--- /dev/null
+#---------------------------------------------------------------------------
+# Makefile
+#
+# Written by Curtis Olson, started May 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)
+#---------------------------------------------------------------------------
+
+
+TARGET = libAstro.a
+
+CFILES = moon.c orbits.c planets.c sky.c stars.c sun.c
+
+OFILES = $(CFILES:.c=.o)
+
+
+include ../make.inc
+
+
+CFLAGS = $(FG_CFLAGS)
+
+
+#---------------------------------------------------------------------------
+# Primary Targets
+#---------------------------------------------------------------------------
+
+$(TARGET): $(OFILES) $(HFILES)
+ $(AR) rv $(TARGET) $(OFILES)
+ $(RANLIB) $(TARGET)
+
+all: $(TARGET)
+
+clean:
+ rm -f *.o $(TARGET) lib*.a *.os2 *~ core
+
+realclean: clean
+
+
+#---------------------------------------------------------------------------
+# Secondary Targets
+#---------------------------------------------------------------------------
+
+include depend
+
+moon.o:
+ $(CC) $(CFLAGS) -c moon.c -o $@
+
+orbits.o:
+ $(CC) $(CFLAGS) -c orbits.c -o $@
+
+planets.o:
+ $(CC) $(CFLAGS) -c planets.c -o $@
+
+sky.c:
+ $(CC) $(CFLAGS) -c sky.c -o $@
+
+stars.c:
+ $(CC) $(CFLAGS) -c stars.c -o $@
+
+sun.o:
+ $(CC) $(CFLAGS) -c sun.c -o $@
+
+
+
+#---------------------------------------------------------------------------
+# $Log$
+# Revision 1.1 1998/01/07 03:16:15 curt
+# Moved from .../Src/Scenery/ to .../Src/Astro/
+#
+# Revision 1.26 1997/12/19 16:45:01 curt
+# Working on scene rendering order and options.
+#
+# Revision 1.25 1997/12/17 23:13:45 curt
+# Began working on rendering the sky.
+#
+# Revision 1.24 1997/11/25 19:25:33 curt
+# Changes to integrate Durk's moon/sun code updates + clean up.
+#
+# Revision 1.23 1997/10/28 21:00:20 curt
+# Changing to new terrain format.
+#
+# Revision 1.22 1997/10/25 03:30:07 curt
+# Misc. tweaks.
+#
+# Revision 1.21 1997/10/25 03:18:26 curt
+# Incorporated sun, moon, and planet position and rendering code contributed
+# by Durk Talsma.
+#
+# Revision 1.20 1997/09/22 14:44:21 curt
+# Continuing to try to align stars correctly.
+#
+# Revision 1.19 1997/08/27 03:30:23 curt
+# Changed naming scheme of basic shared structures.
+#
+# Revision 1.18 1997/08/02 19:10:12 curt
+# Incorporated mesh2GL.c into mesh.c
+#
+# Revision 1.17 1997/07/23 21:52:23 curt
+# Put comments around the text after an #endif for increased portability.
+#
+# Revision 1.16 1997/07/20 02:19:11 curt
+# First stab at a system to generate os2 makefiles automatically.
+#
+# Revision 1.15 1997/07/12 02:24:47 curt
+# Added ranlib.
+#
+# Revision 1.14 1997/06/29 21:16:47 curt
+# More twiddling with the Scenery Management system.
+#
+# Revision 1.13 1997/06/27 21:38:10 curt
+# Working on Makefile structure.
+#
+# Revision 1.12 1997/06/27 20:03:37 curt
+# Working on Makefile structure.
+#
+# Revision 1.11 1997/06/26 22:14:57 curt
+# Beginning work on a scenery management system.
+#
+# Revision 1.10 1997/06/26 19:08:34 curt
+# Restructuring make, adding automatic "make dep" support.
+#
+# Revision 1.9 1997/06/25 15:39:48 curt
+# Minor changes to compile with rsxnt/win32.
+#
+# Revision 1.8 1997/06/21 17:58:07 curt
+# directory shuffling ...
+#
+# Revision 1.1 1997/06/21 17:39:28 curt
+# Moved to the ParseScn subdirectory.
+#
+# Revision 1.6 1997/06/21 17:12:55 curt
+# Capitalized subdirectory names.
+#
+# Revision 1.5 1997/05/31 19:16:29 curt
+# Elevator trim added.
+#
+# Revision 1.4 1997/05/27 17:48:50 curt
+# Added -f flag to flex to generate a "fast" scanner.
+#
+# Revision 1.3 1997/05/23 15:40:40 curt
+# Added GNU copyright headers.
+#
+# Revision 1.2 1997/05/17 00:17:01 curt
+# Cosmetic changes.
+#
+# Revision 1.1 1997/05/16 16:07:02 curt
+# Initial revision.
+#
--- /dev/null
+astro.o: astro.c ../XGL/xgl.h astro.h stars.h moon.h orbits.h \
+ ../Time/fg_time.h ../Time/../Include/types.h \
+ ../Time/../Flight/flight.h ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h planets.h sun.h \
+ ../Include/constants.h ../Include/general.h ../Main/views.h \
+ ../Main/../Include/types.h ../Main/../Flight/flight.h \
+ ../Main/../Math/mat3.h ../Main/../Time/fg_time.h \
+ ../Aircraft/aircraft.h ../Aircraft/../Flight/flight.h \
+ ../Aircraft/../Controls/controls.h \
+ ../Aircraft/../Controls/../Include/limits.h
+moon.o: moon.c ../XGL/xgl.h orbits.h ../Time/fg_time.h \
+ ../Time/../Include/types.h ../Time/../Flight/flight.h \
+ ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h moon.h ../Aircraft/aircraft.h \
+ ../Aircraft/../Flight/flight.h ../Aircraft/../Controls/controls.h \
+ ../Aircraft/../Controls/../Include/limits.h ../Include/constants.h \
+ ../Include/general.h ../Main/views.h ../Main/../Include/types.h \
+ ../Main/../Flight/flight.h ../Main/../Math/mat3.h \
