/*
* The 3D Studio File Format Library
* Copyright (C) 1996-2007 by Jan Eric Kyprianidis <www.lib3ds.org>
* All rights reserved.
*
* This program 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.
*
* 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 Lesser General Public  
* License for more details.
*
* You should  have received  a copy of the GNU Lesser General Public License
* along with  this program;  if not, write to the  Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: 3dsplay.c,v 1.14 2007/06/18 06:51:53 jeh Exp $
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <lib3ds/file.h>
#include <lib3ds/camera.h>
#include <lib3ds/mesh.h>
#include <lib3ds/node.h>
#include <lib3ds/material.h>
#include <lib3ds/matrix.h>
#include <lib3ds/vector.h>
#include <lib3ds/light.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

// OS X has a different path than everyone else
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#ifdef	USE_SDL
#include <SDL_image.h>
#endif




#define	MOUSE_SCALE	.1	/* degrees/pixel movement */

/*!
\example player.c

Previews a <i>3DS</i> file using OpenGL.

\code
Syntax: player filename
\endcode

\warning To compile this program you must have OpenGL and glut installed.
*/


typedef	enum {ROTATING, WALKING} RunMode;

static	RunMode runMode = ROTATING;

static const char* filepath=NULL;
static char datapath[256];
static char filename[256];
static int dbuf=1;
static int halt=0;
static int flush=0;
static int anti_alias=1;

static const char* camera=0;
static Lib3dsFile *file=0;
static float current_frame=0.0;
static int gl_width;
static int gl_height;
static int menu_id=0;
static int show_object=1;
static int show_bounds=0;
static int rotating = 0;
static int show_cameras = 0;
static int show_lights = 0;

static int cameraList, lightList;	/* Icon display lists */

static Lib3dsVector bmin, bmax;
static float	sx, sy, sz, size;	/* bounding box dimensions */
static float	cx, cy, cz;		/* bounding box center */

static	float	view_rotx = 0., view_roty = 0., view_rotz = 0.;
static	float	anim_rotz = 0.;

static	int	mx, my;

static const GLfloat white[4] = {1.,1.,1.,1.};
static const GLfloat dgrey[4] = {.25,.25,.25,1.};
static const GLfloat grey[4] = {.5,.5,.5,1.};
static const GLfloat lgrey[4] = {.75,.75,.75,1.};
static const GLfloat black[] = {0.,0.,0.,1.};
static const GLfloat red[4] = {1.,0.,0.,1.};
static const GLfloat green[4] = {0.,1.,0.,1.};
static const GLfloat blue[4] = {0.,0.,1.,1.};


static	void	solidBox(double bx, double by, double bz);
static	void	solidCylinder(double r, double h, int slices);
static	int	callback(void (*cb)(int m, int d, void *), void *client);
static	void	call_callback(int idx, int data);

static void solidBox(double bx, double by, double bz);
static void solidCylinder(double r, double h, int slices);
static const char *Basename(const char *filename);


// texture size: by now minimum standard
#define	TEX_XSIZE	1024
#define	TEX_YSIZE	1024

struct _player_texture
{
  int valid; // was the loading attempt successful ? 
#ifdef	USE_SDL
  SDL_Surface *bitmap;
#else
  void *bitmap;
#endif
  GLuint tex_id; //OpenGL texture ID
  float scale_x, scale_y; // scale the texcoords, as OpenGL thinks in TEX_XSIZE and TEX_YSIZE
};

typedef struct _player_texture Player_texture; 
Player_texture *pt; 
int tex_mode; // Texturing active ? 

#define	NA(a)	(sizeof(a)/sizeof(a[0]))

#ifndef	MIN
#define	MIN(a,b) ((a)<(b)?(a):(b))
#define	MAX(a,b) ((a)>(b)?(a):(b))
#endif




static	void
menu_cb(int value)
{
  call_callback(value, 0);
}


/*!
* Switch cameras based on user's menu choice.
*/
static void
camera_menu(int menu, int value, void *client)
{
  Lib3dsCamera *c = (Lib3dsCamera*)client;
  view_rotx = view_roty = view_rotz = anim_rotz = 0.;
  camera=c->name;
}


/*!
* Toggle an arbitrary int (bool) variable
*/
static	void
toggle_bool(int menu, int value, void *client)
{
  int *var = client;
  *var = !*var;
  glutPostRedisplay();
}



/*!
* Build the menu
*/
static void
build_menu()
{
  Lib3dsCamera *c;
  int i;
  menu_id=glutCreateMenu(menu_cb);

  for (c=file->cameras,i=0; c; c=c->next,++i)
    glutAddMenuEntry(c->name, callback(camera_menu, c));

  glutAddMenuEntry("Show cameras", callback(toggle_bool, &show_cameras));
  glutAddMenuEntry("Show lights", callback(toggle_bool, &show_lights));
  glutAddMenuEntry("Show bounds", callback(toggle_bool, &show_bounds));
}


