/************************************************************************** * sky.c -- model sky with an upside down "bowl" * * Written by Curtis Olson, started December 1997. * * Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id$ * (Log is kept at end of this file) **************************************************************************/ #ifdef WIN32 # include #endif #include /* #include #include #include */ #include #include "../XGL/xgl.h" #include "sky.h" #include "../Time/event.h" #include "../Time/fg_time.h" #include "../Aircraft/aircraft.h" #include "../Flight/flight.h" #include "../Include/constants.h" #include "../Main/views.h" #include "../Math/fg_random.h" /* #include "../Include/general.h" */ /* in meters of course */ #define CENTER_ELEV 25000.0 #define INNER_RADIUS 50000.0 #define INNER_ELEV 20000.0 #define MIDDLE_RADIUS 70000.0 #define MIDDLE_ELEV 8000.0 #define OUTER_RADIUS 80000.0 #define OUTER_ELEV 0.0 static float inner_vertex[12][3]; static float middle_vertex[12][3]; static float outer_vertex[12][3]; static float inner_color[12][4]; static float middle_color[12][4]; static float outer_color[12][4]; /* Calculate the sky structure vertices */ void fgSkyVerticesInit() { float theta; int i; printf(" Generating the sky dome vertices.\n"); for ( i = 0; i < 12; i++ ) { theta = (i * 30.0) * DEG_TO_RAD; inner_vertex[i][0] = cos(theta) * INNER_RADIUS; inner_vertex[i][1] = sin(theta) * INNER_RADIUS; inner_vertex[i][2] = INNER_ELEV; /* printf(" %.2f %.2f\n", cos(theta) * INNER_RADIUS, sin(theta) * INNER_RADIUS); */ middle_vertex[i][0] = cos((double)theta) * MIDDLE_RADIUS; middle_vertex[i][1] = sin((double)theta) * MIDDLE_RADIUS; middle_vertex[i][2] = MIDDLE_ELEV; outer_vertex[i][0] = cos((double)theta) * OUTER_RADIUS; outer_vertex[i][1] = sin((double)theta) * OUTER_RADIUS; outer_vertex[i][2] = OUTER_ELEV; } } /* (Re)calculate the sky colors at each vertex */ void fgSkyColorsInit() { struct fgLIGHT *l; float sun_angle, diff; float outer_param[3], outer_amt[3], outer_diff[3]; float middle_param[3], middle_amt[3], middle_diff[3]; int i, j; l = &cur_light_params; printf(" Generating the sky colors for each vertex.\n"); /* setup for the possibility of sunset effects */ sun_angle = l->sun_angle * RAD_TO_DEG; printf(" Sun angle in degrees = %.2f\n", sun_angle); if ( (sun_angle > 80.0) && (sun_angle < 100.0) ) { /* 0.0 - 0.4 */ outer_param[0] = (10.0 - fabs(90.0 - sun_angle)) / 25.0; outer_param[1] = (10.0 - fabs(90.0 - sun_angle)) / 45.0; outer_param[2] = 0.0; middle_param[0] = (10.0 - fabs(90.0 - sun_angle)) / 40.0; middle_param[1] = (10.0 - fabs(90.0 - sun_angle)) / 60.0; middle_param[2] = 0.0; outer_diff[0] = outer_param[0] / 6.0; outer_diff[1] = outer_param[1] / 6.0; outer_diff[2] = outer_param[2] / 6.0; middle_diff[0] = middle_param[0] / 6.0; middle_diff[1] = middle_param[1] / 6.0; middle_diff[2] = middle_param[2] / 6.0; } else { outer_param[0] = outer_param[1] = outer_param[2] = 0.0; middle_param[0] = middle_param[1] = middle_param[2] = 0.0; outer_diff[0] = outer_diff[1] = outer_diff[2] = 0.0; middle_diff[0] = middle_diff[1] = middle_diff[2] = 0.0; } /* printf(" outer_red_param = %.2f outer_red_diff = %.2f\n", outer_red_param, outer_red_diff); */ /* calculate transition colors between sky