/*  earth.c  texture globe  needs   readtex.c   and   earth_sm.rgb  
 *  A little bit different "Hello, World!" program ;-)
 *  Author: Norman Walter
 *  e-mail: walternn@studi.informatik.uni-stuttgart.de
 *  www: http://www.norman-interactive.com
 *  Date: 22.3.2002
 */


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#include <time.h>

#define ANIMATE 10
#define POINT_FILTER 20
#define LINEAR_FILTER 21
#define FASTER 30
#define SLOWER 31
#define QUIT 100


static int frames=0,timefps,timebase=0;
   int qt, rt;

static GLuint Globe, Globe2, Globe3, Globe4;

static GLboolean Animate = GL_TRUE;

static GLfloat Xrot = -66.55, Yrot = -23.45, Zrot = 0.0;
static GLfloat DZrot = 1.0;
static GLfloat rotation = 0.0;
static GLboolean rotate = GL_TRUE;

void DisplaySplash();

static void drawText(GLfloat x, GLfloat y, char * msg)
{
    int   i, len;

    glPushMatrix();
    glLoadIdentity();
    glTranslatef( 0.0, 0.0, -10.0 ); /* -10 from 10 in frustum */
    glRasterPos2f(x, y); /* relative to -1.0 1.0 in frustum */
    len = strlen(msg);
    glColor3f(1.0f, 1.0f, 1.0f);
    for (i=0; i<len; i++)
    glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, msg[i]);
    glPopMatrix();
}


static void Idle( void )
{
  if(Animate)
  {
    Zrot += DZrot;
    if(Zrot > 360.0)
    {
      Zrot -= 360.0;
    }
    glutPostRedisplay();
  }
}


static void Display( void )
{
   ++frames;
   timefps=glutGet(GLUT_ELAPSED_TIME);
   int fps;
   struct tm *today;
   time_t   my_time;
   char ascii_string[100];
   my_time = time(&my_time);
   today = localtime(&my_time);
   strcpy(ascii_string, asctime(today));
		        
   if (timefps - timebase > 1000) {
      fps = (frames*1000.0/(timefps-timebase));
      timebase = timefps;                
      frames = 0;
   }
   char sFPS[256]={0};   
   sprintf( sFPS, "%d FPS", fps );
		
   glClear( GL_COLOR_BUFFER_BIT | GLUT_DEPTH | GL_DEPTH_BUFFER_BIT );
   glEnable(GL_DEPTH_TEST);
   glDepthFunc(GL_LEQUAL);

   float lPos[] = {0.0,0.0,9.0,0.0};
   glLightfv(GL_LIGHT0,GL_POSITION,lPos);
   glEnable(GL_LIGHTING);
   glEnable(GL_LIGHT0);
   glShadeModel(GL_SMOOTH);
   float diff[] = {1.0,1.0,1.0,1.0};
   glMaterialfv(GL_FRONT,GL_DIFFUSE,diff);

   glPushMatrix();
   rotation += 1.0f;
   if ( rotate ){
   //   glRotatef(rotation++, 1, 1, 1);
      if ( rotation > 360.0f ){
         rotation = 0.0f;
      }
   }
   
   glPushMatrix();
     //glTranslatef( 1.2f, 1.2f, 1.2f);
    //glTranslatef( 0.0f, 0.0f, 2.0f);
      glRotatef( rotation, 0, 0, 1 );
      glRotatef(Xrot, 1.0, 0.0, 0.0);
      glRotatef(Yrot, 0.0, 1.0, 0.0);
      glRotatef(Zrot, 0.0, 0.0, 1.0);
      glScalef(2.5, 2.5, 2.5);
      glCallList(Globe);
   glPopMatrix();
   
   glPushMatrix();
      glRotatef( rotation, 0, 0, 1 );
     //glTranslatef( -1.2f, -1.2f, -1.2f);
     //glTranslatef( 0.0f, 0.0f, 2.0f);
      glRotatef(Xrot, 1.0, 0.0, 0.0 );
      glRotatef(Yrot, 0.0, 1.0, 0.0 );
      glRotatef(Zrot, 0.0, 0.0, 1.0 );
      glScalef(2.5, 2.5, 2.5);
      glCallList(Globe2);
   glPopMatrix();
   
   glPushMatrix();
     //glTranslatef( 9.0f, 0.0f, 0.0f);
     //glTranslatef( 0.0f, 0.0f, 0.0f);
      glRotatef(Xrot, 1.0, 0.0, 0.0 );
      glRotatef(Yrot, 0.0, 1.0, 0.0 );
      glRotatef(Zrot, 0.0, 0.0, 1.0 );
      glScalef(2.5, 2.5, 2.5);
      glCallList(Globe3);
   glPopMatrix();
   
   glPushMatrix();
     //glTranslatef( -1.2f, -1.2f, -1.2f);
     //glTranslatef( 0.0f, 0.0f, 0.0f);
      glRotatef(Xrot, 1.0, 0.0, 0.0 );
      glRotatef(Yrot, 0.0, 1.0, 0.0 );
      glRotatef(Zrot, 0.0, 0.0, 1.0 );
      glScalef(2.5, 2.5, 2.5);
      glCallList(Globe4);
   glPopMatrix();

   glDisable(GL_LIGHTING);
   drawText(-0.9, -0.7, sFPS);
   drawText(-0.9, -0.8, "Right click for menu :)");
   drawText(-0.9, -0.9, ascii_string);
   glutSwapBuffers();
} /* end display */


