#include "D3D12UiRenderer.h"

#include <XCEngine/Rendering/RenderSurfacePipelineUtils.h>
#include <XCEngine/RHI/D3D12/D3D12CommandList.h>
#include <XCEngine/RHI/D3D12/D3D12DescriptorHeap.h>
#include <XCEngine/RHI/D3D12/D3D12DescriptorSet.h>
#include <XCEngine/RHI/D3D12/D3D12PipelineLayout.h>
#include <XCEngine/RHI/RHICommandList.h>
#include <XCEngine/RHI/RHIEnums.h>
#include <XCEngine/RHI/RHITypes.h>

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <utility>

namespace XCEngine::UI::Editor::Host {

namespace {

using ::XCEngine::RHI::BlendFactor;
using ::XCEngine::RHI::BlendOp;
using ::XCEngine::RHI::BufferDesc;
using ::XCEngine::RHI::BufferType;
using ::XCEngine::RHI::ColorWriteMask;
using ::XCEngine::RHI::ComparisonFunc;
using ::XCEngine::RHI::CullMode;
using ::XCEngine::RHI::DescriptorHeapType;
using ::XCEngine::RHI::DescriptorPoolDesc;
using ::XCEngine::RHI::DescriptorSetLayoutBinding;
using ::XCEngine::RHI::DescriptorSetLayoutDesc;
using ::XCEngine::RHI::DescriptorType;
using ::XCEngine::RHI::D3D12CommandList;
using ::XCEngine::RHI::D3D12DescriptorSet;
using ::XCEngine::RHI::D3D12DescriptorHeap;
using ::XCEngine::RHI::FilterMode;
using ::XCEngine::RHI::FillMode;
using ::XCEngine::RHI::Format;
using ::XCEngine::RHI::FrontFace;
using ::XCEngine::RHI::GraphicsPipelineDesc;
using ::XCEngine::RHI::PrimitiveTopology;
using ::XCEngine::RHI::PrimitiveTopologyType;
using ::XCEngine::RHI::RHICommandList;
using ::XCEngine::RHI::Rect;
using ::XCEngine::RHI::ResourceViewDesc;
using ::XCEngine::RHI::ResourceViewDimension;
using ::XCEngine::RHI::RHIPipelineLayoutDesc;
using ::XCEngine::RHI::SamplerDesc;
using ::XCEngine::RHI::ShaderVisibility;
using ::XCEngine::RHI::TextureAddressMode;
using ::XCEngine::RHI::Viewport;
using ::XCEngine::Rendering::RenderContext;
using ::XCEngine::Rendering::RenderSurface;
using ::XCEngine::UI::UIColor;
using ::XCEngine::UI::UIDrawCommand;
using ::XCEngine::UI::UIDrawCommandType;
using ::XCEngine::UI::UIDrawData;
using ::XCEngine::UI::UIDrawList;
using ::XCEngine::UI::UILinearGradientDirection;
using ::XCEngine::UI::UIPoint;
using ::XCEngine::UI::UIRect;
using ::XCEngine::UI::UITextureHandle;

constexpr std::uint64_t kMinDynamicVertexBufferBytes = 16u * 1024u;
constexpr std::uint64_t kMinDynamicInstanceBufferBytes = 16u * 1024u;

enum class UiPrimitiveKind : int {
    Textured = 0,
    RectFill = 1,
    RectOutline = 2,
    CircleFill = 3,
    CircleOutline = 4,
    TriangleFill = 5
};

struct UiQuadVertex {
    float corner[2] = {};
    float uv[2] = {};
};

const UiQuadVertex kUnitQuadVertices[] = {
    { { 0.0f, 0.0f }, { 0.0f, 0.0f } },
    { { 1.0f, 0.0f }, { 1.0f, 0.0f } },
    { { 1.0f, 1.0f }, { 1.0f, 1.0f } },
    { { 0.0f, 1.0f }, { 0.0f, 1.0f } }
};

const std::uint32_t kUnitQuadIndices[] = { 0u, 1u, 2u, 0u, 2u, 3u };

const char kPrimitiveUiPassHlsl[] = R"(
cbuffer UiConstants : register(b0) {
    float2 gInvViewportSize;
    float2 gPadding;
};

struct VSInput {
    float2 corner : POSITION0;
    float2 unitUv : TEXCOORD0;
    float2 origin : POSITION1;
    float2 axisX : TEXCOORD1;
    float2 axisY : TEXCOORD2;
    float2 uvMin : TEXCOORD3;
    float2 uvMax : TEXCOORD4;
    float4 color : COLOR0;
    float4 secondaryColor : COLOR1;
    float4 params : TEXCOORD5;
    float4 aux0 : TEXCOORD6;
    float4 aux1 : TEXCOORD7;
};

struct VSOutput {
    float4 position : SV_POSITION;
    float2 unitUv : TEXCOORD0;
    float2 localPos : TEXCOORD1;
    float2 size : TEXCOORD2;
    float2 sampleUv : TEXCOORD3;
    float4 color : COLOR0;
    float4 secondaryColor : COLOR1;
    float4 params : TEXCOORD4;
    float4 aux0 : TEXCOORD5;
    float4 aux1 : TEXCOORD6;
};

