// Filename: vrmlToEggConverter.cxx
// Created by:  drose (01Oct04)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////

#include "vrmlToEggConverter.h"
#include "vrmlAppearance.h"
#include "indexedFaceSet.h"
#include "vrmlNodeType.h"
#include "parse_vrml.h"
#include "vrmlParser.h"
#include "eggGroupNode.h"
#include "eggGroup.h"
#include "eggData.h"
#include "deg_2_rad.h"

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::Constructor
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
VRMLToEggConverter::
VRMLToEggConverter() {
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::Copy Constructor
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
VRMLToEggConverter::
VRMLToEggConverter(const VRMLToEggConverter &copy) :
  SomethingToEggConverter(copy)
{
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::Destructor
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
VRMLToEggConverter::
~VRMLToEggConverter() {
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::make_copy
//       Access: Public, Virtual
//  Description: Allocates and returns a new copy of the converter.
////////////////////////////////////////////////////////////////////
SomethingToEggConverter *VRMLToEggConverter::
make_copy() {
  return new VRMLToEggConverter(*this);
}


////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::get_name
//       Access: Public, Virtual
//  Description: Returns the English name of the file type this
//               converter supports.
////////////////////////////////////////////////////////////////////
string VRMLToEggConverter::
get_name() const {
  return "VRML";
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::get_extension
//       Access: Public, Virtual
//  Description: Returns the common extension of the file type this
//               converter supports.
////////////////////////////////////////////////////////////////////
string VRMLToEggConverter::
get_extension() const {
  return "wrl";
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::convert_file
//       Access: Public, Virtual
//  Description: Handles the reading of the input file and converting
//               it to egg.  Returns true if successful, false
//               otherwise.
////////////////////////////////////////////////////////////////////
bool VRMLToEggConverter::
convert_file(const Filename &filename) {
  clear_error();

  VrmlScene *scene = parse_vrml(filename);
  if (scene == (VrmlScene *)NULL) {
    return false;
  }

  if (_egg_data->get_coordinate_system() == CS_default) {
    _egg_data->set_coordinate_system(CS_yup_right);
  }

  // First, resolve all the DEF/USE references, and count the number
  // of times each node is USEd.
  Nodes nodes;
  VrmlScene::iterator si;
  for (si = scene->begin(); si != scene->end(); ++si) {
    get_all_defs((*si)._node, nodes);
  }

  // Now go through the hierarchy again, and this time actually
  // build the egg structure.
  VrmlScene::const_iterator csi;
  for (csi = scene->begin(); csi != scene->end(); ++csi) {
    vrml_node((*csi)._node, &get_egg_data(), LMatrix4d::ident_mat());
  }

  return !had_error();
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::get_all_defs
//       Access: Private
//  Description: Makes a first pass through the VRML hierarchy,
//               identifying all nodes marked with a DEF code, and
//               also counting the times each one is referenced by
//               USE.  Later, we'll need this information: if a node
//               is referenced at least once, we need to define it as
//               an instance node.
////////////////////////////////////////////////////////////////////
void VRMLToEggConverter::
get_all_defs(SFNodeRef &vrml, VRMLToEggConverter::Nodes &nodes) {
  Nodes::iterator ni;
  
  switch (vrml._type) {
  case SFNodeRef::T_def:
    // If this is a node definition, add it to the map.
    nassertv(vrml._name != NULL);
    nassertv(vrml._p != NULL);
    /*
      This happens too often to bother yelling about it.
    ni = nodes.find(vrml._name);
    if (ni != nodes.end()) {
      cerr << "Warning: node name " << vrml._name 
	   << " appears multiple times.\n";
    }
    */
    nodes[vrml._name] = vrml._p;
    break;

  case SFNodeRef::T_use:
    // If it's a reference, resolve it.
    nassertv(vrml._name != NULL);
    ni = nodes.find(vrml._name);
    if (ni == nodes.end()) {
      cerr << "Unknown node reference: " << vrml._name << "\n";
    } else {
      // Increment the use count of the node.
      (*ni).second->_use_count++;

