/*  Starshatter OpenSource Distribution
    Copyright (c) 1997-2004, Destroyer Studios LLC.
    All Rights Reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    * Neither the name "Destroyer Studios" nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    SUBSYSTEM:    Magic.exe
    FILE:         ModelFileMAG.cpp
    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    File loader for MAG format models
*/

#include "stdafx.h"
#include "Magic.h"
#include "MagicDoc.h"
#include "ModelFileMAG.h"

#include "Bitmap.h"
#include "Polygon.h"
#include "List.h"

// +--------------------------------------------------------------------+

struct MaterialMag6 {
   char        name[Material::NAMELEN];
   char        shader[Material::NAMELEN];
   float       power;      // highlight sharpness (big=shiny)
   float       brilliance; // diffuse power function
   float       bump;       // bump level (0=none)
   DWORD       blend;      // alpha blend type
   bool        shadow;     // material casts shadow
   bool        luminous;   // verts have their own lighting

   Color       ambient_color;
   Color       diffuse_color;
   Color       specular_color;
   Color       emissive_color;

   float       ambient_value;
   float       diffuse_value;
   float       specular_value;
   float       emissive_value;

   BYTE        tex_diffuse;
   BYTE        tex_specular;
   BYTE        tex_bumpmap;
   BYTE        tex_emissive;
};

// +--------------------------------------------------------------------+

ModelFileMAG::ModelFileMAG(const char* fname)
   : ModelFile(fname)
{
}

ModelFileMAG::~ModelFileMAG()
{
}

// +--------------------------------------------------------------------+

bool
ModelFileMAG::Load(Model* m, double scale)
{
   if (m && scale > 0 && strlen(filename) > 0) {
      ModelFile::Load(m, scale);

      bool        result = false;
      FILE*       fp     = fopen(filename, "rb");

      // check MAG file:
      if (!fp) {
         ::MessageBox(0, "File Open Failed:\nMagic could not open the requested file.", "ERROR", MB_OK);
         return result;
      }

      ZeroMemory(pname, 64);
      strncpy(pname, filename, 63);

      char file_id[5];
      fread(file_id, 4, 1, fp);
      file_id[4] = '\0';
      int version = 1;

      if (!strcmp(file_id, "MAG6")) {
         version = 6;
      }
      else if (!strcmp(file_id, "MAG5")) {
         version = 5;
      }
      else if (!strcmp(file_id, "MAG4")) {
         version = 4;
      }
      else {
         ::MessageBox(0, "File Open Failed:\nThe requested file uses an invalid format.", "ERROR", MB_OK);
         fclose(fp);
         return result;
      }

      // get ready to load, delete existing model:
      m->GetSurfaces().destroy();
      m->GetMaterials().destroy();
      *pnverts   = 0;
      *pnpolys   = 0;

      // now load the model:
      switch (version) {
      case 4:
      case 5:
         result = LoadMag5(fp, m, scale);
         break;

      case 6:
         result = LoadMag6(fp, m, scale);
         break;

      default:
         break;
      }

      fclose(fp);
      return true;
   }

   return false;
}

// +--------------------------------------------------------------------+

bool
ModelFileMAG::Save(Model* m)
{
   if (m) {
      ModelFile::Save(m);

      FILE* fp = fopen(filename, "wb");
      if (!fp) {
         ::MessageBox(0, "Save Failed:\nMagic could not open the file for writing.", "ERROR", MB_OK);
         return FALSE;
      }

      fwrite("MAG6", 4, 1, fp);

      int            i      = 0;
      int            ntex   = 0;
      int            nmtls  = 0;
      int            nsurfs = m->NumSurfaces();
      List<Bitmap>   textures;