/*!
* Time function, called every frame
*/
static	void
timer_cb(int value)
{
  glutPostRedisplay();

  if (!halt) {
    view_rotz += anim_rotz;
    current_frame+=1.0;
    if (current_frame>file->frames) {
      current_frame=0;
    }
    lib3ds_file_eval(file, current_frame);
    glutTimerFunc(10, timer_cb, 0);
  }
}

static	void
set_halt(int h)
{
  if( h != halt ) {
    halt = h;
    if( !halt )
      glutTimerFunc(10, timer_cb, 0);
  }
}



/*!
* Initialize OpenGL
*/
static void
init(void)
{
  glClearColor(0.5, 0.5, 0.5, 1.0);
  glShadeModel(GL_SMOOTH);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glDisable(GL_LIGHT1);
  glDepthFunc(GL_LEQUAL);
  glEnable(GL_DEPTH_TEST);
  glCullFace(GL_BACK);
  //glDisable(GL_NORMALIZE);
  //glPolygonOffset(1.0, 2);
}


/*!
* Load the model from .3ds file.
*/
static void
load_model(void)
{
  file=lib3ds_file_load(filepath);
  if (!file) {
    puts("3dsplayer: Error: Loading 3DS file failed.\n");
    exit(1);
  }

  /* No nodes?  Fabricate nodes to display all the meshes. */
  if( !file->nodes )
  {
    Lib3dsMesh *mesh;
    Lib3dsNode *node;

    for(mesh = file->meshes; mesh != NULL; mesh = mesh->next)
    {
      node = lib3ds_node_new_object();
      strcpy(node->name, mesh->name);
      node->parent_id = LIB3DS_NO_PARENT;
      lib3ds_file_insert_node(file, node);
    }
  }

  lib3ds_file_eval(file, 1.0f);
  lib3ds_file_bounding_box_of_nodes(file, LIB3DS_TRUE, LIB3DS_FALSE, LIB3DS_FALSE, bmin, bmax);
  sx = bmax[0] - bmin[0];
  sy = bmax[1] - bmin[1];
  sz = bmax[2] - bmin[2];
  size = MAX(sx, sy); size = MAX(size, sz);
  cx = (bmin[0] + bmax[0])/2;
  cy = (bmin[1] + bmax[1])/2;
  cz = (bmin[2] + bmax[2])/2;


  /* No cameras in the file?  Add four */

  if( !file->cameras ) {

    /* Add some cameras that encompass the bounding box */

    Lib3dsCamera *camera = lib3ds_camera_new("Camera_X");
    camera->target[0] = cx;
    camera->target[1] = cy;
    camera->target[2] = cz;
    memcpy(camera->position, camera->target, sizeof(camera->position));
    camera->position[0] = bmax[0] + 1.5 * MAX(sy,sz);
    camera->near_range = ( camera->position[0] - bmax[0] ) * .5;
    camera->far_range = ( camera->position[0] - bmin[0] ) * 2;
    lib3ds_file_insert_camera(file, camera);

    /* Since lib3ds considers +Y to be into the screen, we'll put
    * this camera on the -Y axis, looking in the +Y direction.
    */
    camera = lib3ds_camera_new("Camera_Y");
    camera->target[0] = cx;
    camera->target[1] = cy;
    camera->target[2] = cz;
    memcpy(camera->position, camera->target, sizeof(camera->position));
    camera->position[1] = bmin[1] - 1.5 * MAX(sx,sz);
    camera->near_range = ( bmin[1] - camera->position[1] ) * .5;
    camera->far_range = ( bmax[1] - camera->position[1] ) * 2;
    lib3ds_file_insert_camera(file, camera);

    camera = lib3ds_camera_new("Camera_Z");
    camera->target[0] = cx;
    camera->target[1] = cy;
    camera->target[2] = cz;
    memcpy(camera->position, camera->target, sizeof(camera->position));
    camera->position[2] = bmax[2] + 1.5 * MAX(sx,sy);
    camera->near_range = ( camera->position[2] - bmax[2] ) * .5;
    camera->far_range = ( camera->position[2] - bmin[2] ) * 2;
    lib3ds_file_insert_camera(file, camera);

    camera = lib3ds_camera_new("Camera_ISO");
    camera->target[0] = cx;
    camera->target[1] = cy;
    camera->target[2] = cz;
    memcpy(camera->position, camera->target, sizeof(camera->position));
    camera->position[0] = bmax[0] + .75 * size;
    camera->position[1] = bmin[1] - .75 * size;
    camera->position[2] = bmax[2] + .75 * size;
    camera->near_range = ( camera->position[0] - bmax[0] ) * .5;
    camera->far_range = ( camera->position[0] - bmin[0] ) * 3;
    lib3ds_file_insert_camera(file, camera);
  }


