Calling texture compression via C#

[ignarmezh]

Hi!
I'm using toktx.exe and ktx.dll for compression textures from .png to .ktx2 via cmd, with commands like:
toktx.exe --encode etc1s --genmipmap --assign_oetf linear --assign_primaries none {newFilePath} {pathOfImage}
Is it possible to call functions from C#? If i add dll as dependencies.
Could you help me how to do it?

[MarkCallow]

@ignarmezh, I assume you mean is it possible to call libktx functions from C# since toktx is an application.*

I know very little about C# but I believe it is a language that manages all memory allocation similar to Java. If that is the case then I expect a native interface module, à la Java's JNI, is needed to enable C# programs to call functions in a native library. There is no such module in this project. If I'm not totally wrong and a module is needed, I'd be happy to accept a contribution to add one.

* Most of what toktx does happens within libktx. The exceptions are scaling and resizing of images and mipmap generation.

I'm converting this to a discussion. If the discussion identifies definitively that something is needed to interface from C#, an issue can be opened to request that something.

[ignarmezh]

@MarkCallow, For that we need a .dll with methods which we can call through c#.
I'm not experienced enough in this matter. but as I know in c# we can add a custom method from dll with special attribute, like:
[DllImport(@"c:\MethodNameLibrary.dll")]
private static extern int methodName(int b);
static void Main(string[] args)
{
Console.WriteLine(methodName(3));
}
About that attribute you can read here

Also, the method in the dynamic library must be declared as:
int __declspec(dllexport) methodName(int b)
{
return b;
}

If there is an available API with a description of the methods, what they do and which parameters they accept, we could call them from C# directly I guess.

Thanks!

[MarkCallow]

I am sorry @ignarmezh. For some reason I am only just seeing your reply to my answer. When built for Windows, there is a dll, ktx.dll and all methods are declared with __declspec(dllexport). All, except Vulkan related are declared in ktx.h. Vulkan ones are in ktxvulkan.h.

The library and headers are in the installable Windows package you can find in the project's Releases section. It sounds like you can add custom methods to your C# to call these functions. If you create a header for these, please submit a PR to add it to KTX-Software.

[HouleAdrien]

Hi, I made simple binding based on this discussion and my knowledge of c# /!\ it doesn't implement everything /!\ , it is just a simple c# binding that does what I wanted .
The only thing I still struggle to with is ktxTexture2_CompressBasis function that just crash/ runs infinitly in my second test of my program.
https://github.com/HouleAdrien/KtxSoftCSharpBindingExample

Edit: my issues with ktxTexture2_CompressBasis is simply that my image seems too big (70 mo) for him and it take a lot of time to compute, but in order to use the other compress function with params I would need to upgrade my interop more, is there an other solution ?

[MarkCallow]

Please try running with a debug version of ktx.dll and see where ktxTexture2_CompressBasis is crashing or what loop it is stuck in.

If you need to pass params there is no alternative to calling ktxTexture2_CompressBasisEx.

[HouleAdrien]

Thanks, for you response , so I tried with the debug version of the dll , and it ends that it is just my file that is way too huge for fast compression but everything works,
I will post a new version of the interop soon on my github with the ktxTexture2_CompressBasisEx function.
And also just a quick question is ktx dll thread safe ? (If I do my c# threads with call to the compression function inside them will it break ?)

Edit: Nevermind when switched back to realease dll and using ktxbasisparams it work like a charm with Huge files