      ListIter<Material> m_iter = m->GetMaterials();
      while (++m_iter) {
         Material* mtl = m_iter.value();
         Bitmap*   bmp = mtl->tex_diffuse;

         if (bmp && !textures.contains(bmp)) {
            textures.append(bmp);
         }

         bmp = mtl->tex_specular;

         if (bmp && !textures.contains(bmp)) {
            textures.append(bmp);
         }

         bmp = mtl->tex_emissive;

         if (bmp && !textures.contains(bmp)) {
            textures.append(bmp);
         }

         bmp = mtl->tex_bumpmap;

         if (bmp && !textures.contains(bmp)) {
            textures.append(bmp);
         }

         nmtls++;
      }

      ListIter<Bitmap> t_iter = textures;
      while (++t_iter) {
         Bitmap* bmp = t_iter.value();
         ntex += strlen(bmp->GetFilename()) + 1;
      }

      nsurfs = m->GetSurfaces().size();

      fwrite(&ntex,   4, 1, fp);
      fwrite(&nmtls,  4, 1, fp);
      fwrite(&nsurfs, 4, 1, fp);

      if (ntex) {
         t_iter.reset();
         while (++t_iter) {
            Bitmap* bmp = t_iter.value();

            fwrite(bmp->GetFilename(),
                   strlen(bmp->GetFilename()) + 1,
                   1,
                   fp);
         }
      }

      if (nmtls) {
         m_iter.reset();
         while (++m_iter) {
            Material*      mtl = m_iter.value();
            MaterialMag6   m6;

            ZeroMemory(&m6, sizeof(m6));

            CopyMemory(m6.name,   mtl->name,   Material::NAMELEN);
            CopyMemory(m6.shader, mtl->shader, Material::NAMELEN);

            m6.ambient_value  = mtl->ambient_value;
            m6.ambient_color  = mtl->ambient_color;
            m6.diffuse_value  = mtl->diffuse_value;
            m6.diffuse_color  = mtl->diffuse_color;
            m6.specular_value = mtl->specular_value;
            m6.specular_color = mtl->specular_color;
            m6.emissive_value = mtl->emissive_value;
            m6.emissive_color = mtl->emissive_color;

            m6.power          = mtl->power;
            m6.brilliance     = mtl->brilliance;
            m6.bump           = mtl->bump;
            m6.blend          = mtl->blend;
            m6.shadow         = mtl->shadow;
            m6.luminous       = mtl->luminous;

            if (mtl->tex_diffuse)
               m6.tex_diffuse  = textures.index(mtl->tex_diffuse) + 1;

            if (mtl->tex_specular)
               m6.tex_specular = textures.index(mtl->tex_specular) + 1;

            if (mtl->tex_emissive)
               m6.tex_emissive = textures.index(mtl->tex_emissive) + 1;

            if (mtl->tex_bumpmap)
               m6.tex_bumpmap  = textures.index(mtl->tex_bumpmap) + 1;

            fwrite(&m6, sizeof(m6), 1, fp);
         }
      }

      ListIter<Surface> s_iter = m->GetSurfaces();
      while (++s_iter) {
         Surface* s = s_iter.value();

         int   nverts  = s->NumVerts();
         int   npolys  = s->NumPolys();
         BYTE  namelen = strlen(s->Name()) + 1;

         fwrite(&nverts,   4, 1,       fp);
         fwrite(&npolys,   4, 1,       fp);
         fwrite(&namelen,  1, 1,       fp);
         fwrite(s->Name(), 1, namelen, fp);

         VertexSet*  vset  = s->GetVertexSet();
         Poly*       polys = s->GetPolys();

         // write vertex set:
         for (int v = 0; v < nverts; v++) {
            fwrite(&vset->loc[v],         sizeof(float), 3, fp);
            fwrite(&vset->nrm[v],         sizeof(float), 3, fp);
            fwrite(&vset->tu[v],          sizeof(float), 1, fp);
            fwrite(&vset->tv[v],          sizeof(float), 1, fp);
         }

