#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);
	
	GLboolean bEdgeFlag=GL_FALSE;
	glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
	
	glBegin(GL_TRIANGLES);
	glEdgeFlag(bEdgeFlag);
	glVertex2f(-0.2f,0.0f);
	glEdgeFlag(GL_TRUE);
	glVertex2f(0.2f,0.0f);
	glVertex2f(0.0f,0.4f);

	glVertex2f(-0.2f,0.0f);
	glVertex2f(-0.6f,-0.2f);
	glEdgeFlag(bEdgeFlag);
	glVertex2f(-0.2f,-0.4f);
	glEdgeFlag(GL_TRUE);

	glVertex2f(-0.2f,-0.4f);
	glVertex2f(0.0f,-0.8f);
	glEdgeFlag(bEdgeFlag);
	glVertex2f(0.2f,-0.4f);
	glEdgeFlag(GL_TRUE);

	glVertex2f(0.2f,-0.4f);
	glVertex2f(0.6f,-0.2f);
	glEdgeFlag(bEdgeFlag);
	glVertex2f(0.2f,0.0f);
	//glEdgeFlag(GL_TRUE);

	glEdgeFlag(bEdgeFlag);
	glVertex2f(-0.2f,0.0f);
	glVertex2f(-0.2f,-0.4f);
	glVertex2f(0.2f,0.0f);
	
        //glEdgeFlag(GL_TRUE);
	glVertex2f(-0.2f,-0.4f);
	glVertex2f(0.2f,-0.4f);
	glVertex2f(0.2f,0.0f);
	//glEdgeFlag(GL_TRUE);
	glEnd();
	glFlush();
}


int main(int argc,char** argv){
    glutInit(&argc, argv);
    glutInitDisplayMode ( GLUT_RGB );
    glutInitWindowPosition( 300, 100 );
    glutInitWindowSize ( 150, 150 );
    glutCreateWindow ( "Esempio 8" );
    glutDisplayFunc( redraw );
    glutMainLoop ();
}