1 /**************************************************************************
2 * views.c -- data structures and routines for managing and view parameters.
4 * Written by Curtis Olson, started August 1997.
6 * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
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.
23 * (Log is kept at end of this file)
24 **************************************************************************/
31 #include <Debug/fg_debug.h>
32 #include <Flight/flight.h>
33 #include <Include/fg_constants.h>
34 #include <Math/mat3.h>
35 #include <Math/polar.h>
36 #include <Math/vector.h>
37 #include <Scenery/scenery.h>
38 #include <Time/fg_time.hxx>
43 /* This is a record containing current view parameters */
44 struct fgVIEW current_view;
47 /* Initialize a view structure */
48 void fgViewInit(struct fgVIEW *v) {
49 fgPrintf( FG_VIEW, FG_INFO, "Initializing View parameters\n");
52 v->goal_view_offset = 0.0;
56 /* Update the view parameters */
57 void fgViewUpdate(fgFLIGHT *f, struct fgVIEW *v, fgLIGHT *l) {
58 MAT3vec vec, forward, v0, minus_z;
59 MAT3mat R, TMP, UP, LOCAL, VIEW;
62 scenery.center.x = scenery.next_center.x;
63 scenery.center.y = scenery.next_center.y;
64 scenery.center.z = scenery.next_center.z;
66 /* calculate the cartesion coords of the current lat/lon/0 elev */
67 v->cur_zero_elev = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
68 FG_Sea_level_radius * FEET_TO_METER);
69 v->cur_zero_elev.x -= scenery.center.x;
70 v->cur_zero_elev.y -= scenery.center.y;
71 v->cur_zero_elev.z -= scenery.center.z;
73 /* calculate view position in current FG view coordinate system */
74 v->abs_view_pos = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
75 FG_Radius_to_vehicle * FEET_TO_METER + 1.0);
76 v->view_pos.x = v->abs_view_pos.x - scenery.center.x;
77 v->view_pos.y = v->abs_view_pos.y - scenery.center.y;
78 v->view_pos.z = v->abs_view_pos.z - scenery.center.z;
80 fgPrintf( FG_VIEW, FG_DEBUG, "Absolute view pos = %.4f, %.4f, %.4f\n",
81 v->abs_view_pos.x, v->abs_view_pos.y, v->abs_view_pos.z);
82 fgPrintf( FG_VIEW, FG_DEBUG, "Relative view pos = %.4f, %.4f, %.4f\n",
83 v->view_pos.x, v->view_pos.y, v->view_pos.z);
85 /* make a vector to the current view position */
86 MAT3_SET_VEC(v0, v->view_pos.x, v->view_pos.y, v->view_pos.z);
88 /* calculate vector to sun's position on the earth's surface */
89 v->to_sun[0] = l->fg_sunpos.x - (v->view_pos.x + scenery.center.x);
90 v->to_sun[1] = l->fg_sunpos.y - (v->view_pos.y + scenery.center.y);
91 v->to_sun[2] = l->fg_sunpos.z - (v->view_pos.z + scenery.center.z);
92 /* printf("Vector to sun = %.2f %.2f %.2f\n",
93 v->to_sun[0], v->to_sun[1], v->to_sun[2]); */
95 /* Derive the LOCAL aircraft rotation matrix (roll, pitch, yaw) */
96 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
97 MAT3rotate(R, vec, FG_Phi);
98 /* printf("Roll matrix\n"); */
99 /* MAT3print(R, stdout); */
101 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
102 /* MAT3mult_vec(vec, vec, R); */
103 MAT3rotate(TMP, vec, FG_Theta);
104 /* printf("Pitch matrix\n"); */
105 /* MAT3print(TMP, stdout); */
108 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
109 /* MAT3mult_vec(vec, vec, R); */
110 /* MAT3rotate(TMP, vec, FG_Psi - FG_PI_2); */
111 MAT3rotate(TMP, vec, -FG_Psi);
112 /* printf("Yaw matrix\n");
113 MAT3print(TMP, stdout); */
114 MAT3mult(LOCAL, R, TMP);
115 /* printf("LOCAL matrix\n"); */
116 /* MAT3print(LOCAL, stdout); */
118 /* Derive the local UP transformation matrix based on *geodetic*
120 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
121 MAT3rotate(R, vec, FG_Longitude); /* R = rotate about Z axis */
122 /* printf("Longitude matrix\n"); */
123 /* MAT3print(R, stdout); */
125 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
126 MAT3mult_vec(vec, vec, R);
127 MAT3rotate(TMP, vec, -FG_Latitude); /* TMP = rotate about X axis */
128 /* printf("Latitude matrix\n"); */
129 /* MAT3print(TMP, stdout); */
131 MAT3mult(UP, R, TMP);
132 /* printf("Local up matrix\n"); */
133 /* MAT3print(UP, stdout); */
135 MAT3_SET_VEC(v->local_up, 1.0, 0.0, 0.0);
136 MAT3mult_vec(v->local_up, v->local_up, UP);
138 /* printf("Local Up = (%.4f, %.4f, %.4f)\n",
139 v->local_up[0], v->local_up[1], v->local_up[2]); */
141 /* Alternative method to Derive local up vector based on