         // write polys:
         for (int n = 0; n < npolys; n++) {
            Poly& poly           = polys[n];
            BYTE  poly_nverts    = (BYTE) poly.nverts;
            BYTE  material_index = 0;
            WORD  poly_verts[8];

            m_iter.reset();
            while (++m_iter && !material_index) {
               if (poly.material == m_iter.value())
                  material_index = m_iter.index() + 1;
            }

            for (int i = 0; i < poly_nverts; i++) {
               poly_verts[i] = poly.verts[i];
            }

            fwrite(&poly_nverts,      sizeof(BYTE),  1, fp);
            fwrite(&material_index,   sizeof(BYTE),  1, fp);
            fwrite(&poly_verts[0],    sizeof(WORD),  poly_nverts, fp);
         }
      }

      return true;
   }

   return false;
}

// +--------------------------------------------------------------------+

struct HomogenousPlane
{
   double distance;
   double normal_x;
   double normal_y;
   double normal_z;
   double normal_w;
};

static void LoadPlane(Plane& p, FILE* fp)
{
   HomogenousPlane tmp;
   fread(&tmp, sizeof(HomogenousPlane), 1, fp);
}

static void LoadFlags(LPDWORD flags, FILE* fp)
{
   DWORD magic_flags;
   fread(&magic_flags, sizeof(DWORD), 1, fp);

   /** MAGIC FLAGS
   enum { FLAT_SHADED =   1,
          LUMINOUS    =   2,
          TRANSLUCENT =   4,  \\ must swap
          CHROMAKEY   =   8,  // these two
          FOREGROUND  =  16,  -- not used
          WIREFRAME   =  32,  -- not used
          SPECULAR1   =  64,
          SPECULAR2   = 128  };
   ***/

   const DWORD magic_mask = 0x0fc3;

   *flags = magic_flags & magic_mask;
}

// +--------------------------------------------------------------------+

static int mcomp(const void* a, const void* b)
{
   Poly* pa = (Poly*) a;
   Poly* pb = (Poly*) b;

   if (pa->sortval == pb->sortval)
      return 0;

   if (pa->sortval < pb->sortval)
      return -1;

   return 1;
}

bool
ModelFileMAG::LoadMag5(FILE* fp, Model* m, double scale)
{
   bool        result = false;
   int         ntex   = 0;
   int         nsurfs = 0;
   double      radius = 0;

   fread(&ntex,   sizeof(ntex),   1, fp);
   fread(&nsurfs, sizeof(nsurfs), 1, fp);

   // create a default gray material:
   Material*   mtl = new Material;

   if (mtl) {
      mtl->Ka = Color::DarkGray;
      mtl->Kd = Color::LightGray;
      mtl->Ks = ColorValue(0.1f,0.1f,0.1f);
      mtl->power = 10.0f;

      mtl->ambient_value  = 0.2f;
      mtl->ambient_color  = Color::DarkGray;
      mtl->diffuse_value  = 0.8f;
      mtl->diffuse_color  = Color::LightGray;
      mtl->specular_value = 0.5f;
      mtl->specular_color = Color::White;
      strcpy_s(mtl->name, "(default)");

      m->GetMaterials().append(mtl);
   }

   // read texture list:
   for (int i = 0; i < ntex; i++) {
      Material*   mtl = new Material;
      char        tname[32];

      if (mtl) {
         mtl->Ka = ColorValue(0.5f,0.5f,0.5f);
         mtl->Kd = ColorValue(1.0f,1.0f,1.0f);
         mtl->Ks = ColorValue(0.2f,0.2f,0.2f);
         mtl->power = 20.0f;

         mtl->ambient_value  = 1.0f;
         mtl->ambient_color  = Color::Gray;
         mtl->diffuse_value  = 1.0f;
         mtl->diffuse_color  = Color::White;
         mtl->specular_value = 0.2f;
         mtl->specular_color = Color::White;

         fread(tname, 32, 1, fp);
         LoadTexture(tname, mtl->tex_diffuse, Bitmap::BMP_SOLID);
         strcpy_s(mtl->name, tname);

         char* dot = strrchr(mtl->name, '.');
         if (dot)
            *dot = 0;

         char* plus = strrchr(mtl->name, '+');
         if (plus)
            *plus = 0;

         m->GetMaterials().append(mtl);
      }
   }

   int nverts = 0;
   int npolys = 0;

   fread(&nverts, 4, 1, fp);
   fread(&npolys, 4, 1, fp);

