ECS/Job system way of doing Texture2D.SetPixel()?

Hello, I have been checking out the samples for ECS and the Job system, and they are pretty cool and seem very powerful - but I had been scratching my head about some basic stuff, and haven't got a strong enough understanding of the new features to really figure it out.

Forgive me if I just haven't dug deep enough yet to "get it" about how everything works now.

With Mono scripts I could just have a reference to a Texture2D then call Texture2D.SetPixel() or Texture2D.SetPixels() followed with Texture2D.Apply() to make changes to a texture at runtime - but of course that was also pretty slow, and in the past I had much better performance using a compute shader to do heavy texture manipulation rather than using the Texture2D class at all, and perhaps now with ECS and Jobs it would make more sense to instead do something completely different than either of those things.

Anybody have any idea about how to do an "ECS way" of texture changes? An example of a use case might be a game like "Worms" - to give you an idea what I'd be trying to do.

 

You can get the Colordata as a NativeArray and process that in a job.

Here is an example:

Code (CSharp):

1.  
2.   struct HoloPanelData {
3.         [ReadOnly] public SharedComponentDataArray<HoloPanel> holoPanel;
4.         public readonly int Length;
5.         public bool Any => Length > 0;
6.     }
7.  
8. struct ResetHoloJob : IJobParallelFor {
9.         [WriteOnly] public NativeArray<Color32> Texture;
10.         public Color32 Color;
11.  
12.         public void Execute(int index) {
13.             Texture[index] = Color;
14.         }
15.     }
16.  
17.  
18.     [Inject] HoloPanelData holoPanelData;
19. protected override JobHandle OnUpdate(JobHandle inputDeps) {
20.         if (!holoPanelData.Any) {
21.             return inputDeps;
22.         }
23.  
24.         NativeArray<Color32> texture = holoPanelData.holoPanel[0].BaseTexture.GetRawTextureData<Color32>();
25.         Color defaultColor = holoPanelData.holoPanel[0].Default;
26.  
27.         var resetHoloJob = new ResetHoloJob {
28.             Texture = texture,
29.             Color = defaultColor,
30.         };
31.         inputDeps = resetHoloJob.Schedule(texture.Length, 64, inputDeps);
32.  
33.         inputDeps.Complete();
34.         holoPanelData.holoPanel[0].BaseTexture.Apply();
35.         return inputDeps; // job.Schedule(this, inputDeps);
36.     }

 

OK cool, I'm going to give that a try and see if I can figure it out! Thanks for the info.

@Spy-Shifty one more thing, could I ask where that example came from? Was that out of an example project (where I could see the rest of the code that worked with that) or was that something else?

 

It's from one of my projects.

I've deleted some specific code...

 

Ah ok, fair enough.

 

So something occured to me while testing this idea - once you have edited the NativeArray then your left using the SetPixels() method and Apply() to actually write that data back to a texture?

Wouldn't that mean your basically still stuck crossing that GPU <> CPU bridge which is where the performance dies doing it "the old way"? If you are indeed stuck with that to push changes - that means that using a compute shader would still outrun this technique by some magnitude...

@Spy-Shifty is that something you found a way around?

 

Yep that is correct and no there is no other way around. So basically a shader would be better....

 

Alrighty, thanks for all the help!