solar_system/window.c

/*!\file window.c
 * \brief Utilisation du raster "maison" pour finaliser le pipeline de
 * rendu 3D. Ici on peut voir les géométries disponibles.
 * \author Farès BELHADJ, amsi@up8.edu
 * \date December 4, 2020.
 * \todo pour les étudiant(e)s : changer la variation de l'angle de
 * rotation pour qu'il soit dépendant du temps et non du framerate
 */
#include <assert.h>
/* inclusion des entêtes de fonctions de gestion de primitives simples
 * de dessin. La lettre p signifie aussi bien primitive que
 * pédagogique. */
#include <GL4D/gl4dp.h>
/* inclure notre bibliothèque "maison" de rendu */
#include "moteur.h"

/* inclusion des entêtes de fonctions de création et de gestion de
 * fenêtres système ouvrant un contexte favorable à GL4dummies. Cette
 * partie est dépendante de la bibliothèque SDL2 */
#include <GL4D/gl4duw_SDL2.h>
#include <SDL_mixer.h>

/* protos de fonctions locales (static) */
static void init(void);
static void draw(void);
static void key(int keycode);
static void sortie(void);
static void pmotion(int x, int y);
static void mouse(int button, int state, int x, int y);
static void goto_obj(float * mvMat);
static void move_to(float posx, float posy , float posz);
static int get_sign(float x, float y);

/*!\brief un identifiant pour l'écran (de dessin) */
static uint _screenId = 0;

// surface representing the Sun.
static surface_t * _sun = NULL;

// surface array representing 8 planets + pluto (dwarf planet).
static surface_t * _planet[9] = { 	NULL, NULL, NULL,
									NULL, NULL, NULL,
									NULL, NULL, NULL };

// surface array representing 18 moons of the planets.
static surface_t * _moon[18] = {NULL, NULL, NULL, NULL,
								NULL, NULL, NULL, NULL,
								NULL, NULL, NULL, NULL,
								NULL, NULL, NULL, NULL,
								NULL, NULL};

/* des variable d'états pour activer/désactiver des options de rendu */
static int _use_tex = 1, _use_color = 0, _use_lighting = 1;

typedef struct cam_t cam_t;

// camera structure, borrowed from sample3d_01-1.6 of GL4Dummies samples.
struct cam_t {
	float x, y, z;
	float theta;
};

static cam_t _cam = {0, 1.0f, 10, 0};

// movement speed.
static float _v = 0.1f;

// window size.
static int _wW = 1200, _wH = 900;

// middle of the window.
static int _xm = 600, _ym = 450;

static int _pause = 0; // boolean value for the pause.
static float _s = 1.0f; // multiplier for angle (for speeding planets movement and rotation).
static int _movement = 1; // boolean to allow movement.
static int _p = -1; // the object (sun, planets, pluto) number to move.
static float _a = 0.0f; // rotation angle.
static int _overview = 0; // boolean to toggle overview (view from the top).

static Mix_Chunk * bsound = NULL;

/*!\brief paramètre l'application et lance la boucle infinie. */
int main(int argc, char ** argv) {
	if (SDL_Init(SDL_INIT_AUDIO) == -1) {
		fprintf(stderr, "SDL_Init: %s\n,", Mix_GetError());
		exit(3);
	}
	/* tentative de création d'une fenêtre pour GL4Dummies */
	if(!gl4duwCreateWindow(argc, argv, /* args du programme */
				"Solar System", /* titre */
				10, 10, _wW, _wH, /* x, y, largeur, heuteur */
				GL4DW_SHOWN) /* état visible */) {
		/* ici si échec de la création souvent lié à un problème d'absence
		 * de contexte graphique ou d'impossibilité d'ouverture d'un
		 * contexte OpenGL (au moins 3.2) */
		return 1;
	}
	/* Pour forcer la désactivation de la synchronisation verticale */
	SDL_GL_SetSwapInterval(0);
	init();
	/* création d'un screen GL4Dummies (texture dans laquelle nous
	 * pouvons dessiner) aux dimensions de la fenêtre */
	_screenId = gl4dpInitScreen();
	/* mettre en place la fonction d'interception clavier */
	gl4duwMouseFunc(mouse);
	gl4duwKeyDownFunc(key);
	gl4duwPassiveMotionFunc(pmotion);
	/* mettre en place la fonction de display */
	gl4duwDisplayFunc(draw);
	/* boucle infinie pour éviter que le programme ne s'arrête et ferme
	 * la fenêtre immédiatement */