  /* No lights in the file?  Add some. */

  if (file->lights == NULL)
  {
    Lib3dsLight *light;

    light = lib3ds_light_new("light0");
    light->spot_light = 0;
    light->see_cone = 0;
    light->color[0] = light->color[1] = light->color[2] = .6;
    light->position[0] = cx + size * .75;
    light->position[1] = cy - size * 1.;
    light->position[2] = cz + size * 1.5;
    light->position[3] = 0.;
    light->outer_range = 100;
    light->inner_range = 10;
    light->multiplier = 1;
    lib3ds_file_insert_light(file, light);

    light = lib3ds_light_new("light1");
    light->spot_light = 0;
    light->see_cone = 0;
    light->color[0] = light->color[1] = light->color[2] = .3;
    light->position[0] = cx - size;
    light->position[1] = cy - size;
    light->position[2] = cz + size * .75;
    light->position[3] = 0.;
    light->outer_range = 100;
    light->inner_range = 10;
    light->multiplier = 1;
    lib3ds_file_insert_light(file, light);

    light = lib3ds_light_new("light2");
    light->spot_light = 0;
    light->see_cone = 0;
    light->color[0] = light->color[1] = light->color[2] = .3;
    light->position[0] = cx;
    light->position[1] = cy + size;
    light->position[2] = cz + size;
    light->position[3] = 0.;
    light->outer_range = 100;
    light->inner_range = 10;
    light->multiplier = 1;
    lib3ds_file_insert_light(file, light);

  }

  if (!file->cameras) {
    fputs("3dsplayer: Error: No Camera found.\n", stderr);
    lib3ds_file_free(file);
    file=0;
    exit(1);
  }
  if (!camera) {
    camera=file->cameras->name;
  }

  lib3ds_file_eval(file,0.);
}



#ifdef  USE_SDL
/**
* Convert an SDL bitmap for use with OpenGL.
*
* Written by Gernot < gz@lysator.liu.se >
*/
void *convert_to_RGB_Surface(SDL_Surface *bitmap)
{
  unsigned char *pixel = (unsigned char *)malloc(sizeof(char) * 4 * bitmap->h * bitmap->w); 
  int soff = 0;   
  int doff = 0;   
  int x, y;
  unsigned char *spixels = (unsigned char *)bitmap->pixels;
  SDL_Palette *pal = bitmap->format->palette; 

  for (y = 0; y < bitmap->h; y++)
    for (x = 0; x < bitmap->w; x++)
    {
      SDL_Color* col = &pal->colors[spixels[soff]];

      pixel[doff] = col->r; 
      pixel[doff+1] = col->g; 
      pixel[doff+2] = col->b; 
      pixel[doff+3] = 255; 
      doff += 4; 
      soff++;
    }

    return (void *)pixel; 
}
#endif




/*!
* Render node recursively, first children, then parent.
* Each node receives its own OpenGL display list.
*/
static void
render_node(Lib3dsNode *node)
{
  ASSERT(file);

  {
    Lib3dsNode *p;
    for (p=node->childs; p!=0; p=p->next) {
      render_node(p);
    }
  }
  if (node->type==LIB3DS_OBJECT_NODE) {
    Lib3dsMesh *mesh;

    if (strcmp(node->name,"$$$DUMMY")==0) {
      return;
    }

    mesh = lib3ds_file_mesh_by_name(file, node->data.object.morph);
    if( mesh == NULL )
      mesh = lib3ds_file_mesh_by_name(file, node->name);

    if (!mesh->user.d) {
      ASSERT(mesh);
      if (!mesh) {
        return;
      }

      mesh->user.d=glGenLists(1);
      glNewList(mesh->user.d, GL_COMPILE);

      {
        unsigned p;
        Lib3dsVector *normalL=malloc(3*sizeof(Lib3dsVector)*mesh->faces);
        Lib3dsMaterial *oldmat = (Lib3dsMaterial *)-1;
        {
          Lib3dsMatrix M;
          lib3ds_matrix_copy(M, mesh->matrix);
          lib3ds_matrix_inv(M);
          glMultMatrixf(&M[0][0]);
        }
        lib3ds_mesh_calculate_normals(mesh, normalL);

        for (p=0; p<mesh->faces; ++p) {
          Lib3dsFace *f=&mesh->faceL[p];
          Lib3dsMaterial *mat=0;
#ifdef	USE_SDL
          Player_texture *pt = NULL;
          int tex_mode = 0;
#endif
          if (f->material[0]) {
            mat=lib3ds_file_material_by_name(file, f->material);
          }

          if( mat != oldmat ) {
            if (mat) {
              if( mat->two_sided )
                glDisable(GL_CULL_FACE);
              else
                glEnable(GL_CULL_FACE);

              glDisable(GL_CULL_FACE);