   // plan on creating four verts per poly:
   int mag_nverts = nverts;
   int next_vert  = nverts;

   nverts            = npolys * 4;
   Surface*    s     = new Surface;
   VertexSet*  vset  = 0;
   Poly*       polys = 0;

   if (s) {
      s->SetName("default");
      s->CreateVerts(nverts);
      s->CreatePolys(npolys);

      vset  = s->GetVertexSet();
      polys = s->GetPolys();

      ZeroMemory(vset->loc,      nverts * sizeof(Vec3));
      ZeroMemory(vset->diffuse,  nverts * sizeof(DWORD));
      ZeroMemory(vset->specular, nverts * sizeof(DWORD));
      ZeroMemory(vset->tu,       nverts * sizeof(float));
      ZeroMemory(vset->tv,       nverts * sizeof(float));
      ZeroMemory(vset->rw,       nverts * sizeof(float));

      // read vertex set:
      int v;
      for (v = 0; v < mag_nverts; v++) {
         Vec3 vert, norm;
         DWORD vstate;

         fread(&vert,    sizeof(Vec3), 1, fp);
         fread(&norm,    sizeof(Vec3), 1, fp);
         fread(&vstate,  sizeof(DWORD), 1, fp);

         vert.SwapYZ();
         vert *= (float) scale;

         norm.SwapYZ();

         vset->loc[v]      = vert;
         vset->nrm[v]      = norm;

         double d = vert.length();
         if (d > radius)
            radius = (float) d;
      }

      while (v < nverts)
         vset->nrm[v++] = Vec3(1,0,0);

      // read polys:
      Vec3  dummy_center;
      DWORD dummy_flags;
      DWORD dummy_color;
      int   texture_num;
      int   poly_nverts;
      int   vert_index_buffer[32];
      float texture_index_buffer[32];

      for (int n = 0; n < npolys; n++) {
         Poly& poly = polys[n];
         poly.vertex_set  = vset;

         fread(&dummy_flags,   sizeof(DWORD), 1, fp);
         fread(&dummy_center,  sizeof(Vec3),  1, fp);
         LoadPlane(poly.plane, fp);
         fread(&dummy_color,   sizeof(DWORD), 1, fp);
         fread(&texture_num,   sizeof(int),   1, fp);

         if (texture_num >= 0 && texture_num < ntex) {
            texture_num++;

            poly.material = m->GetMaterials()[texture_num];
            poly.sortval  = texture_num;

            if (dummy_flags & 2) { // luminous
               Material* mtl = m->GetMaterials()[texture_num];

               mtl->ambient_value  = 0.0f;
               mtl->ambient_color  = Color::Black;
               mtl->diffuse_value  = 0.0f;
               mtl->diffuse_color  = Color::Black;
               mtl->specular_value = 0.0f;
               mtl->specular_color = Color::Black;
               mtl->emissive_value = 1.0f;
               mtl->emissive_color = Color::White;

               mtl->Ka = ColorValue(0,0,0,0);
               mtl->Kd = ColorValue(0,0,0,0);
               mtl->Ks = ColorValue(0,0,0,0);
               mtl->Ke = ColorValue(1,1,1,1);

               mtl->tex_emissive = mtl->tex_diffuse;
            }
         }
         else {
            poly.material = m->GetMaterials().first(); // default material
            poly.sortval  = 1000;
         }

         // hack: store flat shaded flag in unused visible byte
         poly.visible = (BYTE) (dummy_flags & 1);

         fread(&poly_nverts,           sizeof(int),   1, fp);
         fread(vert_index_buffer,      sizeof(int),   poly_nverts, fp);

         if (poly_nverts == 3)
            s->AddIndices(3);

         else if (poly_nverts == 4)
            s->AddIndices(6);

         poly.nverts = poly_nverts;
         for (int vi = 0; vi < poly_nverts; vi++) {
            int v = vert_index_buffer[vi];

            if (vset->rw[v] > 0) {
               vset->CopyVertex(next_vert, v);
               v = next_vert++;
            }

            vset->rw[v] = 1;
            poly.verts[vi] = v;
         }
      
         fread(texture_index_buffer, sizeof(float), poly_nverts, fp); // tu's
         for (int vi = 0; vi < poly_nverts; vi++) {
            int v = poly.verts[vi];
            vset->tu[v] = texture_index_buffer[vi];
         }

         fread(texture_index_buffer, sizeof(float), poly_nverts, fp); // tv's
         for (int vi = 0; vi < poly_nverts; vi++) {
            int v = poly.verts[vi];
            vset->tv[v] = texture_index_buffer[vi];
         }

