Panda3D

alphaTestAttrib.cxx

00001 // Filename: alphaTestAttrib.cxx
00002 // Created by:  drose (04Mar02)
00003 //
00004 ////////////////////////////////////////////////////////////////////
00005 //
00006 // PANDA 3D SOFTWARE
00007 // Copyright (c) Carnegie Mellon University.  All rights reserved.
00008 //
00009 // All use of this software is subject to the terms of the revised BSD
00010 // license.  You should have received a copy of this license along
00011 // with this source code in a file named "LICENSE."
00012 //
00013 ////////////////////////////////////////////////////////////////////
00014 
00015 #include "alphaTestAttrib.h"
00016 #include "graphicsStateGuardianBase.h"
00017 #include "dcast.h"
00018 #include "bamReader.h"
00019 #include "bamWriter.h"
00020 #include "datagram.h"
00021 #include "datagramIterator.h"
00022 
00023 TypeHandle AlphaTestAttrib::_type_handle;
00024 int AlphaTestAttrib::_attrib_slot;
00025 
00026 ////////////////////////////////////////////////////////////////////
00027 //     Function: AlphaTestAttrib::make
00028 //       Access: Published, Static
00029 //  Description: Constructs a new AlphaTestAttrib object.
00030 ////////////////////////////////////////////////////////////////////
00031 CPT(RenderAttrib) AlphaTestAttrib::
00032 make(PandaCompareFunc mode, PN_stdfloat reference_value) {
00033   assert((reference_value >=0.0f) && (reference_value <=1.0f));
00034   AlphaTestAttrib *attrib = new AlphaTestAttrib(mode,reference_value);
00035   return return_new(attrib);
00036 }
00037 
00038 ////////////////////////////////////////////////////////////////////
00039 //     Function: AlphaTestAttrib::make_default
00040 //       Access: Published, Static
00041 //  Description: Returns a RenderAttrib that corresponds to whatever
00042 //               the standard default properties for render attributes
00043 //               of this type ought to be.
00044 ////////////////////////////////////////////////////////////////////
00045 CPT(RenderAttrib) AlphaTestAttrib::
00046 make_default() {
00047   return return_new(new AlphaTestAttrib);
00048 }
00049 
00050 ////////////////////////////////////////////////////////////////////
00051 //     Function: AlphaTestAttrib::output
00052 //       Access: Public, Virtual
00053 //  Description: 
00054 ////////////////////////////////////////////////////////////////////
00055 void AlphaTestAttrib::
00056 output(ostream &out) const {
00057   out << get_type() << ":";
00058   output_comparefunc(out,_mode);
00059   out << "," << _reference_alpha;
00060 }
00061 
00062 ////////////////////////////////////////////////////////////////////
00063 //     Function: AlphaTestAttrib::compare_to_impl
00064 //       Access: Protected, Virtual
00065 //  Description: Intended to be overridden by derived AlphaTestAttrib
00066 //               types to return a unique number indicating whether
00067 //               this AlphaTestAttrib is equivalent to the other one.
00068 //
00069 //               This should return 0 if the two AlphaTestAttrib objects
00070 //               are equivalent, a number less than zero if this one
00071 //               should be sorted before the other one, and a number
00072 //               greater than zero otherwise.
00073 //
00074 //               This will only be called with two AlphaTestAttrib
00075 //               objects whose get_type() functions return the same.
00076 ////////////////////////////////////////////////////////////////////
00077 int AlphaTestAttrib::
00078 compare_to_impl(const RenderAttrib *other) const {
00079   const AlphaTestAttrib *ta;
00080   DCAST_INTO_R(ta, other, 0);
00081   int compare_result = ((int)_mode - (int)ta->_mode) ;
00082   if (compare_result != 0) {
00083     return compare_result;
00084   }
00085    
00086   if (_reference_alpha != ta->_reference_alpha) {
00087     return _reference_alpha < ta->_reference_alpha ? -1 : 1;
00088   }
00089 
00090   return 0;
00091 }
00092 
00093 ////////////////////////////////////////////////////////////////////
00094 //     Function: AlphaTestAttrib::get_hash_impl
00095 //       Access: Protected, Virtual
00096 //  Description: Intended to be overridden by derived RenderAttrib
00097 //               types to return a unique hash for these particular
00098 //               properties.  RenderAttribs that compare the same with
00099 //               compare_to_impl(), above, should return the same
00100 //               hash; RenderAttribs that compare differently should
00101 //               return a different hash.
