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 **************************************************************************/
27 #include <Main/views.h>
29 #include <Include/fg_constants.h>
31 #include <Flight/flight.h>
32 #include <Math/mat3.h>
33 #include <Math/polar.h>
34 #include <Math/vector.h>
35 #include <Scenery/scenery.h>
36 #include <Time/fg_time.h>
37 #include <Main/fg_debug.h>
39 /* This is a record containing current view parameters */
40 struct fgVIEW current_view;
43 /* Initialize a view structure */
44 void fgViewInit(struct fgVIEW *v) {
45 fgPrintf( FG_VIEW, FG_INFO, "Initializing View parameters\n");
48 v->goal_view_offset = 0.0;
52 /* Update the view parameters */
53 void fgViewUpdate(fgFLIGHT *f, struct fgVIEW *v, struct fgLIGHT *l) {
54 MAT3vec vec, forward, v0, minus_z;
55 MAT3mat R, TMP, UP, LOCAL, VIEW;
58 scenery.center.x = scenery.next_center.x;
59 scenery.center.y = scenery.next_center.y;
60 scenery.center.z = scenery.next_center.z;
62 /* calculate the cartesion coords of the current lat/lon/0 elev */
63 v->cur_zero_elev = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
64 FG_Sea_level_radius * FEET_TO_METER);
65 v->cur_zero_elev.x -= scenery.center.x;
66 v->cur_zero_elev.y -= scenery.center.y;
67 v->cur_zero_elev.z -= scenery.center.z;
69 /* calculate view position in current FG view coordinate system */
70 v->abs_view_pos = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
71 FG_Radius_to_vehicle * FEET_TO_METER + 1.0);
72 v->view_pos.x = v->abs_view_pos.x - scenery.center.x;
73 v->view_pos.y = v->abs_view_pos.y - scenery.center.y;
74 v->view_pos.z = v->abs_view_pos.z - scenery.center.z;
76 fgPrintf( FG_VIEW, FG_DEBUG, "Absolute view pos = %.4f, %.4f, %.4f\n",
77 v->abs_view_pos.x, v->abs_view_pos.y, v->abs_view_pos.z);
78 fgPrintf( FG_VIEW, FG_DEBUG, "Relative view pos = %.4f, %.4f, %.4f\n",
79 v->view_pos.x, v->view_pos.y, v->view_pos.z);
81 /* make a vector to the current view position */
82 MAT3_SET_VEC(v0, v->view_pos.x, v->view_pos.y, v->view_pos.z);
84 /* calculate vector to sun's position on the earth's surface */
85 v->to_sun[0] = l->fg_sunpos.x - (v->view_pos.x + scenery.center.x);
86 v->to_sun[1] = l->fg_sunpos.y - (v->view_pos.y + scenery.center.y);
87 v->to_sun[2] = l->fg_sunpos.z - (v->view_pos.z + scenery.center.z);
88 /* printf("Vector to sun = %.2f %.2f %.2f\n",
89 v->to_sun[0], v->to_sun[1], v->to_sun[2]); */
91 /* Derive the LOCAL aircraft rotation matrix (roll, pitch, yaw) */
92 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
93 MAT3rotate(R, vec, FG_Phi);
94 /* printf("Roll matrix\n"); */
95 /* MAT3print(R, stdout); */
97 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
98 /* MAT3mult_vec(vec, vec, R); */
99 MAT3rotate(TMP, vec, FG_Theta);
100 /* printf("Pitch matrix\n"); */
101 /* MAT3print(TMP, stdout); */
104 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
105 /* MAT3mult_vec(vec, vec, R); */
106 /* MAT3rotate(TMP, vec, FG_Psi - FG_PI_2); */
107 MAT3rotate(TMP, vec, -FG_Psi);
108 /* printf("Yaw matrix\n");
109 MAT3print(TMP, stdout); */
110 MAT3mult(LOCAL, R, TMP);
111 /* printf("LOCAL matrix\n"); */
112 /* MAT3print(LOCAL, stdout); */
114 /* Derive the local UP transformation matrix based on *geodetic*
116 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
117 MAT3rotate(R, vec, FG_Longitude); /* R = rotate about Z axis */
118 /* printf("Longitude matrix\n"); */
119 /* MAT3print(R, stdout); */
121 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
122 MAT3mult_vec(vec, vec, R);
123 MAT3rotate(TMP, vec, -FG_Latitude); /* TMP = rotate about X axis */
124 /* printf("Latitude matrix\n"); */
125 /* MAT3print(TMP, stdout); */
127 MAT3mult(UP, R, TMP);
128 /* printf("Local up matrix\n"); */
129 /* MAT3print(UP, stdout); */
131 MAT3_SET_VEC(v->local_up, 1.0, 0.0, 0.0);
132 MAT3mult_vec(v->local_up, v->local_up, UP);
134 /* printf("Local Up = (%.4f, %.4f, %.4f)\n",
135 v->local_up[0], v->local_up[1], v->local_up[2]); */
