// Copyright 2018 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "dawn/native/vulkan/SamplerVk.h"

#include "dawn/native/vulkan/DeviceVk.h"
#include "dawn/native/vulkan/FencedDeleter.h"
#include "dawn/native/vulkan/UtilsVulkan.h"
#include "dawn/native/vulkan/VulkanError.h"

namespace dawn::native::vulkan {

    namespace {
        VkSamplerAddressMode VulkanSamplerAddressMode(wgpu::AddressMode mode) {
            switch (mode) {
                case wgpu::AddressMode::Repeat:
                    return VK_SAMPLER_ADDRESS_MODE_REPEAT;
                case wgpu::AddressMode::MirrorRepeat:
                    return VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT;
                case wgpu::AddressMode::ClampToEdge:
                    return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
            }
            UNREACHABLE();
        }

        VkFilter VulkanSamplerFilter(wgpu::FilterMode filter) {
            switch (filter) {
                case wgpu::FilterMode::Linear:
                    return VK_FILTER_LINEAR;
                case wgpu::FilterMode::Nearest:
                    return VK_FILTER_NEAREST;
            }
            UNREACHABLE();
        }

        VkSamplerMipmapMode VulkanMipMapMode(wgpu::FilterMode filter) {
            switch (filter) {
                case wgpu::FilterMode::Linear:
                    return VK_SAMPLER_MIPMAP_MODE_LINEAR;
                case wgpu::FilterMode::Nearest:
                    return VK_SAMPLER_MIPMAP_MODE_NEAREST;
            }
            UNREACHABLE();
        }
    }  // anonymous namespace

    // static
    ResultOrError<Ref<Sampler>> Sampler::Create(Device* device,
                                                const SamplerDescriptor* descriptor) {
        Ref<Sampler> sampler = AcquireRef(new Sampler(device, descriptor));
        DAWN_TRY(sampler->Initialize(descriptor));
        return sampler;
    }

    MaybeError Sampler::Initialize(const SamplerDescriptor* descriptor) {
        VkSamplerCreateInfo createInfo = {};
        createInfo.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
        createInfo.pNext = nullptr;
        createInfo.flags = 0;
        createInfo.magFilter = VulkanSamplerFilter(descriptor->magFilter);
        createInfo.minFilter = VulkanSamplerFilter(descriptor->minFilter);
        createInfo.mipmapMode = VulkanMipMapMode(descriptor->mipmapFilter);
        createInfo.addressModeU = VulkanSamplerAddressMode(descriptor->addressModeU);
        createInfo.addressModeV = VulkanSamplerAddressMode(descriptor->addressModeV);
        createInfo.addressModeW = VulkanSamplerAddressMode(descriptor->addressModeW);
        createInfo.mipLodBias = 0.0f;
        if (descriptor->compare != wgpu::CompareFunction::Undefined) {
            createInfo.compareOp = ToVulkanCompareOp(descriptor->compare);
            createInfo.compareEnable = VK_TRUE;
        } else {
            // Still set the compareOp so it's not garbage.
            createInfo.compareOp = VK_COMPARE_OP_NEVER;
            createInfo.compareEnable = VK_FALSE;
        }
        createInfo.minLod = descriptor->lodMinClamp;
        createInfo.maxLod = descriptor->lodMaxClamp;
        createInfo.unnormalizedCoordinates = VK_FALSE;

        Device* device = ToBackend(GetDevice());
        uint16_t maxAnisotropy = GetMaxAnisotropy();
        if (device->GetDeviceInfo().features.samplerAnisotropy == VK_TRUE && maxAnisotropy > 1) {
            createInfo.anisotropyEnable = VK_TRUE;
            // https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VkSamplerCreateInfo.html
            createInfo.maxAnisotropy =
                std::min(static_cast<float>(maxAnisotropy),
                         device->GetDeviceInfo().properties.limits.maxSamplerAnisotropy);
        } else {
            createInfo.anisotropyEnable = VK_FALSE;
            createInfo.maxAnisotropy = 1;
        }

        DAWN_TRY(CheckVkSuccess(
            device->fn.CreateSampler(device->GetVkDevice(), &createInfo, nullptr, &*mHandle),
            "CreateSampler"));

        SetLabelImpl();

        return {};
    }

    Sampler::~Sampler() = default;

    void Sampler::DestroyImpl() {
        SamplerBase::DestroyImpl();
        if (mHandle != VK_NULL_HANDLE) {
            ToBackend(GetDevice())->GetFencedDeleter()->DeleteWhenUnused(mHandle);
            mHandle = VK_NULL_HANDLE;
        }
    }

    VkSampler Sampler::GetHandle() const {
        return mHandle;
    }

    void Sampler::SetLabelImpl() {
        SetDebugName(ToBackend(GetDevice()), VK_OBJECT_TYPE_SAMPLER,
                     reinterpret_cast<uint64_t&>(mHandle), "Dawn_Sampler", GetLabel());
    }

}  // namespace dawn::native::vulkan