#include <GL/glut.h>
#include <math.h>
#include <stdio.h>

Macros
#define	pi 3.142857

Functions
void	myWireSphere (GLfloat radius, int slices, int stacks)

void	display ()

void	timer (int v)

void	reshape (GLint w, GLint h)

int	main (int argc, char **argv)

Variables
static bool	spinning = true

static const int	FPS = 20

static GLfloat	current_rot = 0.0

static int	year = 0

static int	day = 0

static GLfloat	u = 0.0

static GLfloat	du = 0.1

Macro Definition Documentation

◆ pi

#define pi 3.142857

Definition at line 8 of file openGL_astronomy_animated.c.

Function Documentation

◆ display()

void display ( void )

Definition at line 40 of file openGL_astronomy_animated.c.

                {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     glPushMatrix();
  
     // Draw sun: a yellow sphere of radius 1 centered at the origin.
     glColor3f(1.0, 1.0, 0.0);
     myWireSphere(1.0, 15, 15);
  
     // Draw planet: a blue sphere of radius 0.2, 2 units away from
     // sun, with a white "pole" for its axis.
     glRotatef((GLfloat)year, 0.0, 1.0, 0.0);
     glTranslatef(2.0, 0.0, 0.0);
     glRotatef((GLfloat)day, 0.0, 1.0, 0.0);
     glColor3f(0.0, 0.0, 1.0);
     myWireSphere(0.2, 15, 15);
     glColor3f(1, 1, 1);
     glBegin(GL_LINES);
     glVertex3f(0, -0.3, 0);
     glVertex3f(0, 0.3, 0);
     glEnd();
  
     glPopMatrix();
     glFlush();
     glutSwapBuffers();
 }

References day, myWireSphere(), and year.

Referenced by main().

◆ main()

int main	(	int	argc,
		char **	argv
	)

Definition at line 112 of file openGL_astronomy_animated.c.

                                 {
     glutInit(&argc, argv);
     glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
     glutInitWindowSize(800, 600);
     glutCreateWindow("Comet, Planet Simulation");
     glutDisplayFunc(display);
     glutReshapeFunc(reshape);
     glutTimerFunc(100, timer, 0);
     glEnable(GL_DEPTH_TEST);
     glutMainLoop();
 }

References display(), reshape(), and timer().

◆ myWireSphere()

void myWireSphere	(	GLfloat	radius,
		int	slices,
		int	stacks
	)

Definition at line 20 of file openGL_astronomy_animated.c.

                                                           {
     glPushMatrix();
     glRotatef(-90.0, 1.0, 0.0, 0.0);
     glutWireSphere(radius, slices, stacks);
     glPopMatrix();
 }

Referenced by display().

◆ reshape()

void reshape	(	GLint	w,
		GLint	h
	)

Definition at line 103 of file openGL_astronomy_animated.c.

                                {
     glViewport(0, 0, w, h);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluPerspective(60.0, (GLfloat)w / (GLfloat)h, 1.0, 40.0);
     glMatrixMode(GL_MODELVIEW);
 }

Referenced by main().

◆ timer()

void timer ( int v )

Definition at line 75 of file openGL_astronomy_animated.c.

                   {
     u += du;
     day = (day + 1) % 360;
     year = (year + 2) % 360;
     glLoadIdentity();
     gluLookAt(20 * cos(u / 8.0) + 12,
               5 * sin(u / 8.0) + 1,
               10 * cos(u / 8.0) + 2,
               0,
               0,
               0,
               0,
               1,
               0);
     glutPostRedisplay();
     glutTimerFunc(1000 / 60, timer, v);
 }