if (obj_heart.x < (left - 1))
    obj_heart.x = left - 1;
if (obj_heart.x > (right - 16))
    obj_heart.x = right - 16;
if (obj_heart.y < (top - 1))
    obj_heart.y = top - 1;
if (obj_heart.y > (bottom - 16))
    obj_heart.y = bottom - 16;