#include <GL/glut.h>

GLsizei winWidth = 400, winHeight = 300;

void init(void)
{
	glClearColor (0.0, 0.0, 1.0, 0.0);

	glMatrixMode (GL_PROJECTION);
	gluOrtho2D (0.0, winWidth, 0.0, winHeight);
}

void displayFcn (void)
{
    glClear (GL_COLOR_BUFFER_BIT);
	glColor3f (1.0, 0.0, 0.0);
	glBegin (GL_POLYGON);
		glVertex2i (50,50);
		glVertex2i (100,50);
		glVertex2i (75,100);
	glEnd ();

	glFlush ( ); 
}
void main (int argc, char** argv)
{
	glutInit (&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowPosition (350, 100);
	glutInitWindowSize (winWidth, winHeight);
	glutCreateWindow ("Triangle Program");

	init();
	glutDisplayFunc (displayFcn);

	glutMainLoop ( );
}