+ ../Main/../Time/fg_time.h
+orbits.o: orbits.c orbits.h ../Time/fg_time.h \
+ ../Time/../Include/types.h ../Time/../Flight/flight.h \
+ ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h ../Include/general.h
+planets.o: planets.c ../Time/fg_time.h ../Time/../Include/types.h \
+ ../Time/../Flight/flight.h ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h orbits.h planets.h sun.h
+sky.o: sky.c ../XGL/xgl.h sky.h ../Time/event.h ../Time/fg_time.h \
+ ../Time/../Include/types.h ../Time/../Flight/flight.h \
+ ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h ../Aircraft/aircraft.h \
+ ../Aircraft/../Flight/flight.h ../Aircraft/../Controls/controls.h \
+ ../Aircraft/../Controls/../Include/limits.h ../Flight/flight.h \
+ ../Include/constants.h ../Main/views.h ../Main/../Include/types.h \
+ ../Main/../Flight/flight.h ../Main/../Math/mat3.h \
+ ../Main/../Time/fg_time.h ../Math/fg_random.h
+stars.o: stars.c ../XGL/xgl.h orbits.h ../Time/fg_time.h \
+ ../Time/../Include/types.h ../Time/../Flight/flight.h \
+ ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h planets.h stars.h \
+ ../Include/constants.h ../Include/general.h ../Aircraft/aircraft.h \
+ ../Aircraft/../Flight/flight.h ../Aircraft/../Controls/controls.h \
+ ../Aircraft/../Controls/../Include/limits.h ../Main/views.h \
+ ../Main/../Include/types.h ../Main/../Flight/flight.h \
+ ../Main/../Math/mat3.h ../Main/../Time/fg_time.h
+sun.o: sun.c ../XGL/xgl.h ../Time/fg_time.h ../Time/../Include/types.h \
+ ../Time/../Flight/flight.h ../Time/../Flight/Slew/slew.h \
+ ../Time/../Flight/LaRCsim/ls_interface.h \
+ ../Time/../Flight/LaRCsim/../flight.h ../Main/views.h \
+ ../Main/../Include/types.h ../Main/../Flight/flight.h \
+ ../Main/../Math/mat3.h ../Main/../Time/fg_time.h orbits.h sun.h
--- /dev/null
+/**************************************************************************
+ * moon.c
+ * Written by Durk Talsma. Started October 1997, for the flight gear project.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#include <math.h>
+#include <GL/glut.h>
+#include "../XGL/xgl.h"
+
+#include "orbits.h"
+#include "moon.h"
+
+#include "../Aircraft/aircraft.h"
+#include "../Include/constants.h"
+#include "../Include/general.h"
+#include "../Main/views.h"
+#include "../Time/fg_time.h"
+
+struct CelestialCoord moonPos;
+
+static float xMoon, yMoon, zMoon;
+static GLint moon;
+
+/*
+static GLfloat vdata[12][3] =
+{
+ {-X, 0.0, Z }, { X, 0.0, Z }, {-X, 0.0, -Z}, {X, 0.0, -Z },
+ { 0.0, Z, X }, { 0.0, Z, -X}, {0.0, -Z, -X}, {0.0, -Z, -X},
+ { Z, X, 0.0 }, { -Z, X, 0.0}, {Z, -X, 0.0 }, {-Z, -X, 0.0}
+};
+
+static GLuint tindices[20][3] =
+{
+ {0,4,1}, {0,9,4}, {9,5,4}, {4,5,8}, {4,8,1},
+ {8,10,1}, {8,3,10}, {5,3,8}, {5,2,3}, {2,7,3},
+ {7,10,3}, {7,6,10}, {7,11,6}, {11,0,6}, {0,1,6},
+ {6,1,10}, {9,0,11}, {9,11,2}, {9,2,5}, {7,2,11}
+};*/
+
+/* -------------------------------------------------------------
+ This section contains the code that generates a yellow
+ Icosahedron. It's under development... (of Course)
+______________________________________________________________*/
+/*
+void NormalizeVector(float v[3])
+{
+ GLfloat d = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
+ if (d == 0.0)
+ {
+ printf("zero length vector\n");
+ return;
+ }
+ v[0] /= d;
+ v[1] /= d;
+ v[2] /= d;
+}
+
+void drawTriangle(float *v1, float *v2, float *v3)
+{
+ xglBegin(GL_POLYGON);
+ //xglBegin(GL_POINTS);
+ xglNormal3fv(v1);
+ xglVertex3fv(v1);
+ xglNormal3fv(v2);
+ xglVertex3fv(v2);
+ xglNormal3fv(v3);
+ xglVertex3fv(v3);
+ xglEnd();
+}
+
+void subdivide(float *v1, float *v2, float *v3, long depth)
+{
+ GLfloat v12[3], v23[3], v31[3];
+ GLint i;
+
+ if (!depth)
+ {
+ drawTriangle(v1, v2, v3);
+ return;
+ }
+ for (i = 0; i < 3; i++)
+ {
+ v12[i] = (v1[i] + v2[i]);
+ v23[i] = (v2[i] + v3[i]);
+ v31[i] = (v3[i] + v1[i]);
+ }
+ NormalizeVector(v12);
+ NormalizeVector(v23);
+ NormalizeVector(v31);
+ subdivide(v1, v12, v31, depth - 1);
+ subdivide(v2, v23, v12, depth - 1);
+ subdivide(v3, v31, v23, depth - 1);
+ subdivide(v12, v23, v31,depth - 1);
+
+} */
+/*
+void display(void)
+{
+ int i;
+ xglClear(GL_COLOR_BUFFER_BIT);
+ xglPushMatrix();
+ xglRotatef(spin, 0.0, 0.0, 0.0);
+ xglColor3f(1.0, 1.0, 0.0);
+// xglBegin(GL_LINE_LOOP);
+ for (i = 0; i < 20; i++)
+ {
+
+ //xglVertex3fv(&vdata[tindices[i][0]][0]);
+ //xglVertex3fv(&vdata[tindices[i][1]][0]);
+ //xglVertex3fv(&vdata[tindices[i][2]][0]);
+
+ subdivide(&vdata[tindices[i][0]][0],
+ &vdata[tindices[i][1]][0],
+ &vdata[tindices[i][2]][0], 3);
+
+
+ }
+// xglEnd();
+ // xglFlush();
+ xglPopMatrix();
+ glutSwapBuffers();
+} */
+
+/* --------------------------------------------------------------
+
+ This section contains the code that calculates the actual
+ position of the moon in the night sky.