and fog */ for ( j = 0; j < 3; j++ ) { outer_amt[j] = outer_param[j]; middle_amt[j] = middle_param[j]; } for ( i = 0; i < 6; i++ ) { for ( j = 0; j < 3; j++ ) { diff = l->sky_color[j] - l->fog_color[j]; inner_color[i][j] = l->sky_color[j] - diff * 0.3; middle_color[i][j] = l->sky_color[j] - diff * 0.9 + middle_amt[j]; outer_color[i][j] = l->fog_color[j] + outer_amt[j]; if ( middle_color[i][j] > 1.00 ) { middle_color[i][j] = 1.00; } if ( middle_color[i][j] < 0.10 ) { middle_color[i][j] = 0.10; } if ( outer_color[i][j] > 1.00 ) { outer_color[i][j] = 1.00; } if ( outer_color[i][j] < 0.10 ) { outer_color[i][j] = 0.10; } } inner_color[i][3] = middle_color[i][3] = outer_color[i][3] = l->sky_color[3]; for ( j = 0; j < 3; j++ ) { outer_amt[j] -= outer_diff[j]; middle_amt[j] -= middle_diff[j]; } /* printf("inner_color[%d] = %.2f %.2f %.2f %.2f\n", i, inner_color[i][0], inner_color[i][1], inner_color[i][2], inner_color[i][3]); printf("middle_color[%d] = %.2f %.2f %.2f %.2f\n", i, middle_color[i][0], middle_color[i][1], middle_color[i][2], middle_color[i][3]); printf("outer_color[%d] = %.2f %.2f %.2f %.2f\n", i, outer_color[i][0], outer_color[i][1], outer_color[i][2], outer_color[i][3]); */ } for ( j = 0; j < 3; j++ ) { outer_amt[j] = 0.0; middle_amt[j] = 0.0; } for ( i = 6; i < 12; i++ ) { for ( j = 0; j < 3; j++ ) { diff = l->sky_color[j] - l->fog_color[j]; inner_color[i][j] = l->sky_color[j] - diff * 0.3; middle_color[i][j] = l->sky_color[j] - diff * 0.9 + middle_amt[j]; outer_color[i][j] = l->fog_color[j] + outer_amt[j]; if ( middle_color[i][j] > 1.00 ) { middle_color[i][j] = 1.00; } if ( middle_color[i][j] < 0.10 ) { middle_color[i][j] = 0.10; } if ( outer_color[i][j] > 1.00 ) { outer_color[i][j] = 1.00; } if ( outer_color[i][j] < 0.15 ) { outer_color[i][j] = 0.15; } } inner_color[i][3] = middle_color[i][3] = outer_color[i][3] = l->sky_color[3]; for ( j = 0; j < 3; j++ ) { outer_amt[j] += outer_diff[j]; middle_amt[j] += middle_diff[j]; } /* printf("inner_color[%d] = %.2f %.2f %.2f %.2f\n", i, inner_color[i][0], inner_color[i][1], inner_color[i][2], inner_color[i][3]); printf("middle_color[%d] = %.2f %.2f %.2f %.2f\n", i, middle_color[i][0], middle_color[i][1], middle_color[i][2], middle_color[i][3]); printf("outer_color[%d] = %.2f %.2f %.2f %.2f\n", i, outer_color[i][0], outer_color[i][1], outer_color[i][2], outer_color[i][3]); */ } } /* Initialize the sky structure and colors */ void fgSkyInit() { printf("Initializing the sky\n"); fgSkyVerticesInit(); /* regester fgSkyColorsInit() as an event to be run periodically */ fgEventRegister("fgSkyColorsInit()", fgSkyColorsInit, FG_EVENT_READY, 30000); } /* Draw the Sky */ void fgSkyRender() { struct fgFLIGHT *f; struct fgLIGHT *l; struct fgVIEW *v; float /* inner_color[4], middle_color[4], diff, */ east_dot, dot, angle; int i; f = ¤t_aircraft.flight; l = &cur_light_params; v = ¤t_view; /* printf("Rendering the sky.\n"); */ xglPushMatrix(); /* calculate the angle between v->surface_to_sun and * v->surface_east. We do this so we can sort out the acos() * ambiguity. I wish I could think of a more efficient way ... :-( */ east_dot = MAT3_DOT_PRODUCT(v->surface_to_sun, v->surface_east); /* printf(" East dot product = %.2f\n", east_dot); */ /* calculate the angle between v->surface_to_sun and * v->surface_south. this is how much we have to rotate the sky * for it to align with the sun */ dot = MAT3_DOT_PRODUCT(v->surface_to_sun, v->surface_south); /* printf(" Dot product = %.2f\n", dot); */ if ( east_dot >= 0 ) { angle = acos(dot); } else { angle = -acos(dot); } /*printf(" Sky needs to rotate = %.3f rads = %.1f degrees.