              /* Texturing added by Gernot < gz@lysator.liu.se > */

              if (mat->texture1_map.name[0]) {		/* texture map? */
                Lib3dsTextureMap *tex = &mat->texture1_map;
                if (!tex->user.p) {		/* no player texture yet? */
                  char texname[1024];
                  pt = malloc(sizeof(*pt));
                  tex->user.p = pt;
                  //snprintf(texname, sizeof(texname), "%s/%s", datapath, tex->name);
                  strcpy(texname, datapath);
                  strcat(texname, "/");
                  strcat(texname, tex->name);
#ifdef	DEBUG
                  printf("Loading texture map, name %s\n", texname);
#endif	/* DEBUG */
#ifdef	USE_SDL
#ifdef  USE_SDL_IMG_load
                  pt->bitmap = IMG_load(texname);
#else
                  pt->bitmap = IMG_Load(texname);
#endif /* IMG_Load */

#else /* USE_SDL */
                  pt->bitmap = NULL;
                  fputs("3dsplayer: Warning: No image loading support, skipping texture.\n", stderr);
#endif /* USE_SDL */
                  if (pt->bitmap) {	/* could image be loaded ? */
                    /* this OpenGL texupload code is incomplete format-wise!
                    * to make it complete, examine SDL_surface->format and
                    * tell us @lib3ds.sf.net about your improvements :-)
                    */
                    int upload_format = GL_RED; /* safe choice, shows errors */
#ifdef USE_SDL
                    int bytespp = pt->bitmap->format->BytesPerPixel;
                    void *pixel = NULL;
                    glGenTextures(1, &pt->tex_id);
#ifdef	DEBUG
                    printf("Uploading texture to OpenGL, id %d, at %d bytepp\n",
                      pt->tex_id, bytespp);
#endif	/* DEBUG */
                    if (pt->bitmap->format->palette) {
                      pixel = convert_to_RGB_Surface(pt->bitmap);
                      upload_format = GL_RGBA;
                    }
                    else {
                      pixel = pt->bitmap->pixels;
                      /* e.g. this could also be a color palette */
                      if (bytespp == 1) upload_format = GL_LUMINANCE;
                      else if (bytespp == 3) upload_format = GL_RGB;
                      else if (bytespp == 4) upload_format = GL_RGBA;
                    }
                    glBindTexture(GL_TEXTURE_2D, pt->tex_id);
                    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
                      TEX_XSIZE, TEX_YSIZE, 0,
                      GL_RGBA, GL_UNSIGNED_BYTE, NULL);
                    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
                    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
                    glTexParameteri(GL_TEXTURE_2D,
                      GL_TEXTURE_MAG_FILTER, GL_LINEAR);
                    glTexParameteri(GL_TEXTURE_2D,
                      GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
                    glTexSubImage2D(GL_TEXTURE_2D,
                      0, 0, 0, pt->bitmap->w, pt->bitmap->h,
                      upload_format, GL_UNSIGNED_BYTE, pixel);
                    pt->scale_x = (float)pt->bitmap->w/(float)TEX_XSIZE;
                    pt->scale_y = (float)pt->bitmap->h/(float)TEX_YSIZE;
#endif /* USE_SDL */
                    pt->valid = 1;
                  }
                  else {
                    fprintf(stderr,
                      "Load of texture %s did not succeed "
                      "(format not supported !)\n",
                      texname);
                    pt->valid = 0;
                  }
                }
                else {
                  pt = (Player_texture *)tex->user.p;
                }
                tex_mode = pt->valid;
              }
              else {
                tex_mode = 0;
              }
              glMaterialfv(GL_FRONT, GL_AMBIENT, mat->ambient);
              glMaterialfv(GL_FRONT, GL_DIFFUSE, mat->diffuse);
              glMaterialfv(GL_FRONT, GL_SPECULAR, mat->specular);
              glMaterialf(GL_FRONT, GL_SHININESS, pow(2, 10.0*mat->shininess));
            }
            else {
              static const Lib3dsRgba a={0.7, 0.7, 0.7, 1.0};
              static const Lib3dsRgba d={0.7, 0.7, 0.7, 1.0};
              static const Lib3dsRgba s={1.0, 1.0, 1.0, 1.0};
              glMaterialfv(GL_FRONT, GL_AMBIENT, a);
              glMaterialfv(GL_FRONT, GL_DIFFUSE, d);
              glMaterialfv(GL_FRONT, GL_SPECULAR, s);
              glMaterialf(GL_FRONT, GL_SHININESS, pow(2, 10.0*0.5));
            }
            oldmat = mat;
          }

          else if (mat != NULL && mat->texture1_map.name[0]) {
            Lib3dsTextureMap *tex = &mat->texture1_map;
            if (tex != NULL && tex->user.p != NULL) {
              pt = (Player_texture *)tex->user.p;
              tex_mode = pt->valid;
            }
          }


