1 // mat.hxx -- a material in the scene graph.
2 // TODO: this class needs to be renamed.
4 // Written by Curtis Olson, started May 1998.
5 // Overhauled by David Megginson, December 2001
7 // Copyright (C) 1998 - 2000 Curtis L. Olson - http://www.flightgear.org/~curt
9 // This program is free software; you can redistribute it and/or
10 // modify it under the terms of the GNU General Public License as
11 // published by the Free Software Foundation; either version 2 of the
12 // License, or (at your option) any later version.
14 // This program is distributed in the hope that it will be useful, but
15 // WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 // General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
30 # error This library requires C++
33 #include <simgear/compiler.h>
35 #include STL_STRING // Standard C++ string library
41 #include <simgear/props/props.hxx>
42 #include <simgear/structure/ssgSharedPtr.hxx>
43 #include <simgear/structure/SGSharedPtr.hxx>
45 #include "matmodel.hxx"
52 * A material in the scene graph.
54 * A material represents information about a single surface type
55 * in the 3D scene graph, including texture, colour, lighting,
56 * tiling, and so on; most of the materials in FlightGear are
57 * defined in the $FG_ROOT/materials.xml file, and can be changed
60 class SGMaterial : public SGReferenced {
65 ////////////////////////////////////////////////////////////////////
66 // Public Constructors.
67 ////////////////////////////////////////////////////////////////////
70 * Construct a material from a set of properties.
72 * @param props A property node containing subnodes with the
73 * state information for the material. This node is usually
74 * loaded from the $FG_ROOT/materials.xml file.
76 SGMaterial( const string &fg_root, const SGPropertyNode *props, const char *season );
80 * Construct a material from an absolute texture path.
82 * @param texture_path A string containing an absolute path
83 * to a texture file (usually RGB).
85 SGMaterial( const string &texpath );
89 * Construct a material around an existing SSG state.
91 * This constructor allows the application to create a custom,
92 * low-level state for the scene graph and wrap a material around
93 * it. Note: the pointer ownership is transferred to the material.
95 * @param s The SSG state for this material.
97 SGMaterial( ssgSimpleState *s );
102 virtual ~SGMaterial( void );
106 ////////////////////////////////////////////////////////////////////
108 ////////////////////////////////////////////////////////////////////
111 * Force the texture to load if it hasn't already.
113 * @return true if the texture loaded, false if it was loaded
116 virtual bool load_texture (int n = -1);
120 * Get the textured state.
122 virtual ssgSimpleState *get_state (int n = -1) const;
126 * Get the number of textures assigned to this material.
128 virtual inline int get_num() const { return _status.size(); }
132 * Get the xsize of the texture, in meters.
134 virtual inline double get_xsize() const { return xsize; }
138 * Get the ysize of the texture, in meters.
140 virtual inline double get_ysize() const { return ysize; }
144 * Get the light coverage.
146 * A smaller number means more generated night lighting.
148 * @return The area (m^2?) covered by each light.
150 virtual inline double get_light_coverage () const { return light_coverage; }
154 * Get the number of randomly-placed objects defined for this material.
156 virtual int get_object_group_count () const { return object_groups.size(); }
160 * Get a randomly-placed object for this material.
162 virtual SGMatModelGroup * get_object_group (int index) const {
163 return object_groups[index];
169 ////////////////////////////////////////////////////////////////////
170 // Protected methods.
171 ////////////////////////////////////////////////////////////////////
174 * Initialization method, invoked by all public constructors.
180 struct _internal_state {
181 _internal_state( ssgSimpleState *s, const string &t, bool l )
182 : state(s), texture_path(t), texture_loaded(l) {}
183 ssgSharedPtr<ssgSimpleState> state;
191 ////////////////////////////////////////////////////////////////////
193 ////////////////////////////////////////////////////////////////////
196 vector<_internal_state> _status;
198 // Round-robin counter
199 unsigned int _current_ptr;
210 // coverage of night lighting.
211 double light_coverage;
213 // material properties
214 sgVec4 ambient, diffuse, specular, emission;
217 vector<SGSharedPtr<SGMatModelGroup> > object_groups;
220 ////////////////////////////////////////////////////////////////////
221 // Internal constructors and methods.
222 ////////////////////////////////////////////////////////////////////
224 SGMaterial( const string &fg_root, const SGMaterial &mat ); // unimplemented
226 void read_properties( const string &fg_root, const SGPropertyNode *props, const char *season );
227 void build_ssg_state( bool defer_tex_load );
228 void set_ssg_state( ssgSimpleState *s );
233 #endif // _SG_MAT_HXX