/*
 * Copyright (c) 1996-1999  Silicon Graphics, Inc.  All rights reserved.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF THE
 * POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* shape_d.c - open a window, clear the background, set up
 *	our world, and draw a five-sided polygon.
 */
#include <GL/glut.h>	/* includes gl.h, glu.h */

#include "checkerror.h"

/* Function Prototypes */
GLvoid initgfx( GLvoid );
GLvoid drawScene( GLvoid );

void
main( int argc, char *argv[] )
{
	GLsizei width, height;

	glutInit( &argc, argv );

	width = glutGet( GLUT_SCREEN_WIDTH ); 
	height = glutGet( GLUT_SCREEN_HEIGHT );
	glutInitWindowPosition( width / 4, height / 4 );
	glutInitWindowSize( width / 2, height / 2 );
	glutInitDisplayMode( GLUT_RGBA );
	glutCreateWindow( argv[0] );

	initgfx();

	glutDisplayFunc( drawScene ); 

	glutMainLoop();
}

GLvoid
initgfx( GLvoid )
{
	/* set the clear color to white */
	glClearColor( 1.0f, 1.0f, 1.0f, 1.0f );

	/* set up our world */
	glOrtho( -3.0f, 3.0f, -3.0f, 3.0f, -1.0f, 1.0f );
}

GLvoid
drawScene( GLvoid )
{
	glClear( GL_COLOR_BUFFER_BIT );

	/* We'll do all our OpenGL rendering here */

	/* Rendering Lab: shape (d) */
	glColor3f( 1.0f, 0.0f, 0.0f );	/* red */
	glBegin( GL_POLYGON );
		glVertex2f( -1.0f, -1.0f );
		glVertex2f( 1.0f, -1.0f );
		glVertex2f( 1.0f, 1.0f );
		glVertex2f( 0.0f, 2.0f );
		glVertex2f( -1.0f, 1.0f );
	glEnd();

	checkError( "drawScene" );
	glFlush();
}