Creating a State Object

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.

Download StateObject.zip.

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.