// Filename: renderState.I
// Created by:  drose (21Feb02)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, 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://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////


////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::Constructor
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
INLINE RenderState::Attribute::
Attribute(const RenderAttrib *attrib, int override) :
  _type(attrib->get_type()),
  _attrib(attrib),
  _override(override)
{
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::Constructor
//       Access: Public
//  Description: This constructor is only used when reading the
//               RenderState from a bam file.  At this point, the
//               attribute pointer is unknown.
////////////////////////////////////////////////////////////////////
INLINE RenderState::Attribute::
Attribute(int override) :
  _override(override)
{
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::Constructor
//       Access: Public
//  Description: This constructor makes an invalid Attribute with no
//               RenderAttrib pointer; its purpose is just to make an
//               object we can use to look up a particular type in the
//               Attribute set.
////////////////////////////////////////////////////////////////////
INLINE RenderState::Attribute::
Attribute(TypeHandle type) :
  _type(type),
  _attrib(NULL),
  _override(0)
{
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::Copy Constructor
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
INLINE RenderState::Attribute::
Attribute(const Attribute &copy) :
  _type(copy._type),
  _attrib(copy._attrib),
  _override(copy._override)
{
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::Copy Assignment Operator
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
INLINE void RenderState::Attribute::
operator = (const Attribute &copy) {
  _type = copy._type;
  _attrib = copy._attrib;
  _override = copy._override;
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::operator <
//       Access: Public
//  Description: This is used by the Attributes set to uniquify
//               RenderAttributes by type.  Only one RenderAttrib of a
//               given type is allowed in the set.  This ordering must
//               also match the ordering reported by compare_to().
////////////////////////////////////////////////////////////////////
INLINE bool RenderState::Attribute::
operator < (const Attribute &other) const {
  return _type < other._type;
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::Attribute::compare_to
//       Access: Public
//  Description: Provides an indication of whether a particular
//               attribute is equivalent to another one, for purposes
//               of generating unique RenderStates.  This should
//               compare all properties of the Attribute, but it is
//               important that the type is compared first, to be
//               consistent with the ordering defined by operator <.
////////////////////////////////////////////////////////////////////
INLINE int RenderState::Attribute::
compare_to(const Attribute &other) const {
  if (_type != other._type) {
    return _type.get_index() - other._type.get_index();
  }
  if (_attrib != other._attrib) {
    return _attrib - other._attrib;
  }
  return _override - other._override;
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::is_empty
//       Access: Published
//  Description: Returns true if the state is empty, false otherwise.
////////////////////////////////////////////////////////////////////
INLINE bool RenderState::
is_empty() const {
  return _attributes.empty();
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::get_num_attribs
//       Access: Published
//  Description: Returns the number of separate attributes indicated
//               in the state.
////////////////////////////////////////////////////////////////////
INLINE int RenderState::
get_num_attribs() const {
  return _attributes.size();
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::get_attrib
//       Access: Published
//  Description: Returns the nth attribute in the state.
////////////////////////////////////////////////////////////////////
INLINE const RenderAttrib *RenderState::
get_attrib(int n) const {
  nassertr(n >= 0 && n < (int)_attributes.size(), NULL);
  return _attributes[n]._attrib;
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::get_override
//       Access: Published
//  Description: Returns the override associated with the nth
//               attribute in the state.
////////////////////////////////////////////////////////////////////
INLINE int RenderState::
get_override(int n) const {
  nassertr(n >= 0 && n < (int)_attributes.size(), 0);
  return _attributes[n]._override;
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::get_bin_index
//       Access: Public
//  Description: Returns the bin index indicated by the CullBinAttrib,
//               if any, associated by this state (or the default bin
//               index if there is no CullBinAttrib).  This function
//               is provided as an optimization for determining this
//               at render time.
////////////////////////////////////////////////////////////////////
INLINE int RenderState::
get_bin_index() const {
  if ((_flags & F_checked_bin_index) == 0) {
    // We pretend this function is const, even though it transparently
    // modifies the internal bin_index cache.
    ((RenderState *)this)->determine_bin_index();
  }
  return _bin_index;
}

////////////////////////////////////////////////////////////////////
//     Function: RenderState::get_draw_order
//       Access: Public
//  Description: Returns the draw order indicated by the
//               CullBinAttrib, if any, associated by this state (or 0
//               if there is no CullBinAttrib).  See get_bin_index().
////////////////////////////////////////////////////////////////////
INLINE int RenderState::
get_draw_order() const {
  if ((_flags & F_checked_bin_index) == 0) {
    // We pretend this function is const, even though it transparently
    // modifies the internal draw_order cache.
    ((RenderState *)this)->determine_bin_index();
  }
  return _draw_order;
}