// 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 <algorithm>

#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()), mHandle, "Dawn_Sampler", GetLabel());
}

}  // namespace dawn::native::vulkan