	gl4duwMainLoop();
	return 0;
}

/*!\brief init de nos données, spécialement les trois surfaces
 * utilisées dans ce code */
void init(void) {
	uint id[9], sun_id, i, moon_id[18];
	int flags = MIX_INIT_MP3;
	int initted = Mix_Init(flags);
	if ((initted & flags) != flags) {
		fprintf(stderr, "Mix_Init: Failed to init required mp3 support!\n");
		fprintf(stderr, "Mix_Init: %s\n,", Mix_GetError());
		exit(2);
	}
	if (Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT, 2, 1024) == -1) {
		fprintf(stderr, "Mix_OpenAudio: %s\n,", Mix_GetError());
		exit(4);
	}
	if (bsound == NULL)
		bsound = Mix_LoadWAV("./space.wav");
	if (Mix_PlayChannel(-1, bsound, 0) < 0)
		fprintf(stderr, "Mix_PlayChannel: %s\n", Mix_GetError());

	
	// create all spheres.
	_sun = mkSphere(12, 12);  /*ça fait 12x12x2 triangles !*/
	for(i = 0; i < 18; ++i) {
		_moon[i] = mkSphere(12, 12);
	}
	for(i = 0; i < 9; ++i) {
		_planet[i] = mkSphere(12, 12);
	}


	// get all textures.
	sun_id 	= getTexFromBMP("images/2k-sun.bmp");
	id[0] 	= getTexFromBMP("images/2k-mercury.bmp");
	id[1] 	= getTexFromBMP("images/2k-venus-surface.bmp");
	id[2] 	= getTexFromBMP("images/2k-earth-daymap.bmp");
	id[3] 	= getTexFromBMP("images/2k-mars.bmp");
	id[4] 	= getTexFromBMP("images/2k-jupiter.bmp");
	id[5] 	= getTexFromBMP("images/2k-saturn.bmp");
	id[6] 	= getTexFromBMP("images/2k-uranus.bmp");
	id[7] 	= getTexFromBMP("images/2k-neptune.bmp");
	id[8] 	= getTexFromBMP("images/pluto.bmp");
	// https://upload.wikimedia.org/wikipedia/commons/4/4f/Moons_of_solar_system_v7.jpg
	// most of the biggest moons are here.
	moon_id[0] 	= getTexFromBMP("images/2k-moon.bmp");
	moon_id[1] 	= getTexFromBMP("images/moons/phobos.bmp");
	moon_id[2] 	= getTexFromBMP("images/moons/deimos.bmp");
	moon_id[3] 	= getTexFromBMP("images/moons/io.bmp");
	moon_id[4] 	= getTexFromBMP("images/moons/europa.bmp");
	moon_id[5] 	= getTexFromBMP("images/moons/ganymede.bmp");
	moon_id[6] 	= getTexFromBMP("images/moons/callisto.bmp");
	moon_id[7] 	= getTexFromBMP("images/moons/enceladus.bmp");
	moon_id[8] 	= getTexFromBMP("images/moons/dione.bmp");
	moon_id[9] 	= getTexFromBMP("images/moons/rhea.bmp");
	moon_id[10] = getTexFromBMP("images/moons/titan.bmp");
	moon_id[11] = getTexFromBMP("images/moons/iapetus.bmp");
	moon_id[12] = getTexFromBMP("images/moons/ariel.bmp");
	moon_id[13] = getTexFromBMP("images/moons/umbriel.bmp");
	moon_id[14] = getTexFromBMP("images/moons/titania.bmp");
	moon_id[15] = getTexFromBMP("images/moons/oberon.bmp");
	moon_id[16] = getTexFromBMP("images/moons/triton.bmp");
	moon_id[17] = getTexFromBMP("images/moons/charon.bmp");

