/**************************************************************************
* 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
#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"
-/* #include "../Aircraft/aircraft.h"*/
-#include "../general.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
- result;
-
- double
- eccAnom, ecl, lonecl, latecl, actTime,
- xv, yv, v, r, xh, yh, zh, xg, yg, zg, xe, ye, ze,
- Ls, Lm, D, F;
-
- /* 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)
- );
- 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);
-
- result.RightAscension = atan2(ye, xe);
- result.Declination = atan2(ze, sqrt(xe*xe + ye*ye));
-
- return result;
+ 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 CelestialCoord
- moonPos;
-
- moon = glGenLists(1);
- glNewList(moon, GL_COMPILE );
- glBegin( GL_POINTS );
- moonPos = fgCalculateMoon(pltOrbElements[1], pltOrbElements[0], cur_time_params);
- printf("Moon found at %f (ra), %f (dec)\n", moonPos.RightAscension, moonPos.Declination);
- /* give the moon a temporary color, for testing purposes */
- glColor3f( 0.0, 1.0, 0.0);
- glVertex3f( 190000.0 * cos(moonPos.RightAscension) * cos(moonPos.Declination),
- 190000.0 * sin(moonPos.RightAscension) * cos(moonPos.Declination),
- 190000.0 * sin(moonPos.Declination) );
- glEnd();
- glEndList();
+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();
+ }
}
-void fgMoonRender()
-{
- double angle;
- static double warp = 0;
- struct VIEW *v;
- struct fgTIME *t;
-
- t = &cur_time_params;
- v = ¤t_view;
-
-
- glDisable( GL_FOG );
- glDisable( GL_LIGHTING );
- glPushMatrix();
- glTranslatef( v->view_pos.x, v->view_pos.y, v->view_pos.z );
- angle = t->gst * 15.0; /* 15 degrees per hour rotation */
- /* warp += 1.0; */
- /* warp = 15.0; */
- warp = 0.0;
- glRotatef( (angle+warp), 0.0, 0.0, -1.0 );
- printf("Rotating moon by %.2f degrees + %.2f degrees\n",angle,warp);
-
- glCallList(moon);
-
- glPopMatrix();
- glEnable( GL_LIGHTING );
- glEnable( GL_FOG );
+
+/* 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 1.2 1997/10/28 21:00:21 curt
-/* Changing to new terrain format.
+/* Revision 1.16 1998/01/06 01:20:24 curt
+/* Tweaks to help building with MSVC++
/*
- * Revision 1.1 1997/10/25 03:16:08 curt
- * Initial revision of code contributed by Durk Talsma.
+ * 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.
*
*/
projects / simgear.git / blobdiff