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.
6 // Copyright (C) 1997 - 2000 Curtis L. Olson - curt@flightgear.org
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
30 # error This library requires C++
33 #include <simgear/compiler.h>
35 #include <plib/sg.h> // plib include
40 #define FG_FOV_MIN 0.1
41 #define FG_FOV_MAX 179.9
44 // Define a structure containing view information
57 // flag forcing a recalc of derived view parameters
64 // the field of view in the x (width) direction
67 // ratio of x and y fov's; fov(y) = fov(x) * fov_ratio
70 // ratio of window width and height; height = width * aspect_ratio
73 // the current view offset angle from forward (rotated about the
76 bool reverse_view_offset;
78 // the goal view offset angle (used for smooth view changes)
79 double goal_view_offset;
81 // geodetic view position
82 sgdVec3 geod_view_pos;
84 // absolute view position in earth coordinates
87 // view position in opengl world coordinates (this is the
88 // abs_view_pos translated to scenery.center)
91 // radius to sea level from center of the earth (m)
92 double sea_level_radius;
94 // cartesion coordinates of current lon/lat if at sea level
95 // translated to scenery.center
98 // height ASL of the terrain for our current view position
99 // (future?) double ground_elev;
101 // pilot offset from center of gravity. The X axis is positive
102 // out the tail, Y is out the right wing, and Z is positive up.
103 // Distances in meters of course.
106 // surface vector heading south
107 sgVec3 surface_south;
109 // surface vector heading east (used to unambiguously align sky
113 // world up vector (normal to the plane tangent to the earth's
114 // surface at the spot we are directly above
117 // sg versions of our friendly matrices
118 sgMat4 VIEW, VIEW_ROT, UP;
120 inline void set_dirty() { dirty = true; }
121 inline void set_clean() { dirty = false; }
123 // Update the view volume, position, and orientation
124 virtual void update() = 0;
132 virtual ~FGViewer( void );
134 virtual void init ();
135 virtual void bind ();
136 virtual void unbind ();
137 virtual void update (int dt);
139 //////////////////////////////////////////////////////////////////////
141 //////////////////////////////////////////////////////////////////////
142 inline void set_fov( double amount ) { fov = amount; }
143 // Don't provide set_fov_ratio explicitely. Use set_aspect_ratio
145 inline void set_aspect_ratio( double r ) {
147 fov_ratio = atan(tan(fov/2 * SG_DEGREES_TO_RADIANS) * aspect_ratio) *
148 SG_RADIANS_TO_DEGREES / (fov/2);
150 inline void set_view_offset( double a ) {
154 inline void inc_view_offset( double amt ) {
158 inline void set_goal_view_offset( double a) {
160 goal_view_offset = a;
161 while ( goal_view_offset < 0 ) {
162 goal_view_offset += 360.0;
164 while ( goal_view_offset > 360.0 ) {
165 goal_view_offset -= 360.0;
168 inline void set_reverse_view_offset( bool val ) {
169 reverse_view_offset = val;
171 inline void set_geod_view_pos( double lon, double lat, double alt ) {
172 // data should be in radians and meters asl
174 // cout << "set_geod_view_pos = " << lon << ", " << lat << ", " << alt
176 sgdSetVec3( geod_view_pos, lon, lat, alt );
178 inline void set_pilot_offset( float x, float y, float z ) {
180 sgSetVec3( pilot_offset, x, y, z );
182 inline void set_sea_level_radius( double r ) {
183 // data should be in meters from the center of the earth
185 sea_level_radius = r;
188 //////////////////////////////////////////////////////////////////////
189 // accessor functions
190 //////////////////////////////////////////////////////////////////////
191 inline int get_type() const { return _type ; }
192 inline int is_a( int t ) const { return get_type() == t ; }
193 inline bool is_dirty() const { return dirty; }
194 inline double get_fov() const { return fov; }
195 inline double get_aspect_ratio() const { return aspect_ratio; }
196 inline double get_fov_ratio() const { return fov_ratio; }
197 inline double get_view_offset() const { return view_offset; }
198 inline bool get_reverse_view_offset() const { return reverse_view_offset; }
199 inline double get_goal_view_offset() const { return goal_view_offset; }
200 inline double *get_geod_view_pos() { return geod_view_pos; }
201 inline float *get_pilot_offset() { return pilot_offset; }
202 inline double get_sea_level_radius() const { return sea_level_radius; }
204 //////////////////////////////////////////////////////////////////////
205 // derived values accessor functions
206 //////////////////////////////////////////////////////////////////////
207 inline double *get_abs_view_pos() {
208 if ( dirty ) { update(); }
211 inline float *get_view_pos() {
212 if ( dirty ) { update(); }
215 inline float *get_zero_elev() {
216 if ( dirty ) { update(); }
220 // inline double get_ground_elev() {
221 // if ( dirty ) { update(); }
222 // return ground_elev;
224 inline float *get_surface_south() {
225 if ( dirty ) { update(); }
226 return surface_south;
228 inline float *get_surface_east() {
229 if ( dirty ) { update(); }
232 inline float *get_world_up() {
233 if ( dirty ) { update(); }
236 inline const sgVec4 *get_VIEW() {
237 if ( dirty ) { update(); }
240 inline const sgVec4 *get_VIEW_ROT() {
241 if ( dirty ) { update(); }
244 inline const sgVec4 *get_UP() {
245 if ( dirty ) { update(); }
251 #endif // _VIEWER_HXX