path: root/Magic2/l3ds.cpp

// copyright (c) 2001 Lev Povalahev


#include "stdafx.h"

#include "l3ds.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

//using namespace std;

//-------------------------------------------------------
// generic stuff
//-------------------------------------------------------
            
typedef unsigned long ulong;

#define SEEK_START           1900
#define SEEK_CURSOR          1901
             
// common chunks
// colors
#define COLOR_F             0x0010
#define COLOR_24            0x0011
#define LIN_COLOR_24        0x0012
#define LIN_COLOR_F         0x0013
// percentage
#define INT_PERCENTAGE      0x0030
#define FLOAT_PERCENTAGE    0x0031
// ambient light
#define AMBIENT_LIGHT       0x2100


#define MAIN3DS             0x4D4D
#define EDIT3DS             0x3D3D  // this is the start of the editor config

// keyframer chunk ids
#define KFDATA              0xB000  // the keyframer section
#define KFHDR               0xB00A
#define OBJECT_NODE_TAG     0xB002  
#define NODE_HDR            0xB010
#define PIVOT               0xB013
#define POS_TRACK_TAG       0xB020
#define ROT_TRACK_TAG       0xB021
#define SCL_TRACK_TAG       0xB022

// material entries
#define MAT_ENTRY           0xAFFF
#define MAT_NAME            0xA000
#define MAT_AMBIENT         0xA010
#define MAT_DIFFUSE         0xA020
#define MAT_SPECULAR        0xA030
#define MAT_SHININESS       0xA040
#define MAT_SHIN2PCT        0xA041
#define MAT_TRANSPARENCY    0xA050
#define MAT_SHADING         0xA100
#define MAT_TWO_SIDE        0xA081
#define MAT_ADDITIVE        0xA083
#define MAT_WIRE            0xA085
#define MAT_FACEMAP         0xA088
#define MAT_WIRESIZE        0xA087
#define MAT_DECAL           0xA082
#define MAT_TEXMAP          0xA200
#define MAT_MAPNAME         0xA300
#define MAT_MAP_TILING      0xA351
#define MAT_MAP_USCALE      0xA354
#define MAT_MAP_VSCALE      0xA356
#define MAT_MAP_UOFFSET     0xA358
#define MAT_MAP_VOFFSET     0xA35A
#define MAT_MAP_ANG         0xA35C
#define MAT_TEX2MAP         0xA33A
#define MAT_OPACMAP         0xA210
#define MAT_BUMPMAP         0xA230
#define MAT_SPECMAP         0xA204
#define MAT_SHINMAP         0xA33C
#define MAT_REFLMAP         0xA220
#define MAT_ACUBIC          0xA310

#define EDIT_OBJECT         0x4000
#define OBJ_TRIMESH         0x4100
#define OBJ_LIGHT           0x4600
#define OBJ_CAMERA          0x4700
#define LIT_OFF             0x4620
#define LIT_SPOT            0x4610
#define TRI_VERTEXLIST      0x4110
#define TRI_VERTEXOPTIONS   0x4111

#define TRI_FACELIST        0x4120
    #define TRI_MAT_GROUP       0x4130
    #define TRI_SMOOTH_GROUP    0x4150

#define TRI_FACEMAPPING     0x4140
#define TRI_MATRIX          0x4160

#define SPOTLIGHT           0x4610

//----------------------------------

#define MAX_SHARED_TRIS     100

// the error reporting routine

void ErrorMsg(const char *msg)
{

}

struct LChunk
{
    unsigned short id;
    uint start;
    uint end;
};

struct LTri
{
    unsigned short a;
    unsigned short b;
    unsigned short c;
    ulong smoothingGroups;
    LVector3 normal;
    LVector3 tangent;
    LVector3 binormal;
    uint materialId;
};

// globals

LColor3 black = {0, 0, 0};

LVector3 zero3 = {0, 0, 0};

LVector4 zero4 = {0, 0, 0, 0};

LMap emptyMap = {0, "", 1, 1, 0, 0, 0};

LVector3 _4to3(const LVector4 &vec)
{
    LVector3 t;
    t.x = vec.x;
    t.y = vec.y;
    t.z = vec.z;
    return t;
}

LVector3 AddVectors(const LVector3 &a, const LVector3 &b)
{
    LVector3 t;
    t.x = a.x+b.x;
    t.y = a.y+b.y;
    t.z = a.z+b.z;
    return t;
}

LVector3 SubtractVectors(const LVector3 &a, const LVector3 &b)
{
    LVector3 t;
    t.x = a.x-b.x;
    t.y = a.y-b.y;
    t.z = a.z-b.z;
    return t;
}

float VectorLength(const LVector3 &vec)
{
    return (float)sqrt(vec.x*vec.x + vec.y*vec.y+vec.z*vec.z);
}

LVector3 NormalizeVector(const LVector3 &vec)
{
    float a = VectorLength(vec);
    if (a == 0)
        return vec;
    float b = 1/a;
    LVector3 v;
    v.x = vec.x*b;
    v.y = vec.y*b;
    v.z = vec.z*b;
    return v;
}

LVector3 CrossProduct(const LVector3 &a, const LVector3 &b)
{
    LVector3 v;
    v.x = a.y*b.z - a.z*b.y;
    v.y = a.z*b.x - a.x*b.z;
    v.z = a.x*b.y - a.y*b.x;
    return v;
}

void LoadIdentityMatrix(LMatrix4 &m)
{
   for (int i = 0; i < 4; i++)
      for (int j = 0; j < 4; j++)
         m.m[i][j] = (i==j) ? 1.0f : 0.0f;
}

