Question

我正在尝试使用Scissoring剪切使用spriteBatch.DrawString方法绘制的文本。

以下是我的Draw方法的一部分：

    public override void Draw(GameTime gameTime, SpriteBatch spriteBatch)
    {

    ...

        spriteBatch.GraphicsDevice.RasterizerState = new RasterizerState();
        spriteBatch.GraphicsDevice.RasterizerState.ScissorTestEnable = true;

        Rectangle rectangle = new Rectangle();
        rectangle.Height = 50;
        rectangle.Width = 1;  //set to 1 just so I'll immediately know if it's working

        spriteBatch.GraphicsDevice.ScissorRectangle = rectangle;

        for (int i = 0; i < career.news.Count; i++)
        {
            Vector2 newsItems = new Vector2(200 + i * 80, 550);
            spriteBatch.DrawString(DefaultText, career.news[i], newsItems, Color.Black);
        }

        spriteBatch.GraphicsDevice.RasterizerState.ScissorTestEnable = false;

  ...

  }

我收到以下错误：

“无法更改只读RasterizerState。状态对象在第一次绑定到GraphicsDevice时变为只读。要更改属性值，请创建一个新的RasterizerState实例。”

我真的不明白，因为我在上面的代码中创建了一个新实例。我错过了什么？

编辑：修改后的代码 - 删除了错误，但裁剪仍无效：

        Rectangle rectangle = new Rectangle();
        rectangle.Height = 50;
        rectangle.Width = 1;

        RasterizerState rasterizerState = new RasterizerState();
        rasterizerState.ScissorTestEnable = true;
        spriteBatch.GraphicsDevice.RasterizerState = rasterizerState;

        spriteBatch.GraphicsDevice.ScissorRectangle = rectangle;

        for (int i = 0; i < career.news.Count; i++)
        {
            Vector2 newsItems = new Vector2(200 + i * 80, 550);
            spriteBatch.DrawString(DefaultText, career.news[i], newsItems, Color.Black);
        }

        RasterizerState rasterizerState2 = new RasterizerState();
        rasterizerState2.ScissorTestEnable = false;
        spriteBatch.GraphicsDevice.RasterizerState = rasterizerState2;

Answer 1

这意味着您无法修改spriteBatch.GraphicsDevice.RasterizerState属性。您需要做的是创建一个实例，设置其属性，然后将其传递给spriteBatch.GraphicsDevice.RasterizerState。

RasterizerState r = new RasterizerState();
r.ScissorTestEnable  = true;
spriteBatch.GraphicsDevice.RasterizerState = r;
....
RasterizerState r1 = new RasterizerState();
r1.ScissorTestEnable = false;
spriteBatch.GraphicsDevice.RasterizerState = r1;

Answer 2

管理自己解决这个问题。

事实证明，剪刀只在spriteBatch.End（）完成。

因此我需要结束所有绘图到此时，使用下面的spriteBatch.Begin（）重载，spriteBatch.End（）来结束剪切的绘图，并使用spriteBatch.Begin（..重新启动绘图的其余部分）。）

spriteBatch.Begin(SpriteSortMode.Immediate, BlendState.AlphaBlend, null, null, rasterizerState);

在xna中使用Rasterizer Scissoring时出错

2 个答案: