simgear/Astro/solarsystem.cxx
2009-09-15 18:31:31 +02:00

266 lines
8.4 KiB
C++

/**************************************************************************
* solarsystem.cxx
* Written by Durk Talsma. Originally started October 1997, for distribution
* with the FlightGear project. Version 2 was written in August and
* September 1998. This code is based upon algorithms and data kindly
* provided by Mr. Paul Schlyter. (pausch@saaf.se).
*
* 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 HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef HAVE_WINDOWS_H
# include <windows.h>
#endif
#include <GL/glut.h>
#include <XGL/xgl.h>
#include <Debug/fg_debug.h>
#include <Time/sunpos.hxx>
#include "solarsystem.hxx"
/***************************************************************************
* default constructor for class SolarSystem:
* or course there can only be one way to create an entire solar system -:) )
* the fgTIME argument is needed to properly initialize the the current orbital
* elements
*************************************************************************/
SolarSystem::SolarSystem(fgTIME *t)
{
if (theSolarSystem)
{
fgPrintf(FG_GENERAL, FG_EXIT, "Error: only one solarsystem allowed\n");
}
theSolarSystem = this;
ourSun = new Star(t);
earthsMoon = new Moon(t);
mercury = new Mercury(t);
venus = new Venus(t);
mars = new Mars(t);
jupiter = new Jupiter(t);
saturn = new Saturn(t);
uranus = new Uranus(t);
neptune = new Neptune(t);
displayList = 0;
};
/* --------------------------------------------------------------------------
the destructor for class SolarSystem;
danger: Huge Explosions ahead! (-:))
------------------------------------------------------------------------*/
SolarSystem::~SolarSystem()
{
delete ourSun;
delete earthsMoon;
delete mercury;
delete venus;
delete mars;
delete jupiter;
delete saturn;
delete uranus;
delete neptune;
//delete pluto;
}
/****************************************************************************
* void SolarSystem::rebuild()
*
* this member function updates the positions for the sun, moon, and planets,
* and then rebuilds the display list.
*
* arguments: none
* return value: none
***************************************************************************/
void SolarSystem::rebuild()
{
fgLIGHT *l = &cur_light_params;
fgTIME *t = &cur_time_params;
float x, y, z,
xx, yy,zz;
double ra, dec;
double x_2, x_4, x_8, x_10;
double magnitude;
GLfloat ambient;
GLfloat amb[4];
GLfloat moonColor[4] = {0.85, 0.75, 0.35, 1.0};
GLfloat black[4] = {0.0, 0.0,0.0,1.0};
GLfloat white[4] = {1.0, 1.0,1.0,1.0};
// Step 1: update all the positions
ourSun->updatePosition(t);
earthsMoon->updatePosition(t, ourSun);
mercury->updatePosition(t, ourSun);
venus->updatePosition(t, ourSun);
mars->updatePosition(t, ourSun);
jupiter->updatePosition(t, ourSun);
saturn->updatePosition(t, ourSun);
uranus->updatePosition(t, ourSun);
neptune->updatePosition(t, ourSun);
fgUpdateSunPos(); // get the right sun angle (especially important when
// running for the first time.
if (displayList)
xglDeleteLists(displayList, 1);
displayList = xglGenLists(1);
// Step 2: rebuild the display list
xglNewList( displayList, GL_COMPILE);
{
// Step 2a: Add the moon...
xglEnable( GL_LIGHTING );
xglEnable( GL_LIGHT0 );
// set lighting parameters
xglLightfv(GL_LIGHT0, GL_AMBIENT, white );
xglLightfv(GL_LIGHT0, GL_DIFFUSE, white );
xglEnable( GL_CULL_FACE );
// Enable blending, in order to effectively eliminate the dark side of the
// moon
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE);
earthsMoon->getPos(&ra, &dec);
x = 60000.0 * cos(ra) * cos (dec);
y = 60000.0 * sin(ra) * cos (dec);
z = 60000.0 * sin(dec);
xx = cos(ra) * cos(dec);
yy = sin(ra) * cos(dec);
zz = sin(dec);
xglMaterialfv(GL_FRONT, GL_AMBIENT, black);
xglMaterialfv(GL_FRONT, GL_DIFFUSE, moonColor);
xglPushMatrix();
{
earthsMoon->newImage(ra,dec);
}
xglPopMatrix();
glDisable(GL_BLEND);
xglDisable(GL_LIGHTING);
// Step 2b: Add the sun
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] = 0.00 + ((ambient * 6.0) - 1.0); // minimum value = 0.8
amb[1] = 0.00 + ((ambient * 11.0) - 3.0); // minimum value = 0.3
amb[2] = 0.00 + ((ambient * 12.0) - 3.6); // minimum value = 0.0
amb[3] = 1.00;
if (amb[0] > 1.0) amb[0] = 1.0;
if (amb[1] > 1.0) amb[1] = 1.0;
if (amb[2] > 1.0) amb[2] = 1.0;
ourSun->getPos(&ra, &dec);
x = 60000.0 * cos(ra) * cos(dec);
y = 60000.0 * sin(ra) * cos(dec);
z = 60000.0 * sin(dec);
xglPushMatrix();
{
// xglPushMatrix();
xglTranslatef(x,y,z);
xglColor3f(amb[0], amb[1], amb[2]);
glutSolidSphere(1400.0, 10, 10);
}
glPopMatrix();
// Step 2c: Add the planets
xglBegin(GL_POINTS);
mercury->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
venus ->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
mars ->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
jupiter->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
saturn ->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
uranus ->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
neptune->getPos(&ra, &dec, &magnitude);addPlanetToList(ra, dec, magnitude);
xglEnd();
xglEnable(GL_LIGHTING);
}
xglEndList();
}
/*****************************************************************************
* double SolarSystem::scaleMagnitude(double magn)
* This private member function rescales the original magnitude, as used in the
* astronomical sense of the word, into a value used by OpenGL to draw a
* convincing Star or planet
*
* Argument: the astronomical magnitude
*
* return value: the rescaled magnitude
****************************************************************************/
double SolarSystem::scaleMagnitude(double magn)
{
double magnitude = (0.0 - magn) / 5.0 + 1.0;
magnitude = magnitude * 0.7 + (3 * 0.1);
if (magnitude > 1.0) magnitude = 1.0;
if (magnitude < 0.0) magnitude = 0.0;
return magnitude;
}
/***************************************************************************
* void SolarSytem::addPlanetToList(double ra, double dec, double magn);
*
* This private member function first causes the magnitude to be properly
* rescaled, and then adds the planet to the display list.
*
* arguments: Right Ascension, declination, and magnitude
*
* return value: none
**************************************************************************/
void SolarSystem::addPlanetToList(double ra, double dec, double magn)
{
double
magnitude = scaleMagnitude ( magn );
fgLIGHT *l = &cur_light_params;
if ((double) (l->sun_angle - FG_PI_2) >
((magnitude - 1.0) * - 20 * DEG_TO_RAD))
{
xglColor3f (magnitude, magnitude, magnitude);
xglVertex3f( 50000.0 * cos (ra) * cos (dec),
50000.0 * sin (ra) * cos (dec),
50000.0 * sin (dec));
}
}
SolarSystem* SolarSystem::theSolarSystem = 0;
/******************************************************************************
* void solarSystemRebuild()
* this a just a wrapper function, provided for use as an interface to the
* event manager
*****************************************************************************/
void solarSystemRebuild()
{
SolarSystem::theSolarSystem->rebuild();
}