LVector4 VectorByMatrix(const LMatrix4 &m, const LVector4 &vec)
{
    LVector4 res;

    res.x = m.m[0][0]*vec.x + m.m[1][0]*vec.y + m.m[2][0]*vec.z + m.m[3][0]*vec.w;
    res.y = m.m[0][1]*vec.x + m.m[1][1]*vec.y + m.m[2][1]*vec.z + m.m[3][1]*vec.w;
    res.z = m.m[0][2]*vec.x + m.m[1][2]*vec.y + m.m[2][2]*vec.z + m.m[3][2]*vec.w;
    res.w = m.m[0][3]*vec.x + m.m[1][3]*vec.y + m.m[2][3]*vec.z + m.m[3][3]*vec.w;

    if (res.w != 0) {
        float b =  1/res.w;
        res.x *= b;
        res.y *= b;
        res.z *= b;
        res.w = 1;
    }
    else {
        res.w = 1;
    }

    return res;
}

void QuatToMatrix(const LVector4 &quat, LMatrix4 &m)
{

}

//-------------------------------------------------------
// LObject implementation
//-------------------------------------------------------

LObject::LObject()
{
    m_name = "";//.clear();
}

LObject::~LObject()
{
    // nothing here
}

void LObject::SetName(const std::string& value)
{
    m_name = value;
}

const std::string& LObject::GetName()
{
    return m_name;
}

bool LObject::IsObject(const std::string &name)
{
    return (m_name == name);
}


//-------------------------------------------------------
// LMaterial implementation
//-------------------------------------------------------

LMaterial::LMaterial()
: LObject()
{
    m_id = 0;
    m_texMap1 = emptyMap;
    m_texMap2 = emptyMap;
    m_opacMap = emptyMap;
    m_bumpMap = emptyMap;
    m_reflMap = emptyMap;
    m_specMap = emptyMap;
    m_ambient = black;
    m_diffuse = black;
    m_specular = black;
    m_shading = sGouraud;
    m_shininess = 0;
    m_transparency = 0;
}

LMaterial::~LMaterial()
{

}

uint LMaterial::GetID()
{
    return m_id;
}

LMap& LMaterial::GetTextureMap1()
{
    return m_texMap1;
}

LMap& LMaterial::GetTextureMap2()
{
    return m_texMap2;
}

LMap& LMaterial::GetOpacityMap()
{
    return m_opacMap;
}

LMap& LMaterial::GetSpecularMap()
{
    return m_specMap;
}

LMap& LMaterial::GetBumpMap()
{
    return m_bumpMap;
}

LMap& LMaterial::GetReflectionMap()
{
    return m_reflMap;
}

LColor3 LMaterial::GetAmbientColor()
{
    return m_ambient;
}

LColor3 LMaterial::GetDiffuseColor()
{
    return m_diffuse;
}

LColor3 LMaterial::GetSpecularColor()
{
    return m_specular;
}

float LMaterial::GetShininess()
{
    return m_shininess;
}

float LMaterial::GetTransparency()
{
    return m_transparency;
}

LShading LMaterial::GetShadingType()
{
    return m_shading;
}

void LMaterial::SetID(uint value)
{
    m_id = value;
}

void LMaterial::SetAmbientColor(const LColor3 &color)
{
    m_ambient = color;
}

void LMaterial::SetDiffuseColor(const LColor3 &color)
{
    m_diffuse = color;
}

void LMaterial::SetSpecularColor(const LColor3 &color)
{
    m_specular = color;
}

void LMaterial::SetShininess(float value)
{
    m_shininess = value;
    if (m_shininess < 0)
        m_shininess = 0;
    if (m_shininess > 1)
        m_shininess = 1;
}

void LMaterial::SetTransparency(float value)
{
    m_transparency = value;
    if (m_transparency < 0)
        m_transparency = 0;
    if (m_transparency > 1)
        m_transparency = 1;
}

void LMaterial::SetShadingType(LShading shading)
{
    m_shading = shading;
}

//-------------------------------------------------------
// LMesh implementation
//-------------------------------------------------------

LMesh::LMesh()
:   LObject()
{
    Clear();
}

LMesh::~LMesh()
{
    Clear();
}

void LMesh::Clear()
{
    m_vertices.clear();
    m_normals.clear();
    m_uv.clear();
    m_tangents.clear();
    m_binormals.clear();
    m_triangles.clear();
    m_tris.clear();
    m_materials.clear();
    LoadIdentityMatrix(m_matrix);
}

uint LMesh::GetVertexCount()
{
    return m_vertices.size();
}

void LMesh::SetVertexArraySize(uint value)
{
    m_vertices.resize(value);
    m_normals.resize(value);
    m_uv.resize(value);
    m_tangents.resize(value);
    m_binormals.resize(value);
}

uint LMesh::GetTriangleCount()
{
    return m_triangles.size();
}

void LMesh::SetTriangleArraySize(uint value)
{
    m_triangles.resize(value);
    m_tris.resize(value);
}

const LVector4& LMesh::GetVertex(uint index)
{
    return m_vertices[index];    
}

const LVector3& LMesh::GetNormal(uint index)
{
    return m_normals[index];
}

const LVector2& LMesh::GetUV(uint index)
{
    return m_uv[index];
}

const LVector3& LMesh::GetTangent(uint index)
{
    return m_tangents[index];
}

const LVector3& LMesh::GetBinormal(uint index)
{
    return m_binormals[index];
}

void LMesh::SetVertex(const LVector4 &vec, uint index)
{
    if (index >= m_vertices.size())
        return;
    m_vertices[index] = vec;
}

void LMesh::SetNormal(const LVector3 &vec, uint index)
{
    if (index >= m_vertices.size())
        return;
    m_normals[index] = vec;
}

void LMesh::SetUV(const LVector2 &vec, uint index)
{
    if (index >= m_vertices.size())
        return;
    m_uv[index] = vec;
}

void LMesh::SetTangent(const LVector3 &vec, uint index)
{
    if (index >= m_vertices.size())
        return;
    m_tangents[index] = vec;    
}

void LMesh::SetBinormal(const LVector3 &vec, uint index)
{
    if (index >= m_vertices.size())
        return;
    m_binormals[index] = vec;
}

const LTriangle& LMesh::GetTriangle(uint index)
{
    return m_triangles[index];
}