Texture2D gTexture : register(t0);
SamplerState gSampler : register(s0);

float2 ToNdc(float2 pixelPos) {
    float2 ndc;
    ndc.x = pixelPos.x * gInvViewportSize.x * 2.0f - 1.0f;
    ndc.y = 1.0f - pixelPos.y * gInvViewportSize.y * 2.0f;
    return ndc;
}

VSOutput MainVS(VSInput input) {
    VSOutput output;
    const float2 pixelPos =
        input.origin +
        input.axisX * input.corner.x +
        input.axisY * input.corner.y;
    const float2 axisLength = float2(length(input.axisX), length(input.axisY));
    output.position = float4(ToNdc(pixelPos), 0.0f, 1.0f);
    output.unitUv = input.corner;
    output.localPos = axisLength * input.corner;
    output.size = axisLength;
    output.sampleUv = lerp(input.uvMin, input.uvMax, input.corner);
    output.color = input.color;
    output.secondaryColor = input.secondaryColor;
    output.params = input.params;
    output.aux0 = input.aux0;
    output.aux1 = input.aux1;
    return output;
}

float CoverageFromSignedDistance(float distance) {
    const float aa = max(fwidth(distance), 1.0f);
    return saturate(0.5f - distance / aa);
}

float RoundedRectSignedDistance(float2 localPos, float2 size, float radius) {
    const float2 halfSize = max(size * 0.5f, float2(0.0f, 0.0f));
    const float resolvedRadius = min(radius, min(halfSize.x, halfSize.y));
    const float2 centered = localPos - halfSize;
    const float2 radiusVector = float2(resolvedRadius, resolvedRadius);
    const float2 q = abs(centered) - (halfSize - radiusVector);
    return length(max(q, float2(0.0f, 0.0f))) + min(max(q.x, q.y), 0.0f) - resolvedRadius;
}

float CircleSignedDistance(float2 localPos, float2 center, float radius) {
    return length(localPos - center) - radius;
}

float Cross2(float2 lhs, float2 rhs) {
    return lhs.x * rhs.y - lhs.y * rhs.x;
}

float TriangleSignedDistance(float2 localPos, float2 p0, float2 p1, float2 p2) {
    const float orientation = Cross2(p1 - p0, p2 - p0);
    if (abs(orientation) <= 1.0e-5f) {
        return 1.0e6f;
    }

    const float sign = orientation >= 0.0f ? 1.0f : -1.0f;
    const float2 edge0 = p1 - p0;
    const float2 edge1 = p2 - p1;
    const float2 edge2 = p0 - p2;
    const float distance0 =
        sign * Cross2(edge0, localPos - p0) / max(length(edge0), 1.0e-5f);
    const float distance1 =
        sign * Cross2(edge1, localPos - p1) / max(length(edge1), 1.0e-5f);
    const float distance2 =
        sign * Cross2(edge2, localPos - p2) / max(length(edge2), 1.0e-5f);
    return -min(distance0, min(distance1, distance2));
}

float4 ResolveGradientColor(VSOutput input) {
    const bool verticalGradient = input.params.w > 0.5f;
    const float span = verticalGradient ? input.size.y : input.size.x;
    const float axisValue = verticalGradient ? input.localPos.y : input.localPos.x;
    const float t = span > 0.0f ? saturate(axisValue / span) : 0.0f;
    return lerp(input.color, input.secondaryColor, t);
}

float4 MainPS(VSOutput input) : SV_TARGET0 {
    const int quadKind = (int)round(input.params.x);
    if (quadKind == 0) {
        return gTexture.Sample(gSampler, input.sampleUv) * input.color;
    }

    float4 baseColor = ResolveGradientColor(input);
    float coverage = 1.0f;

    if (quadKind == 1) {
        const float distance = RoundedRectSignedDistance(input.localPos, input.size, input.params.y);
        coverage = CoverageFromSignedDistance(distance);
    } else if (quadKind == 2) {
        const float outerDistance =
            RoundedRectSignedDistance(input.localPos, input.size, input.params.y);
        const float innerRadius = max(0.0f, input.params.y - input.params.z);
        const float2 insetVector = float2(input.params.z, input.params.z);
        const float2 innerSize = max(input.size - insetVector * 2.0f, float2(0.0f, 0.0f));
        const float2 innerLocalPos = input.localPos - insetVector;
        const float innerDistance =
            RoundedRectSignedDistance(innerLocalPos, innerSize, innerRadius);
        coverage =
            CoverageFromSignedDistance(outerDistance) *
            (1.0f - CoverageFromSignedDistance(innerDistance));
    } else if (quadKind == 3) {
        const float2 center = input.size * 0.5f;
        const float distance = CircleSignedDistance(input.localPos, center, input.params.y);
        coverage = CoverageFromSignedDistance(distance);
    } else if (quadKind == 4) {
        const float2 center = input.size * 0.5f;
        const float distance =
            abs(length(input.localPos - center) - input.params.y) -
            input.params.z * 0.5f;
        coverage = CoverageFromSignedDistance(distance);
    } else if (quadKind == 5) {
        const float2 p0 = input.aux0.xy;
        const float2 p1 = input.aux0.zw;
        const float2 p2 = input.aux1.xy;
        const float distance = TriangleSignedDistance(input.localPos, p0, p1, p2);
        coverage = CoverageFromSignedDistance(distance);
    }