          {
            int i;

            if (tex_mode) {
              //printf("Binding texture %d\n", pt->tex_id);
              glEnable(GL_TEXTURE_2D);
              glBindTexture(GL_TEXTURE_2D, pt->tex_id);
            }

            glBegin(GL_TRIANGLES);
            glNormal3fv(f->normal);
            for (i=0; i<3; ++i) {
              glNormal3fv(normalL[3*p+i]);

              if (tex_mode) {
                glTexCoord2f(mesh->texelL[f->points[i]][1]*pt->scale_x,
                  pt->scale_y - mesh->texelL[f->points[i]][0]*pt->scale_y);
              }

              glVertex3fv(mesh->pointL[f->points[i]].pos);
            }
            glEnd();

            if (tex_mode)
              glDisable(GL_TEXTURE_2D);
          }
        }

        free(normalL);
      }

      glEndList();
    }

    if (mesh->user.d) {
      Lib3dsObjectData *d;

      glPushMatrix();
      d=&node->data.object;
      glMultMatrixf(&node->matrix[0][0]);
      glTranslatef(-d->pivot[0], -d->pivot[1], -d->pivot[2]);
      glCallList(mesh->user.d);
      /* glutSolidSphere(50.0, 20,20); */
      glPopMatrix();
      if( flush )
        glFlush();
    }
  }
}




/*!
* Update information about a light.  Try to find corresponding nodes
* if possible, and copy values from nodes into light struct.
*/

static void
light_update(Lib3dsLight *l)
{
  Lib3dsNode *ln, *sn;

  ln = lib3ds_file_node_by_name(file, l->name, LIB3DS_LIGHT_NODE);
  sn = lib3ds_file_node_by_name(file, l->name, LIB3DS_SPOT_NODE);

  if( ln != NULL ) {
    memcpy(l->color, ln->data.light.col, sizeof(Lib3dsRgb));
    memcpy(l->position, ln->data.light.pos, sizeof(Lib3dsVector));
  }

  if( sn != NULL )
    memcpy(l->spot, sn->data.spot.pos, sizeof(Lib3dsVector));
}




static	void
draw_bounds(Lib3dsVector tgt)
{
  double cx,cy,cz;
  double lx,ly,lz;

  lx = sx / 10.; ly = sy / 10.; lz = sz / 10.;
  cx = tgt[0]; cy = tgt[1]; cz = tgt[2];

  glDisable(GL_LIGHTING);
  glColor4fv(white);
  glBegin(GL_LINES);
  glVertex3f(bmin[0],bmin[1],bmin[2]);
  glVertex3f(bmax[0],bmin[1],bmin[2]);
  glVertex3f(bmin[0],bmax[1],bmin[2]);
  glVertex3f(bmax[0],bmax[1],bmin[2]);
  glVertex3f(bmin[0],bmin[1],bmax[2]);
  glVertex3f(bmax[0],bmin[1],bmax[2]);
  glVertex3f(bmin[0],bmax[1],bmax[2]);
  glVertex3f(bmax[0],bmax[1],bmax[2]);

  glVertex3f(bmin[0],bmin[1],bmin[2]);
  glVertex3f(bmin[0],bmax[1],bmin[2]);
  glVertex3f(bmax[0],bmin[1],bmin[2]);
  glVertex3f(bmax[0],bmax[1],bmin[2]);
  glVertex3f(bmin[0],bmin[1],bmax[2]);
  glVertex3f(bmin[0],bmax[1],bmax[2]);
  glVertex3f(bmax[0],bmin[1],bmax[2]);
  glVertex3f(bmax[0],bmax[1],bmax[2]);

  glVertex3f(bmin[0],bmin[1],bmin[2]);
  glVertex3f(bmin[0],bmin[1],bmax[2]);
  glVertex3f(bmax[0],bmin[1],bmin[2]);
  glVertex3f(bmax[0],bmin[1],bmax[2]);
  glVertex3f(bmin[0],bmax[1],bmin[2]);
  glVertex3f(bmin[0],bmax[1],bmax[2]);
  glVertex3f(bmax[0],bmax[1],bmin[2]);
  glVertex3f(bmax[0],bmax[1],bmax[2]);

  glVertex3f(cx-size/32, cy, cz);
  glVertex3f(cx+size/32, cy, cz);
  glVertex3f(cx, cy-size/32, cz);
  glVertex3f(cx, cy+size/32, cz);
  glVertex3f(cx, cy, cz-size/32);
  glVertex3f(cx, cy, cz+size/32);
  glEnd();


  glColor4fv(red);
  glBegin(GL_LINES);
  glVertex3f(0.,0.,0.);
  glVertex3f(lx,0.,0.);
  glEnd();

  glColor4fv(green);
  glBegin(GL_LINES);
  glVertex3f(0.,0.,0.);
  glVertex3f(0.,ly,0.);
  glEnd();

  glColor4fv(blue);
  glBegin(GL_LINES);
  glVertex3f(0.,0.,0.);
  glVertex3f(0.,0.,lz);
  glEnd();

  glEnable(GL_LIGHTING);
}


static void
draw_light(const GLfloat *pos, const GLfloat *color)
{
  glMaterialfv(GL_FRONT, GL_EMISSION, color);
  glPushMatrix();
  glTranslatef(pos[0], pos[1], pos[2]);
  glScalef(size/20, size/20, size/20);
  glCallList(lightList);
  glPopMatrix();
}



