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/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>
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 printf("Initializing View parameters\n");
48 v->goal_view_offset = 0.0;
52 /* Update the view parameters */
53 void fgViewUpdate(struct 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->view_pos = fgPolarToCart(FG_Longitude, FG_Lat_geocentric,
67 FG_Radius_to_vehicle * FEET_TO_METER + 1.0);
68 v->view_pos.x -= scenery.center.x;
69 v->view_pos.y -= scenery.center.y;
70 v->view_pos.z -= scenery.center.z;
72 printf("View pos = %.4f, %.4f, %.4f\n",
73 v->view_pos.x, v->view_pos.y, v->view_pos.z);
75 /* make a vector to the current view position */
76 MAT3_SET_VEC(v0, v->view_pos.x, v->view_pos.y, v->view_pos.z);
78 /* calculate vector to sun's position on the earth's surface */
79 v->to_sun[0] = l->fg_sunpos.x - (v->view_pos.x + scenery.center.x);
80 v->to_sun[1] = l->fg_sunpos.y - (v->view_pos.y + scenery.center.y);
81 v->to_sun[2] = l->fg_sunpos.z - (v->view_pos.z + scenery.center.z);
82 /* printf("Vector to sun = %.2f %.2f %.2f\n",
83 v->to_sun[0], v->to_sun[1], v->to_sun[2]); */
85 /* Derive the LOCAL aircraft rotation matrix (roll, pitch, yaw) */
86 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
87 MAT3rotate(R, vec, FG_Phi);
88 /* printf("Roll matrix\n"); */
89 /* MAT3print(R, stdout); */
91 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
92 /* MAT3mult_vec(vec, vec, R); */
93 MAT3rotate(TMP, vec, FG_Theta);
94 /* printf("Pitch matrix\n"); */
95 /* MAT3print(TMP, stdout); */
98 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
99 /* MAT3mult_vec(vec, vec, R); */
100 /* MAT3rotate(TMP, vec, FG_Psi - FG_PI_2); */
101 MAT3rotate(TMP, vec, -FG_Psi);
102 /* printf("Yaw matrix\n");
103 MAT3print(TMP, stdout); */
104 MAT3mult(LOCAL, R, TMP);
105 /* printf("LOCAL matrix\n"); */
106 /* MAT3print(LOCAL, stdout); */
108 /* Derive the local UP transformation matrix based on *geodetic*
110 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
111 MAT3rotate(R, vec, FG_Longitude); /* R = rotate about Z axis */
112 /* printf("Longitude matrix\n"); */
113 /* MAT3print(R, stdout); */
115 MAT3_SET_VEC(vec, 0.0, 1.0, 0.0);
116 MAT3mult_vec(vec, vec, R);
117 MAT3rotate(TMP, vec, -FG_Latitude); /* TMP = rotate about X axis */
118 /* printf("Latitude matrix\n"); */
119 /* MAT3print(TMP, stdout); */
121 MAT3mult(UP, R, TMP);
122 /* printf("Local up matrix\n"); */
123 /* MAT3print(UP, stdout); */
125 MAT3_SET_VEC(v->local_up, 1.0, 0.0, 0.0);
126 MAT3mult_vec(v->local_up, v->local_up, UP);
128 /* printf("Local Up = (%.4f, %.4f, %.4f)\n",
129 v->local_up[0], v->local_up[1], v->local_up[2]); */
131 /* Alternative method to Derive local up vector based on
132 * *geodetic* coordinates */
133 /* alt_up = fgPolarToCart(FG_Longitude, FG_Latitude, 1.0); */
134 /* printf(" Alt Up = (%.4f, %.4f, %.4f)\n",
135 alt_up.x, alt_up.y, alt_up.z); */
137 /* Derive the VIEW matrix */
138 MAT3mult(VIEW, LOCAL, UP);
139 /* printf("VIEW matrix\n"); */
140 /* MAT3print(VIEW, stdout); */
142 /* generate the current up, forward, and fwrd-view vectors */
143 MAT3_SET_VEC(vec, 1.0, 0.0, 0.0);
144 MAT3mult_vec(v->view_up, vec, VIEW);
146 MAT3_SET_VEC(vec, 0.0, 0.0, 1.0);
147 MAT3mult_vec(forward, vec, VIEW);
148 /* printf("Forward vector is (%.2f,%.2f,%.2f)\n", forward[0], forward[1],
151 MAT3rotate(TMP, v->view_up, v->view_offset);
152 MAT3mult_vec(v->view_forward, forward, TMP);
154 /* Given a vector from the view position to the point on the
155 * earth's surface the sun is directly over, map into onto the
156 * local plane representing "horizontal". */
157 map_vec_onto_cur_surface_plane(v->local_up, v0, v->to_sun,
159 MAT3_NORMALIZE_VEC(v->surface_to_sun, ntmp);
160 /* printf("Surface direction to sun is %.2f %.2f %.2f\n",
161 v->surface_to_sun[0], v->surface_to_sun[1], v->surface_to_sun[2]); */
162 /* printf("Should be close to zero = %.2f\n",
163 MAT3_DOT_PRODUCT(v->local_up, v->surface_to_sun)); */
165 /* Given a vector pointing straight down (-Z), map into onto the
166 * local plane representing "horizontal". This should give us the
167 * local direction for moving "south". */
168 MAT3_SET_VEC(minus_z, 0.0, 0.0, -1.0);
169 map_vec_onto_cur_surface_plane(v->local_up, v0, minus_z, v->surface_south);
170 MAT3_NORMALIZE_VEC(v->surface_south, ntmp);
171 /* printf("Surface direction directly south %.2f %.2f %.2f\n",
172 v->surface_south[0], v->surface_south[1], v->surface_south[2]); */
174 /* now calculate the surface east vector */
175 MAT3rotate(TMP, v->view_up, FG_PI_2);
176 MAT3mult_vec(v->surface_east, v->surface_south, TMP);
177 /* printf("Surface direction directly east %.2f %.2f %.2f\n",
178 v->surface_east[0], v->surface_east[1], v->surface_east[2]); */
179 /* printf("Should be close to zero = %.2f\n",
180 MAT3_DOT_PRODUCT(v->surface_south, v->surface_east)); */
185 /* Revision 1.10 1998/01/19 19:27:09 curt
186 /* Merged in make system changes from Bob Kuehne <rpk@sgi.com>
187 /* This should simplify things tremendously.
189 * Revision 1.9 1998/01/13 00:23:09 curt
190 * Initial changes to support loading and management of scenery tiles. Note,
191 * there's still a fair amount of work left to be done.
193 * Revision 1.8 1997/12/30 22:22:33 curt
194 * Further integration of event manager.
196 * Revision 1.7 1997/12/30 20:47:45 curt
197 * Integrated new event manager with subsystem initializations.
199 * Revision 1.6 1997/12/22 04:14:32 curt
200 * Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
202 * Revision 1.5 1997/12/18 04:07:02 curt
203 * Worked on properly translating and positioning the sky dome.
205 * Revision 1.4 1997/12/17 23:13:36 curt
206 * Began working on rendering a sky.
208 * Revision 1.3 1997/12/15 23:54:50 curt
209 * Add xgl wrappers for debugging.
210 * Generate terrain normals on the fly.
212 * Revision 1.2 1997/12/10 22:37:48 curt
213 * Prepended "fg" on the name of all global structures that didn't have it yet.
214 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
216 * Revision 1.1 1997/08/27 21:31:17 curt