    return float4(baseColor.rgb, baseColor.a * coverage);
}
)";

struct FloatPoint {
    float x = 0.0f;
    float y = 0.0f;
};

struct FloatRect {
    float left = 0.0f;
    float top = 0.0f;
    float right = 0.0f;
    float bottom = 0.0f;
};

struct ClipState {
    Rect scissor = {};
    FloatRect rect = {};
};

struct UiConstants {
    float invViewportSize[2] = {};
    float padding[2] = {};
};

std::string HrToString(const char* operation, HRESULT hr) {
    char buffer[128] = {};
    sprintf_s(buffer, "%s failed with hr=0x%08X.", operation, static_cast<unsigned int>(hr));
    return buffer;
}

float ClampDpiScale(float dpiScale) {
    return dpiScale > 0.0f ? dpiScale : 1.0f;
}

float ResolveFontSize(float fontSize) {
    return fontSize > 0.0f ? fontSize : 16.0f;
}

float SnapToPixel(float value, float dpiScale) {
    return std::round(value * ClampDpiScale(dpiScale));
}

FloatRect ToPixelRect(const UIRect& rect, float dpiScale) {
    return FloatRect{
        SnapToPixel(rect.x, dpiScale),
        SnapToPixel(rect.y, dpiScale),
        SnapToPixel(rect.x + rect.width, dpiScale),
        SnapToPixel(rect.y + rect.height, dpiScale)
    };
}

FloatPoint ToPixelPoint(const UIPoint& point, float dpiScale) {
    return FloatPoint{
        SnapToPixel(point.x, dpiScale),
        SnapToPixel(point.y, dpiScale)
    };
}

FloatRect IntersectFloatRect(const FloatRect& lhs, const FloatRect& rhs) {
    return FloatRect{
        (std::max)(lhs.left, rhs.left),
        (std::max)(lhs.top, rhs.top),
        (std::min)(lhs.right, rhs.right),
        (std::min)(lhs.bottom, rhs.bottom)
    };
}

bool IsEmptyRect(const FloatRect& rect) {
    return rect.right <= rect.left || rect.bottom <= rect.top;
}

Rect ClampScissor(const FloatRect& rect, const Rect& renderArea) {
    Rect clamped = {};
    clamped.left = (std::max)(renderArea.left, static_cast<int>(std::floor(rect.left)));
    clamped.top = (std::max)(renderArea.top, static_cast<int>(std::floor(rect.top)));
    clamped.right = (std::min)(renderArea.right, static_cast<int>(std::ceil(rect.right)));
    clamped.bottom = (std::min)(renderArea.bottom, static_cast<int>(std::ceil(rect.bottom)));
    if (clamped.right < clamped.left) {
        clamped.right = clamped.left;
    }
    if (clamped.bottom < clamped.top) {
        clamped.bottom = clamped.top;
    }
    return clamped;
}

bool IsEmptyScissor(const Rect& rect) {
    return rect.right <= rect.left || rect.bottom <= rect.top;
}

constexpr std::uint64_t kFnvOffsetBasis = 14695981039346656037ull;
constexpr std::uint64_t kFnvPrime = 1099511628211ull;

void HashBytes(
    std::uint64_t& hash,
    const void* data,
    std::size_t size) {
    const auto* bytes = static_cast<const unsigned char*>(data);
    for (std::size_t index = 0u; index < size; ++index) {
        hash ^= static_cast<std::uint64_t>(bytes[index]);
        hash *= kFnvPrime;
    }
}

void HashFloat(std::uint64_t& hash, float value) {
    std::uint32_t bits = 0u;
    static_assert(sizeof(bits) == sizeof(value));
    std::memcpy(&bits, &value, sizeof(bits));
    HashBytes(hash, &bits, sizeof(bits));
}

void HashBool(std::uint64_t& hash, bool value) {
    const std::uint8_t encoded = value ? 1u : 0u;
    HashBytes(hash, &encoded, sizeof(encoded));
}

void HashString(std::uint64_t& hash, std::string_view value) {
    const std::size_t size = value.size();
    HashBytes(hash, &size, sizeof(size));
    if (!value.empty()) {
        HashBytes(hash, value.data(), value.size());
    }
}

void HashTextureHandle(std::uint64_t& hash, const UITextureHandle& texture) {
    HashBytes(hash, &texture.nativeHandle, sizeof(texture.nativeHandle));
    HashBytes(hash, &texture.width, sizeof(texture.width));
    HashBytes(hash, &texture.height, sizeof(texture.height));
    HashBytes(hash, &texture.kind, sizeof(texture.kind));
    HashBytes(hash, &texture.resourceHandle, sizeof(texture.resourceHandle));
}

void HashPoint(std::uint64_t& hash, const UIPoint& point) {
    HashFloat(hash, point.x);
    HashFloat(hash, point.y);
}

void HashRect(std::uint64_t& hash, const UIRect& rect) {
    HashFloat(hash, rect.x);
    HashFloat(hash, rect.y);
    HashFloat(hash, rect.width);
    HashFloat(hash, rect.height);
}

std::uint64_t BuildDrawListContentHash(const UIDrawList& drawList) {
    std::uint64_t hash = kFnvOffsetBasis;
    HashString(hash, drawList.GetDebugName());