+
+----------------------------------------------------------------*/
+
+struct CelestialCoord fgCalculateMoon(struct OrbElements params,
+ struct OrbElements sunParams,
+ struct fgTIME t)
+{
+ struct CelestialCoord
+ geocCoord, topocCoord;
+
+
+ double
+ eccAnom, ecl, lonecl, latecl, actTime,
+ xv, yv, v, r, xh, yh, zh, xg, yg, zg, xe, ye, ze,
+ Ls, Lm, D, F, mpar, gclat, rho, HA, g;
+
+ struct fgAIRCRAFT *a;
+ struct fgFLIGHT *f;
+
+ a = ¤t_aircraft;
+ f = &a->flight;
+
+/* calculate the angle between ecliptic and equatorial coordinate system */
+ actTime = fgCalcActTime(t);
+ ecl = fgDegToRad(23.4393 - 3.563E-7 * actTime); // in radians of course
+
+ /* calculate the eccentric anomaly */
+ eccAnom = fgCalcEccAnom(params.M, params.e);
+
+ /* calculate the moon's distance (d) and true anomaly (v) */
+ xv = params.a * ( cos(eccAnom) - params.e);
+ yv = params.a * ( sqrt(1.0 - params.e*params.e) * sin(eccAnom));
+ v =atan2(yv, xv);
+ r = sqrt(xv*xv + yv*yv);
+
+ /* estimate the geocentric rectangular coordinates here */
+ xh = r * (cos(params.N) * cos(v + params.w) - sin(params.N) * sin(v + params.w) * cos(params.i));
+ yh = r * (sin(params.N) * cos(v + params.w) + cos(params.N) * sin(v + params.w) * cos(params.i));
+ zh = r * (sin(v + params.w) * sin(params.i));
+
+ /* calculate the ecliptic latitude and longitude here */
+ lonecl = atan2( yh, xh);
+ latecl = atan2( zh, sqrt( xh*xh + yh*yh));
+
+ /* calculate a number of perturbations */
+ Ls = sunParams.M + sunParams.w;
+ Lm = params.M + params.w + params.N;
+ D = Lm - Ls;
+ F = Lm - params.N;
+
+ lonecl += fgDegToRad(
+ - 1.274 * sin (params.M - 2*D) // the Evection
+ + 0.658 * sin (2 * D) // the Variation
+ - 0.186 * sin (sunParams.M) // the yearly variation
+ - 0.059 * sin (2*params.M - 2*D)
+ - 0.057 * sin (params.M - 2*D + sunParams.M)
+ + 0.053 * sin (params.M + 2*D)
+ + 0.046 * sin (2*D - sunParams.M)
+ + 0.041 * sin (params.M - sunParams.M)
+ - 0.035 * sin (D) // the Parallactic Equation
+ - 0.031 * sin (params.M + sunParams.M)
+ - 0.015 * sin (2*F - 2*D)
+ + 0.011 * sin (params.M - 4*D)
+ ); /* Pheeuuwwww */
+ latecl += fgDegToRad(
+ - 0.173 * sin (F - 2*D)
+ - 0.055 * sin (params.M - F - 2*D)
+ - 0.046 * sin (params.M + F - 2*D)
+ + 0.033 * sin (F + 2*D)
+ + 0.017 * sin (2 * params.M + F)
+ ); /* Yep */
+
+ r += (
+ - 0.58 * cos(params.M - 2*D)
+ - 0.46 * cos(2*D)
+ ); /* Ok! */
+
+ xg = r * cos(lonecl) * cos(latecl);
+ yg = r * sin(lonecl) * cos(latecl);
+ zg = r * sin(latecl);
+
+ xe = xg;
+ ye = yg * cos(ecl) - zg * sin(ecl);
+ ze = yg * sin(ecl) + zg * cos(ecl);
+
+
+
+
+ geocCoord.RightAscension = atan2(ye, xe);
+ geocCoord.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
+
+ /* New since 25 december 1997 */
+ /* Calculate the moon's topocentric position instead of it's geocentric! */
+
+ mpar = asin( 1 / r); /* calculate the moon's parrallax, i.e. the apparent size of the
+ (equatorial) radius of the Earth, as seen from the moon */
+ gclat = FG_Latitude - 0.083358 * sin (2 * fgDegToRad( FG_Latitude));
+ rho = 0.99883 + 0.00167 * cos(2 * fgDegToRad(FG_Latitude));
+
+ if (geocCoord.RightAscension < 0)
+ geocCoord.RightAscension += (2*FG_PI);
+
+ HA = t.lst - (3.8197186 * geocCoord.RightAscension);
+
+ g = atan (tan(gclat) / cos( (HA / 3.8197186)));
+
+
+
+ topocCoord.RightAscension = geocCoord.RightAscension - mpar * rho * cos(gclat) * sin(HA) / cos(geocCoord.Declination);
+ topocCoord.Declination = geocCoord.Declination - mpar * rho * sin(gclat) * sin(g - geocCoord.Declination) / sin(g);
+ return topocCoord;
+}
+
+
+void fgMoonInit() {
+ struct fgLIGHT *l;
+ static int dl_exists = 0;
+
+ printf("Initializing the Moon\n");
+
+ l = &cur_light_params;
+
+ /* position the moon */
+ fgSolarSystemUpdate(&(pltOrbElements[1]), cur_time_params);
+ moonPos = fgCalculateMoon(pltOrbElements[1], pltOrbElements[0],
+ cur_time_params);
+#ifdef DEBUG
+ printf("Moon found at %f (ra), %f (dec)\n", moonPos.RightAscension,
+ moonPos.Declination);
+#endif
+
+ xMoon = 60000.0 * cos(moonPos.RightAscension) * cos(moonPos.Declination);
+ yMoon = 60000.0 * sin(moonPos.RightAscension) * cos(moonPos.Declination);
+ zMoon = 60000.0 * sin(moonPos.Declination);
+
+ if ( !dl_exists ) {
+ dl_exists = 1;
+
+ /* printf("First time through, creating moon display list\n"); */
+
+ moon = xglGenLists(1);
+ xglNewList(moon, GL_COMPILE );
+
+ /* xglMaterialfv(GL_FRONT, GL_AMBIENT, l->scene_clear);
+ xglMaterialfv(GL_FRONT, GL_DIFFUSE, moon_color); */
+
+
+ glutSolidSphere(1.0, 10, 10);
+
+ xglEndList();
+ }
+}
+
+
+/* Draw the moon */
+void fgMoonRender() {
+ struct fgLIGHT *l;
+ GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
+
+ /* printf("Rendering moon\n"); */
+
+ l = &cur_light_params;
+
+ xglMaterialfv(GL_FRONT, GL_AMBIENT, l->sky_color );
+ xglMaterialfv(GL_FRONT, GL_DIFFUSE, white);
+
+ xglPushMatrix();
+ xglTranslatef(xMoon, yMoon, zMoon);
+ xglScalef(1400, 1400, 1400);
+
+ xglCallList(moon);
+
+ xglPopMatrix();
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:16 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.16 1998/01/06 01:20:24 curt
+ * Tweaks to help building with MSVC++
+ *
+ * Revision 1.15 1998/01/05 18:44:35 curt
+ * Add an option to advance/decrease time from keyboard.
+ *
+ * Revision 1.14 1997/12/30 20:47:50 curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.13 1997/12/30 16:41:00 curt
+ * Added log at end of file.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * moon.h
+ *
+ * Written 1997 by Durk Talsma, started October, 1997.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#ifndef _MOON_H_
+#define _MOON_H_
+
+
+#include "orbits.h"
+
+#include "../Time/fg_time.h"
+#include <math.h>
+
+#define X .525731112119133606
+#define Z .850650808352039932
+
+
+ /* Initialize the Moon Display management Subsystem */
+void fgMoonInit();
+
+/* Draw the Stars */
+void fgMoonRender();
+
+struct CelestialCoord fgCalculateMoon(struct OrbElements Params,
+ struct OrbElements sunParams,
+ struct fgTIME t);
+
+extern struct OrbElements pltOrbElements[9];
+
+#endif /* _MOON_H_ */
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:16 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.4 1997/12/11 04:43:56 curt
+ * Fixed sun vector and lighting problems. I thing the moon is now lit
+ * correctly.
+ *
+ * Revision 1.3 1997/11/25 19:25:35 curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.2 1997/10/25 03:24:23 curt
+ * Incorporated sun, moon, and star positioning code contributed by Durk Talsma.
+ *
+ * Revision 1.1 1997/10/25 03:16:09 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * orbits.c - calculates the orbital elements of the sun, moon and planets.