LTriangle2 LMesh::GetTriangle2(uint index)
{
    LTriangle2 f;
    LTriangle t = GetTriangle(index);
    f.vertices[0] = GetVertex(t.a);
    f.vertices[1] = GetVertex(t.b);
    f.vertices[2] = GetVertex(t.c);

    f.vertexNormals[0] = GetNormal(t.a);
    f.vertexNormals[1] = GetNormal(t.b);
    f.vertexNormals[2] = GetNormal(t.c);
    
    f.textureCoords[0] = GetUV(t.a);
    f.textureCoords[1] = GetUV(t.b);
    f.textureCoords[2] = GetUV(t.c);
    
    LVector3 a, b;

    a = SubtractVectors(_4to3(f.vertices[1]), _4to3(f.vertices[0]));
    b = SubtractVectors(_4to3(f.vertices[1]), _4to3(f.vertices[2]));

    f.faceNormal = CrossProduct(b, a);

    f.faceNormal = NormalizeVector(f.faceNormal);

    f.materialId = m_tris[index].materialId;
    
    return f;
}

LMatrix4 LMesh::GetMatrix()
{
    return m_matrix;
}

void LMesh::SetMatrix(LMatrix4 m)
{
    m_matrix = m;
}

void LMesh::TransformVertices()
{
    for (uint i=0; i<m_vertices.size(); i++)
        m_vertices[i] = VectorByMatrix(m_matrix, m_vertices[i]);

    LoadIdentityMatrix(m_matrix);
}

void LMesh::CalcNormals(bool useSmoothingGroups)
{
    uint i;
    // first calculate the face normals
    for (i=0; i<m_triangles.size(); i++)
    {
        LVector3 a, b;
        a = SubtractVectors(_4to3(m_vertices[m_tris[i].b]), _4to3(m_vertices[m_tris[i].a]));
        b = SubtractVectors(_4to3(m_vertices[m_tris[i].b]), _4to3(m_vertices[m_tris[i].c]));
        m_tris[i].normal = NormalizeVector(CrossProduct(b, a));
    }

    std::vector< std::vector<int> > array;
    array.resize(m_vertices.size());
    for (i=0; i<m_triangles.size(); i++)
    {
        uint k = m_tris[i].a;
        array[k].push_back(i);

        k = m_tris[i].b;
        array[k].push_back(i);

        k = m_tris[i].c;
        array[k].push_back(i);
    } 

    LVector3 temp;
    
    if (!useSmoothingGroups)
    {
        // now calculate the normals without using smoothing groups
        for (i=0; i<m_vertices.size(); i++)
        {
            temp = zero3;
            int t = array[i].size();

            for (int k=0; k<t; k++)
            {
                temp.x += m_tris[array[i][k]].normal.x;
                temp.y += m_tris[array[i][k]].normal.y;
                temp.z += m_tris[array[i][k]].normal.z;
            }
            m_normals[i] = NormalizeVector(temp);
        }
    }
    else
    {
        // now calculate the normals _USING_ smoothing groups
        // I'm assuming a triangle can only belong to one smoothing group at a time!
        std::vector<ulong> smGroups;
        std::vector< std::vector <uint> > smList;
        
        uint loop_size = m_vertices.size();

        for (i=0; i<loop_size; i++)
        {
            int t = array[i].size();

            if (t == 0)
                continue;

            smGroups.clear();
            smList.clear();
            smGroups.push_back(m_tris[array[i][0]].smoothingGroups);
            smList.resize(smGroups.size());
            smList[smGroups.size()-1].push_back(array[i][0]);

            // first build a list of smoothing groups for the vertex
            for (int k=0; k<t; k++)
            {
                bool found = false;
                for (uint j=0; j<smGroups.size(); j++)
                {
                    if (m_tris[array[i][k]].smoothingGroups == smGroups[j])
                    {
                        smList[j].push_back(array[i][k]);
                        found = true;
                    }
                }
                if (!found)
                {
                    smGroups.push_back(m_tris[array[i][k]].smoothingGroups);
                    smList.resize(smGroups.size());
                    smList[smGroups.size()-1].push_back(array[i][k]);
                }
            }
            // now we have the list of faces for the vertex sorted by smoothing groups


            // now duplicate the vertices so that there's only one smoothing group "per vertex"
            if (smGroups.size() > 1)
                for (uint j=1; j< smGroups.size(); j++)
                {
                    m_vertices.push_back(m_vertices[i]);
                    m_normals.push_back(m_normals[i]);
                    m_uv.push_back(m_uv[i]);
                    m_tangents.push_back(m_tangents[i]);
                    m_binormals.push_back(m_binormals[i]);
                    
                    uint t = m_vertices.size()-1;
                    for (uint h=0; h<smList[j].size(); h++)
                    {
                        if (m_tris[smList[j][h]].a == i)
                            m_tris[smList[j][h]].a = t;
                        if (m_tris[smList[j][h]].b == i)
                            m_tris[smList[j][h]].b = t;
                        if (m_tris[smList[j][h]].c == i)
                            m_tris[smList[j][h]].c = t;
                    }
                }
        }
        