    const std::size_t commandCount = drawList.GetCommandCount();
    HashBytes(hash, &commandCount, sizeof(commandCount));

    for (const UIDrawCommand& command : drawList.GetCommands()) {
        HashBytes(hash, &command.type, sizeof(command.type));
        HashRect(hash, command.rect);
        HashPoint(hash, command.position);
        HashPoint(hash, command.uvMin);
        HashPoint(hash, command.uvMax);
        HashFloat(hash, command.color.r);
        HashFloat(hash, command.color.g);
        HashFloat(hash, command.color.b);
        HashFloat(hash, command.color.a);
        HashFloat(hash, command.secondaryColor.r);
        HashFloat(hash, command.secondaryColor.g);
        HashFloat(hash, command.secondaryColor.b);
        HashFloat(hash, command.secondaryColor.a);
        HashFloat(hash, command.thickness);
        HashFloat(hash, command.rounding);
        HashFloat(hash, command.radius);
        HashFloat(hash, command.fontSize);
        HashBool(hash, command.intersectWithCurrentClip);
        HashBytes(hash, &command.gradientDirection, sizeof(command.gradientDirection));
        HashTextureHandle(hash, command.texture);
        HashString(hash, command.text);
    }

    return hash;
}

void WriteColor(float outColor[4], const UIColor& color) {
    outColor[0] = color.r;
    outColor[1] = color.g;
    outColor[2] = color.b;
    outColor[3] = color.a;
}

void AppendBatch(
    std::vector<D3D12UiRenderer::UiBatch>& batches,
    std::uint32_t firstInstance,
    std::uint32_t instanceCount,
    D3D12_GPU_DESCRIPTOR_HANDLE textureHandle,
    const Rect& scissor) {
    if (instanceCount == 0u || textureHandle.ptr == 0u || IsEmptyScissor(scissor)) {
        return;
    }

    if (!batches.empty()) {
        D3D12UiRenderer::UiBatch& lastBatch = batches.back();
        if (lastBatch.textureHandle.ptr == textureHandle.ptr &&
            lastBatch.scissorRect.left == scissor.left &&
            lastBatch.scissorRect.top == scissor.top &&
            lastBatch.scissorRect.right == scissor.right &&
            lastBatch.scissorRect.bottom == scissor.bottom &&
            lastBatch.firstInstance + lastBatch.instanceCount == firstInstance) {
            lastBatch.instanceCount += instanceCount;
            return;
        }
    }

    D3D12UiRenderer::UiBatch batch = {};
    batch.firstInstance = firstInstance;
    batch.instanceCount = instanceCount;
    batch.textureHandle = textureHandle;
    batch.scissorRect = scissor;
    batches.push_back(batch);
}

void AppendPrimitiveInstance(
    std::vector<D3D12UiRenderer::UiPrimitiveInstance>& instances,
    std::vector<D3D12UiRenderer::UiBatch>& batches,
    const FloatPoint& origin,
    const FloatPoint& axisX,
    const FloatPoint& axisY,
    const UIPoint& uvMin,
    const UIPoint& uvMax,
    const UIColor& color,
    const UIColor& secondaryColor,
    UiPrimitiveKind primitiveKind,
    float radius,
    float thickness,
    float gradientDirection,
    const float aux0[4],
    const float aux1[4],
    D3D12_GPU_DESCRIPTOR_HANDLE textureHandle,
    const Rect& scissor) {
    if (textureHandle.ptr == 0u || IsEmptyScissor(scissor)) {
        return;
    }

    D3D12UiRenderer::UiPrimitiveInstance instance = {};
    instance.origin[0] = origin.x;
    instance.origin[1] = origin.y;
    instance.axisX[0] = axisX.x;
    instance.axisX[1] = axisX.y;
    instance.axisY[0] = axisY.x;
    instance.axisY[1] = axisY.y;
    instance.uvMin[0] = uvMin.x;
    instance.uvMin[1] = uvMin.y;
    instance.uvMax[0] = uvMax.x;
    instance.uvMax[1] = uvMax.y;
    WriteColor(instance.color, color);
    WriteColor(instance.secondaryColor, secondaryColor);
    instance.params[0] = static_cast<float>(static_cast<int>(primitiveKind));
    instance.params[1] = radius;
    instance.params[2] = thickness;
    instance.params[3] = gradientDirection;
    std::memcpy(instance.aux0, aux0, sizeof(instance.aux0));
    std::memcpy(instance.aux1, aux1, sizeof(instance.aux1));
    const std::uint32_t firstInstance = static_cast<std::uint32_t>(instances.size());
    instances.push_back(instance);
    AppendBatch(batches, firstInstance, 1u, textureHandle, scissor);
}