+ * For inclusion in flight gear
+ *
+ * Written 1997 by Durk Talsma, started October 19, 1997.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#include <string.h>
+
+#include "orbits.h"
+
+#include "../Include/general.h"
+#include "../Time/fg_time.h"
+
+
+struct OrbElements pltOrbElements[9];
+
+
+double fgCalcActTime(struct fgTIME t)
+{
+ double
+ actTime, UT;
+ int year;
+
+ /* a hack. This one introduces the 2000 problem into the program */
+ year = t.gmt->tm_year + 1900;
+
+ /* calculate the actual time, rember to add 1 to tm_mon! */
+ actTime = 367 * year - 7 *
+ (year + ((t.gmt->tm_mon+1) + 9) / 12) / 4 + 275 *
+ (t.gmt->tm_mon+1) / 9 + t.gmt->tm_mday - 730530;
+
+ UT = t.gmt->tm_hour + ((double) t.gmt->tm_min / 60);
+ /*printf("UT = %f\n", UT); */
+ actTime += (UT / 24.0);
+ #define DEBUG 1
+ #ifdef DEBUG
+ /* printf(" Actual Time:\n"); */
+ /* printf(" current day = %f\t", actTime); */
+ /* printf(" GMT = %d, %d, %d, %d, %d, %d\n",
+ year, t.gmt->tm_mon, t.gmt->tm_mday,
+ t.gmt->tm_hour, t.gmt->tm_min, t.gmt->tm_sec); */
+ #endif
+ return actTime;
+}
+
+/* convert degrees to radians */
+double fgDegToRad(double angle)
+{
+ return (angle * PIOVER180);
+}
+
+double fgCalcEccAnom(double M, double e)
+{
+ double
+ eccAnom, E0, E1, diff;
+
+ eccAnom = M + e * sin(M) * (1.0 + e * cos(M));
+ /* iterate to achieve a greater precision for larger eccentricities */
+ if (e > 0.05)
+ {
+ E0 = eccAnom;
+ do
+ {
+ E1 = E0 - (E0 - e * sin(E0) - M) / (1 - e * cos(E0));
+ diff = abs(E0 - E1);
+ E0 = E1;
+ }
+ while (diff > fgDegToRad(0.001));
+ return E0;
+ }
+ return eccAnom;
+}
+
+
+
+void fgReadOrbElements(struct OrbElements *dest, FILE *src)
+{
+ char line[256];
+ int i,j;
+ j = 0;
+ do
+ {
+ fgets(line, 256,src);
+ for (i = 0; i < 256; i++)
+ {
+ if (line[i] == '#')
+ line[i] = 0;
+ }
+ /*printf("Reading line %d\n", j++); */
+ }
+ while (!(strlen(line)));
+ sscanf(line, "%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf\n",
+ &dest->NFirst, &dest->NSec,
+ &dest->iFirst, &dest->iSec,
+ &dest->wFirst, &dest->wSec,
+ &dest->aFirst, &dest->aSec,
+ &dest->eFirst, &dest->eSec,
+ &dest->MFirst, &dest->MSec);
+}
+
+
+void fgSolarSystemInit(struct fgTIME t)
+{
+ struct fgGENERAL *g;
+ char path[80];
+ int i;
+ FILE *data;
+
+ printf("Initializing solar system\n");
+
+ /* build the full path name to the orbital elements database file */
+ g = &general;
+ path[0] = '\0';
+ strcat(path, g->root_dir);
+ strcat(path, "/Scenery/");
+ strcat(path, "Planets.dat");
+
+ if ( (data = fopen(path, "r")) == NULL )
+ {
+ printf("Cannot open data file: '%s'\n", path);
+ return;
+ }
+ #ifdef DEBUG
+ printf(" reading datafile %s\n", path);
+ #endif
+
+ /* for all the objects... */
+ for (i = 0; i < 9; i ++)
+ {
+ /* ...read from the data file ... */
+ fgReadOrbElements(&pltOrbElements[i], data);
+ /* ...and calculate the actual values */
+ fgSolarSystemUpdate(&pltOrbElements[i], t);
+ }
+
+}
+
+
+void fgSolarSystemUpdate(struct OrbElements *planet, struct fgTIME t)
+{
+ double
+ actTime;
+
+ actTime = fgCalcActTime(t);
+
+ /* calculate the actual orbital elements */
+ planet->M = fgDegToRad(planet->MFirst + (planet->MSec * actTime)); // angle in radians
+ planet->w = fgDegToRad(planet->wFirst + (planet->wSec * actTime)); // angle in radians
+ planet->N = fgDegToRad(planet->NFirst + (planet->NSec * actTime)); // angle in radians
+ planet->i = fgDegToRad(planet->iFirst + (planet->iSec * actTime)); // angle in radians
+ planet->e = planet->eFirst + (planet->eSec * actTime);
+ planet->a = planet->aFirst + (planet->aSec * actTime);
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:17 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.6 1997/12/30 20:47:52 curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.5 1997/12/15 23:55:02 curt
+ * Add xgl wrappers for debugging.
+ * Generate terrain normals on the fly.
+ *
+ * Revision 1.4 1997/12/10 22:37:51 curt
+ * Prepended "fg" on the name of all global structures that didn't have it yet.
+ * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
+ *
+ * Revision 1.3 1997/11/25 23:20:44 curt
+ * Changed planets.dat Planets.dat
+ *
+ * Revision 1.2 1997/11/25 19:25:36 curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.1 1997/10/25 03:16:10 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * orbits.h - calculates the orbital elements of the sun, moon and planets.
+ * For inclusion in flight gear
+ *
+ * Written 1997 by Durk Talsma, started October 19, 1997.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#ifndef ORBITS_H
+#define ORBITS_H
+
+
+#include <stdio.h>
+#include <math.h>
+
+#include "../Time/fg_time.h"
+
+
+
+#define STANDARDEPOCH 2000
+#define PIOVER180 1.74532925199433E-002
+
+struct SunPos {
+ double xs;
+ double ys;
+ double dist;
+};
+
+struct OrbElements {
+ double NFirst; /* longitude of the ascending node first part */
+ double NSec; /* longitude of the ascending node second part */
+ double iFirst; /* inclination to the ecliptic first part */
+ double iSec; /* inclination to the ecliptic second part */
+ double wFirst; /* first part of argument of perihelion */
+ double wSec; /* second part of argument of perihelion */
+ double aFirst; /* semimayor axis first part*/
+ double aSec; /* semimayor axis second part */
+ double eFirst; /* eccentricity first part */
+ double eSec; /* eccentricity second part */
+ double MFirst; /* Mean anomaly first part */
+ double MSec; /* Mean anomaly second part */
+
+ double N, i, w, a, e, M; /* the resultant orbital elements, obtained from the former */
+};
+
+struct CelestialCoord {
+ double RightAscension;
+ double Declination;
+ double distance;
+ double magnitude;
+};
+
+
+double fgDegToRad(double angle);
+double fgCalcEccAnom(double M, double e);
+double fgCalcActTime(struct fgTIME t);
+
+void fgReadOrbElements(struct OrbElements *dest, FILE *src);
+void fgSolarSystemInit(struct fgTIME t);
+void fgSolarSystemUpdate(struct OrbElements *planets, struct fgTIME t);
+
+
+#endif /* ORBITS_H */
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:17 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.2 1997/12/30 16:36:52 curt
+ * Merged in Durk's changes ...