        // now rebuild a face list for each vertex, since the old one is invalidated
        for (i=0; i<array.size(); i++)
            array[i].clear();
        array.clear();
        array.resize(m_vertices.size());
        for (i=0; i<m_triangles.size(); i++)
        {
            uint k = m_tris[i].a;
            array[k].push_back(i);

            k = m_tris[i].b;
            array[k].push_back(i);

            k = m_tris[i].c;
            array[k].push_back(i);
        } 

        // now compute the normals
        for (i=0; i<m_vertices.size(); i++)
        {
            temp = zero3;
            int t = array[i].size();

            for (int k=0; k<t; k++)
            {
                temp.x += m_tris[array[i][k]].normal.x;
                temp.y += m_tris[array[i][k]].normal.y;
                temp.z += m_tris[array[i][k]].normal.z;
            }
            m_normals[i] = NormalizeVector(temp);
        }

    }
   
    // copy m_tris to m_triangles
    for (i=0; i<m_triangles.size(); i++)
    {
        m_triangles[i].a = m_tris[i].a;
        m_triangles[i].b = m_tris[i].b;
        m_triangles[i].c = m_tris[i].c;
    }
      
}

void LMesh::CalcTextureSpace()
{
    // a understandable description of how to do that can be found here:
    // http://members.rogers.com/deseric/tangentspace.htm
    // first calculate the tangent for each triangle
    LVector3 x_vec,
             y_vec,
             z_vec;
    LVector3 v1, v2;
    for (uint i=0; i<m_triangles.size(); i++)
    {
        v1.x = m_vertices[m_tris[i].b].x - m_vertices[m_tris[i].a].x;
        v1.y = m_uv[m_tris[i].b].x - m_uv[m_tris[i].a].x;
        v1.z = m_uv[m_tris[i].b].y - m_uv[m_tris[i].a].y;
        
        v2.x = m_vertices[m_tris[i].c].x - m_vertices[m_tris[i].a].x;
        v2.y = m_uv[m_tris[i].c].x - m_uv[m_tris[i].a].x;
        v2.z = m_uv[m_tris[i].c].y - m_uv[m_tris[i].a].y;

        x_vec = CrossProduct(v1, v2);

        v1.x = m_vertices[m_tris[i].b].y - m_vertices[m_tris[i].a].y;
        v1.y = m_uv[m_tris[i].b].x - m_uv[m_tris[i].a].x;
        v1.z = m_uv[m_tris[i].b].y - m_uv[m_tris[i].a].y;

        v2.x = m_vertices[m_tris[i].c].y - m_vertices[m_tris[i].a].y;
        v2.y = m_uv[m_tris[i].c].x - m_uv[m_tris[i].a].x;
        v2.z = m_uv[m_tris[i].c].y - m_uv[m_tris[i].a].y;

        y_vec = CrossProduct(v1, v2);

        v1.x = m_vertices[m_tris[i].b].z - m_vertices[m_tris[i].a].z;
        v1.y = m_uv[m_tris[i].b].x - m_uv[m_tris[i].a].x;
        v1.z = m_uv[m_tris[i].b].y - m_uv[m_tris[i].a].y;

        v2.x = m_vertices[m_tris[i].c].z - m_vertices[m_tris[i].a].z;
        v2.y = m_uv[m_tris[i].c].x - m_uv[m_tris[i].a].x;
        v2.z = m_uv[m_tris[i].c].y - m_uv[m_tris[i].a].y;

        z_vec = CrossProduct(v1, v2);

        m_tris[i].tangent.x = -(x_vec.y/x_vec.x);
        m_tris[i].tangent.y = -(y_vec.y/y_vec.x);
        m_tris[i].tangent.z = -(z_vec.y/z_vec.x);

        m_tris[i].binormal.x = -(x_vec.z/x_vec.x);
        m_tris[i].binormal.y = -(y_vec.z/y_vec.x);
        m_tris[i].binormal.z = -(z_vec.z/z_vec.x);

    }

    // now for each vertex build a list of face that share this vertex
    std::vector< std::vector<int> > array;
    array.resize(m_vertices.size());
    for (i=0; i<m_triangles.size(); i++)
    {
        uint k = m_tris[i].a;
        array[k].push_back(i);

        k = m_tris[i].b;
        array[k].push_back(i);

        k = m_tris[i].c;
        array[k].push_back(i);
    } 

    // now average the tangents and compute the binormals as (tangent X normal)
    for (i=0; i<m_vertices.size(); i++)
    {
        v1 = zero3;
        v2 = zero3;
        int t = array[i].size();

        for (int k=0; k<t; k++)
        {
            v1.x += m_tris[array[i][k]].tangent.x;
            v1.y += m_tris[array[i][k]].tangent.y;
            v1.z += m_tris[array[i][k]].tangent.z;

            v2.x += m_tris[array[i][k]].binormal.x;
            v2.y += m_tris[array[i][k]].binormal.y;
            v2.z += m_tris[array[i][k]].binormal.z;
        }
        m_tangents[i] = NormalizeVector(v1);
        //m_binormals[i] = NormalizeVector(v2);
        
        m_binormals[i] = NormalizeVector(CrossProduct(m_tangents[i], m_normals[i]));
    }
}

void LMesh::Optimize(LOptimizationLevel value)
{
    switch (value)
    {
    case oNone:
        TransformVertices();
        break;
    case oSimple:
        TransformVertices();
        CalcNormals(false);
        break;
    case oFull:
        TransformVertices();
        CalcNormals(true);
        CalcTextureSpace();
        break;
    }
}

void LMesh::SetTri(const LTri &tri, uint index)
{
    if (index >= m_triangles.size())
        return;
    m_tris[index] = tri;
}

LTri& LMesh::GetTri(uint index)
{
    return m_tris[index];
}

uint LMesh::GetMaterial(uint index)
{
    return m_materials[index];
}

uint LMesh::AddMaterial(uint id)
{
    m_materials.push_back(id);
    return m_materials.size()-1;
}

uint LMesh::GetMaterialCount()
{
    return m_materials.size();
}

//-------------------------------------------------------
// LLight implementation
//-------------------------------------------------------