00102 ////////////////////////////////////////////////////////////////////
00103 size_t AlphaTestAttrib::
00104 get_hash_impl() const {
00105   size_t hash = 0;
00106   hash = int_hash::add_hash(hash, (int)_mode);
00107   hash = float_hash().add_hash(hash, _reference_alpha);
00108   return hash;
00109 }
00110 
00111 ////////////////////////////////////////////////////////////////////
00112 //     Function: AlphaTestAttrib::get_auto_shader_attrib_impl
00113 //       Access: Protected, Virtual
00114 //  Description: 
00115 ////////////////////////////////////////////////////////////////////
00116 CPT(RenderAttrib) AlphaTestAttrib::
00117 get_auto_shader_attrib_impl(const RenderState *state) const {
00118   return this;
00119 }
00120 
00121 ////////////////////////////////////////////////////////////////////
00122 //     Function: AlphaTestAttrib::register_with_read_factory
00123 //       Access: Public, Static
00124 //  Description: Tells the BamReader how to create objects of type
00125 //               AlphaTestAttrib.
00126 ////////////////////////////////////////////////////////////////////
00127 void AlphaTestAttrib::
00128 register_with_read_factory() {
00129   BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
00130 }
00131 
00132 ////////////////////////////////////////////////////////////////////
00133 //     Function: AlphaTestAttrib::write_datagram
00134 //       Access: Public, Virtual
00135 //  Description: Writes the contents of this object to the datagram
00136 //               for shipping out to a Bam file.
00137 ////////////////////////////////////////////////////////////////////
00138 void AlphaTestAttrib::
00139 write_datagram(BamWriter *manager, Datagram &dg) {
00140   RenderAttrib::write_datagram(manager, dg);
00141 
00142   dg.add_int8(_mode);
00143   dg.add_stdfloat(_reference_alpha);
00144 }
00145 
00146 ////////////////////////////////////////////////////////////////////
00147 //     Function: AlphaTestAttrib::make_from_bam
00148 //       Access: Protected, Static
00149 //  Description: This function is called by the BamReader's factory
00150 //               when a new object of type AlphaTestAttrib is encountered
00151 //               in the Bam file.  It should create the AlphaTestAttrib
00152 //               and extract its information from the file.
00153 ////////////////////////////////////////////////////////////////////
00154 TypedWritable *AlphaTestAttrib::
00155 make_from_bam(const FactoryParams &params) {
00156   AlphaTestAttrib *attrib = new AlphaTestAttrib;
00157   DatagramIterator scan;
00158   BamReader *manager;
00159 
00160   parse_params(params, scan, manager);
00161   attrib->fillin(scan, manager);
00162 
00163   return attrib;
00164 }
00165 
00166 ////////////////////////////////////////////////////////////////////
00167 //     Function: AlphaTestAttrib::fillin
00168 //       Access: Protected
00169 //  Description: This internal function is called by make_from_bam to
00170 //               read in all of the relevant data from the BamFile for
00171 //               the new AlphaTestAttrib.
00172 ////////////////////////////////////////////////////////////////////
00173 void AlphaTestAttrib::
00174 fillin(DatagramIterator &scan, BamReader *manager) {
00175   RenderAttrib::fillin(scan, manager);
00176 
00177   _mode = (PandaCompareFunc)scan.get_int8();
00178   _reference_alpha = scan.get_stdfloat();
00179 }
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