GraphicsPipelineDesc BuildBaseUiPipelineDesc(
    ::XCEngine::RHI::RHIPipelineLayout* pipelineLayout,
    const RenderSurface& surface) {
    GraphicsPipelineDesc pipelineDesc = {};
    pipelineDesc.pipelineLayout = pipelineLayout;
    pipelineDesc.topologyType =
        static_cast<std::uint32_t>(PrimitiveTopologyType::Triangle);
    ::XCEngine::Rendering::ApplySingleColorAttachmentPropertiesToGraphicsPipelineDesc(
        surface,
        pipelineDesc);

    pipelineDesc.inputLayout.elements = {
        { "POSITION", 0, static_cast<std::uint32_t>(Format::R32G32_Float), 0, 0, 0, 0 },
        { "TEXCOORD", 0, static_cast<std::uint32_t>(Format::R32G32_Float), 0, 8, 0, 0 },
        { "COLOR", 0, static_cast<std::uint32_t>(Format::R32G32B32A32_Float), 0, 16, 0, 0 }
    };

    pipelineDesc.rasterizerState.fillMode =
        static_cast<std::uint32_t>(FillMode::Solid);
    pipelineDesc.rasterizerState.cullMode =
        static_cast<std::uint32_t>(CullMode::None);
    pipelineDesc.rasterizerState.frontFace =
        static_cast<std::uint32_t>(FrontFace::CounterClockwise);
    pipelineDesc.rasterizerState.depthClipEnable = true;
    pipelineDesc.rasterizerState.scissorTestEnable = true;

    pipelineDesc.blendState.blendEnable = true;
    pipelineDesc.blendState.srcBlend =
        static_cast<std::uint32_t>(BlendFactor::SrcAlpha);
    pipelineDesc.blendState.dstBlend =
        static_cast<std::uint32_t>(BlendFactor::InvSrcAlpha);
    pipelineDesc.blendState.srcBlendAlpha =
        static_cast<std::uint32_t>(BlendFactor::One);
    pipelineDesc.blendState.dstBlendAlpha =
        static_cast<std::uint32_t>(BlendFactor::InvSrcAlpha);
    pipelineDesc.blendState.blendOp =
        static_cast<std::uint32_t>(BlendOp::Add);
    pipelineDesc.blendState.blendOpAlpha =
        static_cast<std::uint32_t>(BlendOp::Add);
    pipelineDesc.blendState.colorWriteMask =
        static_cast<std::uint8_t>(ColorWriteMask::All);

    pipelineDesc.depthStencilState.depthTestEnable = false;
    pipelineDesc.depthStencilState.depthWriteEnable = false;
    pipelineDesc.depthStencilState.depthFunc =
        static_cast<std::uint32_t>(ComparisonFunc::Always);
    return pipelineDesc;
}

GraphicsPipelineDesc BuildPrimitiveUiPipelineDesc(
    ::XCEngine::RHI::RHIPipelineLayout* pipelineLayout,
    const RenderSurface& surface) {
    GraphicsPipelineDesc pipelineDesc = BuildBaseUiPipelineDesc(pipelineLayout, surface);
    pipelineDesc.inputLayout.elements = {
        { "POSITION", 0, static_cast<std::uint32_t>(Format::R32G32_Float), 0, 0, 0, 0 },
        { "TEXCOORD", 0, static_cast<std::uint32_t>(Format::R32G32_Float), 0, 8, 0, 0 },
        { "POSITION", 1, static_cast<std::uint32_t>(Format::R32G32_Float), 1, 0, 1, 1 },
        { "TEXCOORD", 1, static_cast<std::uint32_t>(Format::R32G32_Float), 1, 8, 1, 1 },
        { "TEXCOORD", 2, static_cast<std::uint32_t>(Format::R32G32_Float), 1, 16, 1, 1 },
        { "TEXCOORD", 3, static_cast<std::uint32_t>(Format::R32G32_Float), 1, 24, 1, 1 },
        { "TEXCOORD", 4, static_cast<std::uint32_t>(Format::R32G32_Float), 1, 32, 1, 1 },
        { "COLOR", 0, static_cast<std::uint32_t>(Format::R32G32B32A32_Float), 1, 40, 1, 1 },
        { "COLOR", 1, static_cast<std::uint32_t>(Format::R32G32B32A32_Float), 1, 56, 1, 1 },
        { "TEXCOORD", 5, static_cast<std::uint32_t>(Format::R32G32B32A32_Float), 1, 72, 1, 1 },
        { "TEXCOORD", 6, static_cast<std::uint32_t>(Format::R32G32B32A32_Float), 1, 88, 1, 1 },
        { "TEXCOORD", 7, static_cast<std::uint32_t>(Format::R32G32B32A32_Float), 1, 104, 1, 1 }
    };

    pipelineDesc.vertexShader.source.assign(
        kPrimitiveUiPassHlsl,
        kPrimitiveUiPassHlsl + std::strlen(kPrimitiveUiPassHlsl));
    pipelineDesc.vertexShader.sourceLanguage = ::XCEngine::RHI::ShaderLanguage::HLSL;
    pipelineDesc.vertexShader.entryPoint = L"MainVS";
    pipelineDesc.vertexShader.profile = L"vs_5_0";

    pipelineDesc.fragmentShader.source.assign(
        kPrimitiveUiPassHlsl,
        kPrimitiveUiPassHlsl + std::strlen(kPrimitiveUiPassHlsl));
    pipelineDesc.fragmentShader.sourceLanguage = ::XCEngine::RHI::ShaderLanguage::HLSL;
    pipelineDesc.fragmentShader.entryPoint = L"MainPS";
    pipelineDesc.fragmentShader.profile = L"ps_5_0";
    return pipelineDesc;
}

