// WormholeDemo.cpp
// NKU CSC 480 Spring 2006 Kirby Program 1
// -----------------------------------------------------------
// Display some wormholes in wireframe.
// Use keys 1 2 3 to choose which variety of wormhole to draw.
//
// EXTRA: Introduces display lists, so we don't have to completely
// recalculate every wormhole vertex at every frame of animation!
//
// Link this program with Wormhole.cpp
// -----------------------------------------------------------

#include <gl/glut.h>
#include <string>
#include <vector>
#include "Geometry.h"
#include "Stopwatch.h"
#include "Wormhole.h"
using namespace csc480 ;
using namespace std ;


Stopwatch G_stopwatch ;          // for pausing animation
int       G_whichWormhole= 0 ;   // user choice of wormholes 0,1,2
int       G_wormhole[3] ;        // IDs of three wormlists stored in display lists



void makeWormholes()
// Creates display lists storing 3 differently shaped wormholes, for later display. 
{
    // "Standard" wormhole.
    G_wormhole[0]= glGenLists(1) ;
    glNewList( G_wormhole[0], GL_COMPILE ) ;
        wormhole( 2.0, 1.0, 1.4, 0.2, 0.1 ) ;
    glEndList() ; 
    
    // Showing that rectangles on floor need not be same size.
    G_wormhole[1]= glGenLists(1) ;
    glNewList( G_wormhole[1], GL_COMPILE ) ;
        wormhole( 1.6, 1.6, 0.70, 0.25, 0.05 )  ;
    glEndList() ; 
   
    // Skinny wormhole. 
    G_wormhole[2]= glGenLists(1) ;
    glNewList( G_wormhole[2], GL_COMPILE ) ;
        wormhole( 2.0, 1.0, 1.4, 0.2, 0.03 ) ;
    glEndList() ; 
}



void display()
// Called by glut whenever scene needs repainting.
{
    // Prepare to draw
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ) ;
    glLoadIdentity() ; 
    glScaled( 0.8, 0.8, 0.8 ) ;

    // Set angle based on time, for animation.
    double angle= G_stopwatch.getValue() / 100 ;
    glPolygonMode( GL_FRONT_AND_BACK, GL_LINE ) ; 
    glRotated( angle, 1,1,1 ) ;

    // Draw the wormhole selected by user via keyboard callback.
    glColor3d( 0.5,0,0 ) ;
    glCallList( G_wormhole[ G_whichWormhole ] ) ;

    glutSwapBuffers() ;
}



void animate()  
// Callback for one frame of animtation.
{
    glutPostRedisplay() ;
} 



void toggleAnimation() 
// Toggle animation on and off. 
{
    if ( G_stopwatch.isStopped() )
    {
        G_stopwatch.start() ;
        glutIdleFunc( animate ) ;
    }
    else
    {
        G_stopwatch.stop() ;
        glutIdleFunc( NULL ) ;
    }
}



void kbDispatch( unsigned char ch, int x, int y )
// Respond to key presses (ASCII key values): toggle animation or select wormhole type. 
{
    if ( ch == ' ' )
        toggleAnimation() ;
    else if ( ch >= '0' && ch <= '2' )
        G_whichWormhole= ch - '0' ;
    glutPostRedisplay() ; 
}



int main( int argc, char** argv )
{
    // Initialize OpenGL. 
    glutInit( &argc, argv ) ;
    glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH ) ; 

    // Window attributes.
    glutInitWindowSize( 600, 600 ) ;
    glutInitWindowPosition( 100, 100 ) ;
    glutCreateWindow( "Csc 480: Wormhole!" ) ;
    glClearColor( 1,1,1,1 ) ; // white background

    // Set projection matrix.
    glMatrixMode( GL_PROJECTION ) ;
    glLoadIdentity() ;
    gluPerspective( 20, 1, 4, 8 ) ;
    gluLookAt( 0,0,6,  0,0,0, 0,1,0 ) ;
    glMatrixMode( GL_MODELVIEW ) ;

    // Build display lists
    makeWormholes();

    // Set callbacks
    glutKeyboardFunc( kbDispatch ) ; 
    glutIdleFunc( animate ) ;
    glutDisplayFunc( display ) ;  

    // Turn control over to event loop.
    G_stopwatch.start() ;
    glutMainLoop() ;
    
    return 0 ;
}