LLight::LLight()
:   LObject()
{
    Clear();
}

LLight::~LLight()
{

}

void LLight::Clear()
{
    m_pos.x = m_pos.y = m_pos.z = 0.0f;
    m_color.r = m_color.g = m_color.b = 0.0f;
    m_spotlight = false;
}

void LLight::SetPosition(LVector3 vec)
{
    m_pos = vec;
}

LVector3 LLight::GetPosition()
{
    return m_pos;
}

void LLight::SetColor(LColor3 color)
{
    m_color = color;
}

LColor3 LLight::GetColor()
{
    return m_color;
}

void LLight::SetSpotlight(bool value)
{
    m_spotlight = value;
}

bool LLight::GetSpotlight()
{
    return m_spotlight;
}

void LLight::SetTarget(LVector3 target)
{
    m_target = target;
}

LVector3 LLight::GetTarget()
{
    return m_target;
}

void LLight::SetHotspot(float value)
{
    m_hotspot = value;
}

float LLight::GetHotspot()
{
    return m_hotspot;
}

void LLight::SetFalloff(float value)
{
    m_falloff = value;
}
    
float LLight::GetFalloff()
{
    return m_falloff;
}

//-------------------------------------------------------
// LImporter implementation
//-------------------------------------------------------

LImporter::LImporter()
{
    Clear();
}       

LImporter::~LImporter()
{
    Clear();
}

uint LImporter::GetMeshCount()
{
    return m_meshes.size();
}

uint LImporter::GetLightCount()
{
    return m_lights.size();
}

uint LImporter::GetMaterialCount()
{
    return m_materials.size();
}

LMesh& LImporter::GetMesh(uint index)
{
    return m_meshes[index];
}

LLight& LImporter::GetLight(uint index)
{
    return m_lights[index];
}

LMaterial& LImporter::GetMaterial(uint index)
{
    return m_materials[index];
}

LMaterial* LImporter::FindMaterial(const std::string& name)
{
    for (uint i=0; i<m_materials.size(); i++)
        if (m_materials[i].IsObject(name))
            return &m_materials[i];
    return 0;
}

LMesh* LImporter::FindMesh(const std::string& name)
{
    for (uint i=0; i<m_meshes.size(); i++)
        if (m_meshes[i].IsObject(name))
            return &m_meshes[i];
    return 0;
}

LLight* LImporter::FindLight(const std::string& name)
{
    for (uint i=0; i<m_lights.size(); i++)
        if (m_lights[i].IsObject(name))
            return &m_lights[i];
    return 0;
}

void LImporter::Clear()
{
    m_meshes.clear();
    m_lights.clear();
    m_materials.clear();
    m_optLevel = oFull;
}

void LImporter::SetOptimizationLevel(LOptimizationLevel value)
{
    m_optLevel = value;        
}

LOptimizationLevel LImporter::GetOptimizationLevel()
{
    return m_optLevel;
}

//-------------------------------------------------------
// L3DS implementation
//-------------------------------------------------------

L3DS::L3DS()
: LImporter()
{
    m_buffer = 0;
    m_bufferSize = 0;
    m_pos = 0;
    m_eof = false;
} 

L3DS::L3DS(const char *filename)
: LImporter()
{
    m_buffer = 0;
    m_bufferSize = 0;
    m_pos = 0;
    m_eof = false;
    LoadFile(filename);
}

L3DS::~L3DS()
{
    if (m_bufferSize > 0)
        free(m_buffer);
}

bool L3DS::LoadFile(const char *filename)
{
    FILE *f;
    f = fopen(filename, "rb");
    if (f == 0)
    {
        ErrorMsg("L3DS::LoadFile - cannot open file");
        return false;
    }
    fseek(f, 0, SEEK_END);
    m_bufferSize = ftell(f);
    fseek(f, 0, SEEK_SET);
    m_buffer = (unsigned char*) calloc(m_bufferSize, 1);
    if (m_buffer == 0)
    {
        ErrorMsg("L3DS::LoadFile - not enough memory (malloc failed)");
        return false;
    }
    if (fread(m_buffer, m_bufferSize, 1, f) != 1)
    {
        fclose(f);
        free(m_buffer);
        m_bufferSize = 0;
        ErrorMsg("L3DS::LoadFile - error reading from file");
        return false;
    }
    fclose(f);
    Clear();
    bool res = Read3DS();
    free(m_buffer);
    m_buffer = 0;
    m_bufferSize = 0;
    return res;
}

short L3DS::ReadShort()
{
    if ((m_buffer!=0) && (m_bufferSize != 0) && ((m_pos+2)<m_bufferSize))
    {
        short *w = (short*)(m_buffer+m_pos);
        short s = *w;//(short)*(m_buffer+m_pos);
        m_pos += 2;
        return s;
    }
    m_eof = true;
    return 0;
}
 
int L3DS::ReadInt()
{
    if ((m_buffer!=0) && (m_bufferSize != 0) && ((m_pos+4)<m_bufferSize))
    {
        int *w = (int*)(m_buffer+m_pos);
        int s = *w;//(int)*(m_buffer+m_pos);
        m_pos += 4;
        return s;
    }
    m_eof = true;
    return 0;
}

char L3DS::ReadChar()
{
    if ((m_buffer!=0) && (m_bufferSize != 0) && ((m_pos+1)<m_bufferSize))
    {
        char s = (char)*(m_buffer+m_pos);
        m_pos += 1;
        return s;
    }
    m_eof = true;
    return 0;
}