	// set texture to an object id and set all options.
	setTexId(_sun, sun_id);
	for(i = 0; i < 18; ++i)
		setTexId(_moon[i], moon_id[i]);
	for(i = 0; i < 9; ++i)
		setTexId(_planet[i], id[i]);
	if(_use_tex) {
		enableSurfaceOption(_sun, SO_USE_TEXTURE);
		for(i = 0; i < 18; ++i)
			enableSurfaceOption(_moon[i], SO_USE_TEXTURE);
		for(i = 0; i < 9; ++i)
			enableSurfaceOption(_planet[i], SO_USE_TEXTURE);
	}
	/* si _use_lighting != 0, on active l'ombrage */
	if(_use_lighting) {
		enableSurfaceOption(_sun, SO_USE_LIGHTING);
		for(i = 0; i < 18; ++i)
			enableSurfaceOption(_moon[i], SO_USE_LIGHTING);
		for(i = 0; i < 9; ++i)
			enableSurfaceOption(_planet[i], SO_USE_LIGHTING);
	}
	disableSurfaceOption(_sun, SO_USE_COLOR);
	for(i = 0; i < 18; ++i)
		disableSurfaceOption(_moon[i], SO_USE_COLOR);
	for(i = 0; i < 9; ++i)
		disableSurfaceOption(_planet[i], SO_USE_COLOR);
	atexit(sortie);
}

// get sign for further move calculation.
static int get_sign(float x, float y) {
	if (x > y)
		return 1;
	return -1;
}

// move to the coordinate.
static void move_to(float posx, float posy , float posz){
	float epsilon = 0.1f; // precision for comparing
	if (fabsf(_cam.x - posx) > epsilon) {
		_cam.x = _cam.x - (get_sign(_cam.x, posx) * 0.09f);
	}
	if (fabsf(_cam.y - posy) > epsilon) {
		_cam.y = _cam.y - (get_sign(_cam.y, posy) * 0.09f);
	}
	if (fabsf(_cam.z - posz) > epsilon) {
		_cam.z = _cam.z - (get_sign(_cam.z, posz) * 0.09f);
	}
}

// go to a choosen object (planet, star, pluto(dwarf))
static void goto_obj(float * mvMat) {
	switch (_p) {
		case 1: // MERCURY
			_a = 0; // reset angle to 0.
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 4.2f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(4.2f, 1.0f, 0.5f);
			break;
		case 2: // VENUS
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 7.9f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(7.9f, 1.0f, 1.0f);
			break;
		case 3: // EARTH
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 10.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(10.0f, 1.0f, 1.0f);
			break;
		case 4: // MARS
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 15.2f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(15.2f, 1.0f, 0.5f);
			break;
		case 5: // JUPITER
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 30.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(30.0f, 1.0f, 5.0f);
			break;
		case 6: // SATURN
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 50.4f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(50.4f, 1.0f, 5.0f);
			break;
		case 7: // NEPTUNE
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 65.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(65.0f, 1.0f, 5.0f);
			break;
		case 8: // URANUS
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 75.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(75.0f, 1.0f, 4.0f);
			break;
		case 9: // PLUTO
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 85.4f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(85.4f, 1.0f, 0.1f);
			break;
		case 0: // SUN
			_a = 0;
			lookAt(mvMat, _cam.x, _cam.y, _cam.z, 0, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f);
			move_to(0.0f, 1.0f, 10.0f);
			break;
	}
}

/*!\brief la fonction appelée à chaque display. */
void draw(void) {
	static float r = 0.0f;
	static double t0 = 0, t, dt;
	t = gl4dGetElapsedTime();
	dt = (t - t0) / 1000.0;
	t0 = t;
	float mvMat[16], projMat[16], nmv[16], cpy[16];
	/* effacer l'écran et le buffer de profondeur */
	gl4dpClearScreen();
	clearDepth();
	/* des macros facilitant le travail avec des matrices et des
	 * vecteurs se trouvent dans la bibliothèque GL4Dummies, dans le
	 * fichier gl4dm.h */
	/* charger un frustum dans projMat */
	MFRUSTUM(projMat, -0.005f, 0.005f, -0.005f, 0.005f, 0.01f, 1000.0f);
	/* charger la matrice identité dans model-view */
	MIDENTITY(mvMat);

	// Y ----> 1.0 - (_ym - (_wH >> 1)) / (float)_wH * 5
	if (_movement)
		lookAt(mvMat, _cam.x, _cam.y, _cam.z, _cam.x - sin(_cam.theta), 1.0, _cam.z - cos(_cam.theta), 0.0, 1.0, 0.0);
	else
		goto_obj(mvMat);

