Source/WebCore/Modules/WebGPU/GPUBindGroupEntry.h

/*
 * Copyright (C) 2021 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 */

#pragma once

#include "GPUBufferBinding.h"
#include "GPUExternalTexture.h"
#include "GPUIntegralTypes.h"
#include "GPUSampler.h"
#include "GPUTextureView.h"
#include <pal/graphics/WebGPU/WebGPUBindGroupEntry.h>
#include <utility>
#include <variant>

namespace WebCore {

using GPUBindingResource = std::variant<RefPtr<GPUSampler>, RefPtr<GPUTextureView>, GPUBufferBinding, RefPtr<GPUExternalTexture>>;

inline PAL::WebGPU::BindingResource convertToBacking(const GPUBindingResource& bindingResource)
{
    return WTF::switchOn(bindingResource, [] (const RefPtr<GPUSampler>& sampler) -> PAL::WebGPU::BindingResource {
        ASSERT(sampler);
        return sampler->backing();
    }, [] (const RefPtr<GPUTextureView>& textureView) -> PAL::WebGPU::BindingResource {
        ASSERT(textureView);
        return textureView->backing();
    }, [] (const GPUBufferBinding& bufferBinding) -> PAL::WebGPU::BindingResource {
        return bufferBinding.convertToBacking();
    }, [] (const RefPtr<GPUExternalTexture>& externalTexture) -> PAL::WebGPU::BindingResource {
        ASSERT(externalTexture);
        return externalTexture->backing();
    });
}

struct GPUBindGroupEntry {
    PAL::WebGPU::BindGroupEntry convertToBacking() const
    {
        return {
            binding,
            WebCore::convertToBacking(resource),
        };
    }

    GPUIndex32 binding { 0 };
    GPUBindingResource resource;
};

}