/*!
* Main display function; called whenever the scene needs to be redrawn.
*/
static void
display(void)
{
  Lib3dsNode *c,*t;
  Lib3dsFloat fov, roll;
  float near, far, dist;
  float *campos;
  float *tgt;
  Lib3dsMatrix M;
  Lib3dsCamera *cam;
  Lib3dsVector v;
  Lib3dsNode *p;

  if( file != NULL && file->background.solid.use )
    glClearColor(file->background.solid.col[0],
    file->background.solid.col[1],
    file->background.solid.col[2], 1.);

  /* TODO: fog */

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  if( anti_alias )
    glEnable(GL_POLYGON_SMOOTH);
  else
    glDisable(GL_POLYGON_SMOOTH);


  if (!file) {
    return;
  }

  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, file->ambient);

  c=lib3ds_file_node_by_name(file, camera, LIB3DS_CAMERA_NODE);
  t=lib3ds_file_node_by_name(file, camera, LIB3DS_TARGET_NODE);

  if( t != NULL )
    tgt = t->data.target.pos;

  if( c != NULL ) {
    fov = c->data.camera.fov;
    roll = c->data.camera.roll;
    campos = c->data.camera.pos;
  }

  if ((cam = lib3ds_file_camera_by_name(file, camera)) == NULL)
    return;

  near = cam->near_range;
  far = cam->far_range;

  if (c == NULL || t == NULL) {
    if( c == NULL ) {
      fov = cam->fov;
      roll = cam->roll;
      campos = cam->position;
    }
    if( t == NULL )
      tgt = cam->target;
  }

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();

  /* KLUDGE alert:  OpenGL can't handle a near clip plane of zero,
  * so if the camera's near plane is zero, we give it a small number.
  * In addition, many .3ds files I've seen have a far plane that's
  * much too close and the model gets clipped away.  I haven't found
  * a way to tell OpenGL not to clip the far plane, so we move it
  * further away.  A factor of 10 seems to make all the models I've
  * seen visible.
  */
  if( near <= 0. ) near = far * .001;

  gluPerspective( fov, 1.0*gl_width/gl_height, near, far);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glRotatef(-90, 1.0,0,0);

  /* User rotates the view about the target point */

  lib3ds_vector_sub(v, tgt, campos);
  dist = lib3ds_vector_length(v);

  glTranslatef(0.,dist, 0.);
  glRotatef(view_rotx, 1., 0., 0.);
  glRotatef(view_roty, 0., 1., 0.);
  glRotatef(view_rotz, 0., 0., 1.);
  glTranslatef(0.,-dist, 0.);

  lib3ds_matrix_camera(M, campos, tgt, roll);
  glMultMatrixf(&M[0][0]);

  /* Lights.  Set them from light nodes if possible.  If not, use the
  * light objects directly.
  */
  {
    static const GLfloat a[] = {0.0f, 0.0f, 0.0f, 1.0f};
    static GLfloat c[] = {1.0f, 1.0f, 1.0f, 1.0f};
    static GLfloat p[] = {0.0f, 0.0f, 0.0f, 1.0f};
    Lib3dsLight *l;

    int li=GL_LIGHT0;
    for (l=file->lights; l; l=l->next) {
      glEnable(li);

      light_update(l);

      c[0] = l->color[0];
      c[1] = l->color[1];
      c[2] = l->color[2];
      glLightfv(li, GL_AMBIENT, a);
      glLightfv(li, GL_DIFFUSE, c);
      glLightfv(li, GL_SPECULAR, c);

      p[0] = l->position[0];
      p[1] = l->position[1];
      p[2] = l->position[2];
      glLightfv(li, GL_POSITION, p);

      if (l->spot_light) {
        p[0] = l->spot[0] - l->position[0];
        p[1] = l->spot[1] - l->position[1];
        p[2] = l->spot[2] - l->position[2];
        glLightfv(li, GL_SPOT_DIRECTION, p);
      }
      ++li;
    }
  }




  if( show_object )
  {
    for (p=file->nodes; p!=0; p=p->next) {
      render_node(p);
    }
  }

  if( show_bounds )
    draw_bounds(tgt);

  if( show_cameras )
  {
    for( cam = file->cameras; cam != NULL; cam = cam->next )
    {
      lib3ds_matrix_camera(M, cam->position, cam->target, cam->roll);
      lib3ds_matrix_inv(M);

      glPushMatrix();
      glMultMatrixf(&M[0][0]);
      glScalef(size/20, size/20, size/20);
      glCallList(cameraList);
      glPopMatrix();
    }
  }

  if( show_lights )
  {
    Lib3dsLight *light;
    for( light = file->lights; light != NULL; light = light->next )
      draw_light(light->position, light->color);
    glMaterialfv(GL_FRONT, GL_EMISSION, black);
  }


  glutSwapBuffers();
}


/*!
*
*/
static void
reshape (int w, int h)
{
  gl_width=w;
  gl_height=h;
  glViewport(0,0,w,h);
}