      // Store the pointer itself in the reference, so we don't have
      // to do this again later.
      vrml._p = (*ni).second;
    }
    return;

  default:
    break;
  }

  VrmlNode *node = vrml._p;
  if (node != NULL) {
    VrmlNode::Fields::iterator fi;
    for (fi = node->_fields.begin(); fi != node->_fields.end(); ++fi) {
      if ((*fi)._type->type == SFNODE) {
	get_all_defs((*fi)._value._sfnode, nodes);
      } else if ((*fi)._type->type == MFNODE) {
	MFArray *children = (*fi)._value._mf;
	MFArray::iterator ci;
	for (ci = children->begin(); ci != children->end(); ++ci) {
	  get_all_defs((*ci)._sfnode, nodes);
	}
      }
    }
  }
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::vrml_node
//       Access: Public
//  Description: Processes a single VRML node, converting it to egg
//               and adding it to the egg file, if appropriate, or
//               doing whatever else should be done.
////////////////////////////////////////////////////////////////////
void VRMLToEggConverter::
vrml_node(const SFNodeRef &vrml, EggGroupNode *egg, 
	  const LMatrix4d &net_transform) {
  const VrmlNode *node = vrml._p;
  if (node != NULL) {
    // Now add it to the egg file at this point.
    if (strcmp(node->_type->getName(), "Group") == 0) {
      vrml_grouping_node(vrml, egg, net_transform, 
                         &VRMLToEggConverter::vrml_group);
    } else if (strcmp(node->_type->getName(), "Transform") == 0) {
      vrml_grouping_node(vrml, egg, net_transform, 
                         &VRMLToEggConverter::vrml_transform);
    } else if (strcmp(node->_type->getName(), "Shape") == 0) {
      vrml_grouping_node(vrml, egg, net_transform, 
                         &VRMLToEggConverter::vrml_shape);
    }
  }
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::vrml_grouping_node
//       Access: Public
//  Description: Begins initial processing of a grouping-type node;
//               that is, any node (like Group, Transform, or Shape)
//               that maps to a <Group> or <Instance> in egg.  This
//               create the group and does any instance-munging
//               necessary, then calls the indicated method with the
//               new parameters.
////////////////////////////////////////////////////////////////////
void VRMLToEggConverter::
vrml_grouping_node(const SFNodeRef &vrml, EggGroupNode *egg,
		   const LMatrix4d &net_transform,
		   void (VRMLToEggConverter::*process_func)
		   (const VrmlNode *node, EggGroup *group,
		    const LMatrix4d &net_transform)) {
  const VrmlNode *node = vrml._p;
  nassertv(node != NULL);
  string name;
  if (vrml._name != NULL) {
    name = vrml._name;
  }

  /*
    The following code fragment was used in the old DWD-style egg
    library.  Currently, the Panda egg library doesn't support
    instance references, so we deal with VRML instances by copying.

  if (vrml._type == SFNodeRef::T_use) {
    // If this is an instancing reference, just add the reference and
    // return; no need for further processing on the node.
    Instances::const_iterator fi = _instances.find(node);
    assert(fi != _instances.end());
    EggInstance *inst = _data.CreateInstance(egg);
    inst->AddGroupRef((*fi).second);
    return;
  }
    */

  PT(EggGroup) group = new EggGroup(name);
  egg->add_child(group);

  LMatrix4d next_transform = net_transform;

  if (node->_use_count > 0) {
    // If this node is referenced one or more times later in the file,
    // we must make it an instance node.
    group->set_group_type(EggGroup::GT_instance);
    next_transform = LMatrix4d::ident_mat();

    // And define the instance for future references.
    //    _instances[node] = group;
  }

  (this->*process_func)(node, group, next_transform);
}


////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::vrml_group
//       Access: Public
//  Description: Creates an Egg group corresponding to the VRML group.
////////////////////////////////////////////////////////////////////
void VRMLToEggConverter::
vrml_group(const VrmlNode *node, EggGroup *group,
	   const LMatrix4d &net_transform) {
  const MFArray *children = node->get_value("children")._mf;
  MFArray::const_iterator ci;
  for (ci = children->begin(); ci != children->end(); ++ci) {
    vrml_node((*ci)._sfnode, group, net_transform);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::vrml_transform
//       Access: Public
//  Description: Creates an Egg group with a transform corresponding
//               to the VRML group.
////////////////////////////////////////////////////////////////////
void VRMLToEggConverter::
vrml_transform(const VrmlNode *node, EggGroup *group,
	       const LMatrix4d &net_transform) {
  const double *scale = node->get_value("scale")._sfvec;
  const double *rotation = node->get_value("rotation")._sfvec;
  const double *translation = node->get_value("translation")._sfvec;

  const double *center = node->get_value("center")._sfvec;
  const double *o = node->get_value("scaleOrientation")._sfvec;

