1 // viewer.hxx -- class for managing a viewer in the flightgear world.
3 // Written by Curtis Olson, started August 1997.
4 // overhaul started October 2000.
5 // partially rewritten by Jim Wilson jim@kelcomaine.com using interface
6 // by David Megginson March 2002
8 // Copyright (C) 1997 - 2000 Curtis L. Olson - curt@flightgear.org
10 // This program is free software; you can redistribute it and/or
11 // modify it under the terms of the GNU General Public License as
12 // published by the Free Software Foundation; either version 2 of the
13 // License, or (at your option) any later version.
15 // This program is distributed in the hope that it will be useful, but
16 // WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 // General Public License for more details.
20 // You should have received a copy of the GNU General Public License
21 // along with this program; if not, write to the Free Software
22 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 # error This library requires C++
35 #include <simgear/compiler.h>
36 #include <simgear/constants.h>
38 #include <plib/sg.h> // plib include
42 #include <Main/location.hxx>
44 #define FG_FOV_MIN 0.1
45 #define FG_FOV_MAX 179.9
52 // Define a structure containing view information
53 class FGViewer : public FGSubsystem {
57 enum fgScalingType { // nominal Field Of View actually applies to ...
58 FG_SCALING_WIDTH, // window width
59 FG_SCALING_MAX, // max(width, height)
60 // FG_SCALING_G_MEAN, // geometric_mean(width, height)
61 // FG_SCALING_INDEPENDENT // whole screen
65 FGViewer( fgViewType Type, bool from_model, int from_model_index,
66 bool at_model, int at_model_index, double x_offset_m,
67 double y_offset_m, double z_offset_m, double near_m );
70 virtual ~FGViewer( void );
72 //////////////////////////////////////////////////////////////////////
73 // Part 1: standard FGSubsystem implementation.
74 //////////////////////////////////////////////////////////////////////
78 virtual void unbind ();
79 void update (double dt);
82 //////////////////////////////////////////////////////////////////////
83 // Part 2: user settings.
84 //////////////////////////////////////////////////////////////////////
86 virtual fgViewType getType() const { return _type; }
87 virtual void setType( int type );
89 // Reference geodetic position of view from position...
90 // These are the actual aircraft position (pilot in
91 // pilot view, model in model view).
92 // FIXME: the model view position (ie target positions)
93 // should be in the model class.
94 virtual double getLongitude_deg () const { return _lon_deg; }
95 virtual double getLatitude_deg () const { return _lat_deg; }
96 virtual double getAltitudeASL_ft () const { return _alt_ft; }
97 virtual void setLongitude_deg (double lon_deg);
98 virtual void setLatitude_deg (double lat_deg);
99 virtual void setAltitude_ft (double alt_ft);
100 virtual void setPosition (double lon_deg, double lat_deg, double alt_ft);
102 // Reference geodetic target position...
103 virtual double getTargetLongitude_deg () const { return _target_lon_deg; }
104 virtual double getTargetLatitude_deg () const { return _target_lat_deg; }
105 virtual double getTargetAltitudeASL_ft () const { return _target_alt_ft; }
106 virtual void setTargetLongitude_deg (double lon_deg);
107 virtual void setTargetLatitude_deg (double lat_deg);
108 virtual void setTargetAltitude_ft (double alt_ft);
109 virtual void setTargetPosition (double lon_deg, double lat_deg, double alt_ft);
114 // Position offsets from reference
115 // These offsets position they "eye" in the scene according to a given
116 // location. For example in pilot view they are used to position the
117 // head inside the aircraft.
118 // Note that in pilot view these are applied "before" the orientation
119 // rotations (see below) so that the orientation rotations have the
120 // effect of the pilot staying in his seat and "looking out" in
121 // different directions.
122 // In chase view these are applied "after" the application of the
123 // orientation rotations listed below. This has the effect of the
124 // eye moving around and "looking at" the object (model) from
126 virtual double getXOffset_m () const { return _x_offset_m; }
127 virtual double getYOffset_m () const { return _y_offset_m; }
128 virtual double getZOffset_m () const { return _z_offset_m; }
129 virtual void setXOffset_m (double x_offset_m);
130 virtual void setYOffset_m (double y_offset_m);
131 virtual void setZOffset_m (double z_offset_m);
132 virtual void setPositionOffsets (double x_offset_m,
139 // Reference orientation rotations...
