LOD_FaceNormalEditor.cpp

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

// implementation of LOD_FaceNormalEditor.h

#include "LOD_FaceNormalEditor.h"

using namespace std;

LOD_FaceNormalEditor::
LOD_FaceNormalEditor(
    LOD_ManMesh2 & mesh
) : m_mesh(mesh) {
};

    LOD_FaceNormalEditor *
LOD_FaceNormalEditor::
New(
    LOD_ManMesh2 &mesh
){
    // build a set of normals of the same size
    // as the number of polys in the mesh

    MEM_SmartPtr<LOD_FaceNormalEditor> output(new LOD_FaceNormalEditor(mesh));

    int face_num = mesh.FaceSet().size();

    MEM_SmartPtr<vector<MT_Vector3> > normals(new vector<MT_Vector3>);
    MEM_SmartPtr<vector<MT_Vector3> > vertex_normals(new vector<MT_Vector3>);

    if (output == NULL ||
        normals == NULL
    ) {
        return NULL;
    }   

    normals->reserve(face_num);
    vertex_normals->reserve(mesh.VertexSet().size());
    output->m_normals = normals.Release();
    output->m_vertex_normals = vertex_normals.Release();

    return output.Release();
};


// Property editor interface

    void
LOD_FaceNormalEditor::
Remove(
    std::vector<LOD_FaceInd> &sorted_faces
){
    
    // assumes a collection of faces sorted in descending order .
    
    vector<MT_Vector3> & normals = m_normals.Ref();

    vector<LOD_FaceInd>::const_iterator it_start = sorted_faces.begin();
    vector<LOD_FaceInd>::const_iterator it_end = sorted_faces.end();

    for (; it_start != it_end; ++it_start) {

        if (normals.size() > 0) {
            MT_Vector3 temp = normals[*it_start];
        
            normals[*it_start] = normals.back();
            normals.back() = temp;

            normals.pop_back();
        }

        // FIXME - through exception
    }
}


    void
LOD_FaceNormalEditor::
Add(
){
    MT_Vector3 zero(0.0f,0.0f,0.0f);
    m_normals->push_back(zero);
}

    void
LOD_FaceNormalEditor::
Update(
    std::vector<LOD_FaceInd> &sorted_faces
){

    vector<MT_Vector3> & normals = m_normals.Ref();

    vector<LOD_FaceInd>::const_iterator it_start = sorted_faces.begin();
    vector<LOD_FaceInd>::const_iterator it_end = sorted_faces.end();

    const vector<LOD_TriFace> &faces = m_mesh.FaceSet();

    for (; it_start != it_end; ++it_start) {        
        normals[*it_start] = ComputeNormal(faces[*it_start]);       
    }   
};

// vertex normals


    void
LOD_FaceNormalEditor::
RemoveVertexNormals(
    vector<LOD_VertexInd> &sorted_verts
){
    vector<MT_Vector3> & vertex_normals = m_vertex_normals.Ref();

    vector<LOD_VertexInd>::const_iterator it_start = sorted_verts.begin();
    vector<LOD_VertexInd>::const_iterator it_end = sorted_verts.end();

    for (; it_start != it_end; ++it_start) {

        if (vertex_normals.size() > 0) {
            MT_Vector3 temp = vertex_normals[*it_start];
        
            vertex_normals[*it_start] = vertex_normals.back();
            vertex_normals.back() = temp;

            vertex_normals.pop_back();
        }

        // FIXME - through exception
    }
};

    void
LOD_FaceNormalEditor::
UpdateVertexNormals(
    vector<LOD_VertexInd> &sorted_verts
){
    vector<MT_Vector3> & vertex_normals = m_vertex_normals.Ref();

    vector<LOD_VertexInd>::const_iterator it_start = sorted_verts.begin();
    vector<LOD_VertexInd>::const_iterator it_end = sorted_verts.end();

    for (; it_start != it_end; ++it_start) {        
        vertex_normals[*it_start] = ComputeVertexNormal(*it_start);     
    }   
}



// Editor specific methods

    void
LOD_FaceNormalEditor::
BuildNormals(
){

    const vector<LOD_TriFace> &faces = m_mesh.FaceSet();
    vector<MT_Vector3> & normals = m_normals.Ref();

    int face_num = faces.size();
    int cur_face = 0;

    for (; cur_face < face_num; ++cur_face) {

        MT_Vector3 new_normal = ComputeNormal(faces[cur_face]); 
        normals.push_back(new_normal); 
    }
    // now build the vertex normals

    vector<MT_Vector3> & vertex_normals = m_vertex_normals.Ref();
    const vector<LOD_Vertex> &verts = m_mesh.VertexSet();

    int vertex_num = verts.size();
    int cur_vertex = 0;

    for (; cur_vertex < vertex_num; ++cur_vertex) {
        MT_Vector3 new_normal = ComputeVertexNormal(cur_vertex);
        vertex_normals.push_back(new_normal);
    }
}

const 
    MT_Vector3 
LOD_FaceNormalEditor::
ComputeNormal(
    const LOD_TriFace &face
) const {

    const vector<LOD_Vertex> &verts = m_mesh.VertexSet();

    MT_Vector3 vec1 = 
        verts[face.m_verts[1]].pos - 
        verts[face.m_verts[0]].pos;

    MT_Vector3 vec2 = 
        verts[face.m_verts[2]].pos - 
        verts[face.m_verts[1]].pos;

    vec1 = vec1.cross(vec2);

    if (!vec1.fuzzyZero()) {
        vec1.normalize();
        return (vec1);
    } else {        
        return (MT_Vector3(1.0,0,0));
    }       
}

const 
    MT_Vector3 
LOD_FaceNormalEditor::
ComputeVertexNormal(
    const LOD_VertexInd v
) const {

    // average the face normals surrounding this
    // vertex and normalize
    const vector<MT_Vector3> & face_normals = m_normals.Ref();

    vector<LOD_FaceInd> vertex_faces;
    vertex_faces.reserve(32);
    
    m_mesh.VertexFaces(v,vertex_faces);
    
    MT_Vector3 normal(0,0,0);

    vector<LOD_FaceInd>::const_iterator face_it = vertex_faces.begin();
    vector<LOD_FaceInd>::const_iterator face_end = vertex_faces.end();

    for (; face_it != face_end; ++face_it) {
        normal += face_normals[*face_it];
    }
    
    if (!normal.fuzzyZero()) {
        normal.normalize();
        return (normal);
    } else {        
        return (MT_Vector3(1.0,0,0));
    }       
}