+ *
+ * Revision 1.1 1997/10/25 03:16:10 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * planets.c
+ *
+ * Written 1997 by Durk Talsma, started October, 1997. For the flight gear
+ * project.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#include "../Time/fg_time.h"
+#include "orbits.h"
+#include "planets.h"
+#include "sun.h"
+
+
+struct CelestialCoord fgCalculatePlanet(struct OrbElements planet,
+ struct OrbElements theSun,
+ struct fgTIME t, int idx)
+{
+ struct CelestialCoord
+ result;
+
+ struct SunPos
+ SolarPosition;
+
+ double
+ eccAnom, r, v, ecl, actTime, R, s, ir, Nr, B, FV, ring_magn,
+ xv, yv, xh, yh, zh, xg, yg, zg, xe, ye, ze;
+
+ actTime = fgCalcActTime(t);
+ /* calculate the angle between ecliptic and equatorial coordinate system */
+ ecl = fgDegToRad(23.4393 - 3.563E-7 * actTime);
+
+
+ /* calculate the eccentric anomaly */
+ eccAnom = fgCalcEccAnom(planet.M, planet.e);
+
+ /* calculate the planets distance (r) and true anomaly (v) */
+ xv = planet.a * (cos(eccAnom) - planet.e);
+ yv = planet.a * (sqrt(1.0 - planet.e*planet.e) * sin(eccAnom));
+ v = atan2(yv, xv);
+ r = sqrt ( xv*xv + yv*yv);
+
+ /* calculate the planets position in 3-dimensional space */
+ xh = r * ( cos(planet.N) * cos(v+planet.w) - sin(planet.N) * sin(v+planet.w) * cos(planet.i));
+ yh = r * ( sin(planet.N) * cos(v+planet.w) + cos(planet.N) * sin(v+planet.w) * cos(planet.i));
+ zh = r * ( sin(v+planet.w) * sin(planet.i));
+
+ /* calculate the ecleptic longitude and latitude */
+
+ /*
+ lonecl = atan2(yh, xh);
+ latecl = atan2(zh, sqrt ( xh*xh + yh*yh));
+ */
+ /* calculate the solar position */
+
+ SolarPosition = fgCalcSunPos(theSun);
+ xg = xh + SolarPosition.xs;
+ yg = yh + SolarPosition.ys;
+ zg = zh;
+
+ xe = xg;
+ ye = yg * cos(ecl) - zg * sin(ecl);
+ ze = yg * sin(ecl) + zg * cos(ecl);
+
+ result.RightAscension = atan2(ye,xe);
+ result.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
+
+
+ /* Let's calculate the brightness of the planet */
+ R = sqrt ( xg*xg + yg*yg + zg*zg);
+ s = SolarPosition.dist;
+ FV = acos( (r*r + R*R - s*s) / (2*r*R));
+ FV *= 57.29578; /* convert radians to degrees */
+ switch(idx)
+ {
+ case 2: /* mercury */
+ result.magnitude = -0.36 + 5*log10( r*R ) + 0.027 * FV + 2.2E-13 * pow(FV, 6);
+ break;
+ case 3: /*venus */
+ result.magnitude = -4.34 + 5*log10( r*R ) + 0.013 * FV + 4.2E-07 * pow(FV,3);
+ break;
+ case 4: /* mars */
+ result.magnitude = -1.51 + 5*log10( r*R ) + 0.016 * FV;
+ break;
+ case 5: /* Jupiter */
+ result.magnitude = -9.25 + 5*log10( r*R ) + 0.014 * FV;
+ break;
+ case 6: /* Saturn */
+
+ ir = 0.4897394;
+ Nr = 2.9585076 + 6.6672E-7*actTime;
+
+ B = asin ( sin (result.Declination) * cos(ir) - cos(result.Declination) * sin (ir) * sin (result.RightAscension - Nr));
+ ring_magn = -2.6 * sin (abs(B)) + 1.2 * pow(sin(B),2);
+ result.magnitude = -9.0 + 5*log10( r*R ) + 0.044 * FV + ring_magn;
+ break;
+ case 7: /* Uranus */
+ result.magnitude = -7.15 + 5*log10( r*R) + 0.001 * FV;
+ break;
+ case 8: /* Neptune */
+ result.magnitude = -6.90 + 5*log10 (r*R) + 0.001 *FV;
+ break;
+ default:
+ printf("index %d out of range !!!!\n", idx);
+ }
+ printf(" Planet found at %f (ra), %f (dec)\n",
+ result.RightAscension, result.Declination);
+ printf(" Geocentric dist %f\n"
+ " Heliocentric dist %f\n"
+ " Distance to the sun %f\n"
+ " Phase angle %f\n"
+ " Brightness %f\n", R, r, s, FV, result.magnitude);
+ return result;
+}
+
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:18 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.4 1997/12/30 20:47:52 curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.3 1997/12/30 16:36:52 curt
+ * Merged in Durk's changes ...
+ *
+ * Revision 1.2 1997/12/12 21:41:29 curt
+ * More light/material property tweaking ... still a ways off.
+ *
+ * Revision 1.1 1997/10/25 03:16:10 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
+
+
--- /dev/null
+/**************************************************************************
+ * planets.h
+ *
+ * Written 1997 by Durk Talsma, started October, 1997. For the flight gear
+ * project.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#ifndef PLANETS_H
+#define PLANETS_H
+
+
+struct CelestialCoord fgCalculatePlanet(struct OrbElements planet,
+ struct OrbElements theSun,
+ struct fgTIME t, int idx);
+
+#endif /* PLANETS_H */
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:18 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.3 1997/12/30 16:36:53 curt
+ * Merged in Durk's changes ...
+ *
+ * Revision 1.2 1997/12/12 21:41:30 curt
+ * More light/material property tweaking ... still a ways off.
+ *
+ * Revision 1.1 1997/10/25 03:16:11 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * 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 <windows.h>
+#endif
+
+#include <math.h>
+/*
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+*/
+
+#include <GL/glut.h>
+#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.)
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * sky.h -- 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)
+ **************************************************************************/
+
+
+/* (Re)generate the display list */
+void fgSkyInit();
+
+/* (Re)calculate the sky colors at each vertex */
+void fgSkyColorsInit();
+
+/* Draw the Sky */
+void fgSkyRender();
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:19 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.2 1997/12/22 23:45:49 curt
+ * First stab at sunset/sunrise sky glow effects.
+ *
+ * Revision 1.1 1997/12/17 23:14:31 curt
+ * Initial revision.
+ * Begin work on rendering the sky. (Rather than just using a clear screen.)
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * stars.c -- data structures and routines for managing and rendering stars.