\n", angle, angle * RAD_TO_DEG); */ /* Translate to view position */ xglTranslatef( v->cur_zero_elev.x, v->cur_zero_elev.y, v->cur_zero_elev.z ); /* printf(" Translated to %.2f %.2f %.2f\n", v->cur_zero_elev.x, v->cur_zero_elev.y, v->cur_zero_elev.z ); */ /* Rotate to proper orientation */ /* printf(" lon = %.2f lat = %.2f\n", FG_Longitude * RAD_TO_DEG, FG_Latitude * RAD_TO_DEG); */ xglRotatef( FG_Longitude * RAD_TO_DEG, 0.0, 0.0, 1.0 ); xglRotatef( 90.0 - FG_Latitude * RAD_TO_DEG, 0.0, 1.0, 0.0 ); xglRotatef( angle * RAD_TO_DEG, 0.0, 0.0, 1.0 ); /* Draw inner/center section of sky*/ xglBegin( GL_TRIANGLE_FAN ); xglColor4fv(l->sky_color); xglVertex3f(0.0, 0.0, CENTER_ELEV); for ( i = 0; i < 12; i++ ) { xglColor4fv( inner_color[i] ); xglVertex3fv( inner_vertex[i] ); } xglColor4fv( inner_color[0] ); xglVertex3fv( inner_vertex[0] ); xglEnd(); /* Draw the middle ring */ xglBegin( GL_TRIANGLE_STRIP ); for ( i = 0; i < 12; i++ ) { xglColor4fv( middle_color[i] ); xglVertex3fv( middle_vertex[i] ); xglColor4fv( inner_color[i] ); xglVertex3fv( inner_vertex[i] ); } xglColor4fv( middle_color[0] ); /* xglColor4f(1.0, 0.0, 0.0, 1.0); */ xglVertex3fv( middle_vertex[0] ); xglColor4fv( inner_color[0] ); /* xglColor4f(1.0, 0.0, 0.0, 1.0); */ xglVertex3fv( inner_vertex[0] ); xglEnd(); /* Draw the outer ring */ xglBegin( GL_TRIANGLE_STRIP ); for ( i = 0; i < 12; i++ ) { xglColor4fv( outer_color[i] ); xglVertex3fv( outer_vertex[i] ); xglColor4fv( middle_color[i] ); xglVertex3fv( middle_vertex[i] ); } xglColor4fv( outer_color[0] ); xglVertex3fv( outer_vertex[0] ); xglColor4fv( middle_color[0] ); xglVertex3fv( middle_vertex[0] ); xglEnd(); xglPopMatrix(); } /* $Log$ /* Revision 1.1 1998/01/07 03:16:19 curt /* Moved from .../Src/Scenery/ to .../Src/Astro/ /* * Revision 1.11 1997/12/30 22:22:38 curt * Further integration of event manager. * * Revision 1.10 1997/12/30 20:47:53 curt * Integrated new event manager with subsystem initializations. * * Revision 1.9 1997/12/30 13:06:57 curt * A couple lighting tweaks ... * * Revision 1.8 1997/12/23 04:58:38 curt * Tweaked the sky coloring a bit to build in structures to allow finer rgb * control. * * Revision 1.7 1997/12/22 23:45:48 curt * First stab at sunset/sunrise sky glow effects. * * Revision 1.6 1997/12/22 04:14:34 curt * Aligned sky with sun so dusk/dawn effects can be correct relative to the sun. * * Revision 1.5 1997/12/19 23:34:59 curt * Lot's of tweaking with sky rendering and lighting. * * Revision 1.4 1997/12/19 16:45:02 curt * Working on scene rendering order and options. * * Revision 1.3 1997/12/18 23:32:36 curt * First stab at sky dome actually starting to look reasonable. :-) * * Revision 1.2 1997/12/18 04:07:03 curt * Worked on properly translating and positioning the sky dome. * * Revision 1.1 1997/12/17 23:14:30 curt * Initial revision. * Begin work on rendering the sky. (Rather than just using a clear screen.) * */