MonoGame - ScissorRectangle无效

Question

我试图用RenderTarget2D和ScissorRectangle创建一个可滚动的日志窗口。然而，ScissorRectangle似乎不起作用。这是代码：

spriteBatch.End();

spriteBatch.Begin(SpriteSortMode.Deferred, null, null, null, new RasterizerState() { ScissorTestEnable = true });

Rectangle scissor = new Rectangle(0, Constants.GAME_AREA_HEIGHT, Constants.GAME_AREA_WIDTH, Constants.LOG_HEIGHT);
Rectangle scissorBackup = this.graphicsDevice.ScissorRectangle;
this.graphicsDevice.ScissorRectangle = scissor;

spriteBatch.Draw(logRenderTarget,
    new Rectangle(0, Constants.GAME_AREA_HEIGHT, Constants.GAME_AREA_WIDTH, Constants.LOG_HEIGHT),
    Color.White
);

this.graphicsDevice.ScissorRectangle = scissorBackup;

spriteBatch.End();

spriteBatch.Begin(SpriteSortMode.Deferred, null, null, null, null);

Answer 1

我决定改用Viewport。但是，似乎MonoGame在调用spriteBatch.End()之前使用了最后一个设置视口。它似乎与ScissorRectangle相同，所以我可以使它也起作用。我在评论中添加了ScissorRectangle特定的代码。这是我的新班级：

public class LogWriter
{
    private GraphicsDevice graphicsDevice;

    private Viewport defaultViewport, logViewport;
    //private Rectangle scissor, scissorBackup;

    public void Init(GraphicsDevice graphicsDevice)
    {
        this.graphicsDevice = graphicsDevice;

        defaultViewport = this.graphicsDevice.Viewport;
        logViewport = new Viewport(0, Constants.GAME_AREA_HEIGHT, Constants.GAME_AREA_WIDTH, Constants.LOG_HEIGHT);

        //scissor = new Rectangle(0, Constants.GAME_AREA_HEIGHT, Constants.GAME_AREA_WIDTH, Constants.LOG_HEIGHT);
        //scissorBackup = this.graphicsDevice.ScissorRectangle;
    }

    public void WriteLog(SpriteBatch spriteBatch)
    {
        this.graphicsDevice.Viewport = logViewport;
        //this.graphicsDevice.ScissorRectangle = scissor;

        spriteBatch.Begin();
        //spriteBatch.Begin(SpriteSortMode.Deferred, null, null, null, new RasterizerState() { ScissorTestEnable = true });

        for (int i = 0; i < Log.Count; i++)
        {
            spriteBatch.DrawString(Scavenger.AssetManager.Font12,
                Log.Entries[i],
                new Vector2(
                    Constants.LOG_MARGIN,
                    Constants.LOG_MARGIN + i * Scavenger.AssetManager.Font12.LineSpacing),
                Color.GreenYellow
            );
        }

        spriteBatch.End();

        this.graphicsDevice.Viewport = defaultViewport;
        //this.graphicsDevice.ScissorRectangle = scissorBackup;
    }
}

在Init()函数中调用

LoadContent()。在绘制了所有其他内容之后，在spriteBatch上调用WriteLog()之后，在Draw()函数中调用End()。