1 // views.hxx -- data structures and routines for managing and view parameters.
3 // Written by Curtis Olson, started August 1997.
5 // Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 # error This library requires C++
32 #include <sg.h> // plib include
34 #include <FDM/flight.hxx>
35 #include <Math/mat3.h>
36 #include <Math/point3d.hxx>
37 #include <Time/fg_time.hxx>
38 #include <Time/light.hxx>
40 #include "options.hxx"
43 // used in views.cxx and tilemgr.cxx
44 #define USE_FAST_FOV_CLIP
47 // Define a structure containing view information
52 // the current offset from forward for viewing
55 // the goal view offset for viewing (used for smooth view changes)
56 double goal_view_offset;
58 // flag forcing update of fov related stuff
61 // fov of view is specified in the y direction, win_ratio is used to
62 // calculate the fov in the X direction = width/height
65 // width & height of window
66 int winWidth, winHeight;
68 // sin and cos of (fov / 2) in Y axis
69 double sin_fov_y, cos_fov_y;
70 double sinlon, coslon;
72 // slope of view frustum edge in eye space Y axis
75 // sin and cos of (fov / 2) in X axis
76 double sin_fov_x, cos_fov_x;
78 // slope of view frustum edge in eye space X axis
81 #if defined( USE_FAST_FOV_CLIP )
82 double fov_x_clip, fov_y_clip;
83 #endif // USE_FAST_FOV_CLIP
85 // View frustum cull ratio (% of tiles culled ... used for
86 // reporting purposes)
89 // Number of triangles rendered;
93 // absolute view position
96 // view position translated to scenery.center
99 // cartesion coordinates of current lon/lat if at sea level
100 // translated to scenery.center*/
101 Point3D cur_zero_elev;
103 // vector in cartesian coordinates from current position to the
104 // postion on the earth's surface the sun is directly over
107 // surface direction to go to head towards sun
108 MAT3vec surface_to_sun;
110 // vector in cartesian coordinates from current position to the
111 // postion on the earth's surface the moon is directly over
114 // surface direction to go to head towards moon
115 MAT3vec surface_to_moon;
117 // surface vector heading south
118 MAT3vec surface_south;
120 // surface vector heading east (used to unambiguously align sky
122 MAT3vec surface_east;
124 // local up vector (normal to the plane tangent to the earth's
125 // surface at the spot we are directly above
128 // up vector for the view (usually point straight up through the
129 // top of the aircraft
132 // the vector pointing straight out the nose of the aircraft
133 MAT3vec view_forward;
135 // Transformation matrix for eye coordinates to aircraft coordinates
138 // Transformation matrix for the view direction offset relative to
139 // the AIRCRAFT matrix
142 // Transformation matrix for aircraft coordinates to world
146 // Combined transformation from eye coordinates to world coordinates
147 MAT3mat EYE_TO_WORLD;
149 // Inverse of EYE_TO_WORLD which is a transformation from world
150 // coordinates to eye coordinates
151 MAT3mat WORLD_TO_EYE;
153 // Current model view matrix;
154 GLfloat MODEL_VIEW[16];
156 sgMat4 sgLOCAL, sgUP, sgVIEW, sgLARC_TO_SSG;
166 // Initialize a view class
169 // Basically, this is a modified version of the Mesa gluLookAt()
170 // function that's been modified slightly so we can capture the
171 // result (and use it later) otherwise this all gets calculated in
172 // OpenGL land and we don't have access to the results.
173 void LookAt( GLdouble eyex, GLdouble eyey, GLdouble eyez,
174 GLdouble centerx, GLdouble centery, GLdouble centerz,
175 GLdouble upx, GLdouble upy, GLdouble upz );
177 // Update the view volume, position, and orientation
178 void UpdateViewParams( void );
180 // Flag to request that UpdateFOV() be called next time
181 // UpdateViewMath() is run.
182 inline void force_update_fov_math() { update_fov = true; }
184 // Update the view parameters
185 void UpdateViewMath( FGInterface *f );
187 // Update the "World to Eye" transformation matrix
188 void UpdateWorldToEye( FGInterface *f );
190 // Update the field of view coefficients
191 void UpdateFOV( const fgOPTIONS& o );
193 // accessor functions
194 inline double get_view_offset() const { return view_offset; }
195 inline void set_view_offset( double a ) { view_offset = a; }
196 inline void inc_view_offset( double amt ) { view_offset += amt; }
197 inline double get_goal_view_offset() const { return goal_view_offset; }
198 inline void set_goal_view_offset( double a) { goal_view_offset = a; }
199 inline double get_win_ratio() const { return win_ratio; }
200 inline void set_win_ratio( double r ) { win_ratio = r; }
201 inline int get_winWidth() const { return winWidth; }
202 inline void set_winWidth( int w ) { winWidth = w; }
203 inline int get_winHeight() const { return winHeight; }
204 inline void set_winHeight( int h ) { winHeight = h; }
205 inline double get_slope_y() const { return slope_y; }
206 inline double get_slope_x() const { return slope_x; }
207 #if defined( USE_FAST_FOV_CLIP )
208 inline double get_fov_x_clip() const { return fov_x_clip; }
209 inline double get_fov_y_clip() const { return fov_y_clip; }
210 #endif // USE_FAST_FOV_CLIP
211 inline double get_vfc_ratio() const { return vfc_ratio; }
212 inline void set_vfc_ratio(double r) { vfc_ratio = r; }
213 inline int get_tris_rendered() const { return tris_rendered; }
214 inline void set_tris_rendered( int tris) { tris_rendered = tris; }
215 inline int get_tris_culled() const { return tris_culled; }
216 inline void set_tris_culled( int tris) { tris_culled = tris; }
217 inline Point3D get_abs_view_pos() const { return abs_view_pos; }
218 inline Point3D get_view_pos() const { return view_pos; }
219 inline Point3D get_cur_zero_elev() const { return cur_zero_elev; }
220 inline double *get_to_sun() { return to_sun; }
221 inline void set_to_sun( double x, double y, double z) {
226 inline double *get_surface_to_sun() { return surface_to_sun; }
227 inline void set_surface_to_sun( double x, double y, double z) {
228 surface_to_sun[0] = x;
229 surface_to_sun[1] = y;
230 surface_to_sun[2] = z;
232 inline double *get_to_moon() { return to_moon; }
233 inline void set_to_moon( double x, double y, double z) {
238 inline double *get_surface_to_moon() { return surface_to_moon; }
239 inline void set_surface_to_moon( double x, double y, double z) {
240 surface_to_moon[0] = x;
241 surface_to_moon[1] = y;
242 surface_to_moon[2] = z;
244 inline double *get_surface_south() { return surface_south; }
245 inline double *get_surface_east() { return surface_east; }
246 inline double *get_local_up() { return local_up; }
247 inline double *get_view_forward() { return view_forward; }
248 inline const MAT3mat *get_WORLD_TO_EYE() const { return &WORLD_TO_EYE; }
249 inline GLfloat *get_MODEL_VIEW() { return MODEL_VIEW; }
253 extern FGView current_view;