UE4笔记-重定义GameViewport 布局（Slate）

最近在研究重新布局GameViewport和DockWidget/TagManager的问题

这里记录一些可能有帮助的链接，有空再继续研究.

参考链接1：https://answers.unrealengine.com/questions/368060/view.html

参考链接2： https://zhuanlan.zhihu.com/p/44206016

参考链接3(Qt +UE4方案)：https://www.cnblogs.com/blueroses/p/9151094.html

参考链接4 打扮家居于TabManager的技术分享：https://www.bilibili.com/video/av60881798?from=search&seid=11876571760089496499

Q.重新布局GameViewport问题：

 // 目前还没弄明白UGameEngine::CreateViewport 和UGameEngine::CreateViewportWidget

目前妥协实现方案：GameViewport分屏 + Tick或GameViewportClient 的Draw里实现修改屏幕大小或绑定FViewport::ViewportResizedEvent的委托都可以

这样就可以配合 Slate的SSplitter组件配合运算实现伪Layout布局了

void UCommonBPLibrary_Core::AdjustViewportSize(UObject * WorldObjectContext, FMargin margin)
{
    UE_LOG(LogTemp, Log, TEXT(" AdjustViewportSize "));
    if (WorldObjectContext->GetWorld() &&
        /*GetWorld()->WorldType == EWorldType::Game &&*/
        GEngine && GEngine->GameViewport)
    {
        FVector2D ViewportSize;
        GEngine->GameViewport->GetViewportSize(ViewportSize);

        // The GameViewport takes some time to initialize
        if (ViewportSize.X > 0 && ViewportSize.Y > 0)
        {

            FMargin relativeMat = FMargin
            {
                margin.Left            /  ViewportSize.X    ,
                margin.Top            /  ViewportSize.Y    ,
                1 - margin.Right    /  ViewportSize.X    ,
                1 - margin.Bottom    /  ViewportSize.Y
            };

            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].OriginX = relativeMat.Left;
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].OriginY = relativeMat.Top;
                                                                             
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].SizeX    = relativeMat.Right;
            GEngine->GameViewport->SplitscreenInfo[0].PlayerData[0].SizeY    = relativeMat.Bottom;
        }
    }
}

 可实现效果：