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 /* calculate the cartesion coords of the current lat/lon/0 elev */
59 v->cur_zero_elev = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
60 FG_Sea_level_radius * FEET_TO_METER);
61 v->cur_zero_elev.x -= scenery.center.x;
62 v->cur_zero_elev.y -= scenery.center.y;
63 v->cur_zero_elev.z -= scenery.center.z;
65 /* calculate view position in current FG view coordinate system */
66 v->abs_view_pos = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
67 FG_Radius_to_vehicle * FEET_TO_METER + 1.0);
68 v->view_pos.x = v->abs_view_pos.x - scenery.center.x;
69 v->view_pos.y = v->abs_view_pos.y - scenery.center.y;
70 v->view_pos.z = v->abs_view_pos.z - scenery.center.z;
72 fgPrintf( FG_VIEW, FG_DEBUG, "Absolute view pos = %.4f, %.4f, %.4f\n",
73 v->abs_view_pos.x, v->abs_view_pos.y, v->abs_view_pos.z);
74 fgPrintf( FG_VIEW, FG_DEBUG, "Relative view pos = %.4f, %.4f, %.4f\n",
75 v->view_pos.x, v->view_pos.y, v->view_pos.z);
77 /* make a vector to the current view position */
78 MAT3_SET_VEC(v0, v->view_pos.x, v->view_pos.y, v->view_pos.z);
80 /* calculate vector to sun's position on the earth's surface */
81 v->to_sun[0] = l->fg_sunpos.x - (v->view_pos.x + scenery.center.x);
82 v->to_sun[1] = l->fg_sunpos.y - (v->view_pos.y + scenery.center.y);
83 v->to_sun[2] = l->fg_sunpos.z - (v->view_pos.z + scenery.center.z);
84 /* printf("Vector to sun = %.2f %.2f %.2f\n",
85 v->to_sun[0], v->to_sun[1], v->to_sun[2]); */
87 /* Derive the LOCAL aircraft rotation matrix (roll, pitch, yaw) */
88 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
89 MAT3rotate(R, vec, FG_Phi);
90 /* printf("Roll matrix\n"); */
91 /* MAT3print(R, stdout); */
93 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
94 /* MAT3mult_vec(vec, vec, R); */
95 MAT3rotate(TMP, vec, FG_Theta);
96 /* printf("Pitch matrix\n"); */
97 /* MAT3print(TMP, stdout); */
100 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
101 /* MAT3mult_vec(vec, vec, R); */
102 /* MAT3rotate(TMP, vec, FG_Psi - FG_PI_2); */
103 MAT3rotate(TMP, vec, -FG_Psi);
104 /* printf("Yaw matrix\n");
105 MAT3print(TMP, stdout); */
106 MAT3mult(LOCAL, R, TMP);
107 /* printf("LOCAL matrix\n"); */
108 /* MAT3print(LOCAL, stdout); */
110 /* Derive the local UP transformation matrix based on *geodetic*
112 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
113 MAT3rotate(R, vec, FG_Longitude); /* R = rotate about Z axis */
114 /* printf("Longitude matrix\n"); */
115 /* MAT3print(R, stdout); */
117 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
118 MAT3mult_vec(vec, vec, R);
119 MAT3rotate(TMP, vec, -FG_Latitude); /* TMP = rotate about X axis */
120 /* printf("Latitude matrix\n"); */
121 /* MAT3print(TMP, stdout); */
123 MAT3mult(UP, R, TMP);
124 /* printf("Local up matrix\n"); */
125 /* MAT3print(UP, stdout); */
127 MAT3_SET_VEC(v->local_up, 1.0, 0.0, 0.0);
128 MAT3mult_vec(v->local_up, v->local_up, UP);
130 /* printf("Local Up = (%.4f, %.4f, %.4f)\n",
131 v->local_up[0], v->local_up[1], v->local_up[2]); */
133 /* Alternative method to Derive local up vector based on
134 * *geodetic* coordinates */
135 /* alt_up = fgPolarToCart(FG_Longitude, FG_Latitude, 1.0); */
136 /* printf(" Alt Up = (%.4f, %.4f, %.4f)\n",
137 alt_up.x, alt_up.y, alt_up.z); */
139 /* Derive the VIEW matrix */
140 MAT3mult(VIEW, LOCAL, UP);
141 /* printf("VIEW matrix\n"); */
142 /* MAT3print(VIEW, stdout); */