140 // These are rotations that represent the plane attitude effect on
141 // the view (in Pilot view). IE The view frustrum rotates as the plane
142 // turns, pitches, and rolls.
143 // In model view (lookat/chaseview) these end up changing the angle that
144 // the eye is looking at the ojbect (ie the model).
145 // FIXME: the FGModel class should have its own version of these so that
146 // it can generate it's own model rotations.
147 virtual double getRoll_deg () const { return _roll_deg; }
148 virtual double getPitch_deg () const {return _pitch_deg; }
149 virtual double getHeading_deg () const {return _heading_deg; }
150 virtual void setRoll_deg (double roll_deg);
151 virtual void setPitch_deg (double pitch_deg);
152 virtual void setHeading_deg (double heading_deg);
153 virtual void setOrientation (double roll_deg, double pitch_deg, double heading_deg);
154 virtual double getTargetRoll_deg () const { return _target_roll_deg; }
155 virtual double getTargetPitch_deg () const {return _target_pitch_deg; }
156 virtual double getTargetHeading_deg () const {return _target_heading_deg; }
157 virtual void setTargetRoll_deg (double roll_deg);
158 virtual void setTargetPitch_deg (double pitch_deg);
159 virtual void setTargetHeading_deg (double heading_deg);
160 virtual void setTargetOrientation (double roll_deg, double pitch_deg, double heading_deg);
165 // Orientation offsets rotations from reference orientation.
166 // Goal settings are for smooth transition from prior
167 // offset when changing view direction.
168 // These offsets are in ADDITION to the orientation rotations listed
170 // In pilot view they are applied after the position offsets in order to
171 // give the effect of the pilot looking around.
172 // In lookat view they are applied before the position offsets so that
173 // the effect is the eye moving around looking at the object (ie the model)
174 // from different angles.
175 virtual double getRollOffset_deg () const { return _roll_offset_deg; }
176 virtual double getPitchOffset_deg () const { return _pitch_offset_deg; }
177 virtual double getHeadingOffset_deg () const { return _heading_offset_deg; }
178 virtual double getGoalRollOffset_deg () const { return _goal_roll_offset_deg; }
179 virtual double getGoalPitchOffset_deg () const { return _goal_pitch_offset_deg; }
180 virtual double getGoalHeadingOffset_deg () const {return _goal_heading_offset_deg; }
181 virtual void setRollOffset_deg (double roll_offset_deg);
182 virtual void setPitchOffset_deg (double pitch_offset_deg);
183 virtual void setHeadingOffset_deg (double heading_offset_deg);
184 virtual void setGoalRollOffset_deg (double goal_roll_offset_deg);
185 virtual void setGoalPitchOffset_deg (double goal_pitch_offset_deg);
186 virtual void setGoalHeadingOffset_deg (double goal_heading_offset_deg);
187 virtual void setOrientationOffsets (double roll_offset_deg,
188 double heading_offset_deg,
189 double pitch_offset_deg);
193 //////////////////////////////////////////////////////////////////////
194 // Part 3: output vectors and matrices in FlightGear coordinates.
195 //////////////////////////////////////////////////////////////////////
197 // Vectors and positions...
200 virtual float * get_view_pos() {if ( _dirty ) { recalc(); } return _view_pos; }
201 // Get the absolute view position in fgfs coordinates.
202 virtual double * get_absolute_view_pos ();
204 virtual float * get_zero_elev() {if ( _dirty ) { recalc(); } return _zero_elev; }
205 // Get world up vector
206 virtual float *get_world_up() {if ( _dirty ) { recalc(); } return _world_up; }
207 // Get the relative (to scenery center) view position in fgfs coordinates.
208 virtual float * getRelativeViewPos ();
209 // Get the absolute zero-elevation view position in fgfs coordinates.
