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>
34 #include <simgear/constants.h>
36 #include <plib/sg.h> // plib include
41 #define FG_FOV_MIN 0.1
42 #define FG_FOV_MAX 179.9
45 // Define a structure containing view information
56 enum fgScalingType { // nominal Field Of View actually applies to ...
57 FG_SCALING_WIDTH, // window width
58 FG_SCALING_MAX, // max(width, height)
59 // FG_SCALING_G_MEAN, // geometric_mean(width, height)
60 // FG_SCALING_INDEPENDENT // whole screen
65 // flag forcing a recalc of derived view parameters
71 fgScalingType scalingType;
73 // the nominal field of view (angle, in degrees)
76 // ratio of window width and height; height = width * aspect_ratio
79 // the current view offset angle from forward (rotated about the
82 bool reverse_view_offset;
84 // the goal view offset angle (used for smooth view changes)
85 double goal_view_offset;
87 // the view tilt angles
89 double goal_view_tilt;
91 // geodetic view position
92 sgdVec3 geod_view_pos;
94 // absolute view position in earth coordinates
97 // view position in opengl world coordinates (this is the
98 // abs_view_pos translated to scenery.center)
101 // radius to sea level from center of the earth (m)
102 double sea_level_radius;
104 // cartesion coordinates of current lon/lat if at sea level
105 // translated to scenery.center
108 // height ASL of the terrain for our current view position
109 // (future?) double ground_elev;
111 // pilot offset from center of gravity. The X axis is positive
112 // out the tail, Y is out the right wing, and Z is positive up.
113 // Distances in meters of course.
116 // surface vector heading south
117 sgVec3 surface_south;
119 // surface vector heading east (used to unambiguously align sky
123 // world up vector (normal to the plane tangent to the earth's
124 // surface at the spot we are directly above
127 // sg versions of our friendly matrices
128 sgMat4 VIEW, VIEW_ROT, UP;
130 inline void set_dirty() { dirty = true; }
131 inline void set_clean() { dirty = false; }
133 // Update the view volume, position, and orientation
134 virtual void update() = 0;
142 virtual ~FGViewer( void );
144 virtual void init ();
145 virtual void bind ();
146 virtual void unbind ();
147 virtual void update (int dt);
149 //////////////////////////////////////////////////////////////////////
151 //////////////////////////////////////////////////////////////////////
153 inline void set_fov( double fov_deg ) {
157 inline void set_aspect_ratio( double r ) {
160 inline void set_view_offset( double a ) {
164 inline void inc_view_offset( double amt ) {
168 inline void set_goal_view_offset( double a) {
170 goal_view_offset = a;
171 while ( goal_view_offset < 0.0 ) {
172 goal_view_offset += SGD_2PI;
174 while ( goal_view_offset > SGD_2PI ) {
175 goal_view_offset -= SGD_2PI;
178 inline void set_reverse_view_offset( bool val ) {
179 reverse_view_offset = val;
181 inline void set_view_tilt( double a ) {
185 inline void inc_view_tilt( double amt ) {
189 inline void set_goal_view_tilt( double a) {
192 while ( goal_view_tilt < 0 ) {
193 goal_view_tilt += 360.0;
195 while ( goal_view_tilt > 360.0 ) {
196 goal_view_tilt -= 360.0;
199 inline void set_geod_view_pos( double lon, double lat, double alt ) {
200 // data should be in radians and meters asl
202 // cout << "set_geod_view_pos = " << lon << ", " << lat << ", " << alt
204 sgdSetVec3( geod_view_pos, lon, lat, alt );
206 inline void set_pilot_offset( float x, float y, float z ) {
208 sgSetVec3( pilot_offset, x, y, z );
210 inline void set_sea_level_radius( double r ) {
211 // data should be in meters from the center of the earth
213 sea_level_radius = r;
216 //////////////////////////////////////////////////////////////////////
217 // accessor functions
218 //////////////////////////////////////////////////////////////////////
219 inline int get_type() const { return _type ; }
220 inline int is_a( int t ) const { return get_type() == t ; }
221 inline bool is_dirty() const { return dirty; }
222 inline double get_fov() const { return fov; }
223 inline double get_aspect_ratio() const { return aspect_ratio; }
224 inline double get_view_offset() const { return view_offset; }
225 inline bool get_reverse_view_offset() const { return reverse_view_offset; }
226 inline double get_goal_view_offset() const { return goal_view_offset; }
227 inline double get_view_tilt() const { return view_tilt; }
228 inline double get_goal_view_tilt() const { return goal_view_tilt; }
229 inline double *get_geod_view_pos() { return geod_view_pos; }
230 inline float *get_pilot_offset() { return pilot_offset; }
231 inline double get_sea_level_radius() const { return sea_level_radius; }
232 // Get horizontal field of view angle, in degrees.
234 // Get vertical field of view angle, in degrees.
237 //////////////////////////////////////////////////////////////////////
238 // derived values accessor functions
239 //////////////////////////////////////////////////////////////////////
240 inline double *get_abs_view_pos() {
241 if ( dirty ) { update(); }
244 inline float *get_view_pos() {
245 if ( dirty ) { update(); }
248 inline float *get_zero_elev() {
249 if ( dirty ) { update(); }
253 // inline double get_ground_elev() {
254 // if ( dirty ) { update(); }
255 // return ground_elev;
257 inline float *get_surface_south() {
258 if ( dirty ) { update(); }
259 return surface_south;
261 inline float *get_surface_east() {
262 if ( dirty ) { update(); }
265 inline float *get_world_up() {
266 if ( dirty ) { update(); }
269 inline const sgVec4 *get_VIEW() {
270 if ( dirty ) { update(); }
273 inline const sgVec4 *get_VIEW_ROT() {
274 if ( dirty ) { update(); }
277 inline const sgVec4 *get_UP() {
278 if ( dirty ) { update(); }
284 #endif // _VIEWER_HXX