What is the texture size limit for avalonia?

[Shadowblitz16]

I want to make a really big tileset but have it long ways instead of a unit square.

So instead of something like 10241024 something like 2564096.

But even a height of 4096 is kinda small that's only 16 256256 tile pages. I was wondering if it's possible to do something like a 25665536 texture?
That would be 256 256*256 tile pages.

Memory optimization can be done later through disk io.

[LaurentInSeattle]

Most likely not an Avalonia limitation but one for the GPU.
Most GPUs support 4096x4096, good ones 8192x8192.
Some very high-end desktop GPUs support 16384x16384.
Keeping texture square is important or else GPU memory is wasted.

[Shadowblitz16]

@LaurentInSeattle doesn't avalonia ui use a software renderer though?
I thought skia sharp was a cpu based renderer.

[LaurentInSeattle]

Nope, software renderer's are usually for reference and debug. Nowadays everything goes to the GPU.

[stevemonaco]

You'll hit the default limit at about 28mb altogether unless you customize the GPU size at startup.

.With(new SkiaOptions()
{
	MaxGpuResourceSizeBytes = 4096 * 4096 * 4 // Could be a lot bigger
})

Besides that, I don't think there are any practical limits from either Avalonia or Skia.

[LaurentInSeattle]

Even the old integrated GPU's from Intel have 2GB of shared memory, so why is it limited to 28 MB ?
Will there be a rendering performance gain to set this MaxGpuResourceSizeBytes option at 2GB ? or more, depending on what's present on the computer ?

[stevemonaco]

Depends on your app's usage. Some features are more resource-heavy, such as snapshot for effects (like UseOpacitySaveLayer) or simply rendering high resolution views or bitmaps. See issues like #20658

I do wish Avalonia had a way to track the usage and if software fallback is happening because of it, but I don't think there is one. Might need to invoke GRContext.GetResourceCacheUsage yourself. The 28mb default was set based on Flutter, according to the commit about 6 years ago. It seems it eventually trickles down into https://learn.microsoft.com/en-us/dotnet/api/skiasharp.grcontext.setresourcecachelimit?view=skiasharp-3.119