  LMatrix4d local_transform = LMatrix4d::ident_mat();

  bool any_transform = false;

  if (scale[0] != 1.0 || scale[1] != 1.0 || scale[2] != 1.0) {
    any_transform = true;
    if (center[0] != 0.0 || center[1] != 0.0 || center[2] != 0.0) {
      local_transform *=
        LMatrix4d::translate_mat(-center[0], -center[1], -center[2]);

      if (o[3] != 0.0) {
	local_transform *= 
          LMatrix4d::rotate_mat(rad_2_deg(-o[3]), LVector3d(o[0], o[1], o[2]));
	local_transform *=
          LMatrix4d::scale_mat(scale[0], scale[1], scale[2]);
	local_transform *= 
          LMatrix4d::rotate_mat(rad_2_deg(o[3]), LVector3d(o[0], o[1], o[2]));

      } else {
	local_transform *=
          LMatrix4d::scale_mat(scale[0], scale[1], scale[2]);
      }
      local_transform *= 
        LMatrix4d::translate_mat(center[0], center[1], center[2]);

    } else {
      if (o[3] != 0.0) {
	local_transform *= 
          LMatrix4d::rotate_mat(rad_2_deg(-o[3]), LVector3d(o[0], o[1], o[2]));
	local_transform *=
          LMatrix4d::scale_mat(scale[0], scale[1], scale[2]);
	local_transform *= 
          LMatrix4d::rotate_mat(rad_2_deg(o[3]), LVector3d(o[0], o[1], o[2]));

      } else {
	local_transform *=
          LMatrix4d::scale_mat(scale[0], scale[1], scale[2]);
      }
    }      
  }

  if (rotation[3] != 0.0) {
    any_transform = true;
    if (center[0] != 0.0 || center[1] != 0.0 || center[2] != 0.0) {
      local_transform *= 
        LMatrix4d::translate_mat(-center[0], -center[1], -center[2]);
      local_transform *= 
        LMatrix4d::rotate_mat(rad_2_deg(rotation[3]),
			      LVector3d(rotation[0], rotation[1], rotation[2]));
      local_transform *=
        LMatrix4d::translate_mat(center[0], center[1], center[2]);

    } else {
      local_transform *=
        LMatrix4d::rotate_mat(rad_2_deg(rotation[3]),
			      LVector3d(rotation[0], rotation[1], rotation[2]));
    }
  }

  if (translation[0] != 0.0 ||
      translation[1] != 0.0 ||
      translation[2] != 0.0) {
    any_transform = true;
    local_transform *=
      LMatrix4d::translate_mat(translation[0], translation[1], translation[2]);
  }

  if (any_transform) {
    group->set_transform(local_transform);
  }

  LMatrix4d next_transform = local_transform * net_transform;

  const MFArray *children = node->get_value("children")._mf;
  MFArray::const_iterator ci;
  for (ci = children->begin(); ci != children->end(); ++ci) {
    vrml_node((*ci)._sfnode, group, next_transform);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: VRMLToEggConverter::vrml_shape
//       Access: Public
//  Description: Creates an Egg group corresponding a VRML shape.
//               This will probably contain a vertex pool and a number
//               of polygons.
////////////////////////////////////////////////////////////////////
void VRMLToEggConverter::
vrml_shape(const VrmlNode *node, EggGroup *group,
	   const LMatrix4d &net_transform) {
  const VrmlNode *geometry = node->get_value("geometry")._sfnode._p;

  if (geometry != NULL) {
    VRMLAppearance appearance(node->get_value("appearance")._sfnode._p);

    if (strcmp(geometry->_type->getName(), "IndexedFaceSet") == 0) {
      IndexedFaceSet ifs(geometry, appearance);
      ifs.convert_to_egg(group, net_transform);
    } else {
      cerr << "Ignoring " << geometry->_type->getName() << "\n";
    }
  }
}