	// SUN
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, (r / 24.5f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 0.0f, 1.0f, 0.0f);
	scale(nmv, 2,2,2);
	transform_n_raster(_sun, nmv, projMat);

	// MERCURY
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, (_a / 87.97f), 0.0f, 1.0f, 0.0f); // orbit mouvement
	translate(nmv, 4.2f, 1.0f, 0.0f);
	scale(nmv, (1/227.0f) * 12.0f, (1/227.0f) * 12.0f, (1/227.0f) * 12.0f);
	rotate(nmv, (r / 59.0f), 0.0f, 1.0f, 0.0f); // rotation
	transform_n_raster(_planet[0], nmv, projMat);

	// VENUS
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, (_a / 224.7f), 0.0f, 1.0f, 0.0f); // orbit mouvement
	translate(nmv, 7.9f, 1.0f, 0.0f);
	scale(nmv, (1/113.0f) * 12.0f, (1/113.0f) * 12.0f, (1/113.0f) * 12.0f);
	rotate(nmv, (r / 243.75f), -0.1773f, -1.0f, 0.0f); // rotation anti-clockwise
	transform_n_raster(_planet[1], nmv, projMat);

	// EARTH
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, (_a / 365.2425f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 10.0f, 1.0f, 0.0f);
	scale(nmv, (1/108.0f) * 12.0f, (1/108.0f) * 12.0f, (1/108.0f) * 12.0f);
	rotate(nmv, r, -0.234f, 1.0f, 0.0f);
	transform_n_raster(_planet[2], nmv, projMat);

	// Moon
	translate(nmv, 4.0f, 0.0f, 0.0f);
	scale(nmv, (1/5.0f) , (1/5.0f), (1/5.0f));
	transform_n_raster(_moon[0], nmv, projMat);

	// MARS
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, (_a / 686.98f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 15.2f, 1.0f, 0.0f);
	scale(nmv, (1/208.0f) * 12.0f, (1/208.0f) * 12.0f, (1/208.0f) * 12.0f);
	rotate(nmv, r / 1.0416f, -0.252f, 1.0f, 0.0f);
	transform_n_raster(_planet[3], nmv, projMat);

	memcpy(cpy, nmv, sizeof cpy);

	// Phobos
	rotate(nmv, r * 4.3f, 0.0f, 0.1f, 0.0f);
	translate(nmv, 10.0f, 1.0f, 0.0f);
	scale(nmv, (1/5.0f), (1/5.0f), (1/5.0f));
	transform_n_raster(_moon[1], nmv, projMat);

	// Deimos
	rotate(cpy, r / 1.5f, 0.0f, 0.1f, 0.0f);
	translate(cpy, 25.0f, 1.0f, 0.0f);
	scale(cpy, (1/6.0f), (1/6.0f), (1/6.0f));
	transform_n_raster(_moon[2], cpy, projMat);

	// JUPITER
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, _a / (12 * 365.2425f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 30.0f, 1.0f, 0.0f);
	scale(nmv, (1/9.7f) * 12.0f, (1/9.7f) * 12.0f, (1/9.7f) * 12.0f);
	rotate(nmv, r / 0.416f, -0.031f, 1.0f, 0.0f);
	transform_n_raster(_planet[4], nmv, projMat);

	memcpy(cpy, nmv, sizeof cpy);

	// Io
	rotate(nmv, r * 3.0f, 0.0f, 0.1f, 0.0f);
	translate(nmv, 3.0f, 0.0f, 0.0f);
	scale(nmv, (1/11.2f), (1/11.2f), (1/11.2f));
	transform_n_raster(_moon[3], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Europa
	rotate(nmv, r / 2.0f, 0.0f, 0.1f, 0.0f);
	translate(nmv, 4.0f, 0.0f, 0.0f);
	scale(nmv, (1/13.2f), (1/13.2f), (1/13.2f));
	transform_n_raster(_moon[4], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Ganymede
	rotate(nmv, r / 3.0f, 0.0f, 0.1f, 0.0f);
	translate(nmv, 5.0f, 0.0f, 0.0f);
	scale(nmv, (1/9.0f), (1/9.0f), (1/9.0f));
	transform_n_raster(_moon[5], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Callisto
	rotate(nmv, r / 5.0f, 0.0f, 0.1f, 0.0f);
	translate(nmv, 6.0f, 0.0f, 0.0f);
	scale(nmv, (1/10.0f), (1/10.0f), (1/10.0f));
	transform_n_raster(_moon[6], nmv, projMat);