+ *
+ * Written by Curtis Olson, started August 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 <windows.h>
+#endif
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include <GL/glut.h>
+#include "../XGL/xgl.h"
+
+#include "orbits.h"
+#include "planets.h"
+#include "stars.h"
+
+#include "../Include/constants.h"
+#include "../Include/general.h"
+#include "../Aircraft/aircraft.h"
+#include "../Main/views.h"
+#include "../Time/fg_time.h"
+
+
+#define EpochStart (631065600)
+#define DaysSinceEpoch(secs) (((secs)-EpochStart)*(1.0/(24*3600)))
+
+
+/* Define four structures, each with varying amounts of stars */
+/* static */ GLint stars[FG_STAR_LEVELS];
+
+
+/* Initialize the Star Management Subsystem */
+void fgStarsInit() {
+ FILE *fd;
+ struct fgGENERAL *g;
+ struct CelestialCoord pltPos;
+ char path[1024];
+ char line[256], name[256];
+ char *front, *end;
+ double right_ascension, declination, magnitude;
+ double ra_save, decl_save;
+ double ra_save1, decl_save1;
+ int count, i, j, max_stars;
+
+ printf("Initializing stars\n");
+
+ g = &general;
+
+ /* build the full path name to the stars data base file */
+ path[0] = '\0';
+ strcat(path, g->root_dir);
+ strcat(path, "/Scenery/");
+ strcat(path, "Stars.dat");
+
+ max_stars = FG_MAX_STARS;
+
+ for ( i = 0; i < FG_STAR_LEVELS; i++ ) {
+ printf(" Loading %d Stars: %s\n", max_stars, path);
+
+ if ( (fd = fopen(path, "r")) == NULL ) {
+ printf("Cannot open star file: '%s'\n", path);
+ return;
+ }
+
+ stars[i] = xglGenLists(1);
+ xglNewList( stars[i], GL_COMPILE );
+ xglBegin( GL_POINTS );
+
+ /* read in each line of the file */
+ count = 0;
+ while ( (fgets(line, 256, fd) != NULL) && (count < max_stars) ) {
+ front = line;
+
+ /* printf(" Read line = %s", front); */
+
+ /* advance to first non-whitespace character */
+ while ( (front[0] == ' ') || (front[0] == '\t') ) {
+ front++;
+ }
+
+ /* printf(" Line length (after trimming) = %d\n", strlen(front));*/
+
+ if ( front[0] == '#' ) {
+ /* comment */
+ } else if ( strlen(front) <= 1 ) {
+ /* blank line */
+ } else {
+ /* star data line */
+
+ /* get name */
+ end = front;
+ while ( end[0] != ',' ) {
+ end++;
+ }
+ end[0] = '\0';
+ strcpy(name, front);
+ front = end;
+ front++;
+
+ sscanf(front, "%lf,%lf,%lf\n",
+ &right_ascension, &declination, &magnitude);
+
+ /*
+ if ( strcmp(name, "Betelgeuse") == 0 ) {
+ printf(" *** Marking %s\n", name);
+ ra_save = right_ascension;
+ decl_save = declination;
+ }
+ */
+
+ /*
+ if ( strcmp(name, "Alnilam") == 0 ) {
+ printf(" *** Marking %s\n", name);
+ ra_save1 = right_ascension;
+ decl_save1 = declination;
+ }
+ */
+
+ /* scale magnitudes to (0.0 - 1.0) */
+ magnitude = (0.0 - magnitude) / 5.0 + 1.0;
+
+ /* scale magnitudes again so they look ok */
+ if ( magnitude > 1.0 ) { magnitude = 1.0; }
+ if ( magnitude < 0.0 ) { magnitude = 0.0; }
+ magnitude =
+ magnitude * 0.7 + (((FG_STAR_LEVELS - 1) - i) * 0.1);
+ /* printf(" Found star: %d %s, %.3f %.3f %.3f\n", count,
+ name, right_ascension, declination, magnitude); */
+
+ xglColor3f( magnitude, magnitude, magnitude );
+ /*xglColor3f(0,0,0);*/
+ xglVertex3f( 50000.0 * cos(right_ascension) * cos(declination),
+ 50000.0 * sin(right_ascension) * cos(declination),
+ 50000.0 * sin(declination) );
+
+ count++;
+ } /* if valid line */
+
+ } /* while */
+
+ fclose(fd);
+
+ /* Add the planets to all four display lists */
+ for ( j = 2; j < 9; j++ ) {
+ pltPos = fgCalculatePlanet(pltOrbElements[j],
+ pltOrbElements[0], cur_time_params, j);
+ /* give the planets a temporary color, for testing purposes */
+ /* xglColor3f( 1.0, 0.0, 0.0); */
+
+ /* scale magnitudes to (0.0 - 1.0) */
+ magnitude = (0.0 - pltPos.magnitude) / 5.0 + 1.0;
+
+ /* scale magnitudes again so they look ok */
+ if ( magnitude > 1.0 ) { magnitude = 1.0; }
+ if ( magnitude < 0.0 ) { magnitude = 0.0; }
+ magnitude =
+ magnitude * 0.7 + (((FG_STAR_LEVELS - 1) - i) * 0.1);
+
+
+ xglColor3f(magnitude, magnitude, magnitude);
+
+ xglVertex3f( 50000.0 * cos(pltPos.RightAscension) *
+ cos(pltPos.Declination),
+ 50000.0 * sin(pltPos.RightAscension) *
+ cos(pltPos.Declination),
+ 50000.0 * sin(pltPos.Declination) );
+ }
+ xglEnd();
+
+ /*
+ xglBegin(GL_LINE_LOOP);
+ xglColor3f(1.0, 0.0, 0.0);
+ xglVertex3f( 50000.0 * cos(ra_save-0.2) * cos(decl_save-0.2),
+ 50000.0 * sin(ra_save-0.2) * cos(decl_save-0.2),
+ 50000.0 * sin(decl_save-0.2) );
+ xglVertex3f( 50000.0 * cos(ra_save+0.2) * cos(decl_save-0.2),
+ 50000.0 * sin(ra_save+0.2) * cos(decl_save-0.2),
+ 50000.0 * sin(decl_save-0.2) );
+ xglVertex3f( 50000.0 * cos(ra_save+0.2) * cos(decl_save+0.2),
+ 50000.0 * sin(ra_save+0.2) * cos(decl_save+0.2),
+ 50000.0 * sin(decl_save+0.2) );
+ xglVertex3f( 50000.0 * cos(ra_save-0.2) * cos(decl_save+0.2),
+ 50000.0 * sin(ra_save-0.2) * cos(decl_save+0.2),
+ 50000.0 * sin(decl_save+0.2) );
+ xglEnd();
+ */
+
+ /*
+ xglBegin(GL_LINE_LOOP);
+ xglColor3f(0.0, 1.0, 0.0);
+ xglVertex3f( 50000.0 * cos(ra_save1-0.2) * cos(decl_save1-0.2),
+ 50000.0 * sin(ra_save1-0.2) * cos(decl_save1-0.2),
+ 50000.0 * sin(decl_save1-0.2) );
+ xglVertex3f( 50000.0 * cos(ra_save1+0.2) * cos(decl_save1-0.2),
+ 50000.0 * sin(ra_save1+0.2) * cos(decl_save1-0.2),
+ 50000.0 * sin(decl_save1-0.2) );
+ xglVertex3f( 50000.0 * cos(ra_save1+0.2) * cos(decl_save1+0.2),
+ 50000.0 * sin(ra_save1+0.2) * cos(decl_save1+0.2),
+ 50000.0 * sin(decl_save1+0.2) );
+ xglVertex3f( 50000.0 * cos(ra_save1-0.2) * cos(decl_save1+0.2),
+ 50000.0 * sin(ra_save1-0.2) * cos(decl_save1+0.2),
+ 50000.0 * sin(decl_save1+0.2) );
+ xglEnd();
+ */
+
+ xglEndList();
+
+ max_stars /= 2;
+ }
+}
+
+
+/* Draw the Stars */
+void fgStarsRender() {
+ struct fgFLIGHT *f;
+ struct fgVIEW *v;
+ struct fgLIGHT *l;
+ struct fgTIME *t;
+ int i;
+
+ f = ¤t_aircraft.flight;
+ l = &cur_light_params;
+ t = &cur_time_params;
+ v = ¤t_view;
+
+ /* FG_PI_2 + 0.1 is about 6 degrees after sundown and before sunrise */
+
+ /* t->sun_angle = 3.0; */ /* to force stars to be drawn (for testing) */
+
+ /* render the stars */
+ if ( l->sun_angle > (FG_PI_2 + 5 * DEG_TO_RAD ) ) {
+ /* determine which star structure to draw */
+ if ( l->sun_angle > (FG_PI_2 + 7.25 * DEG_TO_RAD ) ) {
+ i = 0;
+ } else if ( l->sun_angle > (FG_PI_2 + 6.50 * DEG_TO_RAD ) ) {
+ i = 1;
+ } else if ( l->sun_angle > (FG_PI_2 + 5.75 * DEG_TO_RAD ) ) {
+ i = 2;
+ } else {
+ i = 3;
+ }
+
+ /* printf("RENDERING STARS = %d (night)\n", i); */
+
+ xglCallList(stars[i]);
+ } else {
+ /* printf("not RENDERING STARS (day)\n"); */
+ }
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:20 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.24 1997/12/30 22:22:39 curt
+ * Further integration of event manager.
