Create stars in a OpenGL solar system

Question

I am creating a solar system in OpenGL C++ in which the earth revolve around the sun .

The only problem that i face now that i can't create stars above the window i tried everything but not helped

Now i have deleted some extra code from here i hope it will work for you guys as those functions were not neccessary or making any change

  #include "Solar.h" #include <stdlib.h> #include <glut.h> static GLenum spinMode = GL_TRUE; static GLenum singleStep = GL_FALSE; static float HourOfDay = 0.0; static float DayOfYear = 0.0; static float AnimateIncrement = 2.0; void Haxxan() { glClear(GL_COLOR_BUFFER_BIT); glBegin(GL_LINES); glColor3f(0.1,0.3,0.9); glVertex2f(-0.9,0.5); glVertex2f(-0.9,0.0); glVertex2f(-0.9,0.25); glVertex2f(-0.7,0.25); glEnd(); glFlush(); } /* * Animate() handles the animation and the redrawing of the * graphics window contents. */ static void Animate(void) { // Clear the redering window glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Now Make stars Using the Vertex //glBegin(GL_LINES); //glColor3f(0.1,0.3,0.9); /*glVertex2f(-0.9,0.5); glVertex2f(-0.9,0.0); glVertex2f(-0.9,0.25); glVertex2f(-0.7,0.25); */ if (spinMode) { // Update the animation state HourOfDay += AnimateIncrement; DayOfYear += AnimateIncrement/40.0; HourOfDay = HourOfDay - ((int)(HourOfDay/24))*24; DayOfYear = DayOfYear - ((int)(DayOfYear/365))*365; } // Clear the current matrix (Modelview) glLoadIdentity(); // Back off eight units to be able to view from the origin. glTranslatef ( 0.0, 0.0, -8.0 ); // Rotate the plane of the elliptic // (rotate the model's plane about the x axis by fifteen degrees) glRotatef( 15.0, 1.0, 0.0, 0.0 ); // Draw the sun -- as a yellow, wireframe sphere glColor3f( 1.0, 1.0, 0.0 ); glutWireSphere( 1.0, 15, 15 ); // Now Draw Stars glColor3f(0.0,0.0,1.0); //glutWireSphere( 0.3, 18, 9 ); //glLineStipple(0.1,0.1); glVertex2f(0.9,0.3); glVertex2f(0.6,0.3); //end stars // Draw the Earth // First position it around the sun // Use DayOfYear to determine its position glRotatef( 360.0*DayOfYear/365.0, 0.0, 1.0, 0.0 ); glTranslatef( 4.0, 0.0, 0.0 ); glPushMatrix(); // Save matrix state // Second, rotate the earth on its axis. // Use HourOfDay to determine its rotation. glRotatef( 360.0*HourOfDay/24.0, 0.0, 1.0, 0.0 ); // Third, draw the earth as a wireframe sphere. glColor3f( 0.2, 0.2, 1.0 ); glutWireSphere( 0.4, 10, 10); glPopMatrix(); // Restore matrix state // Draw the moon. // Use DayOfYear to control its rotation around the earth glRotatef( 360.0*12.0*DayOfYear/365.0, 0.0, 1.0, 0.0 ); glTranslatef( 0.7, 0.0, 0.0 ); glColor3f( 0.3, 0.7, 0.3 ); glutWireSphere( 0.1, 5, 5 ); /* make me glRotatef( 360.0*12.0*DayOfYear/365.0, 0.0, 1.0, 0.0 ); glTranslatef( 0.1, 1.0, 0.2 ); glColor3f( 0.0, 0.7, 1.0 ); glutWireSphere( 0.1, 3, 2 ); */ // Flush the pipeline, and swap the buffers glFlush(); glutSwapBuffers(); if ( singleStep ) { spinMode = GL_FALSE; } glutPostRedisplay(); // Request a re-draw for animation purposes } // Initialize OpenGL's rendering modes void OpenGLInit(void) { // glClear(GL_COLOR_BUFFER_BIT); //glBegin(GL_LINES); //glColor3f(0.1,0.3,0.9); //glVertex2f(-0.9,0.5); //glVertex2f(-0.9,0.0); // glutDisplayFunc(Haxxan); glShadeModel( GL_FLAT ); glClearColor( 0.0, 0.0, 0.0, 0.0 ); glClearDepth( 1.0 ); glEnable( GL_DEPTH_TEST ); } // ResizeWindow is called when the window is resized static void ResizeWindow(int w, int h) { float aspectRatio; h = (h == 0) ? 1 : h; w = (w == 0) ? 1 : w; glViewport( 0, 0, w, h ); // View port uses whole window aspectRatio = (float)w/(float)h; // Set up the projection view matrix (not very well!) glMatrixMode( GL_PROJECTION ); glLoadIdentity(); gluPerspective( 60.0, aspectRatio, 1.0, 30.0 ); // Select the Modelview matrix glMatrixMode( GL_MODELVIEW ); } // Main routine // Set up OpenGL, hook up callbacks, and start the main loop int main( int argc, char** argv ) { // Need to double buffer for animation glutInit(&argc,argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH ); // Create and position the graphics window glutInitWindowPosition( 0, 0 ); glutInitWindowSize( 600, 360 ); glutCreateWindow( "Solar System Demo" ); // Initialize OpenGL. OpenGLInit(); // Set up callback functions for key presses // Set up the callback function for resizing windows glutReshapeFunc( ResizeWindow ); // Callback for graphics image redrawing glutDisplayFunc( Animate ); // Start the main loop. glutMainLoop never returns. glutMainLoop( ); return(0); } 

