The first function is drawBoxes(). This does all the drawing in the program. The initial block of code is
glColor4fv( red );
glBegin( GL_LINE_STRIP );
glVertex2f( -0.7, -0.7 );
glVertex2f( 0.7, -0.7 );
glVertex2f( 0.7, 0.7 );
glVertex2f( -0.7, 0.7 );
glVertex2f( -0.7, -0.7 );
glEnd();