/*
Displays "Hello World" using OGL - Open Graphics Library
http://en.wikipedia.org/wiki/OpenGL
http://www.lighthouse3d.com/opengl/glut/index.php?1	(tutorial w/ Glut)
http://freeglut.sourceforge.net/ (Glut updated)
*/

#include <GL/glut.h>
#define font GLUT_BITMAP_HELVETICA_18
#define tx "Hello World !"

void text(void) /* write text in color buffer */
{
	char *p, tex[] = tx;
	p = tex;
	glColor3d(1.0, 1.0, 0.0);
	glRasterPos2d(-.5, 0.);
	while(*p) glutBitmapCharacter(font, *p++);
}

void display() /* display text */
{    		
	glClear(GL_COLOR_BUFFER_BIT);	
	text();
	glFlush();
}

void reshape(int width, int height)  /* when window is moved or reshaped */
{    
	glViewport(0, 0, width, height);    
	glMatrixMode(GL_PROJECTION);    
	glLoadIdentity();    
	glOrtho(-1, 1, -1, 1, -1, 1);    
	glMatrixMode(GL_MODELVIEW);
	display();
}  

int main(int argc, char **argv)
{    
	glutInit(&argc, argv);    
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);    
	glutInitWindowPosition(50, 50);    
	glutInitWindowSize(500, 500);    
	glutCreateWindow("Hello World OpenGL");    
	glClearColor(0,0,0,0);    
	glutDisplayFunc(display);    
	glutReshapeFunc(reshape);    
	glutMainLoop();    
	return 0;
}