uvScrollNode.cxx

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/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file uvScrollNode.cxx
 * @author drose
 * @date 2002-03-16
 */

#include "uvScrollNode.h"

#include "bamReader.h"
#include "cullTraverserData.h"
#include "datagram.h"
#include "datagramIterator.h"
#include "luse.h"
#include "renderState.h"
#include "texMatrixAttrib.h"
#include "textureStage.h"
#include "transformState.h"

TypeHandle UvScrollNode::_type_handle;


/**
 * Returns a newly-allocated Node that is a shallow copy of this one.  It will
 * be a different Node pointer, but its internal data may or may not be shared
 * with that of the original Node.
 */
PandaNode *UvScrollNode::
make_copy() const {
  return new UvScrollNode(*this);
}

/**
 * Tells the BamReader how to create objects of type UvScrollNode.
 */
void UvScrollNode::
register_with_read_factory() {
  BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
}

/**
 * Writes the contents of this object to the datagram for shipping out to a
 * Bam file.
 */
void UvScrollNode::
write_datagram(BamWriter *manager, Datagram &dg) {
  PandaNode::write_datagram(manager, dg);
  dg.add_stdfloat(_u_speed);
  dg.add_stdfloat(_v_speed);
  if (manager->get_file_minor_ver() >= 33) {
    dg.add_stdfloat(_w_speed);
  }
  if (manager->get_file_minor_ver() >= 22) {
    dg.add_stdfloat(_r_speed);
  }
}

/**
 * This function is called by the BamReader's factory when a new object of
 * type ModelNode is encountered in the Bam file.  It should create the
 * ModelNode and extract its information from the file.
 */
TypedWritable *UvScrollNode::
make_from_bam(const FactoryParams &params) {
  UvScrollNode *node = new UvScrollNode("");
  DatagramIterator scan;
  BamReader *manager;

  parse_params(params, scan, manager);
  node->fillin(scan, manager);

  return node;
}

/**
 * This internal function is called by make_from_bam to read in all of the
 * relevant data from the BamFile for the new ModelNode.
 */
void UvScrollNode::
fillin(DatagramIterator &scan, BamReader *manager) {
  PandaNode::fillin(scan, manager);

  _u_speed = scan.get_stdfloat();
  _v_speed = scan.get_stdfloat();
  if (manager->get_file_minor_ver() >= 33) {
    _w_speed = scan.get_stdfloat();
  }
  if (manager->get_file_minor_ver() >= 22) {
    _r_speed = scan.get_stdfloat();
  }

}

/**
 * This function will be called during the cull traversal to perform any
 * additional operations that should be performed at cull time.  This may
 * include additional manipulation of render state or additional
 * visible/invisible decisions, or any other arbitrary operation.
 *
 * Note that this function will *not* be called unless set_cull_callback() is
 * called in the constructor of the derived class.  It is necessary to call
 * set_cull_callback() to indicated that we require cull_callback() to be
 * called.
 *
 * By the time this function is called, the node has already passed the
 * bounding-volume test for the viewing frustum, and the node's transform and
 * state have already been applied to the indicated CullTraverserData object.
 *
 * The return value is \true if this node should be visible, or false if it
 * should be culled.
 */
bool UvScrollNode::
cull_callback(CullTraverser * trav, CullTraverserData &data) {
  double elapsed = ClockObject::get_global_clock()->get_frame_time() - _start_time;
  CPT(TransformState) ts = TransformState::make_pos_hpr(
    LVecBase3(cmod(elapsed * _u_speed, 1.0) / 1.0,
              cmod(elapsed * _v_speed, 1.0) / 1.0,
              cmod(elapsed * _w_speed, 1.0) / 1.0),
    LVecBase3((cmod(elapsed * _r_speed, 1.0) / 1.0) * 360, 0, 0));

  CPT(RenderAttrib) tm = TexMatrixAttrib::make(TextureStage::get_default(), ts);
  CPT(RenderState) rs = RenderState::make_empty()->set_attrib(tm);
  data._state = data._state->compose(rs);

  return true;
}

/**
 * Returns true if it is generally safe to flatten out this particular kind of
 * PandaNode by duplicating instances (by calling dupe_for_flatten()), false
 * otherwise (for instance, a Camera cannot be safely flattened, because the
 * Camera pointer itself is meaningful).
 */
bool UvScrollNode::
safe_to_flatten() const {
  return false;
}

/**
 * Returns true if it is generally safe to combine this with other nodes,
 * which it isn't, so don't.  Ever.
 */
bool UvScrollNode::
safe_to_combine() const {
  return false;
}