#include <GL/glut.h>
#include <stdlib.h>

void redesenha()
{
    glClearColor(0.0,0.0,0.0,0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
    
    glColor3f(1.0,0.0,0.0);
    glBegin(GL_POLYGON);        		
   		glVertex2i(120, 50);
   		glVertex2i(120, 70);   		
   		glVertex2i(100, 80);   		
        glVertex2i(80, 70); 
        glVertex2i(80, 50);  	   		
	glEnd();

    glFlush();
}

main(int argc, char *argv[])
{
    GLint w,t;
    GLint cx, cy;

    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA | GLUT_DEPTH);
    glutInitWindowSize(400,400); /* Antes do glutCreateWIndow */
    glutInitWindowPosition(0,0);
    glutCreateWindow("Transformações Geométricas");
    
    glClearColor(1.0f, 1.0f, 1.0f, 0.0f); //dene cor de fundo
    glMatrixMode(GL_PROJECTION); //carrega a matriz de projeção
    glLoadIdentity(); //lê a matriz identidade
  
    gluOrtho2D(0,200,0,150); /* Apos CreateWindow */
    glutDisplayFunc(redesenha); 
         
    glutDisplayFunc(redesenha);


    glutMainLoop(); 


    return EXIT_SUCCESS;
}