1 // sky.cxx -- ssg based sky model
3 // Written by Curtis Olson, started December 1997.
4 // SSG-ified by Curtis Olson, February 2000.
6 // Copyright (C) 1997-2000 Curtis L. Olson - curt@flightgear.org
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.
29 #include <plib/ssg.h> // plib include
35 SGSky::SGSky( void ) {
40 SGSky::~SGSky( void ) {
44 // initialize the sky and connect the components to the scene graph at
45 // the provided branch
46 void SGSky::build( double sun_size, double moon_size,
47 int nplanets, sgdVec3 *planet_data,
49 int nstars, sgdVec3 *star_data, double star_dist )
51 pre_root = new ssgRoot;
52 post_root = new ssgRoot;
54 pre_selector = new ssgSelector;
55 post_selector = new ssgSelector;
57 pre_transform = new ssgTransform;
58 post_transform = new ssgTransform;
61 pre_transform -> addKid( dome->build() );
63 planets = new SGStars;
64 pre_transform -> addKid( planets->build(nplanets, planet_data,
69 pre_transform -> addKid( stars->build(nstars, star_data, star_dist) );
72 pre_transform -> addKid( moon->build(tex_path, moon_size) );
75 pre_transform -> addKid( oursun->build(tex_path, sun_size) );
77 pre_selector->addKid( pre_transform );
78 pre_selector->clrTraversalMaskBits( SSGTRAV_HOT );
80 post_selector->addKid( post_transform );
81 post_selector->clrTraversalMaskBits( SSGTRAV_HOT );
83 pre_root->addKid( pre_selector );
84 post_root->addKid( post_selector );
88 // repaint the sky components based on current value of sun_angle,
89 // sky, and fog colors.
91 // sun angle in degrees relative to verticle
92 // 0 degrees = high noon
93 // 90 degrees = sun rise/set
94 // 180 degrees = darkest midnight
95 bool SGSky::repaint( sgVec4 sky_color, sgVec4 fog_color,
96 double sun_angle, double moon_angle,
97 int nplanets, sgdVec3 *planet_data,
98 int nstars, sgdVec3 *star_data )
100 dome->repaint( sky_color, fog_color, sun_angle );
101 oursun->repaint( sun_angle );
102 moon->repaint( moon_angle );
103 planets->repaint( sun_angle, nplanets, planet_data );
104 stars->repaint( sun_angle, nstars, star_data );
106 for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
107 cloud_layers[i]->repaint( fog_color );
114 // reposition the sky at the specified origin and orientation
116 // lon specifies a rotation about the Z axis
117 // lat specifies a rotation about the new Y axis
118 // spin specifies a rotation about the new Z axis (this allows
119 // additional orientation for the sunrise/set effects and is used by
120 // the skydome and perhaps clouds.
121 bool SGSky::reposition( sgVec3 view_pos, sgVec3 zero_elev, sgVec3 view_up,
122 double lon, double lat, double spin,
124 double sun_ra, double sun_dec, double sun_dist,
125 double moon_ra, double moon_dec, double moon_dist )
127 double angle = gst * 15; // degrees
128 dome->reposition( zero_elev, lon, lat, spin );
129 oursun->reposition( view_pos, angle, sun_ra, sun_dec, sun_dist );
130 moon->reposition( view_pos, angle, moon_ra, moon_dec, moon_dist );
131 planets->reposition( view_pos, angle );
132 stars->reposition( view_pos, angle );
134 for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
135 cloud_layers[i]->reposition( zero_elev, view_up, lon, lat );
142 // draw background portions of the sky
143 void SGSky::draw_background() {
144 ssgCullAndDraw( pre_root );
148 // draw scenery elements of the sky
149 void SGSky::draw_scene() {
150 ssgCullAndDraw( post_root );
154 void SGSky::add_cloud_layer( double asl ) {
155 SGCloudLayer *layer = new SGCloudLayer;
156 post_transform -> addKid( layer->build(tex_path, 20000.0f, asl) );
157 cloud_layers.push_back( layer );