	// SATURN
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, _a / (30 * 365.2425f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 50.4f, 1.0f, 0.0f);
	scale(nmv, (1/11.4f) * 12.0f, (1/11.4f) * 12.0f, (1/11.4f) * 12.0f);
	rotate(nmv, r / 0.4583f, -0.267f, 1.0f, 0.0f);
	transform_n_raster(_planet[5], nmv, projMat);

	memcpy(cpy, nmv, sizeof cpy);

	// Enceladus
	rotate(nmv, r * 5.0f, 0.0f, 0.1f, 0.0f);
	translate(nmv, 2.0f, 0.0f, 0.0f);
	scale(nmv, (1/20.0f), (1/20.0f), (1/20.0f));
	transform_n_raster(_moon[7], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Dione
	rotate(nmv, r * 4.0f, 0.0f, 0.01f, 0.0f);
	translate(nmv, 3.0f, 0.0f, 0.0f);
	scale(nmv, (1/18.0f), (1/18.0f), (1/18.0f));
	transform_n_raster(_moon[8], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Rhea
	rotate(nmv, r * 3.0f, 0.0f, 0.01f, 0.0f);
	translate(nmv, 4.0f, 0.0f, 0.0f);
	scale(nmv, (1/15.0f), (1/15.0f), (1/15.0f));
	transform_n_raster(_moon[9], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Titan
	rotate(nmv, r / 4.0f, 0.0f, 0.01f, 0.0f);
	translate(nmv, 6.0f, 0.0f, 0.0f);
	scale(nmv, (1/10.0f), (1/10.0f), (1/10.0f));
	transform_n_raster(_moon[10], nmv, projMat);

	memcpy(nmv, cpy, sizeof nmv);

	// Iapetus
	rotate(nmv, r / 6.0f, 0.0f, 0.01f, 0.0f);
	translate(nmv, 7.0f, 0.0f, 0.0f);
	scale(nmv, (1/14.0f), (1/14.0f), (1/14.0f));
	transform_n_raster(_moon[11], nmv, projMat);

	// URANUS
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, _a / (84 * 365.2425f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 65.0f, 1.0f, 0.0f);
	scale(nmv, (1/26.8f) * 12.0f, (1/26.8f) * 12.0f, (1/26.8f) * 12.0f);
	rotate(nmv, r / 0.7083f, -0.978f, 0.0f, 0.0f);
	transform_n_raster(_planet[6], nmv, projMat);

	memcpy(cpy, nmv, sizeof cpy);

	// Ariel
	rotate(nmv, r , 0.01f, 0.0f, 0.0f);
	translate(nmv, 0.0f, 3.0f, 0.0f);
	scale(nmv, (1/20.0f), (1/20.0f), (1/20.0f));
	transform_n_raster(_moon[12], nmv, projMat);

	memcpy (nmv, cpy, sizeof nmv);

	// Umbriel
	rotate(nmv, r / 2.0f, 0.01f, 0.0f, 0.0f);
	translate(nmv, 0.0f, 4.0f, 0.0f);
	scale(nmv, (1/20.0f), (1/20.0f), (1/20.0f));
	transform_n_raster(_moon[13], nmv, projMat);

	memcpy (nmv, cpy, sizeof nmv);

	// Titania
	rotate(nmv, r / 3.0f, 0.01f, 0.0f, 0.0f);
	translate(nmv, 0.0f, 5.0f, 0.0f);
	scale(nmv, (1/17.0f), (1/17.0f), (1/17.0f));
	transform_n_raster(_moon[14], nmv, projMat);

	memcpy (nmv, cpy, sizeof nmv);

	// Oberon
	rotate(nmv, r / 5.0f, 0.01f, 0.0f, 0.0f);
	translate(nmv, 0.0f, 6.0f, 0.0f);
	scale(nmv, (1/17.0f), (1/17.0f), (1/17.0f));
	transform_n_raster(_moon[15], nmv, projMat);

