2 // views.cxx -- 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)
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 // 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 // Calculate 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 // make a vector to the current view position
155 MAT3_SET_VEC(v0, v->view_pos.x, v->view_pos.y, v->view_pos.z);
157 // Given a vector pointing straight down (-Z), map into onto the
158 // local plane representing "horizontal". This should give us the
159 // local direction for moving "south".
160 MAT3_SET_VEC(minus_z, 0.0, 0.0, -1.0);
161 map_vec_onto_cur_surface_plane(v->local_up, v0, minus_z, v->surface_south);
162 MAT3_NORMALIZE_VEC(v->surface_south, ntmp);
163 // printf( "Surface direction directly south %.2f %.2f %.2f\n",
164 // v->surface_south[0], v->surface_south[1], v->surface_south[2]);
166 // now calculate the surface east vector
167 MAT3rotate(TMP, v->view_up, FG_PI_2);
168 MAT3mult_vec(v->surface_east, v->surface_south, TMP);
169 // printf( "Surface direction directly east %.2f %.2f %.2f\n",
170 // v->surface_east[0], v->surface_east[1], v->surface_east[2]);
171 // printf( "Should be close to zero = %.2f\n",
172 // MAT3_DOT_PRODUCT(v->surface_south, v->surface_east));
177 // Revision 1.3 1998/04/25 20:24:02 curt
178 // Cleaned up initialization sequence to eliminate interdependencies
179 // between sun position, lighting, and view position. This creates a
180 // valid single pass initialization path.
182 // Revision 1.2 1998/04/24 00:49:22 curt
183 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
184 // Trying out some different option parsing code.
185 // Some code reorganization.
187 // Revision 1.1 1998/04/22 13:25:45 curt
188 // C++ - ifing the code.
189 // Starting a bit of reorganization of lighting code.
191 // Revision 1.16 1998/04/18 04:11:29 curt
192 // Moved fg_debug to it's own library, added zlib support.
194 // Revision 1.15 1998/02/20 00:16:24 curt
195 // Thursday's tweaks.
197 // Revision 1.14 1998/02/09 15:07:50 curt
200 // Revision 1.13 1998/02/07 15:29:45 curt
201 // Incorporated HUD changes and struct/typedef changes from Charlie Hotchkiss
202 // <chotchkiss@namg.us.anritsu.com>
204 // Revision 1.12 1998/01/29 00:50:28 curt
205 // Added a view record field for absolute x, y, z position.
207 // Revision 1.11 1998/01/27 00:47:58 curt
208 // Incorporated Paul Bleisch's <bleisch@chromatic.com> new debug message
209 // system and commandline/config file processing code.
211 // Revision 1.10 1998/01/19 19:27:09 curt
212 // Merged in make system changes from Bob Kuehne <rpk@sgi.com>
213 // This should simplify things tremendously.
215 // Revision 1.9 1998/01/13 00:23:09 curt
216 // Initial changes to support loading and management of scenery tiles. Note,
217 // there's still a fair amount of work left to be done.
219 // Revision 1.8 1997/12/30 22:22:33 curt
220 // Further integration of event manager.
222 // Revision 1.7 1997/12/30 20:47:45 curt
223 // Integrated new event manager with subsystem initializations.
225 // Revision 1.6 1997/12/22 04:14:32 curt
226 // Aligned sky with sun so dusk/dawn effects can be correct relative to the sun.
228 // Revision 1.5 1997/12/18 04:07:02 curt
229 // Worked on properly translating and positioning the sky dome.
231 // Revision 1.4 1997/12/17 23:13:36 curt
232 // Began working on rendering a sky.
234 // Revision 1.3 1997/12/15 23:54:50 curt
235 // Add xgl wrappers for debugging.
236 // Generate terrain normals on the fly.
238 // Revision 1.2 1997/12/10 22:37:48 curt
239 // Prepended "fg" on the name of all global structures that didn't have it yet.
240 // i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
242 // Revision 1.1 1997/08/27 21:31:17 curt