} // namespace

bool D3D12UiRenderer::TextRunCacheKey::operator==(const TextRunCacheKey& other) const {
    return text == other.text &&
        fontSizeTenths == other.fontSizeTenths &&
        dpiScaleMilli == other.dpiScaleMilli;
}

std::size_t D3D12UiRenderer::TextRunCacheKeyHash::operator()(
    const TextRunCacheKey& key) const {
    const std::size_t textHash = std::hash<std::string>{}(key.text);
    const std::size_t fontHash = std::hash<int>{}(key.fontSizeTenths);
    const std::size_t dpiHash = std::hash<int>{}(key.dpiScaleMilli);
    return textHash ^ (fontHash << 1u) ^ (dpiHash << 2u);
}

bool D3D12UiRenderer::CompiledDrawListKey::operator==(
    const CompiledDrawListKey& other) const {
    return contentHash == other.contentHash &&
        renderWidth == other.renderWidth &&
        renderHeight == other.renderHeight &&
        dpiScaleMilli == other.dpiScaleMilli;
}

std::size_t D3D12UiRenderer::CompiledDrawListKeyHash::operator()(
    const CompiledDrawListKey& key) const {
    const std::size_t contentHashValue = std::hash<std::uint64_t>{}(key.contentHash);
    const std::size_t widthHash = std::hash<std::uint32_t>{}(key.renderWidth);
    const std::size_t heightHash = std::hash<std::uint32_t>{}(key.renderHeight);
    const std::size_t dpiHash = std::hash<int>{}(key.dpiScaleMilli);
    return contentHashValue ^
        (widthHash << 1u) ^
        (heightHash << 2u) ^
        (dpiHash << 3u);
}

bool D3D12UiRenderer::Initialize(
    D3D12WindowRenderer& windowRenderer,
    D3D12UiTextureHost& textureHost,
    D3D12UiTextSystem& textSystem) {
    const float dpiScale = m_dpiScale;
    Shutdown();

    m_windowRenderer = &windowRenderer;
    m_textureHost = &textureHost;
    m_textSystem = &textSystem;
    m_dpiScale = ClampDpiScale(dpiScale);
    m_lastError.clear();
    return true;
}

void D3D12UiRenderer::Shutdown() {
    ReleaseTextRunCache();
    ReleaseCompiledDrawListCache();
    if (m_textureHost != nullptr) {
        m_textureHost->ReleaseTexture(m_whiteTexture);
    } else {
        m_whiteTexture = {};
    }

    DestroyResources();
    m_windowRenderer = nullptr;
    m_textureHost = nullptr;
    m_textSystem = nullptr;
    m_dpiScale = 1.0f;
    m_compiledDrawListFrameCounter = 0u;
    m_lastError.clear();
}

void D3D12UiRenderer::SetDpiScale(float dpiScale) {
    const float resolvedScale = ClampDpiScale(dpiScale);
    if (std::abs(m_dpiScale - resolvedScale) > 0.0001f) {
        ReleaseTextRunCache();
        ReleaseCompiledDrawListCache();
    }
    m_dpiScale = resolvedScale;
}

float D3D12UiRenderer::GetDpiScale() const {
    return m_dpiScale;
}

const std::string& D3D12UiRenderer::GetLastError() const {
    return m_lastError;
}

bool D3D12UiRenderer::EnsureWhiteTexture() {
    if (m_whiteTexture.IsValid()) {
        return true;
    }

    if (m_textureHost == nullptr) {
        m_lastError = "EnsureWhiteTexture requires an initialized texture host.";
        return false;
    }

    const std::uint8_t whitePixel[4] = { 255u, 255u, 255u, 255u };
    std::string error = {};
    if (!m_textureHost->LoadTextureFromRgba(
            whitePixel,
            1u,
            1u,
            m_whiteTexture,
            error)) {
        m_lastError = error.empty()
            ? "Failed to create the UI white texture."
            : error;
        return false;
    }

    return true;
}

const D3D12UiRenderer::CachedTextRun* D3D12UiRenderer::ResolveTextRun(
    std::string_view text,
    float fontSize,
    std::uint64_t currentFrameId) {
    if (m_textureHost == nullptr || m_textSystem == nullptr) {
        return nullptr;
    }

    TextRunCacheKey cacheKey = {};
    cacheKey.text.assign(text);
    cacheKey.fontSizeTenths =
        static_cast<int>(std::lround(ResolveFontSize(fontSize) * 10.0f));
    cacheKey.dpiScaleMilli =
        static_cast<int>(std::lround(ClampDpiScale(m_dpiScale) * 1000.0f));

    const auto found = m_textRunCache.find(cacheKey);
    if (found != m_textRunCache.end()) {
        found->second.lastUsedFrame = currentFrameId;
        return &found->second;
    }

    std::string error = {};
    D3D12UiTextSystem::RasterizedTextRun rasterizedText = {};
    if (!m_textSystem->RasterizeTextMask(text, fontSize, rasterizedText, error)) {
        m_lastError = error.empty()
            ? "Failed to rasterize the UI text run."
            : error;
        return nullptr;
    }