         DWORD unused[32];
         fread(unused, 16, 1, fp);
      }

      // pass 2 (adjust vertex normals for flat polys):
      for (int n = 0; n < npolys; n++) {
         Poly& poly = polys[n];

         poly.plane = Plane(vset->loc[poly.verts[0]],
                            vset->loc[poly.verts[2]],
                            vset->loc[poly.verts[1]]);

         // hack: retrieve flat shaded flag from unused visible byte
         if (poly.visible) {
            int poly_nverts = poly.nverts;

            for (int vi = 0; vi < poly_nverts; vi++) {
               int v = poly.verts[vi];
               vset->nrm[v] = poly.plane.normal;
            }
         }
      }

      // sort the polys by material index:
      qsort((void*) polys, npolys, sizeof(Poly), mcomp);

      // then assign them to cohesive segments:
      Segment* segment = 0;

      for (int n = 0; n < npolys; n++) {
         if (segment && segment->material == polys[n].material) {
            segment->npolys++;
         }
         else {
            segment = 0;
         }

         if (!segment) {
            segment = new Segment;

            segment->npolys   = 1;
            segment->polys    = &polys[n];
            segment->material = segment->polys->material;

            s->GetSegments().append(segment);
         }
      }

      s->BuildHull();
      m->GetSurfaces().append(s);

      *pnverts = nverts;
      *pnpolys = npolys;
      *pradius = (float) radius;

      result = nverts && npolys;
   }

   return result;
}

// +--------------------------------------------------------------------+

bool
ModelFileMAG::LoadMag6(FILE* fp, Model* m, double scale)
{
   bool           result = false;
   int            i      = 0;
   int            ntex   = 0;
   int            nmtls  = 0;
   int            nsurfs = 0;
   double         radius = 0;
   List<Bitmap>   textures;

   fread(&ntex,   sizeof(ntex),   1, fp); // size of texture block
   fread(&nmtls,  sizeof(nmtls),  1, fp); // number of materials
   fread(&nsurfs, sizeof(nsurfs), 1, fp); // number of surfaces

   // read texture list:
   if (ntex) {
      char*          buffer      = new char[ntex];
      char*          p           = buffer;
      Bitmap*        bmp         = 0;

      fread(buffer, ntex, 1, fp);

      while (p < buffer + ntex) {
         LoadTexture(p, bmp, Bitmap::BMP_SOLID);
         textures.append(bmp);

         p += strlen(p) + 1;
      }

      delete [] buffer;
   }

   for (i = 0; i < nmtls; i++) {
      MaterialMag6   m6;
      Material*      mtl = new Material;

      fread(&m6, sizeof(m6), 1, fp);

      if (mtl) {
         CopyMemory(mtl->name,   m6.name,   Material::NAMELEN);
         CopyMemory(mtl->shader, m6.shader, Material::NAMELEN);

         mtl->ambient_value   = m6.ambient_value;
         mtl->ambient_color   = m6.ambient_color;
         mtl->diffuse_value   = m6.diffuse_value;
         mtl->diffuse_color   = m6.diffuse_color;
         mtl->specular_value  = m6.specular_value;
         mtl->specular_color  = m6.specular_color;
         mtl->emissive_value  = m6.emissive_value;
         mtl->emissive_color  = m6.emissive_color;

         mtl->Ka = ColorValue(mtl->ambient_color)  * mtl->ambient_value;
         mtl->Kd = ColorValue(mtl->diffuse_color)  * mtl->diffuse_value;
         mtl->Ks = ColorValue(mtl->specular_color) * mtl->specular_value;
         mtl->Ke = ColorValue(mtl->emissive_color) * mtl->emissive_value;