float L3DS::ReadFloat()
{
    if ((m_buffer!=0) && (m_bufferSize != 0) && ((m_pos+4)<m_bufferSize))
    {
        float *w = (float*)(m_buffer+m_pos);
        float s = *w;//(float)*(m_buffer+m_pos);
        m_pos += 4;
        return s;
    }
    m_eof = true;
    return 0.0;
}

byte L3DS::ReadByte()
{
    if ((m_buffer!=0) && (m_bufferSize != 0) && ((m_pos+1)<m_bufferSize))
    {
        byte s = (byte)*(m_buffer+m_pos);
        m_pos += 1;
        return s;
    }
    m_eof = true;
    return 0;
}

int L3DS::ReadASCIIZ(char *buf, int max_count)
{
    int count;
    if ((m_buffer==0) || (m_bufferSize == 0) || (m_pos>=m_bufferSize))
    {
        count = 0;
        m_eof = true;
        return count;
    }
    count = 0;
    char c = ReadChar();
    while ((c!=0) && (count<max_count-1))
    {
        buf[count] = c;
        count ++;
        c = ReadChar();
    }
    buf[count] = 0;
    return count;
}

void L3DS::Seek(int offset, int origin)
{
    if (origin == SEEK_START)
        m_pos = offset;
    if (origin == SEEK_CURSOR)
        m_pos += offset;
    if (m_pos < 0)
        m_pos = 0;
    if (m_pos >= m_bufferSize)
        m_pos = m_bufferSize-1;
    m_eof = false;
}

uint L3DS::Pos()
{
    return m_pos;
}

LChunk L3DS::ReadChunk()
{
    LChunk chunk;
    chunk.id = ReadShort();
    int a = ReadInt();
    chunk.start = Pos();
    chunk.end = chunk.start+a-6;
    return chunk;
}

bool L3DS::FindChunk(LChunk &target, const LChunk &parent)
{
    if (Pos() >= parent.end)
        return false;
    LChunk chunk;
    chunk = ReadChunk();
    while (( chunk.id != target.id) && (chunk.end <= parent.end))
    {
        SkipChunk(chunk);
        if (chunk.end >= parent.end)
            break;
        chunk = ReadChunk();
    }
    if (chunk.id == target.id)
    {
        target.start = chunk.start;
        target.end = chunk.end;
        return true;
    }
    return false;
}

void L3DS::SkipChunk(const LChunk &chunk)
{
    Seek(chunk.end, SEEK_START);
}

void L3DS::GotoChunk(const LChunk &chunk)
{
    Seek(chunk.start, SEEK_START);
}

LColor3 L3DS::ReadColor(const LChunk &chunk)
{
    LColor3 col = black;
    GotoChunk(chunk);
    switch (chunk.id)
    {
    case COLOR_F:
        col.r = ReadFloat();
        col.g = ReadFloat();
        col.b = ReadFloat();
        break;
    case COLOR_24:
        col.r = ReadByte()/255.0f;
        col.g = ReadByte()/255.0f;
        col.b = ReadByte()/255.0f;
        break;
    case LIN_COLOR_F:
        col.r = ReadFloat();
        col.g = ReadFloat();
        col.b = ReadFloat();
        break;
    case LIN_COLOR_24:
        col.r = ReadByte()/255.0f;
        col.g = ReadByte()/255.0f;
        col.b = ReadByte()/255.0f;
        break;
    default:
        ErrorMsg("L3DS::ReadColor - error this is not a color chunk");
    }
    return col;
}

float L3DS::ReadPercentage(const LChunk &chunk)
{
    GotoChunk(chunk);
    switch (chunk.id)
    {
    case INT_PERCENTAGE:
        return (ReadShort()/100.0f);
    case FLOAT_PERCENTAGE:
        return ReadFloat();
    }
    ErrorMsg("L3DS::ReadPercentage - error, the chunk is not a percentage chunk");
    return 0;
}

bool L3DS::Read3DS()
{
    LChunk mainchunk;
    LChunk edit;
    edit.id = EDIT3DS;
    mainchunk = ReadChunk();
    if (mainchunk.id != MAIN3DS)
    {
        ErrorMsg("L3DS::Read3DS - wrong file format");
        return false;
    }
    if (!FindChunk(edit, mainchunk))
        return false;
    LChunk obj;
    LChunk ml;

    GotoChunk(edit);
    obj.id = MAT_ENTRY;
    while (FindChunk(obj, edit))
    {
        ReadMaterial(obj);
        SkipChunk(obj);
    }
    GotoChunk(edit);

    obj.id = EDIT_OBJECT;
    {
        while (FindChunk(obj, edit))
        {
            ReadASCIIZ(m_objName, 99);
            ml = ReadChunk();
            if (ml.id == OBJ_TRIMESH)
                ReadMesh(ml);
            if (ml.id == OBJ_LIGHT)
                ReadLight(ml);
            SkipChunk(obj);
        }
    }
    
    // read the keyframer data here to find out correct object orientation

    LChunk keyframer;
    keyframer.id = KFDATA;

    LChunk objtrack;
    objtrack.id = OBJECT_NODE_TAG;

