RenderTarget Usage

[Curerious]

As far as I understand, there's two types of RenderTarget being used in a script, one being " SharpDX.Direct2D1.WindowRenderTarget", another being "SharpDX.Direct2D1.WicRenderTarget" as the following link claimed:

https://ninjatrader.com/support/helpguides/nt8/NT%20HelpGuide%20English.html?rendertarget.htm

My Questions:
1. Is RenderTarget only available at OnRender() and OnRenderTargetChange() ?
2. Should I explicitly write different logic for different types of RenderTarget under OnRender() and OnRenderTargetChange()? If so, how to separate them?

[NinjaTrader_Gaby]

Hello Curerious,

Thank you for your post.

RenderTarget is not only available from those two methods, it is available from other methods after it is created. However it often gets disposed, and a new object is created which updates with OnRenderTargetChanged().

Render objects should be instantiated in OnRenderTargetChanged when a new RenderTarget object is generated. This is noted in the Help Guide:

"Since there are multiple RenderTargets, you MUST ensure the resource being used belongs to the destination target. In practice, all you need to understand is if you are using a device resource (e.g., custom SharpDX Brush) throughout different event methods, you should recreate these resource during OnRenderTargetChanged() which ensures the device resource is updated correctly as the devices context changes."

https://ninjatrader.com/support/helpguides/nt8/onrendertargetchanged.htm

Note that the actual logic to draw/render should be in OnRender(), which runs when rendering the chart.

These examples might help to clarify how this works:

https://forum.ninjatrader.com/forum/ninjatrader-8/indicator-development/98639-performance-optimization?p=789606#post789606

https://ninjatraderecosystem.com/user-app-share-download/jtrealstats-realtime-level-ii-tick-volume/

[Curerious]

Hey Gaby

Thanks for replying, I saw the script you mentioned but it still uses the RenderTarget only within the OnRender method and OnRenderTargetChanged method, Do you happen to have an example of it being used outside of those two methods?

In addition, I see the script also use the RenderTarget interchangeably, Could you also provide me an example of it being used separately into SharpDX.Direct2D1.WindowRenderTarget and SharpDX.Direct2D1.WicRenderTarget ?

Thank you!

[NinjaTrader_Gaby]

Hello Curerious,

Thank you for your response.

It's not necessarily that RenderTarget is literally being used in an outside method, for example in Jtrealstats you can see that a PathGeometry SharpDX object is created from the CreateGeometry() method. The PathGeometry object would be the RenderTarget in this instance. It can and will get disposed of, and then updated, which is what drives OnRenderTarget changed.

Could you also provide me an example of it being used separately into SharpDX.Direct2D1.WindowRenderTarget and SharpDX.Direct2D1.WicRenderTarget ?

We do not have an example of this. Please see the note about multiple render targets:

"Since there are multiple RenderTargets, you MUST ensure the resource being used belongs to the destination target. In practice, all you need to understand is if you are using a device resource (e.g., custom SharpDX Brush) throughout different event methods, you should recreate these resource during OnRenderTargetChanged() which ensures the device resource is updated correctly as the devices context changes."

[Curerious]

Got you, thanks Gaby!

[NinjaTrader_Gaby]

No problem, please let me know if you need further guidance / clarification.