static void Reshape( int width, int height )
{
   glViewport( 0, 0, width, height );
   glMatrixMode( GL_PROJECTION );
   glLoadIdentity();
   //glOrtho(-1.0, 1.0, -1.0, 1.0, 10.0, 10.0);
   glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 );
   glMatrixMode( GL_MODELVIEW );
   glLoadIdentity();
   glTranslatef( 0.0, 0.0, -70.0 );
} /* end reshape */


static void ModeMenu(int entry)
{
   if (entry==ANIMATE) {
      Animate = !Animate;
   }
   else if (entry==POINT_FILTER) {
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   }
   else if (entry==LINEAR_FILTER) {
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
   }
   else if (entry==QUIT) {
      exit(0);
   }
   else if (entry==SLOWER) {
	   DZrot /= 2;
   }
   else if (entry==FASTER) {
	   DZrot *= 2;
   }
   glutPostRedisplay();
} /* end ModeMenu */


static void Key( unsigned char key, int x, int y )
{
   switch (key) {
      case 27:
     exit(0);
     break;
   }
   glutPostRedisplay();
}


static void Init( void )
{
   glClearColor (0.0, 0.0, 0.0, 0.0);
   glClear( GL_COLOR_BUFFER_BIT | GLUT_DEPTH | GL_DEPTH_BUFFER_BIT );

   qt = loadTexture("earth_small.rgb");
   //rt = loadTexture("earth_small.rgb");
   


   /* globe and globe2 */
   GLUquadricObj *q = gluNewQuadric();
   Globe = glGenLists(1);
   glNewList(Globe, GL_COMPILE);
     glTranslatef( 0.0f, 0.0f, -2.0f);
     gluQuadricNormals(q, GL_SMOOTH);
     gluQuadricTexture(q, GL_TRUE);
     gluSphere (q, 1.0, 15, 15);
   glEndList();
   gluDeleteQuadric(q);

   GLUquadricObj *r = gluNewQuadric();
   Globe2 = glGenLists(1);
   glNewList(Globe2, GL_COMPILE);
     glTranslatef( 0.0f, 0.0f, 2.0f);
     gluQuadricNormals(r, GL_SMOOTH);
     gluQuadricTexture(r, GL_TRUE);
     gluSphere (r, 1.0, 15, 15);
   glEndList();
   gluDeleteQuadric(r);

   GLUquadricObj *s = gluNewQuadric();
   Globe3 = glGenLists(1);
   glNewList(Globe3, GL_COMPILE);
     glTranslatef( 2.0f, 0.0f, 0.0f);
     gluQuadricNormals(s, GL_SMOOTH);
     gluQuadricTexture(s, GL_TRUE);
     gluSphere (s, 1.0, 15, 15);
   glEndList();
   gluDeleteQuadric(s);
   
   GLUquadricObj *t = gluNewQuadric();
   Globe4 = glGenLists(1);
   glNewList(Globe4, GL_COMPILE);
     glTranslatef( -2.0f, 0.0f, 0.0f);
     gluQuadricNormals(t, GL_SMOOTH);
     gluQuadricTexture(t, GL_TRUE);
     gluSphere (t, 1.0, 15, 15);
   glEndList();
   gluDeleteQuadric(t);

   glEnable(GL_CULL_FACE);
   glEnable(GL_NORMALIZE);
   Reshape(400,400);
   glutTimerFunc( 50, DisplaySplash, 0 );
} /* end init */

int loadTexture(char *file){
   int retval;
   int wtf;
   glGenTextures(1, &retval);
   glBindTexture(GL_TEXTURE_2D, retval);
   wtf = LoadRGBMipmaps(file, GL_RGB);
   glEnable( GL_TEXTURE_2D );
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,  GL_LINEAR);

   return retval; 
}
void DisplaySplash(){
   struct tm *today ;
   time_t   my_time;
   int tnext = 0;
   my_time = time(&my_time);
   today = localtime(&my_time);
   tnext = today->tm_sec + 3;
   glutSetWindowTitle("Splash Screen");
   glClear( GL_COLOR_BUFFER_BIT | GLUT_DEPTH | GL_DEPTH_BUFFER_BIT );
   drawText(-0.9, -0.7, "Splashing");

   glutSwapBuffers();
   while ( tnext > today->tm_sec ){
      my_time = time(&my_time);
      today = localtime(&my_time);
   }
   glutSetWindowTitle("");
}
int main(int argc, char *argv[])
{
   int pwid;

   glutInit( &argc, argv );
   glutInitWindowSize( 400, 400 );

   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

   pwid = glutCreateWindow(argv[0]);
   Init();

   glutReshapeFunc( Reshape );
   glutKeyboardFunc( Key );
   glutDisplayFunc( Display );
   glutIdleFunc( Idle );

   glutCreateMenu(ModeMenu);
   glutAddMenuEntry("Point Filtered", POINT_FILTER);
   glutAddMenuEntry("Linear Filtered", LINEAR_FILTER);
   glutAddMenuEntry("Toggle Animation", ANIMATE);
   glutAddMenuEntry("Rotate Faster", FASTER);
   glutAddMenuEntry("Rotate Slower", SLOWER);
   glutAddMenuEntry("Quit", QUIT);
   glutAttachMenu(GLUT_RIGHT_BUTTON);

   glutMainLoop();
   return 0;
} /* end main of earth.c */