    CachedTextRun cachedText = {};
    cachedText.offsetX = rasterizedText.offsetX;
    cachedText.offsetY = rasterizedText.offsetY;
    cachedText.width = static_cast<float>(rasterizedText.width);
    cachedText.height = static_cast<float>(rasterizedText.height);
    cachedText.lastUsedFrame = currentFrameId;
    cachedText.hasPixels =
        rasterizedText.width > 0u &&
        rasterizedText.height > 0u &&
        !rasterizedText.rgbaPixels.empty();

    if (cachedText.hasPixels) {
        if (!m_textureHost->LoadTextureFromRgba(
                rasterizedText.rgbaPixels.data(),
                rasterizedText.width,
                rasterizedText.height,
                cachedText.texture,
                error)) {
            m_lastError = error.empty()
                ? "Failed to upload the UI text run texture."
                : error;
            return nullptr;
        }
        cachedText.textureHandle.ptr = static_cast<UINT64>(cachedText.texture.nativeHandle);
    }

    const auto [insertedIt, inserted] =
        m_textRunCache.emplace(std::move(cacheKey), std::move(cachedText));
    (void)inserted;
    return &insertedIt->second;
}

void D3D12UiRenderer::ReleaseTextRunCache() {
    if (m_textureHost != nullptr) {
        for (auto& [key, cachedText] : m_textRunCache) {
            m_textureHost->ReleaseTexture(cachedText.texture);
            cachedText.textureHandle = {};
        }
    }
    m_textRunCache.clear();
}

void D3D12UiRenderer::PruneTextRunCache(std::uint64_t currentFrameId) {
    constexpr std::size_t kTextRunCacheMaxEntries = 512u;
    constexpr std::uint64_t kTextRunCacheRetentionFrames = 240u;
    if (m_textRunCache.size() <= kTextRunCacheMaxEntries) {
        return;
    }

    const std::uint64_t pruneBeforeFrame =
        currentFrameId > kTextRunCacheRetentionFrames
            ? currentFrameId - kTextRunCacheRetentionFrames
            : 0u;

    bool evictedAny = false;
    for (auto it = m_textRunCache.begin(); it != m_textRunCache.end();) {
        if (it->second.lastUsedFrame <= pruneBeforeFrame) {
            if (m_textureHost != nullptr) {
                m_textureHost->ReleaseTexture(it->second.texture);
            }
            it = m_textRunCache.erase(it);
            evictedAny = true;
        } else {
            ++it;
        }
    }

    if (evictedAny) {
        ReleaseCompiledDrawListCache();
    }
}

void D3D12UiRenderer::ReleaseCompiledDrawListCache() {
    m_compiledDrawListCache.clear();
}

bool D3D12UiRenderer::EnsureInitialized(
    const RenderContext& renderContext,
    const RenderSurface& surface) {
    const Format renderTargetFormat =
        ::XCEngine::Rendering::ResolveSurfaceColorFormat(surface, 0u);
    const std::uint32_t sampleCount =
        ::XCEngine::Rendering::ResolveSurfaceSampleCount(surface);
    const std::uint32_t sampleQuality =
        ::XCEngine::Rendering::ResolveSurfaceSampleQuality(surface);

    if (m_device == renderContext.device &&
        m_backendType == renderContext.backendType &&
        m_pipelineLayout != nullptr &&
        m_primitivePipelineState != nullptr &&
        m_constantPool != nullptr &&
        m_constantSet != nullptr &&
        m_samplerPool != nullptr &&
        m_samplerSet != nullptr &&
        m_sampler != nullptr &&
        m_quadVertexBuffer != nullptr &&
        m_quadVertexBufferView != nullptr &&
        m_quadIndexBuffer != nullptr &&
        m_quadIndexBufferView != nullptr &&
        m_renderTargetFormat == renderTargetFormat &&
        m_renderTargetSampleCount == sampleCount &&
        m_renderTargetSampleQuality == sampleQuality) {
        return true;
    }

    DestroyResources();
    return CreateResources(renderContext, surface);
}

bool D3D12UiRenderer::CreateResources(
    const RenderContext& renderContext,
    const RenderSurface& surface) {
    if (!renderContext.IsValid() ||
        renderContext.device == nullptr ||
        !::XCEngine::Rendering::HasSingleColorAttachment(surface) ||
        ::XCEngine::Rendering::ResolveSurfaceColorFormat(surface, 0u) == Format::Unknown) {
        m_lastError = "CreateResources requires a valid single-color render surface.";
        return false;
    }

    m_device = renderContext.device;
    m_backendType = renderContext.backendType;
    m_renderTargetFormat =
        ::XCEngine::Rendering::ResolveSurfaceColorFormat(surface, 0u);
    m_renderTargetSampleCount =
        ::XCEngine::Rendering::ResolveSurfaceSampleCount(surface);
    m_renderTargetSampleQuality =
        ::XCEngine::Rendering::ResolveSurfaceSampleQuality(surface);

    DescriptorSetLayoutBinding constantBinding = {};
    constantBinding.binding = 0u;
    constantBinding.type = static_cast<std::uint32_t>(DescriptorType::CBV);
    constantBinding.count = 1u;
    constantBinding.visibility = static_cast<std::uint32_t>(ShaderVisibility::All);

    DescriptorSetLayoutBinding textureBinding = {};
    textureBinding.binding = 0u;
    textureBinding.type = static_cast<std::uint32_t>(DescriptorType::SRV);
    textureBinding.count = 1u;
    textureBinding.visibility = static_cast<std::uint32_t>(ShaderVisibility::All);