	// NEPTUNE
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, _a / (165 * 365.2425f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 75.0f, 1.0f, 0.0f);
	scale(nmv, (1/27.7f) * 12.0f, (1/27.7f) * 12.0f, (1/27.7f) * 12.0f);
	rotate(nmv, r / 0.6f, -0.283f, 1.0f, 0.0f);
	transform_n_raster(_planet[7], nmv, projMat);

	// Triton
	rotate(nmv, r / 5.0f, 0.0f, 0.01f, 0.0f);
	translate(nmv, 3.0f, 0.0f, 0.0f);
	scale(nmv, (1/10.0f), (1/10.0f), (1/10.0f));
	transform_n_raster(_moon[16], nmv, projMat);

	// PLUTO
	memcpy(nmv, mvMat, sizeof nmv); /* copie mvMat dans nmv */
	rotate(nmv, _a / (248 * 365.2425f), 0.0f, 1.0f, 0.0f);
	translate(nmv, 85.4f, 1.0f, 0.0f);
	scale(nmv, (1/500.0f) * 12.0f, (1/500.0f) * 12.0f, (1/500.0f) * 12.0f);
	rotate(nmv, r / 6.4, -0.119f, 1.0f, 0.0f);
	transform_n_raster(_planet[8], nmv, projMat);

	// Charon
	rotate(nmv, r / 5.0f, 0.0f, 0.01f, 0.0f);
	translate(nmv, 3.0f, 0.0f, 0.0f);
	scale(nmv, (1/13.0f), (1/13.0f), (1/13.0f));
	transform_n_raster(_moon[16], nmv, projMat);

	/* déclarer qu'on a changé (en bas niveau) des pixels du screen  */
	gl4dpScreenHasChanged();
	/* fonction permettant de raffraîchir l'ensemble de la fenêtre*/
	gl4dpUpdateScreen(NULL);
	if (!_pause){
		_a += ((360.0 * dt) / 60) * _s; // 360 in 1 minute so 1 day = 1 min
		r += ((360.0 * dt) / 60) * _s; // 360 in 1 minute so 1 day = 1 min
	}
}

