S
Silk.NET•2y ago
tannergooding

what in particular are you having

what in particular are you having trouble with? F# has ref T via byref<'T>, in T via inref<'T>, out T via outref<'T> you can declare pointers via nativeptr<'T> and for external functions in particular (DllImport) it directly supports T* and T& for pointers/byrefs
3 Replies
Unslinga
Unslinga•2y ago
I was having an issue with this in particular: 
c#
private bool CheckValidationLayerSupport()
{
    uint layerCount = 0;
    vk!.EnumerateInstanceLayerProperties(ref layerCount, null);
    var availableLayers = new LayerProperties[layerCount];
    fixed (LayerProperties* availableLayersPtr = availableLayers)
    {
        vk!.EnumerateInstanceLayerProperties(ref layerCount, availableLayersPtr);
    }

    var availableLayerNames = availableLayers
        .Select(layer => Marshal.PtrToStringAnsi((IntPtr)layer.LayerName))
        .ToHashSet();

    return validationLayers.All(availableLayerNames.Contains);
}
c#
private bool CheckValidationLayerSupport()
{
    uint layerCount = 0;
    vk!.EnumerateInstanceLayerProperties(ref layerCount, null);
    var availableLayers = new LayerProperties[layerCount];
    fixed (LayerProperties* availableLayersPtr = availableLayers)
    {
        vk!.EnumerateInstanceLayerProperties(ref layerCount, availableLayersPtr);
    }

    var availableLayerNames = availableLayers
        .Select(layer => Marshal.PtrToStringAnsi((IntPtr)layer.LayerName))
        .ToHashSet();

    return validationLayers.All(availableLayerNames.Contains);
}
I cannot find any F# equivalent of var availableLayers = new LayerProperties[layerCount];, I only get let layers = LayerProperties layerCount which returns LayerProperties and not an array, as well as not being able to replicate 
c#
fixed (LayerProperties* availableLayersPtr = availableLayers)
    {
        vk!.EnumerateInstanceLayerProperties(ref layerCount, availableLayersPtr);
    }
c#
fixed (LayerProperties* availableLayersPtr = availableLayers)
    {
        vk!.EnumerateInstanceLayerProperties(ref layerCount, availableLayersPtr);
    }
in any capacity
tannergooding
tannergoodingOP•2y ago
you want let availableLayers = Array.zeroCreate layerCount pretty sure https://learn.microsoft.com/en-us/dotnet/fsharp/language-reference/arrays#create-arrays F# in general has a lot of the functionality either in patterns or via custom F# helper types https://github.com/tannergooding/fsharp-demoapp is an older demo-app I did that has some Win32 interop and does software rendering using hardware intrinsics, entirely in F#
Unslinga
Unslinga•2y ago
Oh man, I didn't even realize that was empty array! let mutable layers: LayerProperties[] = Array.zeroCreate <| int layerCount this works
https://discord.com/channels/521092042781229087/607634593201520651/1202199796719554561
Now I can put this idea to rest a little while longer 
f#
do
            use ptr = fixed layers
            vk.EnumerateInstanceLayerProperties(&layerCount, ptr) |> ignore
f#
do
            use ptr = fixed layers
            vk.EnumerateInstanceLayerProperties(&layerCount, ptr) |> ignore

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