    GotoChunk(mainchunk);
    if (FindChunk(keyframer, mainchunk)) 
    {   // keyframer chunk is present
        GotoChunk(keyframer);
        while (FindChunk(objtrack, keyframer))
        {
            ReadKeyframeData(objtrack);
            SkipChunk(objtrack);
        }
    }

    for (uint i=0; i<m_meshes.size(); i++) {
        m_meshes[i].Optimize(m_optLevel);
    }

    m_pos = 0;
    strcpy(m_objName, "");
    return true;
}

void L3DS::ReadLight(const LChunk &parent)
{
    float t;
    LVector3 v;
    LLight light;
    light.SetName(m_objName);
    GotoChunk(parent);
    LChunk chunk = ReadChunk();
    if (chunk.id == OBJ_LIGHT)
    {
        v.x = ReadFloat();
        v.y = ReadFloat();
        v.z = ReadFloat();
        if (chunk.end < parent.end)
            chunk = ReadChunk();
        while (chunk.end <= parent.end)
        {
            switch (chunk.id)
            {
            case COLOR_24:
            case COLOR_F:
            case LIN_COLOR_F:
            case LIN_COLOR_24:
                light.SetColor(ReadColor(chunk));
                break;
            case SPOTLIGHT:
                v.x = ReadFloat();
                v.y = ReadFloat();
                v.z = ReadFloat();
                light.SetTarget(v);
                t = ReadFloat();
                light.SetHotspot(t);
                t = ReadFloat();
                light.SetFalloff(t);
                break;
            default:
                break;
            }
            SkipChunk(chunk);
            if (chunk.end >= parent.end)
                break;
            chunk = ReadChunk();

        }
    }
    m_lights.push_back(light);
}

void L3DS::ReadMesh(const LChunk &parent)
{
    unsigned short count, i;
    LVector4 p;
    LMatrix4 m;
    LVector2 t;
    p.w = 1.0f;
    LMesh mesh;
    mesh.SetName(m_objName);
    GotoChunk(parent);
    LChunk chunk = ReadChunk();
    while (chunk.end <= parent.end)
    {
        switch (chunk.id)
        {
        case TRI_VERTEXLIST:
            count = ReadShort();
            mesh.SetVertexArraySize(count);
            for (i=0; i < count; i++)
            {
                p.x = ReadFloat();
                p.y = ReadFloat();
                p.z = ReadFloat();
                mesh.SetVertex(p, i);
            }
            break;
        case TRI_FACEMAPPING:
            count = ReadShort();
            if (mesh.GetVertexCount() == 0)
                mesh.SetVertexArraySize(count);
            for (i=0; i < count; i++)
            {
                t.x = ReadFloat();
                t.y = ReadFloat();
                mesh.SetUV(t, i);
            }
            break;
        case TRI_FACELIST:
            ReadFaceList(chunk, mesh);
            break;
        case TRI_MATRIX:
           {
              for (int i = 0; i < 4; i++)
                 for (int j = 0; j < 3; j++)
                    m.m[i][j] = ReadFloat();

               m.m[0][3] = 0.0f;
               m.m[1][3] = 0.0f;
               m.m[2][3] = 0.0f;
               m.m[3][3] = 1.0f;

               mesh.SetMatrix(m);
           }
            break;
        default:
            break;
        }
        SkipChunk(chunk);
        if (chunk.end >= parent.end)
            break;
        chunk = ReadChunk();
    }
    m_meshes.push_back(mesh);
}

void L3DS::ReadFaceList(const LChunk &chunk, LMesh &mesh)
{
    // variables 
    unsigned short count, t;    
    uint i;
    LTri tri;
    LChunk ch;
    char str[20];
    //uint mat;

    // consistency checks
    if (chunk.id != TRI_FACELIST)
    {
        ErrorMsg("L3DS::ReadFaceList - internal error: wrong chunk passed as parameter");
        return;
    }
    GotoChunk(chunk);
    tri.smoothingGroups = 1;
    // read the number of faces
    count = ReadShort();
    mesh.SetTriangleArraySize(count);
    for (i=0; i<count; i++)
    {
        tri.a = ReadShort();
        tri.b = ReadShort();
        tri.c = ReadShort();
        ReadShort();
        mesh.SetTri(tri, i);
    }
    // now read the optional chunks
    ch = ReadChunk();
    while (ch.end <= chunk.end)
    {
        switch (ch.id)
        {
        case TRI_MAT_GROUP: {
               ReadASCIIZ(str, 20);
               int mat_id = FindMaterial(str)->GetID();
               mesh.AddMaterial(mat_id);
               count = ReadShort();
               for (i=0; i<count; i++) {
                   t = ReadShort();
                   mesh.GetTri(t).materialId = mat_id;
               }
            }
            break;

        case TRI_SMOOTH_GROUP:
            for (i=0; i<mesh.GetTriangleCount(); i++)
                mesh.GetTri(i).smoothingGroups = (ulong) ReadInt();
            break;
        }
        SkipChunk(ch);
        ch = ReadChunk();
    }
}

void L3DS::ReadMaterial(const LChunk &parent)
{
    // variables
    LChunk chunk;
    LChunk child;
    char str[30];
    LMaterial mat;
    short sh;

    GotoChunk(parent);

    chunk = ReadChunk();
    while (chunk.end <= parent.end)
    {
        switch (chunk.id)
        {
        case MAT_NAME:
            ReadASCIIZ(str, 30);
            mat.SetName(str);
            break;
        case MAT_AMBIENT:
            child = ReadChunk();
            mat.SetAmbientColor(ReadColor(child));
            break;
        case MAT_DIFFUSE:
            child = ReadChunk();
            mat.SetDiffuseColor(ReadColor(child));
            break;
        case MAT_SPECULAR:
            child = ReadChunk();
            mat.SetSpecularColor(ReadColor(child));
            break;
        case MAT_SHININESS:
            child = ReadChunk();
            mat.SetShininess(ReadPercentage(child));
            break;
        case MAT_TRANSPARENCY:
            child = ReadChunk();
            mat.SetTransparency(ReadPercentage(child));
            break;
        case MAT_SHADING:
            sh = ReadShort();
            switch (sh)
            {
            case 0:
                mat.SetShadingType(sWireframe);
                break;
            case 1:
                mat.SetShadingType(sFlat);
                break;
            case 2:
                mat.SetShadingType(sGouraud);
                break;
            case 3:
                mat.SetShadingType(sPhong);
                break;
            case 4:
                mat.SetShadingType(sMetal);
                break;
            }
            break;
        case MAT_WIRE:
            mat.SetShadingType(sWireframe);
            break;
        case MAT_TEXMAP:
            ReadMap(chunk, mat.GetTextureMap1());
            break;
        case MAT_TEX2MAP:
            ReadMap(chunk, mat.GetTextureMap2());
            break;
        case MAT_OPACMAP:
            ReadMap(chunk, mat.GetOpacityMap());
            break;
        case MAT_BUMPMAP:
            ReadMap(chunk, mat.GetBumpMap());
            break;
        case MAT_SPECMAP:
            ReadMap(chunk, mat.GetSpecularMap());
            break;
        case MAT_REFLMAP:
            child = ReadChunk();
            mat.GetReflectionMap().strength = ReadPercentage(child);
            SkipChunk(child);
            child = ReadChunk();
            if (child.id != MAT_MAPNAME)
            {
                ErrorMsg("L3DS::ReadMaterial - error, expected chunk not found");
                return;
            }
            ReadASCIIZ(str, 30);
            if (strcmp(str, "") == 0)
                strcpy(mat.GetReflectionMap().mapName, "auto");
            break;
        }
        
