/* demoQuadric.c   */
/*
	Purpose -  create a quadric geometric object
*/


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

#define KEY_ESC 27  /* GLUT doesn't supply this  */


/* Global variables */
GLUquadricObj* pQuadric;


GLvoid keyboard(GLubyte key, GLint x, GLint y)
{
	switch (key) 
	{
	case KEY_ESC:
		exit(0);   /* exit when ESC pressed */
	break;
	}
}

GLvoid checkError( const char* const label )
{
	GLenum error;
	error = glGetError();
	while (GL_NO_ERROR != error )
	{
		fprintf(stderr,"%s: %s\n", label, gluErrorString(error) );
		error = glGetError();
	}
}

/* 
	Note that the CALLBACK is necessary to work under MS Windows.
	To make this work on unix as well as MS Windows, do this:
		#ifndef WIN32
		#define CALLBACK
		#endif
*/

GLvoid CALLBACK checkError2( GLvoid )
{
	checkError("Quadric Error");
}


GLvoid display(GLvoid)
{
	/* Do all your OpenGL rendering here  */
	GLfloat ww;
	GLfloat wh;

	glClear(GL_COLOR_BUFFER_BIT);

	glLoadIdentity();  /* reset modelview  */

	/* get current window size */
	ww = glutGet(GLUT_WINDOW_WIDTH);
	wh = glutGet(GLUT_WINDOW_HEIGHT);

	/* Draw a tapering cylinder with
		baseRadius = 1.0,
		topRadius = 0.5,
		height = 0.8,
		slices = 12,
		stacks = 6
	*/

	glRotatef(45.0, 1.0, 1.0, 0.0);

	/* First viewport  */
	glViewport(0,0,ww/2,wh/2);

	gluQuadricDrawStyle( pQuadric, GLU_POINT );
	gluCylinder(pQuadric, 1.0, 0.5, 0.8, 12, 6 );  
/*	draw another object :
	gluQuadricDrawStyle( pQuadric, GLU_LINE );
	gluPartialDisk( pQuadric, 0.4, 1.0, 12, 6, 0.0, 120.0);  */

	/* Second viewport  */
	glViewport(ww/2,0,ww/2,wh/2);
	gluQuadricDrawStyle( pQuadric, GLU_LINE );
	gluCylinder(pQuadric, 1.0, 0.5, 0.8, 12, 6 );

	/* Third viewport */
	glViewport(0,wh/2,ww/2,wh/2);
	gluQuadricDrawStyle( pQuadric, GLU_SILHOUETTE );
	gluCylinder(pQuadric, 1.0, 0.5, 0.8, 12, 6 );

	/* Fourth viewport */
	glViewport(ww/2,wh/2,ww/2,wh/2);
	gluQuadricDrawStyle( pQuadric, GLU_FILL );
	gluCylinder(pQuadric, 1.0, 0.5, 0.8, 12, 6 );

	checkError("display");
	glFlush();
}

void init(void)
{
	/* set background color */
	glClearColor(0.4,0.4,0.7,1.0);
	/* set the 2D orthographic projection */
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-2.0,2.0,-2.0,2.0,-2.0,2.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

}

int main(int argc, char* argv[])
{
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB );  

	glutCreateWindow(argv[0]);

	init();

	glutDisplayFunc(display);
	glutKeyboardFunc(keyboard);

	/* allocate a quadric creation object */
	pQuadric = gluNewQuadric();

	/* Set up quadric error callback function  */
	gluQuadricCallback( pQuadric, GLU_ERROR, checkError2 );

	glutMainLoop();

	/* After finishing with a quadric creation object, we should delete it;
	but the execution never gets to here.  */

	gluDeleteQuadric( pQuadric );

	return 0;
}