137 /* Alternative method to Derive local up vector based on
138 * *geodetic* coordinates */
139 /* alt_up = fgPolarToCart(FG_Longitude, FG_Latitude, 1.0); */
140 /* printf(" Alt Up = (%.4f, %.4f, %.4f)\n",
141 alt_up.x, alt_up.y, alt_up.z); */
143 /* Calculate the VIEW matrix */
144 MAT3mult(VIEW, LOCAL, UP);
145 /* printf("VIEW matrix\n"); */
146 /* MAT3print(VIEW, stdout); */
148 /* generate the current up, forward, and fwrd-view vectors */
149 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
150 MAT3mult_vec(v->view_up, vec, VIEW);
152 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
153 MAT3mult_vec(forward, vec, VIEW);
154 /* printf("Forward vector is (%.2f,%.2f,%.2f)\n", forward[0], forward[1],
157 MAT3rotate(TMP, v->view_up, v->view_offset);
158 MAT3mult_vec(v->view_forward, forward, TMP);
160 /* Given a vector from the view position to the point on the
161 * earth's surface the sun is directly over, map into onto the
162 * local plane representing "horizontal". */
163 map_vec_onto_cur_surface_plane(v->local_up, v0, v->to_sun,
165 MAT3_NORMALIZE_VEC(v->surface_to_sun, ntmp);
166 /* printf("Surface direction to sun is %.2f %.2f %.2f\n",
167 v->surface_to_sun[0], v->surface_to_sun[1], v->surface_to_sun[2]); */
168 /* printf("Should be close to zero = %.2f\n",
169 MAT3_DOT_PRODUCT(v->local_up, v->surface_to_sun)); */
171 /* Given a vector pointing straight down (-Z), map into onto the
172 * local plane representing "horizontal". This should give us the
173 * local direction for moving "south". */
174 MAT3_SET_VEC(minus_z, 0.0, 0.0, -1.0);
175 map_vec_onto_cur_surface_plane(v->local_up, v0, minus_z, v->surface_south);
176 MAT3_NORMALIZE_VEC(v->surface_south, ntmp);
177 /* printf("Surface direction directly south %.2f %.2f %.2f\n",
178 v->surface_south[0], v->surface_south[1], v->surface_south[2]); */
180 /* now calculate the surface east vector */
181 MAT3rotate(TMP, v->view_up, FG_PI_2);
182 MAT3mult_vec(v->surface_east, v->surface_south, TMP);
183 /* printf("Surface direction directly east %.2f %.2f %.2f\n",
184 v->surface_east[0], v->surface_east[1], v->surface_east[2]); */
185 /* printf("Should be close to zero = %.2f\n",
186 MAT3_DOT_PRODUCT(v->surface_south, v->surface_east)); */
191 /* Revision 1.15 1998/02/20 00:16:24 curt
192 /* Thursday's tweaks.
194 * Revision 1.14 1998/02/09 15:07:50 curt
197 * Revision 1.13 1998/02/07 15:29:45 curt
198 * Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
199 * <chotchkiss@namg.us.anritsu.com>
201 * Revision 1.12 1998/01/29 00:50:28 curt
202 * Added a view record field for absolute x, y, z position.
204 * Revision 1.11 1998/01/27 00:47:58 curt
205 * Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
206 * system and commandline/config file processing code.
208 * Revision 1.10 1998/01/19 19:27:09 curt
209 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
210 * This should simplify things tremendously.
212 * Revision 1.9 1998/01/13 00:23:09 curt
213 * Initial changes to support loading and management of scenery tiles. Note,
214 * there's still a fair amount of work left to be done.
216 * Revision 1.8 1997/12/30 22:22:33 curt
217 * Further integration of event manager.
219 * Revision 1.7 1997/12/30 20:47:45 curt
220 * Integrated new event manager with subsystem initializations.
222 * Revision 1.6 1997/12/22 04:14:32 curt
223 * Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
225 * Revision 1.5 1997/12/18 04:07:02 curt
226 * Worked on properly translating and positioning the sky dome.
228 * Revision 1.4 1997/12/17 23:13:36 curt
229 * Began working on rendering a sky.
231 * Revision 1.3 1997/12/15 23:54:50 curt
232 * Add xgl wrappers for debugging.
233 * Generate terrain normals on the fly.
235 * Revision 1.2 1997/12/10 22:37:48 curt
236 * Prepended "fg" on the name of all global structures that didn't have it yet.
237 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
239 * Revision 1.1 1997/08/27 21:31:17 curt