        SkipChunk(chunk);
        chunk = ReadChunk();
    }
    m_materials.push_back(mat);
    m_materials[m_materials.size()-1].SetID(m_materials.size()-1);
}

void L3DS::ReadMap(const LChunk &chunk, LMap& map)
{
    LChunk child;
    char str[20];
    GotoChunk(chunk);
    child = ReadChunk();
    while (child.end <= chunk.end)
    {
        switch (child.id)
        {
        case INT_PERCENTAGE:
            map.strength = ReadPercentage(child);
            break;
        case MAT_MAPNAME:
            ReadASCIIZ(str, 20);
            strcpy(map.mapName, str);
            break;
        case MAT_MAP_USCALE:
            map.uScale = ReadFloat();
            break;
        case MAT_MAP_VSCALE:
            map.vScale = ReadFloat();
            break;
        case MAT_MAP_UOFFSET:
            map.uOffset = ReadFloat();
            break;
        case MAT_MAP_VOFFSET:
            map.vOffset = ReadFloat();
            break;
        case MAT_MAP_ANG:
            map.angle = ReadFloat();
            break;
        }
        SkipChunk(child);
        child = ReadChunk();
    }
}

void L3DS::ReadKeyframeData(const LChunk &parent)
{
    uint frames = 0;

    LChunk node_hdr;
    node_hdr.id = NODE_HDR;

    char str[20];
    LMesh *mesh;
    
    GotoChunk(parent);
    if (!FindChunk(node_hdr, parent))
        return;
    GotoChunk(node_hdr);
    ReadASCIIZ(str, 19);
    mesh = FindMesh(str);
    if (mesh == 0)
        return;
    GotoChunk(parent);

    // read the pivot
    LVector3 pivot = zero3;

    LChunk pivotchunk;
    pivotchunk.id = PIVOT;
    if (FindChunk(pivotchunk, parent))
    {
        GotoChunk(pivotchunk);
        pivot.x = ReadFloat();
        pivot.y = ReadFloat();
        pivot.z = ReadFloat();
    }
    GotoChunk(parent);

    // read frame 0 from the position track
    LVector3 pos = zero3;

    frames = 0;

    LChunk poschunk;
    poschunk.id = POS_TRACK_TAG;
    if (FindChunk(poschunk, parent))
    {
        GotoChunk(poschunk);
        // read the trackheader structure
        ReadShort();
        ReadInt();
        ReadInt();
        frames = ReadInt();
        if (frames > 0)
        {
            ReadKeyheader();
            pos.x = ReadFloat();
            pos.y = ReadFloat();
            pos.z = ReadFloat();
        }
    }
    GotoChunk(parent);

    // now read the rotation track
    LVector4 rot = zero4;

    LChunk rotchunk;
    rotchunk.id = ROT_TRACK_TAG;

    frames = 0;
    if (FindChunk(rotchunk, parent))
    {
        GotoChunk(rotchunk);
        // read the trackheader structure
        ReadShort();
        ReadInt();
        ReadInt();
        frames = ReadInt();
        if (frames > 0)
        {
            ReadKeyheader();
            rot.x = ReadFloat();
            rot.y = ReadFloat();
            rot.z = ReadFloat();
            rot.w = ReadFloat();
        }
    }
    GotoChunk(parent);

    // now read the scaling chunk
    LVector3 scale;
    scale.x = 1;
    scale.y = 1;
    scale.z = 1;

    LChunk scalechunk;
    scalechunk.id = SCL_TRACK_TAG;

    frames = 0;

    if (FindChunk(scalechunk, parent))
    {
        GotoChunk(scalechunk);
        // read the trackheader structure
        ReadShort();
        ReadInt();
        ReadInt();
        frames = ReadInt();
        if (frames > 0)
        {
            ReadKeyheader();
            scale.x = ReadFloat();
            scale.y = ReadFloat();
            scale.z = ReadFloat();
        }
    }
    GotoChunk(parent);


}

long L3DS::ReadKeyheader()
{
    long frame;
    frame = ReadInt();
    short opts = ReadShort();
    if (opts & 32768) // 32768 is 1000000000000000 binary
    {  // tension is present
        ReadFloat();
    }
    if (opts & 16384) // 16384 is 0100000000000000 binary
    {  // continuity is present
        ReadFloat();
    }
    if (opts & 8192)
    {  // bias info present
        ReadFloat();
    }
    if (opts & 4096)
    {  // "ease to" present
        ReadFloat();
    }
    if (opts & 2048)
    {  // "ease from" present
        ReadFloat();
    }
    return frame;
}