210 virtual float * getZeroElevViewPos ();
211 // Get surface east vector
212 virtual float *get_surface_east() { if ( _dirty ) { recalc(); } return _surface_east; }
213 // Get surface south vector
214 virtual float *get_surface_south() {if ( _dirty ) { recalc(); } return _surface_south; }
217 virtual const sgVec4 *get_VIEW() { if ( _dirty ) { recalc(); } return VIEW; }
218 virtual const sgVec4 *get_UP() { if ( _dirty ) { recalc(); } return UP; }
220 //////////////////////////////////////////////////////////////////////
221 // Part 4: View and frustrum data setters and getters
222 //////////////////////////////////////////////////////////////////////
224 virtual void set_fov( double fov_deg ) {
227 virtual double get_fov() const { return _fov_deg; }
228 virtual double get_h_fov(); // Get horizontal fov, in degrees.
229 virtual double get_v_fov(); // Get vertical fov, in degrees.
231 virtual void set_aspect_ratio( double r ) {
234 virtual double get_aspect_ratio() const { return _aspect_ratio; }
236 virtual double getNear_m () const { return _ground_level_nearplane_m; }
237 inline void setNear_m (double near_m) {
238 _ground_level_nearplane_m = near_m;
241 //////////////////////////////////////////////////////////////////////
242 // Part 5: misc setters and getters
243 //////////////////////////////////////////////////////////////////////
245 inline void set_dirty() { _dirty = true; }
246 inline void set_clean() { _dirty = false; }
251 //////////////////////////////////////////////////////////////////
253 //////////////////////////////////////////////////////////////////
255 // flag forcing a recalc of derived view parameters
258 mutable sgdVec3 _absolute_view_pos;
259 mutable sgVec3 _relative_view_pos;
260 mutable sgVec3 _zero_elev_view_pos;
265 double _target_lon_deg;
266 double _target_lat_deg;
267 double _target_alt_ft;
272 double _target_roll_deg;
273 double _target_pitch_deg;
274 double _target_heading_deg;
276 // Position offsets from center of gravity. The X axis is positive
277 // out the tail, Y is out the right wing, and Z is positive up.
278 // distance in meters
283 // orientation offsets from reference (_goal* are for smoothed transitions)
284 double _roll_offset_deg;
285 double _pitch_offset_deg;
286 double _heading_offset_deg;
287 double _goal_roll_offset_deg;
288 double _goal_pitch_offset_deg;
289 double _goal_heading_offset_deg;
291 // used to set nearplane when at ground level for this view
292 double _ground_level_nearplane_m;
295 fgScalingType _scaling_type;
297 // view is looking from a model
299 int _from_model_index; // number of model (for multi model)
301 // view is looking at a model
303 int _at_model_index; // number of model (for multi model)
305 FGLocation * _location;
306 FGLocation * _target_location;
308 // the nominal field of view (angle, in degrees)
311 // ratio of window width and height; height = width * aspect_ratio
312 double _aspect_ratio;
314 bool _reverse_view_offset;
316 // view position in opengl world coordinates (this is the
317 // abs_view_pos translated to scenery.center)
320 // cartesion coordinates of current lon/lat if at sea level
321 // translated to scenery.center
324 // surface vector heading south
325 sgVec3 _surface_south;
327 // surface vector heading east (used to unambiguously align sky
329 sgVec3 _surface_east;
331 // world up vector (normal to the plane tangent to the earth's
332 // surface at the spot we are directly above
335 // up vector for the view (usually point straight up through the
336 // top of the aircraft
339 // sg versions of our friendly matrices
341 sgMat4 LOCAL, TRANS, LARC_TO_SSG;
343 // Transformation matrix for the view direction offset relative to
344 // the AIRCRAFT matrix
347 //////////////////////////////////////////////////////////////////
348 // private functions //
349 //////////////////////////////////////////////////////////////////
352 void recalcPositionVectors (double lon_deg, double lat_deg, double alt_ft) const;
353 void updateFromModelLocation (FGLocation * location);
354 void recalcOurOwnLocation (double lon_deg, double lat_deg, double alt_ft,
355 double roll_deg, double pitch_deg, double heading_deg);
357 // add to _heading_offset_deg
358 inline void incHeadingOffset_deg( double amt ) {
360 _heading_offset_deg += amt;
363 // add to _pitch_offset_deg
364 inline void incPitchOffset_deg( double amt ) {
366 _pitch_offset_deg += amt;
369 inline void set_reverse_view_offset( bool val ) {
370 _reverse_view_offset = val;
376 #endif // _VIEWER_HXX