Creating a Direct3D renderer class_Direct3D Rendering Cookbook-QQ阅读男生科幻网

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Creating a Direct3D renderer class

In this recipe, we will look at the final component of our sample rendering framework, the renderer. These are classes that implement specific rendering logic, such as drawing a mesh or utility classes that wish to participate within the Direct3D resource lifecycle management of the rendering framework.

Getting ready

We continue on from where we left off in the Using the sample rendering framework recipe.

How to do it…

We will first look at the steps necessary to create a Common.RendererBase descendent and then how this class would be created, initialized, and finally execute its Direct3D draw commands.

Creating a renderer class within the sample framework requires the following minimal code:

public class MyRenderer : Common.RendererBase
{
   // Create device dependent resources
   protected override void CreateDeviceDependentResources()
   { ... }

   // Create size dependent resources
   protected override void CreateSizeDependentResources()
   { ... }

   // Perform rendering commands
   protected override void DoRender()
   { ... }
}

Within a class that is ultimately descending from D3DApplicationBase, you would create and initialize an instance of this renderer class as follows:
```
var myRenderer = ToDispose(new MyRenderer());
myRenderer.Initialize(this);
```
Finally, within a render loop, we can tell the renderer instance to perform its draw commands as shown in the following line of code:
```
myRenderer.Render();
```

How it works…

The Common.RendererBase abstract class is similar to the D3DApplicationBase class. It follows the same approach for managing the lifecycle of Direct3D resources by using the SharpDX.Component class and the CreateDeviceDependentResources and CreateSizeDependentResources methods. In addition, a public Render method is available for executing the renderer's Direct3D commands.

The following class diagram shows the available methods and properties:

Sample rendering framework renderer class diagram

Implementations of the RendererBase class included in the rendering framework sample code includes the TextRenderer and the FpsRenderer classes. The text renderer uses the Direct2D device and context to render text of the specified font, size, and color at the desired screen location. The FPS renderer descends from the text renderer and displays the current frame rate and frame time (100 frames simple moving average).