+ *
+ * Revision 1.23 1997/12/30 20:47:53 curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.22 1997/12/30 16:36:53 curt
+ * Merged in Durk's changes ...
+ *
+ * Revision 1.21 1997/12/19 23:35:00 curt
+ * Lot's of tweaking with sky rendering and lighting.
+ *
+ * Revision 1.20 1997/12/15 23:55:03 curt
+ * Add xgl wrappers for debugging.
+ * Generate terrain normals on the fly.
+ *
+ * Revision 1.19 1997/12/12 19:53:00 curt
+ * Working on lightling and material properties.
+ *
+ * Revision 1.18 1997/12/10 22:37:52 curt
+ * Prepended "fg" on the name of all global structures that didn't have it yet.
+ * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
+ *
+ * Revision 1.17 1997/12/09 04:25:33 curt
+ * Working on adding a global lighting params structure.
+ *
+ * Revision 1.16 1997/11/25 19:25:38 curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.15 1997/10/30 12:38:45 curt
+ * Working on new scenery subsystem.
+ *
+ * Revision 1.14 1997/10/28 21:00:22 curt
+ * Changing to new terrain format.
+ *
+ * Revision 1.13 1997/10/25 03:18:28 curt
+ * Incorporated sun, moon, and planet position and rendering code contributed
+ * by Durk Talsma.
+ *
+ * Revision 1.12 1997/09/23 00:29:43 curt
+ * Tweaks to get things to compile with gcc-win32.
+ *
+ * Revision 1.11 1997/09/22 14:44:21 curt
+ * Continuing to try to align stars correctly.
+ *
+ * Revision 1.10 1997/09/20 03:34:32 curt
+ * Still trying to get those durned stars aligned properly.
+ *
+ * Revision 1.9 1997/09/18 16:20:09 curt
+ * At dusk/dawn add/remove stars in stages.
+ *
+ * Revision 1.8 1997/09/16 22:14:52 curt
+ * Tweaked time of day lighting equations. Don't draw stars during the day.
+ *
+ * Revision 1.7 1997/09/16 15:50:31 curt
+ * Working on star alignment and time issues.
+ *
+ * Revision 1.6 1997/09/05 14:17:31 curt
+ * More tweaking with stars.
+ *
+ * Revision 1.5 1997/09/05 01:35:59 curt
+ * Working on getting stars right.
+ *
+ * Revision 1.4 1997/09/04 02:17:38 curt
+ * Shufflin' stuff.
+ *
+ * Revision 1.3 1997/08/29 17:55:28 curt
+ * Worked on properly aligning the stars.
+ *
+ * Revision 1.2 1997/08/27 21:32:30 curt
+ * Restructured view calculation code. Added stars.
+ *
+ * Revision 1.1 1997/08/27 03:34:48 curt
+ * Initial revision.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * stars.h -- data structures and routines for managing and rendering stars.
+ *
+ * Written by Curtis Olson, started August 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)
+ **************************************************************************/
+
+
+#ifndef STARS_H
+#define STARS_H
+
+
+#define FG_MAX_STARS 500
+#define FG_STAR_LEVELS 4 /* how many star transitions */
+#define FG_MIN_STAR_MAG 0.738750 /* magnitude of weakest star we'll display */
+
+/* Initialize the Star Management Subsystem */
+void fgStarsInit();
+
+/* Draw the Stars */
+void fgStarsRender();
+extern struct OrbElements pltOrbElements[9];
+extern struct fgTIME cur_time_params;
+
+#endif /* STARS_H */
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:20 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.6 1997/10/25 03:18:29 curt
+ * Incorporated sun, moon, and planet position and rendering code contributed
+ * by Durk Talsma.
+ *
+ * Revision 1.5 1997/09/18 16:20:09 curt
+ * At dusk/dawn add/remove stars in stages.
+ *
+ * Revision 1.4 1997/09/05 01:36:00 curt
+ * Working on getting stars right.
+ *
+ * Revision 1.3 1997/08/29 17:55:28 curt
+ * Worked on properly aligning the stars.
+ *
+ * Revision 1.2 1997/08/27 21:32:30 curt
+ * Restructured view calculation code. Added stars.
+ *
+ * Revision 1.1 1997/08/27 03:34:50 curt
+ * Initial revision.
+ *
+ */
--- /dev/null
+/**************************************************************************
+ * sun.c
+ *
+ * Written 1997 by Durk Talsma, started October, 1997. For the flight gear
+ * project.
