Creating a State Object

XNA Game Studio 4.0
Demonstrates how to create a state object using any of the state object classes: BlendState, DepthStencilState, RasterizerState, or SamplerState.

The Complete Sample

The code in this topic shows you the technique. You can download a complete code sample for this topic, including full source code and any additional supporting files required by the sample.

Creating a State Object

To create a state object

  1. Declare three state object variables as fields in your game.

    This example declares three rasterizer state objects and uses them to change the culling state.

    RasterizerState rsCullNone;
  2. Create a customizable state object.

    Create a state object from the RasterizerState class and initialize it by explicitly setting the cull mode.

    rsCullNone = new RasterizerState();
    rsCullNone.CullMode = CullMode.None;
    rsCullNone.FillMode = FillMode.WireFrame;
    rsCullNone.MultiSampleAntiAlias = false;
  3. Respond to the user pressing the A key on a gamepad to change the culling mode.

    The application starts with culling turned off; toggle between culling modes by pushing the A key on a gamepad. Unlike a customizable state object, use a built-in state object to create an object with a set of predefined state.

    if (GamePad.GetState(PlayerIndex.One).Buttons.A == ButtonState.Pressed)
        changeState = true;
    if ((changeState) && (GamePad.GetState(PlayerIndex.One).Buttons.A == ButtonState.Released))
        if (GraphicsDevice.RasterizerState.CullMode == CullMode.None)
            GraphicsDevice.RasterizerState = RasterizerState.CullCounterClockwise;
        else if (GraphicsDevice.RasterizerState.CullMode == CullMode.CullCounterClockwiseFace)
            GraphicsDevice.RasterizerState = RasterizerState.CullClockwise;
        else if (GraphicsDevice.RasterizerState.CullMode == CullMode.CullClockwiseFace)
            GraphicsDevice.RasterizerState = rsCullNone;
        changeState = false;

    The example contains two triangles. The first one is rendered if you select clockwise winding order; the second triangle is rendered if you select counterclockwise winding order; both triangles are rendered if you select no culling.

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