Answer 1

well i figured it out.

i used the vertices to animate an X as like a star so i guess it will work and it worked the professor was happy so i hope this will help for others too

  static void Animate(void)
  {
  // Clear the redering window
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   if (spinMode) {
    // Update the animation state
    HourOfDay += AnimateIncrement;
    DayOfYear += AnimateIncrement/40.0;

    HourOfDay = HourOfDay - ((int)(HourOfDay/28))*24;
    DayOfYear = DayOfYear - ((int)(DayOfYear/365))*365;
    }

 // Clear the current matrix (Modelview)
 glLoadIdentity();

 // Back off eight units to be able to view from the origin.
 glTranslatef ( 0.0, 0.0, -8.0 );

 // Rotate the plane of the elliptic
 // (rotate the model's plane about the x axis by fifteen degrees)
 glRotatef( 15.0, 1.0, 0.0, 0.0 );

 // Draw the sun    -- as a yellow, wireframe sphere
 glColor3f( 1.0, 1.0, 0.0 );
 glutWireSphere( 1.0, 15, 15 );

 glBegin(GL_LINES);
 glColor3f(1.0,1.0,1.0);
 //star 1
 glVertex2f(0.4,2.5);
 glVertex2f(0.6,2.6);

 glVertex2f(0.6,2.5);
 glVertex2f(0.4,2.6);
 // star 2
 glVertex2f(0.8,1.5);
 glVertex2f(1.1,1.7);

 glVertex2f(1.1,1.5);
 glVertex2f(0.8,1.7);
 // star 3
 glVertex2f(0.8,3.5);
 glVertex2f(1.1,3.7);

 glVertex2f(1.1,3.5);
 glVertex2f(0.8,3.7);

 //star 4
 glVertex2f(2.2,1.5);
 glVertex2f(2.4,1.7);

 glVertex2f(2.4,1.5);
 glVertex2f(2.2,1.7);

 //star 5
 glVertex2f(-2.2,3.5);
 glVertex2f(-2.4,3.7);

 glVertex2f(-2.4,3.5);
 glVertex2f(-2.2,3.7);

 //star 6
 glVertex2f(-0.4,2.5);
 glVertex2f(-0.6,2.6);

 glVertex2f(-0.6,2.5);
 glVertex2f(-0.4,2.6);

 //star 7
 glVertex2f(-3.4,2.5); 
 glVertex2f(-3.6,2.6);

 glVertex2f(-3.6,2.5);
 glVertex2f(-3.4,2.6);

 //star 8
 glVertex2f(-4.4,2.5);
 glVertex2f(-4.6,2.6);

 glVertex2f(-4.6,2.5);
 glVertex2f(-4.4,2.6);

 //star 9
 glVertex2f(-4.2,3.5);
 glVertex2f(-4.4,3.7);

 glVertex2f(-4.4,3.5);
 glVertex2f(-4.2,3.7);
 glEnd();
 // Now Draw Stars
 glColor3f(0.0,0.0,1.0);
 //glutWireSphere( 0.3, 18, 9 );
 //glLineStipple(0.1,0.1);
 glVertex2f(0.9,0.3);
 glVertex2f(0.6,0.3);

 //end stars
  // Draw the Earth
 // First position it around the sun
 //     Use DayOfYear to determine its position
 glRotatef( 360.0*DayOfYear/365.0, 0.0, 1.0, 0.0 );
 glTranslatef( 4.0, 0.0, 0.0 );
 glPushMatrix();                        // Save matrix state
 // Second, rotate the earth on its axis.
 //     Use HourOfDay to determine its rotation.
 glRotatef( 360.0*HourOfDay/24.0, 0.0, 1.0, 0.0 );
 // Third, draw the earth as a wireframe sphere.
 glColor3f( 0.2, 0.2, 1.0 );
 glutWireSphere( 0.4, 10, 10);
 //glutSolidSphere(0.4,10,10);
 glPopMatrix();                     // Restore matrix state

 // Draw the moon.
 // Use DayOfYear to control its rotation around the earth
 glRotatef( 360.0*12.0*DayOfYear/365.0, 0.0, 1.0, 0.0 );
 // glRotatef( 360.0*60.0*DayOfYear/1000.0, 0.0, 1.0, 0.0 );
 glTranslatef( 0.7, 0.0, 0.0 );
 glColor3f( 0.3, 0.7, 0.3 );
 glutWireSphere( 0.1, 5, 5 );

 */
 // Flush the pipeline, and swap the buffers
 glFlush();
 glutSwapBuffers();

 if ( singleStep ) {
    spinMode = GL_FALSE;
 }

 glutPostRedisplay();       // Request a re-draw for animation purposes

 }