * http://creativecommons.org/licenses/LGPL/2.1/
 *
 * 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
package toxi.geom.mesh;

import java.io.PrintWriter;
import toxi.geom.Vec3D;

/**
 * Extremely bare bones PovRAY 3D format exporter. Purely handles the writing of
 * data to the .inc file, as a mesh2 object. See {@link TriangleMesh}
 * for details. Logic heavily borrowed from toxis STL/obj writer, 
 * but adjusted for PovRAY and external use
 *
 * @see TriangleMesh#saveAsPOV(povWriter)
 */
public class POVWriter {
    


    final String COMMA = ", ";
    /**
     * 
     */
    public final String VERSION = "0.4";
    /**
     * 
     */
    protected PrintWriter povWriter;
    /**
     * Track the number of vertices written to file
     */
    protected int numVerticesWritten = 0;
    /**
     * Track the number of normals written to file
     */
    protected int numNormalsWritten = 0;

    /**
     * Handles PrintWriter input
     * @param pw
     */
    public void beginSave(PrintWriter pw) {
        povWriter = pw;
        handleBeginSave();
    }


    /**
     * close the mesh declaration
     */
    public void endSave() {
        povWriter.println("}"); // end of mesh2 declaration
    }

    /**
     * Write face indices as as vector
     * @param a
     * @param b
     * @param c
     */
    public void face(int a, int b, int c) {
        povWriter.println(buildVector(a, b, c));
    }


    /**
     * Track the number of normals written to file
     * @return
     */
    public int getCurrNormalOffset() {
        return numNormalsWritten;
    }

    /**
     * Track the number of vertices written to file
     * @return
     */
    public int getCurrVertexOffset() {
        return numVerticesWritten;
    }

    /**
     * Print a header, and initialise counts
     */
    protected void handleBeginSave() {
        povWriter.println("// generated by POVExport v" + VERSION);
        numVerticesWritten = 0;
        numNormalsWritten = 0;
    }

    /**
     * Begin the mesh2 output as a PovRAY declaration
     * @param name
     */
    public void beginMesh2(String name) {
        StringBuilder pov = new StringBuilder("#declare ");
        pov.append(name);
        pov.append(" = mesh2{\n");
        pov.append("\tvertex_vectors {");
        povWriter.println(pov);
    }

    /**
     * End the current section ie vertex_vector, normal_vector or face_indices
     */
    public void endSection() {
        povWriter.println("\t}");
    }

    /**
     * Output start of normal_vectors
     * @param count
     */
    public void beginNormals(int count) {
        povWriter.println("\tnormal_vectors{");
        total(count);
    }

    /**
     * Output start of face_indices
     * @param count
     */
    public void beginIndices(int count) {
        povWriter.println("\tface_indices{");
        total(count);
    }

    /**
     * Used to output total count vertex_vector, normal_vector & face_indices
     * @param count
     */
    public void total(int count) {
        povWriter.println(String.format("\t%d,", count));
    }

    /**
     * Write normal as PovRAY vector
     * @param n
     */
    public void normal(Vec3D n) {
        povWriter.println(buildVector(n));
        numNormalsWritten++;
    }

    /**
     * Write vertex as PovRAY vector
     * @param v
     */
    public void vertex(Vec3D v) {
        povWriter.println(buildVector(v));
        numVerticesWritten++;
    }

    private StringBuilder buildVector(int a, int b, int c) {
        StringBuilder my_vector = new StringBuilder(120);
        my_vector.append('\t').append('<');
        my_vector.append(a).append(COMMA);
        my_vector.append(b).append(COMMA);
        my_vector.append(c).append('>');        
        return my_vector.append(COMMA);
    }
    
    /**
     * The Y and Z coordinates are multiplied by -1 to handle the conversion of
     * processing coordinate system to PovRAY coordinate system.
     * @param v
     * @return 
     */

    private StringBuilder buildVector(Vec3D v) {
        StringBuilder my_vector = new StringBuilder(120);
        my_vector.append('\t').append('<');
        my_vector.append(v.x).append(COMMA);
        my_vector.append(v.y * -1).append(COMMA);
        my_vector.append(v.z * -1).append('>');        
        return my_vector.append(COMMA);
    }
}