M: mandel-gadget draw-gadget* ( gadget -- )
    drop
    GL_PROJECTION glMatrixMode
    glLoadIdentity
    -1 1 2dup 2dup glOrtho
    GL_MODELVIEW glMatrixMode
    glLoadIdentity
    COLOR: red gl-color
    { -1 -1 } { 1 1 } gl-line ;