#include<GL/glut.h>
#include<GL/gl.h>
#include<GL/glu.h>


void redraw(){
	glClearColor(0.0,0.0,0.0,1.0);
	glClear(GL_COLOR_BUFFER_BIT);
	glBegin(GL_TRIANGLE_STRIP);
	glColor3f(1.0,1.0,1.0);
	glVertex2f(-0.8,-0.8);
	glColor3f(1.0,0.0,0.0);
	glVertex2f(0.5,0.2);
	glColor3f(0.0,1.0,0.0);
	glVertex2f(-0.16,0.11);
	glColor3f(0.0,0.0,1.0);
	glVertex2f(-0.5,0.6);
	glVertex2f(-0.4,0.0);
        glEnd();
	glFlush();
}


int main(int argc,char** argv){
    glutInit(&argc, argv);
    glutInitDisplayMode ( GLUT_RGB );
    glutInitWindowPosition( 300, 100 );
    glutInitWindowSize ( 150, 150 );
    glutCreateWindow ( "Esempio 4" );
    glutDisplayFunc( redraw );
    glutMainLoop ();
}