/* demoScene.c  */

/*
	Purpose: create a scene using push/pop and GLUT3D models
*/

#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <math.h>

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


/* Global Definitions */

static const GLfloat green[] = {0.0, 1.0, 0.0};
static const GLfloat red[] = {1.0, 0.0, 0.0};
static const GLfloat blue[] = {0.0, 0.0, 1.0};

static const GLdouble cubeSize   = 10.0;

static const GLdouble coneBase   = 3.0;
static const GLdouble coneHeight = 10.0;
static const GLint coneSlices    = 8;
static const GLint coneStacks    = 15;

static const GLdouble sphereRadius = 4.0;
static const GLint sphereSlices    = 8;
static const GLint sphereStacks    = 15;

void printHelp( void )
{
	fprintf(stdout,
		"\ndemoScene - using push and pop\n\n"
		"Escape key - exit the program\n\n");
}

GLvoid keyboard( GLubyte key, GLint x, GLint y )
{
	switch ( key ) 
	{
	case KEY_ESC:
		exit(0);
	}
}

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();
	}
}

GLvoid reshape( GLint width, GLint height )
{
	GLdouble aspect;
	aspect = (GLdouble) width / (GLdouble) height;

	/* We still want the output to cover the whole window */
	glViewport(0, 0, width, height);

	glMatrixMode( GL_PROJECTION );
	glLoadIdentity();

	/* Get the viewing volume to have the correct aspect ratio */
	gluPerspective(45.0, aspect, 1.0, 300.0);  

	glMatrixMode(GL_MODELVIEW);
}


GLvoid drawConeAndSphere( GLvoid )
{
	glPushMatrix();
		/* Move to the side of the cube */
		glTranslatef(10.0, 0.0, 0.0);

		/* Now rotate the cone */
		glPushMatrix();
			glRotatef(-90.0, 1.0, 0.0, 0.0);
			glRotatef(90.0, 0.0, 1.0, 0.0);
			/* Draw the first cone */
			glColor3fv(red);
			glutWireCone(coneBase,coneHeight,coneSlices,coneStacks);
		glPopMatrix();
			
		/* Move to the side of the cone and draw the sphere */
		glPushMatrix();
			glTranslatef(14.0, 0.0, 0.0);
			glColor3fv(blue);
  			glutWireSphere(sphereRadius, sphereSlices, sphereStacks);	
		glPopMatrix();

	glPopMatrix();
}

GLvoid drawScene( GLvoid )
{	
	glClear(GL_COLOR_BUFFER_BIT);
	
	glColor3fv(blue);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	
    /* Translate into the viewing volume */
	glTranslatef(0.0f, 0.0f, -75.0f); 

	glPushMatrix();
	    /* Draw the cube */
	    glRotatef(30, 0.0, 1.0, 0.0);
	    glutWireCube(cubeSize);
	glPopMatrix();

	{
		int angle;
		for( angle = 0; angle < 360; angle += 90 )
		{
			glPushMatrix();
				glRotatef( angle, 0.0, 0.0, 1.0 );
				drawConeAndSphere();
			glPopMatrix();
		}
	}

	glFlush();
}


GLvoid init( GLvoid )
{
	glClearColor( 1.0, 1.0, 1.0, 1.0 );

}

int main(int argc, char *argv[])
{
	glutInit(&argc, argv);
	glutCreateWindow(argv[0]);
	
	init();
	
	glutKeyboardFunc( keyboard );
	glutReshapeFunc( reshape );
	glutDisplayFunc( drawScene );
	
	glutMainLoop();

	return 0;
}