142 * *geodetic* coordinates */
143 /* alt_up = fgPolarToCart(FG_Longitude, FG_Latitude, 1.0); */
144 /* printf(" Alt Up = (%.4f, %.4f, %.4f)\n",
145 alt_up.x, alt_up.y, alt_up.z); */
147 /* Calculate the VIEW matrix */
148 MAT3mult(VIEW, LOCAL, UP);
149 /* printf("VIEW matrix\n"); */
150 /* MAT3print(VIEW, stdout); */
152 /* generate the current up, forward, and fwrd-view vectors */
153 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
154 MAT3mult_vec(v->view_up, vec, VIEW);
156 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
157 MAT3mult_vec(forward, vec, VIEW);
158 /* printf("Forward vector is (%.2f,%.2f,%.2f)\n", forward[0], forward[1],
161 MAT3rotate(TMP, v->view_up, v->view_offset);
162 MAT3mult_vec(v->view_forward, forward, TMP);
164 /* Given a vector from the view position to the point on the
165 * earth's surface the sun is directly over, map into onto the
166 * local plane representing "horizontal". */
167 map_vec_onto_cur_surface_plane(v->local_up, v0, v->to_sun,
169 MAT3_NORMALIZE_VEC(v->surface_to_sun, ntmp);
170 /* printf("Surface direction to sun is %.2f %.2f %.2f\n",
171 v->surface_to_sun[0], v->surface_to_sun[1], v->surface_to_sun[2]); */
172 /* printf("Should be close to zero = %.2f\n",
173 MAT3_DOT_PRODUCT(v->local_up, v->surface_to_sun)); */
175 /* Given a vector pointing straight down (-Z), map into onto the
176 * local plane representing "horizontal". This should give us the
177 * local direction for moving "south". */
178 MAT3_SET_VEC(minus_z, 0.0, 0.0, -1.0);
179 map_vec_onto_cur_surface_plane(v->local_up, v0, minus_z, v->surface_south);
180 MAT3_NORMALIZE_VEC(v->surface_south, ntmp);
181 /* printf("Surface direction directly south %.2f %.2f %.2f\n",
182 v->surface_south[0], v->surface_south[1], v->surface_south[2]); */
184 /* now calculate the surface east vector */
185 MAT3rotate(TMP, v->view_up, FG_PI_2);
186 MAT3mult_vec(v->surface_east, v->surface_south, TMP);
187 /* printf("Surface direction directly east %.2f %.2f %.2f\n",
188 v->surface_east[0], v->surface_east[1], v->surface_east[2]); */
189 /* printf("Should be close to zero = %.2f\n",
190 MAT3_DOT_PRODUCT(v->surface_south, v->surface_east)); */
195 /* Revision 1.2 1998/04/24 00:49:22 curt
196 /* Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
197 /* Trying out some different option parsing code.
198 /* Some code reorganization.
200 * Revision 1.1 1998/04/22 13:25:45 curt
201 * C++ - ifing the code.
202 * Starting a bit of reorganization of lighting code.
204 * Revision 1.16 1998/04/18 04:11:29 curt
205 * Moved fg_debug to it's own library, added zlib support.
207 * Revision 1.15 1998/02/20 00:16:24 curt
210 * Revision 1.14 1998/02/09 15:07:50 curt
213 * Revision 1.13 1998/02/07 15:29:45 curt
214 * Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
215 * <chotchkiss@namg.us.anritsu.com>
217 * Revision 1.12 1998/01/29 00:50:28 curt
218 * Added a view record field for absolute x, y, z position.
220 * Revision 1.11 1998/01/27 00:47:58 curt
221 * Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
222 * system and commandline/config file processing code.
224 * Revision 1.10 1998/01/19 19:27:09 curt
225 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
226 * This should simplify things tremendously.
228 * Revision 1.9 1998/01/13 00:23:09 curt
229 * Initial changes to support loading and management of scenery tiles. Note,
230 * there's still a fair amount of work left to be done.
232 * Revision 1.8 1997/12/30 22:22:33 curt
233 * Further integration of event manager.
235 * Revision 1.7 1997/12/30 20:47:45 curt
236 * Integrated new event manager with subsystem initializations.
238 * Revision 1.6 1997/12/22 04:14:32 curt
239 * Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
241 * Revision 1.5 1997/12/18 04:07:02 curt
242 * Worked on properly translating and positioning the sky dome.
244 * Revision 1.4 1997/12/17 23:13:36 curt
245 * Began working on rendering a sky.
247 * Revision 1.3 1997/12/15 23:54:50 curt
248 * Add xgl wrappers for debugging.
249 * Generate terrain normals on the fly.
251 * Revision 1.2 1997/12/10 22:37:48 curt
252 * Prepended "fg" on the name of all global structures that didn't have it yet.
253 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
255 * Revision 1.1 1997/08/27 21:31:17 curt