/*!
*
*/
static void
keyboard(unsigned char key, int x, int y)
{
  switch (key) {
case 27:
  exit(0);
  break;
case 'h':
  set_halt(!halt);
  break;
case 'a':
  anim_rotz += .05;
  break;
case 'A':
  anim_rotz -= .05;
  break;
case 'r':
  view_rotx = view_roty = view_rotz = anim_rotz = 0.;
  break;
case 'z':
  view_roty += 5.;
  break;
case 'Z':
  view_roty -= 5.;
  break;
case 'b':
  show_bounds = !show_bounds;
  break;
case 'o':
  show_object = !show_object;
  break;
case '\001':
  anti_alias = !anti_alias;
  break;
  }
}


/*!
* Respond to mouse buttons.  Action depends on current operating mode.
*/
static	void
mouse_cb(int button, int state, int x, int y)
{
  mx = x; my = y;
  switch( button ) {
case GLUT_LEFT_BUTTON:
  switch( runMode ) {
case ROTATING: rotating = state == GLUT_DOWN; break;
default: break;
  }
  break;
default:
  break;
  }
}


/*!
* Respond to mouse motions; left button rotates the image or performs
* other action according to current operating mode.
*/
static void
drag_cb(int x, int y)
{
  if( rotating ) {
    view_rotz += MOUSE_SCALE * (x - mx);
    view_rotx += MOUSE_SCALE * (y - my);
    mx = x;
    my = y;
    glutPostRedisplay();
  }
}


/*!
* Create camera and light icons
*/
static void
create_icons()
{
  GLUquadricObj *qobj;

#define	CBX	.25	// camera body dimensions
#define	CBY	1.5
#define	CBZ	1.

  qobj = gluNewQuadric();
  gluQuadricDrawStyle(qobj, GLU_FILL);
  gluQuadricNormals(qobj, GLU_SMOOTH);

  cameraList = glGenLists(1);
  glNewList(cameraList, GL_COMPILE);
  glMaterialfv(GL_FRONT, GL_AMBIENT, dgrey);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, lgrey);
  glMaterialfv(GL_FRONT, GL_SPECULAR, black);
  glEnable(GL_CULL_FACE);
  solidBox(CBX,CBY,CBZ);
  glPushMatrix();
  glTranslatef(0.,.9,1.8);
  glRotatef(90., 0.,1.,0.);
  solidCylinder(1., CBX*2, 12);
  glTranslatef(0.,-1.8,0.);
  solidCylinder(1., CBX*2, 12);
  glPopMatrix();
  glDisable(GL_CULL_FACE);
  glPushMatrix();
  glTranslated(0.,CBY,0.);
  glRotated(-90., 1.,0.,0.);
  gluCylinder(qobj, .2, .5, 1., 12, 1);
  glPopMatrix();
  glEndList();

  lightList = glGenLists(1);
  glNewList(lightList, GL_COMPILE);
  glPushMatrix();
  glMaterialfv(GL_FRONT, GL_AMBIENT, dgrey);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, dgrey);
  glMaterialfv(GL_FRONT, GL_SPECULAR, grey);
  glEnable(GL_CULL_FACE);
  gluSphere(qobj, .5, 12., 6.);
  glRotated(180.,1.,0.,0.);
  glMaterialfv(GL_FRONT, GL_EMISSION, dgrey);
  gluCylinder(qobj, .2, .2, 1., 12, 1);
  glPopMatrix();
  glEndList();
}


void decompose_datapath(const char *fn)
{
  const char *ptr = strrchr(fn, '/');

  if (ptr == NULL) {
    strcpy(datapath, ".");
    strcpy(filename, fn);
  }
  else {
    strcpy(filename, ptr+1);
    strcpy(datapath, fn);
    datapath[ptr - fn] = '\0';
  }
}


/*!
*
*/
int
main(int argc, char** argv)
{
  char *progname = argv[0];

  glutInit(&argc, argv);

  for(++argv; --argc > 0; ++argv)
  {
    if( strcmp(*argv, "-help") ==  0 || strcmp(*argv, "--help") == 0 )
    {
      fputs("View a 3DS model file using OpenGL.\n", stderr);
      fputs("Usage: 3dsplayer [-nodb|-aa|-flush] <filename>\n", stderr);
#ifndef USE_SDL
      fputs("Texture rendering is not available; install SDL_image and recompile.\n", stderr);
#endif
      exit(0);
    }
    else if( strcmp(*argv, "-nodb") == 0 )
      dbuf = 0;
    else if( strcmp(*argv, "-aa") == 0 )
      anti_alias = 1;
    else if( strcmp(*argv, "-flush") == 0 )
      flush = 1;
    else {
      filepath = *argv;
      decompose_datapath(filepath);
    }
  }