         mtl->power           = m6.power;
         mtl->brilliance      = m6.brilliance;
         mtl->bump            = m6.bump;
         mtl->blend           = m6.blend;
         mtl->shadow          = m6.shadow;
         mtl->luminous        = m6.luminous;

         if (m6.tex_diffuse && m6.tex_diffuse <= textures.size())
            mtl->tex_diffuse = textures[m6.tex_diffuse - 1];

         if (m6.tex_specular && m6.tex_specular <= textures.size())
            mtl->tex_specular = textures[m6.tex_specular - 1];

         if (m6.tex_emissive && m6.tex_emissive <= textures.size())
            mtl->tex_emissive = textures[m6.tex_emissive - 1];

         if (m6.tex_bumpmap && m6.tex_bumpmap <= textures.size())
            mtl->tex_bumpmap = textures[m6.tex_bumpmap - 1];

         m->GetMaterials().append(mtl);
      }
   }

   for (i = 0; i < nsurfs; i++) {
      int   nverts  = 0;
      int   npolys  = 0;
      BYTE  namelen = 0;
      char  name[128];

      fread(&nverts,  4, 1,       fp);
      fread(&npolys,  4, 1,       fp);
      fread(&namelen, 1, 1,       fp);
      fread(name,     1, namelen, fp);

      Surface* surface = new Surface;
      surface->SetName(name);
      surface->CreateVerts(nverts);
      surface->CreatePolys(npolys);

      VertexSet*  vset  = surface->GetVertexSet();
      Poly*       polys = surface->GetPolys();

      ZeroMemory(polys, sizeof(Poly) * npolys);

      // read vertex set:
      for (int v = 0; v < nverts; v++) {
         fread(&vset->loc[v],         sizeof(float), 3, fp);
         fread(&vset->nrm[v],         sizeof(float), 3, fp);
         fread(&vset->tu[v],          sizeof(float), 1, fp);
         fread(&vset->tv[v],          sizeof(float), 1, fp);

         double d = vset->loc[v].length();
         if (d > radius)
            radius = d;
      }

      // read polys:
      for (int n = 0; n < npolys; n++) {
         Poly& poly           = polys[n];
         BYTE  poly_nverts    = 0;
         BYTE  material_index = 0;
         WORD  poly_verts[8];

         fread(&poly_nverts,      sizeof(BYTE),  1, fp);
         fread(&material_index,   sizeof(BYTE),  1, fp);
         fread(&poly_verts[0],    sizeof(WORD),  poly_nverts, fp);

         if (poly_nverts >= 3) {
            poly.nverts = poly_nverts;

            for (int i = 0; i < poly_nverts; i++) {
               poly.verts[i] = poly_verts[i];
            }
         }
         else {
            poly.sortval = 666;
         }

         if (material_index > 0) {
            poly.material = m->GetMaterials()[material_index-1];
            poly.sortval  = material_index;
         }
         else if (m->NumMaterials()) {
            poly.material = m->GetMaterials().first();
            poly.sortval  = 1;
         }
         else {
            poly.sortval  = 1000;
         }

         if (poly.nverts == 3)
            surface->AddIndices(3);

         else if (poly.nverts == 4)
            surface->AddIndices(6);

         poly.vertex_set = vset;
         poly.plane = Plane(vset->loc[poly.verts[0]],
                            vset->loc[poly.verts[2]],
                            vset->loc[poly.verts[1]]);
      }

      // sort the polys by material index:
      qsort((void*) polys, npolys, sizeof(Poly), mcomp);

      // then assign them to cohesive segments:
      Segment* segment = 0;

      for (int n = 0; n < npolys; n++) {
         if (segment && segment->material == polys[n].material) {
            segment->npolys++;
         }
         else {
            segment = 0;
         }

         if (!segment) {
            segment = new Segment;

            segment->npolys   = 1;
            segment->polys    = &polys[n];
            segment->material = segment->polys->material;

            surface->GetSegments().append(segment);
         }
      }

      surface->ComputeTangents();
      surface->BuildHull();
      m->GetSurfaces().append(surface);

      *pnverts = nverts;
      *pnpolys = npolys;
      *pradius = (float) radius;

      result = nverts && npolys;
   }

   return result;
}