GraphicsDevice.ResolveRenderTarget Method

Artikel
12/10/2010

Signifies that the device has finished drawing to a render target and prepares the render target for a call to RenderTarget2D.GetTexture or RenderTargetCube.GetTexture.

Namespace: Microsoft.Xna.Framework.Graphics
Assembly: Microsoft.Xna.Framework (in microsoft.xna.framework.dll)

Syntax

public void ResolveRenderTarget (
         int index
)

Parameters

index
Index of the render target to resolve.

Exceptions

Exception type	Condition
ArgumentException	An invalid render target index was requested. Note that on Xbox 360, there is only one render target available and index must be zero.
InvalidOperationException	ResolveRenderTarget may not be called when the current render target is null. Use ResolveBackBuffer instead.

Remarks

On Windows, non-multisampled render targets are not cleared when ResolveRenderTarget is called. Multisampled render targets, and all render targets on the Xbox 360, are cleared when ResolveRenderTarget is called.

Warning

On Xbox 360, all render targets (including the back buffer) share the same memory. Because of this, the previous content of any render target is lost when the render target is changed with SetRenderTarget or when Present is called, which has the same effect as swapping the render target.

To preserve the data in a render target, it is necessary to resolve it, either with ResolveRenderTarget or ResolveBackBuffer. Just remember to resolve the render target before switching the render target to avoid losing data that you want to preserve.

Example

Before calling ResolveRenderTarget, set the render target on the device using SetRenderTarget, complete any drawing code, and then call ResolveRenderTarget to resolve the data from the draw call to the currently set render target.

// Create a new render target to receive the drawn data.
renderTarget = new RenderTarget2D(
    graphics.GraphicsDevice,
    // In this case, we are creating
    // a render target to match half of a split screen:
    leftViewPort.Width,
    leftViewPort.Height,
    // Number of levels in the render target:
    1,
    // Use the same surface format as the back buffer.
    graphics.GraphicsDevice.PresentationParameters.BackBufferFormat );

// Set the render target on the device.
graphics.GraphicsDevice.SetRenderTarget( 0, renderTarget );

// TODO: Add your code to draw to the render target here.
// For example, this could be a call to Mesh.Draw, 
// a SpriteBatch Begin-End sequence, or a call to
// DrawIndexedPrimitives, as you would have called them
// in the Draw method of your application.

// Resolve the data from the draw call to the currently set render target.
graphics.GraphicsDevice.ResolveRenderTarget( 0 );

// Call GetTexture to retrieve the render target data and save it to a texture.
capturedTexture = renderTarget.GetTexture();

// Set the device render target back to the back buffer.
graphics.GraphicsDevice.SetRenderTarget( 0, null );

Platforms

Xbox 360, Windows XP SP2, Windows Vista

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