+ *
+ * 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)
+ **************************************************************************/
+
+#include <GL/glut.h>
+#include "../XGL/xgl.h"
+
+#include "../Time/fg_time.h"
+#include "../Main/views.h"
+#include "orbits.h"
+#include "sun.h"
+
+GLint sun_obj;
+
+static struct CelestialCoord sunPos;
+
+float xSun, ySun, zSun;
+
+struct SunPos fgCalcSunPos(struct OrbElements params)
+{
+ double
+ EccAnom, lonSun,
+ xv, yv, v, r;
+ struct SunPos
+ solarPosition;
+
+ /* calculate the eccentric anomaly */
+ EccAnom = fgCalcEccAnom(params.M, params.e);
+
+ /* calculate the Suns distance (r) and its true anomaly (v) */
+ xv = cos(EccAnom) - params.e;
+ yv = sqrt(1.0 - params.e*params.e) * sin(EccAnom);
+ v = atan2(yv, xv);
+ r = sqrt(xv*xv + yv*yv);
+
+ /* calculate the the Sun's true longitude (lonsun) */
+ lonSun = v + params.w;
+
+ /* convert true longitude and distance to ecliptic rectangular geocentric
+ coordinates (xs, ys) */
+ solarPosition.xs = r * cos(lonSun);
+ solarPosition.ys = r * sin(lonSun);
+ solarPosition.dist = r;
+ return solarPosition;
+}
+
+
+struct CelestialCoord fgCalculateSun(struct OrbElements params, struct fgTIME t)
+{
+ struct CelestialCoord
+ result;
+ struct SunPos
+ SolarPosition;
+ double
+ xe, ye, ze, ecl, actTime;
+
+ /* calculate the angle between ecliptic and equatorial coordinate system */
+ actTime = fgCalcActTime(t);
+ ecl = fgDegToRad(23.4393 - 3.563E-7 * actTime); // Angle now in Rads
+
+ /* calculate the sun's ecliptic position */
+ SolarPosition = fgCalcSunPos(params);
+
+ /* convert ecliptic coordinates to equatorial rectangular geocentric coordinates */
+ xe = SolarPosition.xs;
+ ye = SolarPosition.ys * cos(ecl);
+ ze = SolarPosition.ys * sin(ecl);
+
+ /* and finally... Calulate Right Ascention and Declination */
+ result.RightAscension = atan2( ye, xe);
+ result.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
+ return result;
+}
+
+
+/* Initialize the Sun */
+void fgSunInit() {
+ static int dl_exists = 0;
+
+ printf(" Initializing the Sun\n");
+
+ fgSolarSystemUpdate(&(pltOrbElements[0]), cur_time_params);
+ sunPos = fgCalculateSun(pltOrbElements[0], cur_time_params);
+#ifdef DEBUG
+ printf("Sun found at %f (ra), %f (dec)\n", sunPos.RightAscension,
+ sunPos.Declination);
+#endif
+
+ xSun = 60000.0 * cos(sunPos.RightAscension) * cos(sunPos.Declination);
+ ySun = 60000.0 * sin(sunPos.RightAscension) * cos(sunPos.Declination);
+ zSun = 60000.0 * sin(sunPos.Declination);
+
+ if ( !dl_exists ) {
+ dl_exists = 1;
+
+ /* printf("First time through, creating sun display list\n"); */
+
+ sun_obj = xglGenLists(1);
+ xglNewList(sun_obj, GL_COMPILE );
+
+ glutSolidSphere(1.0, 10, 10);
+
+ xglEndList();
+ }
+}
+
+
+/* Draw the Sun */
+void fgSunRender() {
+ struct fgVIEW *v;
+ struct fgTIME *t;
+ struct fgLIGHT *l;
+ /* GLfloat color[4] = { 0.85, 0.65, 0.05, 1.0 }; */
+ GLfloat color[4] = { 1.00, 1.00, 1.00, 1.00 };
+ double x_2, x_4, x_8, x_10;
+ GLfloat ambient;
+ GLfloat amb[3], diff[3];
+
+
+ t = &cur_time_params;
+ v = ¤t_view;
+ l = &cur_light_params;
+
+ x_2 = l->sun_angle * l->sun_angle;
+ x_4 = x_2 * x_2;
+ x_8 = x_4 * x_4;
+ x_10 = x_8 * x_2;
+
+ ambient = (0.4 * pow(1.1, -x_10 / 30.0));
+ if ( ambient < 0.3 ) ambient = 0.3;
+ if ( ambient > 1.0 ) ambient = 1.0;
+
+ amb[0] = 0.50 + ((ambient * 6.66) - 1.6);
+ amb[1] = 0.00 + ((ambient * 6.66) - 1.6);
+ amb[2] = 0.00 + ((ambient * 6.66) - 1.6);
+ amb[3] = 0.00;
+#ifdef DEBUG
+ printf("Color of the sun: %f, %f, %f\n"
+ "Ambient value : %f\n"
+ "Sun Angle : %f\n" , amb[0], amb[1], amb[2], ambient, t->sun_angle);
+#endif
+ diff[0] = 0.0;
+ diff[1] = 0.0;
+ diff[2] = 0.0;
+ diff[3] = 1.0;
+
+ /* set lighting parameters */
+ xglLightfv(GL_LIGHT0, GL_AMBIENT, color );
+ xglLightfv(GL_LIGHT0, GL_DIFFUSE, color );
+ xglMaterialfv(GL_FRONT, GL_AMBIENT, amb);
+ xglMaterialfv(GL_FRONT, GL_DIFFUSE, diff);
+ xglMaterialfv(GL_FRONT, GL_SHININESS, diff);
+ xglMaterialfv(GL_FRONT, GL_EMISSION, diff);
+ xglMaterialfv(GL_FRONT, GL_SPECULAR, diff);
+
+ /* xglDisable( GL_LIGHTING ); */
+
+ xglPushMatrix();
+ xglTranslatef(xSun, ySun, zSun);
+ xglScalef(1400, 1400, 1400);
+
+ xglColor3f(0.85, 0.65, 0.05);
+
+ xglCallList(sun_obj);
+
+ xglPopMatrix();
+
+ /* xglEnable( GL_LIGHTING ); */
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:20 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.12 1998/01/05 18:44:36 curt
+ * Add an option to advance/decrease time from keyboard.
+ *
+ * Revision 1.11 1997/12/30 23:09:40 curt
+ * Worked on winding problem without luck, so back to calling glFrontFace()
+ * 3 times for each scenery area.
+ *
+ * Revision 1.10 1997/12/30 20:47:54 curt
+ * Integrated new event manager with subsystem initializations.
+ *
+ * Revision 1.9 1997/12/30 16:36:54 curt
+ * Merged in Durk's changes ...
+ *
+ * Revision 1.8 1997/12/19 23:35:00 curt
+ * Lot's of tweaking with sky rendering and lighting.
+ *
+ * Revision 1.7 1997/12/17 23:12:16 curt
+ * Fixed so moon and sun display lists aren't recreate periodically.
+ *
+ * Revision 1.6 1997/12/15 23:55:04 curt
+ * Add xgl wrappers for debugging.
+ * Generate terrain normals on the fly.
+ *
+ * Revision 1.5 1997/12/12 21:41:31 curt
+ * More light/material property tweaking ... still a ways off.
+ *
+ * Revision 1.4 1997/12/10 22:37:53 curt
+ * Prepended "fg" on the name of all global structures that didn't have it yet.
+ * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
+ *
+ * Revision 1.3 1997/12/09 05:11:56 curt
+ * Working on tweaking lighting.
+ *
+ * Revision 1.2 1997/11/25 19:25:39 curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.1 1997/10/25 03:16:11 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
+
+
+
+
+
--- /dev/null
+/**************************************************************************
+ * sun.h
+ *
+ * Written 1997 by Durk Talsma, started October, 1997. For the flight gear
+ * project.
+ *
+ * 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)
+ **************************************************************************/
+
+
+#ifndef SUN_H
+#define SUN_H
+
+
+struct SunPos fgCalcSunPos(struct OrbElements sunParams);
+extern struct OrbElements pltOrbElements[9];
+
+/* Initialize the Sun */
+void fgSunInit();
+
+/* Draw the Sun */
+void fgSunRender();
+
+
+#endif /* SUN_H */
+
+
+/* $Log$
+/* Revision 1.1 1998/01/07 03:16:21 curt
+/* Moved from .../Src/Scenery/ to .../Src/Astro/
+/*
+ * Revision 1.3 1997/12/11 04:43:56 curt
+ * Fixed sun vector and lighting problems. I thing the moon is now lit
+ * correctly.
+ *
+ * Revision 1.2 1997/11/25 19:25:39 curt
+ * Changes to integrate Durk's moon/sun code updates + clean up.
+ *
+ * Revision 1.1 1997/10/25 03:16:12 curt
+ * Initial revision of code contributed by Durk Talsma.
+ *
+ */
projects / flightgear.git / commitdiff