Why ClampToBorder and ClampToZero are disabled?

[devprofile98]

Hi, thank you for your work and effort in maintaining wgpu-native. My question is, why are ClampToBorder and ClampToZero still disabled?

// TODO: requires wgpu.h api change
// WGPUNativeFeature_AddressModeClampToZero = 0x00030011,
// WGPUNativeFeature_AddressModeClampToBorder = 0x00030012,

[almarklein]

Probably because wgpu.h will need API to expose the corresponding extra AddressMode enum fields.

[devprofile98]

Thanks, do you know if it is because of the differences between different API compatibility or just not implemented yet? Because I think it is implemented in the wgpu-core.

[almarklein]

I'm not sure if/when it is implemented in wgpu-core. I'd certainly check that first, but otherwise it's most likely simply not implemented yet.

[devprofile98]

Thank you very much.

[lisyarus]

It appears that both clamp_to_border and clamp_to_zero are exposed as native features: https://github.com/gfx-rs/wgpu/blob/37c38e0741ebec5856dc49d65ed4737b6ff5f8d5/wgpu-types/src/features.rs#L836-L863

but only clamp_to_border is exposed in wgt::AddressMode: https://github.com/gfx-rs/wgpu/blob/trunk/wgpu-types/src/lib.rs#L6842-L6865

[devprofile98]

Hi @lisyarus, With all due respect, I ended up using this simple snippet; it might help others in the meantime.

    if projCoords.x < 0.0 || projCoords.x > 1.0 || projCoords.y < 0.0 || projCoords.y > 1.0 {
        return 0.0; // No shadow for out-of-bounds
    }

[lisyarus]

Hi @lisyarus, With all due respect, I ended up using this simple snippet; it might help others in the meantime.

    if projCoords.x < 0.0 || projCoords.x > 1.0 || projCoords.y < 0.0 || projCoords.y > 1.0 {
        return 0.0; // No shadow for out-of-bounds
    }

Yep, afaik that's pretty standard in shadow mapping implementations. You can write it somewhat more simd-friendly (though maybe harder to read) in NDC coordinates as

if (any(abs(ndcCoord.xy) > vec2f(1.0))) {
    return 0.0;
}

[devprofile98]

Wow, Thanks!