  if (filepath == NULL) {
    fputs("3dsplayer: Error: No 3DS file specified\n", stderr);
    exit(1);
  }

  glutInitDisplayMode(GLUT_DEPTH | GLUT_RGB | (dbuf ? GLUT_DOUBLE:0) );
  glutInitWindowSize(500, 500);
  glutInitWindowPosition(100, 100);
  glutCreateWindow(filepath != NULL ? Basename(filepath) : progname);

  init();
  create_icons();
  load_model();

  build_menu();
  glutAttachMenu(2);

  glutDisplayFunc(display);
  glutReshapeFunc(reshape);
  glutKeyboardFunc(keyboard);
  glutMouseFunc(mouse_cb);
  glutMotionFunc(drag_cb);
  glutTimerFunc(10, timer_cb, 0);
  glutMainLoop();
  return(0);
}





/* A few small utilities, so generic that they probably
* don't even belong in this file.
*/



/*!
* Render a box, centered at 0,0,0
*
* Box may be rendered with face culling enabled.
*/
static void
solidBox(double bx, double by, double bz)
{
  glBegin(GL_POLYGON);
  glNormal3d(0.,0.,1.);
  glVertex3d(bx,by,bz);
  glVertex3d(-bx,by,bz);
  glVertex3d(-bx,-by,bz);
  glVertex3d(bx,-by,bz);
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3d(0.,0.,-1.);
  glVertex3d(-bx,by,-bz);
  glVertex3d(bx,by,-bz);
  glVertex3d(bx,-by,-bz);
  glVertex3d(-bx,-by,-bz);
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3d(0.,-1.,0.);
  glVertex3d(-bx,by,bz);
  glVertex3d(bx,by,bz);
  glVertex3d(bx,by,-bz);
  glVertex3d(-bx,by,-bz);
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3d(0.,-1.,0.);
  glVertex3d(bx,-by,bz);
  glVertex3d(-bx,-by,bz);
  glVertex3d(-bx,-by,-bz);
  glVertex3d(bx,-by,-bz);
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3d(1.,0.,0.);
  glVertex3d(bx,by,bz);
  glVertex3d(bx,-by,bz);
  glVertex3d(bx,-by,-bz);
  glVertex3d(bx,by,-bz);
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3d(-1.,0.,0.);
  glVertex3d(-bx,by,-bz);
  glVertex3d(-bx,-by,-bz);
  glVertex3d(-bx,-by,bz);
  glVertex3d(-bx,by,bz);
  glEnd();
}



/*!
* Render a cylinder with end caps, along the Z axis centered at 0,0,0
*
* Cylinder may be rendered with face culling enabled.
*/
static void
solidCylinder(double r, double h, int slices)
{
  GLUquadricObj *qobj = gluNewQuadric();
  gluQuadricDrawStyle(qobj, GLU_FILL);
  gluQuadricNormals(qobj, GLU_SMOOTH);

  glPushMatrix();
  glTranslated(0., 0., -h/2);
  gluCylinder( qobj, r, r, h, slices, 1 );
  glPushMatrix();
  glRotated(180., 1.,0.,0.);
  gluDisk( qobj, 0., r, slices, 1 );
  glPopMatrix();
  glTranslated(0., 0., h);
  gluDisk( qobj, 0., r, slices, 1 );
  glPopMatrix();
}


static const char *
Basename(const char *filename)
{
  char *ptr = strrchr(filename, '/');
  return ptr != NULL ? ptr+1 : filename;
}



/*
* This module is a crude front end to the GLUT menu system, allowing for
* slightly more sophisticated callbacks.
*/

#include <stdio.h>

#define	MAX_CALLBACKS	100

typedef struct {
  void (*cb)(int, int, void *);
  void	*client;
} Callback;


static	Callback	callbacks[MAX_CALLBACKS];
static	int		ncb = 0;

/*!
* Register a callback, returning an integer value suitable for
* passing to glutAddMenuEntry()
*
* \param cb Callback function to be called.
* \param client Data to be passed to the callback.
*
* \return integer callback id
*/
static int
callback(void (*cb)(int, int, void *client), void *client)
{
  if( ncb == 0 )
  {
    int i;
    for(i=0; i < NA(callbacks); ++i)
      callbacks[i].cb = NULL;
  }
  else if( ncb >= NA(callbacks) ) {
    fprintf(stderr,
      "callback() out of callbacks, try changing MAX_CALLBACKS\n");
  }

  callbacks[ncb].cb = cb;
  callbacks[ncb].client = client;
  return ncb++;
}


/*!
* Call the indexed callback.
*
* \param idx Callback index.
* \param data Data to be passed to the callback
*/
static void
call_callback(int idx, int data)
{
  if( idx >= 0 && idx < NA(callbacks) && callbacks[idx].cb != NULL )
    callbacks[idx].cb(idx, data, callbacks[idx].client);
}