bool mglnrel::clipLine(Point2d& pt1, Point2d& pt2, const Box2d& _box)
{
Box2d box (_box);
box.normalize();
unsigned code1, code2;
code1 = ClipCode(pt1, box);
code2 = ClipCode(pt2, box);
for ( ; ; )
{
if (!(code1 | code2)) // 完全在矩形内
return true;
if (code1 & code2) // 完全在矩形外
return false;
float x = 0.f, y = 0.f;
unsigned code;
if (code1) // 起点不在矩形内
code = code1;
else // 终点不在矩形内
code = code2;
if (code & 0x1000) // 上
{
x = pt1.x + (pt2.x - pt1.x) * (box.ymax - pt1.y) / (pt2.y - pt1.y);
y = box.ymax;
}
else if (code & 0x0100) // 下
{
x = pt1.x + (pt2.x - pt1.x) * (box.ymin - pt1.y) / (pt2.y - pt1.y);
y = box.ymin;
}
else if (code & 0x0001) // 左
{
y = pt1.y + (pt2.y - pt1.y) * (box.xmin - pt1.x) / (pt2.x - pt1.x);
x = box.xmin;
}
else if (code & 0x0010) // 右
{
y = pt1.y + (pt2.y - pt1.y) * (box.xmax - pt1.x) / (pt2.x - pt1.x);
x = box.xmax;
}
if (code == code1)
{
pt1.x = x;
pt1.y = y;
code1 = ClipCode(pt1, box);
}
else
{
pt2.x = x;
pt2.y = y;
code2 = ClipCode(pt2, box);
}
}
}
void MgCmdManagerImpl::getBoundingBox(Box2d& box, const MgMotion* sender)
{
MgCommand* cmd = sender->cmds()->getCommand();
Box2d selbox;
if (cmd && strcmp(cmd->getName(), MgCmdSelect::Name()) == 0) {
MgCmdSelect* sel = (MgCmdSelect*)cmd;
selbox = sel->getBoundingBox(sender);
}
box = selbox.isEmpty() ? Box2d(sender->pointM, 0, 0) : selbox;
box *= sender->view->xform()->modelToDisplay();
box.normalize();
}