* (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)
{
EccAnom = fgCalcEccAnom(params.M, params.e);
/* calculate the Suns distance (r) and its true anomaly (v) */
- xv = cos(EccAnom) - params.e;
+ 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 Suns true longitude (lonsun) */
+ /* calculate the the Sun's true longitude (lonsun) */
lonSun = v + params.w;
/* convert true longitude and distance to ecliptic rectangular geocentric
- coordinates (xs, ys) */
+ 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
+
+ if ( !dl_exists ) {
+ dl_exists = 1;
+
+ /* printf("First time through, creating sun display list\n"); */
+
+ sun_obj = xglGenLists(1);
+ xglNewList(sun_obj, GL_COMPILE );
+
+ xSun = 60000.0 * cos(sunPos.RightAscension) * cos(sunPos.Declination);
+ ySun = 60000.0 * sin(sunPos.RightAscension) * cos(sunPos.Declination);
+ zSun = 60000.0 * sin(sunPos.Declination);
+
+ 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 1997/10/25 03:16:11 curt
-/* Initial revision of code contributed by Durk Talsma.
+/* 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.
+ *
*/
+
+
+
+
+
projects / simgear.git / blobdiff