144 /* generate the current up, forward, and fwrd-view vectors */
145 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
146 MAT3mult_vec(v->view_up, vec, VIEW);
148 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
149 MAT3mult_vec(forward, vec, VIEW);
150 /* printf("Forward vector is (%.2f,%.2f,%.2f)\n", forward[0], forward[1],
153 MAT3rotate(TMP, v->view_up, v->view_offset);
154 MAT3mult_vec(v->view_forward, forward, TMP);
156 /* Given a vector from the view position to the point on the
157 * earth's surface the sun is directly over, map into onto the
158 * local plane representing "horizontal". */
159 map_vec_onto_cur_surface_plane(v->local_up, v0, v->to_sun,
161 MAT3_NORMALIZE_VEC(v->surface_to_sun, ntmp);
162 /* printf("Surface direction to sun is %.2f %.2f %.2f\n",
163 v->surface_to_sun[0], v->surface_to_sun[1], v->surface_to_sun[2]); */
164 /* printf("Should be close to zero = %.2f\n",
165 MAT3_DOT_PRODUCT(v->local_up, v->surface_to_sun)); */
167 /* Given a vector pointing straight down (-Z), map into onto the
168 * local plane representing "horizontal". This should give us the
169 * local direction for moving "south". */
170 MAT3_SET_VEC(minus_z, 0.0, 0.0, -1.0);
171 map_vec_onto_cur_surface_plane(v->local_up, v0, minus_z, v->surface_south);
172 MAT3_NORMALIZE_VEC(v->surface_south, ntmp);
173 /* printf("Surface direction directly south %.2f %.2f %.2f\n",
174 v->surface_south[0], v->surface_south[1], v->surface_south[2]); */
176 /* now calculate the surface east vector */
177 MAT3rotate(TMP, v->view_up, FG_PI_2);
178 MAT3mult_vec(v->surface_east, v->surface_south, TMP);
179 /* printf("Surface direction directly east %.2f %.2f %.2f\n",
180 v->surface_east[0], v->surface_east[1], v->surface_east[2]); */
181 /* printf("Should be close to zero = %.2f\n",
182 MAT3_DOT_PRODUCT(v->surface_south, v->surface_east)); */
187 /* Revision 1.13 1998/02/07 15:29:45 curt
188 /* Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
189 /* <chotchkiss@namg.us.anritsu.com>
191 * Revision 1.12 1998/01/29 00:50:28 curt
192 * Added a view record field for absolute x, y, z position.
194 * Revision 1.11 1998/01/27 00:47:58 curt
195 * Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
196 * system and commandline/config file processing code.
198 * Revision 1.10 1998/01/19 19:27:09 curt
199 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
200 * This should simplify things tremendously.
202 * Revision 1.9 1998/01/13 00:23:09 curt
203 * Initial changes to support loading and management of scenery tiles. Note,
204 * there's still a fair amount of work left to be done.
206 * Revision 1.8 1997/12/30 22:22:33 curt
207 * Further integration of event manager.
209 * Revision 1.7 1997/12/30 20:47:45 curt
210 * Integrated new event manager with subsystem initializations.
212 * Revision 1.6 1997/12/22 04:14:32 curt
213 * Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
215 * Revision 1.5 1997/12/18 04:07:02 curt
216 * Worked on properly translating and positioning the sky dome.
218 * Revision 1.4 1997/12/17 23:13:36 curt
219 * Began working on rendering a sky.
221 * Revision 1.3 1997/12/15 23:54:50 curt
222 * Add xgl wrappers for debugging.
223 * Generate terrain normals on the fly.
225 * Revision 1.2 1997/12/10 22:37:48 curt
226 * Prepended "fg" on the name of all global structures that didn't have it yet.
227 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
229 * Revision 1.1 1997/08/27 21:31:17 curt