/*!\brief intercepte l'événement clavier pour modifier les options. */
void key(int keycode) {
	double step = 5.0;
	int i;
	switch(keycode) {
		case GL4DK_UP:
			if (_movement)
				_cam.y += 5;
			break;
		case GL4DK_DOWN:
			if (_movement)
				_cam.y -= 5;
			break;
		case GL4DK_RIGHT:
			if (!_pause)
				_s += 30.0f;
			break;
		case GL4DK_LEFT:
			if (!_pause)
				_s -= 30.0f;
			break;
		case GL4DK_w:
			if (_movement) {
				_cam.x += -_v * step * sin(_cam.theta);
				_cam.z += -_v * step * cos(_cam.theta);
			}
			break;
		case GL4DK_s:
			if (_movement) {
				_cam.x += _v * step * sin(_cam.theta);
				_cam.z += _v * step * cos(_cam.theta);
			}
			break;
		case GL4DK_a:
			if (_movement)
				_cam.theta += _v * step;
			break;
		case GL4DK_d:
			if (_movement)
				_cam.theta -= _v * step;
			break;
		case GL4DK_p:
			if (_pause == 0)
				_pause = 1;
			else
				_pause = 0;
			break;
		case GL4DK_MINUS:
			_v -= 0.01f;
			if (_v < 0.01f){
				_v = 0.01f;
			}
			break;
		case GL4DK_EQUALS:
			_v += 0.01f;
			if (_v > 0.5f){
				_v = 0.5f;
			}
			break;
		case GL4DK_o:
			if (_movement) {
				if (!_overview) {
					_overview = !_overview;
					_cam.x = 0.0f;
					_cam.y = 200.0f;
					_cam.z = 0.0f;
					_cam.theta = 0.0f;
				} else {
					_overview = !_overview;
					_cam.x = 0.0f;
					_cam.y = 1.0f;
					_cam.z = 10.0f;
					_cam.theta = 0.0f;
				}
			}
			break;
		case GL4DK_r:
			_p = -1;
			_pause = 0;
			_movement = 1;
			break;
		case GL4DK_q:
			exit(0);
			break;
		case GL4DK_0:
			_p = 0;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_1:
			_p = 1;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_2:
			_p = 2;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_3:
			_p = 3;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_4:
			_p = 4;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_5:
			_p = 5;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_6:
			_p = 6;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_7:
			_p = 7;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_8:
			_p = 8;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_9:
			_p = 9;
			_pause = 1;
			_movement = 0;
			_cam.x = (int)_cam.x;
			_cam.y = (int)_cam.y;
			_cam.z = (int)_cam.z;
			break;
		case GL4DK_t: /* 't' la texture */
			_use_tex = !_use_tex;
			if(_use_tex) {
				enableSurfaceOption(_sun, SO_USE_TEXTURE);
				for(i = 0; i < 18; ++i)
					enableSurfaceOption(_moon[i], SO_USE_TEXTURE);
				for(i = 0; i < 9; ++i)
					enableSurfaceOption(_planet[i], SO_USE_TEXTURE);
			} else {
				disableSurfaceOption(_sun, SO_USE_TEXTURE);
				for(i = 0; i < 18; ++i)
					disableSurfaceOption(_moon[i], SO_USE_TEXTURE);
				for(i = 0; i < 9; ++i)
					disableSurfaceOption(_planet[i], SO_USE_TEXTURE);
			}
			break;
		case GL4DK_c: /* 'c' utiliser la couleur */
			_use_color = !_use_color;
			if(_use_color) {
				enableSurfaceOption(_sun, SO_USE_COLOR);
				for(i = 0; i < 18; ++i)
					enableSurfaceOption(_moon[i], SO_USE_COLOR);
				for(i = 0; i < 9; ++i)
					enableSurfaceOption(_planet[i], SO_USE_COLOR);
			} else {
				disableSurfaceOption(_sun, SO_USE_COLOR);
				for(i = 0; i < 18; ++i)
					disableSurfaceOption(_moon[i], SO_USE_COLOR);
				for(i = 0; i < 9; ++i)
					disableSurfaceOption(_planet[i], SO_USE_COLOR);
			}
			break;
		case GL4DK_l: /* 'l' utiliser l'ombrage par la méthode Gouraud */
			_use_lighting = !_use_lighting;
			if(_use_lighting) {
				enableSurfaceOption(_sun, SO_USE_LIGHTING);
				for(i = 0; i < 18; ++i)
					enableSurfaceOption(_moon[i], SO_USE_LIGHTING);
				for(i = 0; i < 9; ++i)
					enableSurfaceOption(_planet[i], SO_USE_LIGHTING);
			} else {
				disableSurfaceOption(_sun, SO_USE_LIGHTING);
				for(i = 0; i < 18; ++i)
					disableSurfaceOption(_moon[i], SO_USE_LIGHTING);
				for(i = 0; i < 9; ++i)
					disableSurfaceOption(_planet[i], SO_USE_LIGHTING);
			}
			break;
		default: break;
	}
}

// handler of mouse motion.
static void pmotion(int x, int y) {
	if (_movement){
		_xm = x;
		_ym = y;
		_cam.theta = -(_xm - (_wW >> 1)) / (float)_wW*10;
	}
}

// handler of mouse buttons.
static void mouse(int button, int state, int x, int y) {
	if (_movement){
		double dtheta = M_PI;
		if (button == GL4D_BUTTON_LEFT)
			_cam.y += dtheta;
		if (button == GL4D_BUTTON_RIGHT)
			_cam.y -= dtheta;
		if (button == GL4D_BUTTON_MIDDLE)
			_cam.y = 1.0f;
	}
}

/*!\brief à appeler à la sortie du programme. */
void sortie(void) {
	int i;
	Mix_CloseAudio();
	Mix_Quit();
	if(_sun) {
		freeSurface(_sun);
		_sun = NULL;
	}
	for(i = 0; i < 18; ++i) {
		if(_moon[i]){
			freeSurface(_moon[i]);
			_moon[i] = NULL;
		}
	}
	for(i = 0; i < 9; ++i) {
		if(_planet[i]){
			freeSurface(_planet[i]);
			_planet[i] = NULL;
		}
	}
	if (bsound)
		Mix_FreeChunk(bsound);
	bsound = NULL;
	/* libère tous les objets produits par GL4Dummies, ici
	 * principalement les screen */
	gl4duClean(GL4DU_ALL);
}