    DescriptorSetLayoutBinding samplerBinding = {};
    samplerBinding.binding = 0u;
    samplerBinding.type = static_cast<std::uint32_t>(DescriptorType::Sampler);
    samplerBinding.count = 1u;
    samplerBinding.visibility = static_cast<std::uint32_t>(ShaderVisibility::All);

    DescriptorSetLayoutDesc setLayouts[3] = {};
    setLayouts[0].bindings = &constantBinding;
    setLayouts[0].bindingCount = 1u;
    setLayouts[1].bindings = &textureBinding;
    setLayouts[1].bindingCount = 1u;
    setLayouts[2].bindings = &samplerBinding;
    setLayouts[2].bindingCount = 1u;

    RHIPipelineLayoutDesc pipelineLayoutDesc = {};
    pipelineLayoutDesc.setLayouts = setLayouts;
    pipelineLayoutDesc.setLayoutCount = 3u;
    m_pipelineLayout = m_device->CreatePipelineLayout(pipelineLayoutDesc);
    if (m_pipelineLayout == nullptr) {
        m_lastError = "Failed to create the D3D12 UI pipeline layout.";
        DestroyResources();
        return false;
    }

    DescriptorPoolDesc constantPoolDesc = {};
    constantPoolDesc.type = DescriptorHeapType::CBV_SRV_UAV;
    constantPoolDesc.descriptorCount = 1u;
    constantPoolDesc.shaderVisible = false;
    m_constantPool = m_device->CreateDescriptorPool(constantPoolDesc);
    if (m_constantPool == nullptr) {
        m_lastError = "Failed to create the D3D12 UI constant descriptor pool.";
        DestroyResources();
        return false;
    }

    m_constantSet = m_constantPool->AllocateSet(setLayouts[0]);
    if (m_constantSet == nullptr) {
        m_lastError = "Failed to allocate the D3D12 UI constant descriptor set.";
        DestroyResources();
        return false;
    }

    SamplerDesc samplerDesc = {};
    samplerDesc.filter = static_cast<std::uint32_t>(FilterMode::Linear);
    samplerDesc.addressU = static_cast<std::uint32_t>(TextureAddressMode::Clamp);
    samplerDesc.addressV = static_cast<std::uint32_t>(TextureAddressMode::Clamp);
    samplerDesc.addressW = static_cast<std::uint32_t>(TextureAddressMode::Clamp);
    samplerDesc.maxAnisotropy = 1u;
    samplerDesc.comparisonFunc = static_cast<std::uint32_t>(ComparisonFunc::Always);
    samplerDesc.minLod = 0.0f;
    samplerDesc.maxLod = 16.0f;
    m_sampler = m_device->CreateSampler(samplerDesc);
    if (m_sampler == nullptr) {
        m_lastError = "Failed to create the D3D12 UI sampler.";
        DestroyResources();
        return false;
    }

    DescriptorPoolDesc samplerPoolDesc = {};
    samplerPoolDesc.type = DescriptorHeapType::Sampler;
    samplerPoolDesc.descriptorCount = 1u;
    samplerPoolDesc.shaderVisible = true;
    m_samplerPool = m_device->CreateDescriptorPool(samplerPoolDesc);
    if (m_samplerPool == nullptr) {
        m_lastError = "Failed to create the D3D12 UI sampler descriptor pool.";
        DestroyResources();
        return false;
    }

    m_samplerSet = m_samplerPool->AllocateSet(setLayouts[2]);
    if (m_samplerSet == nullptr) {
        m_lastError = "Failed to allocate the D3D12 UI sampler descriptor set.";
        DestroyResources();
        return false;
    }

    m_samplerSet->UpdateSampler(0u, m_sampler);
    auto* samplerDescriptorSet = static_cast<D3D12DescriptorSet*>(m_samplerSet);
    m_samplerGpuHandle = samplerDescriptorSet->GetGPUHandleForBinding(0u);
    if (m_samplerGpuHandle.ptr == 0u) {
        m_lastError = "Failed to resolve the D3D12 UI sampler GPU descriptor handle.";
        DestroyResources();
        return false;
    }

    m_primitivePipelineState = m_device->CreatePipelineState(
        BuildPrimitiveUiPipelineDesc(m_pipelineLayout, surface));
    if (m_primitivePipelineState == nullptr || !m_primitivePipelineState->IsValid()) {
        m_lastError = "Failed to create the D3D12 UI primitive pipeline state.";
        DestroyResources();
        return false;
    }

    BufferDesc quadVertexBufferDesc = {};
    quadVertexBufferDesc.size = sizeof(kUnitQuadVertices);
    quadVertexBufferDesc.stride = static_cast<std::uint32_t>(sizeof(UiQuadVertex));
    quadVertexBufferDesc.bufferType = static_cast<std::uint32_t>(BufferType::Vertex);
    m_quadVertexBuffer =
        m_device->CreateBuffer(quadVertexBufferDesc, kUnitQuadVertices, sizeof(kUnitQuadVertices));
    if (m_quadVertexBuffer == nullptr) {
        m_lastError = "Failed to create the D3D12 UI unit-quad vertex buffer.";
        DestroyResources();
        return false;
    }
    m_quadVertexBuffer->SetStride(quadVertexBufferDesc.stride);
    m_quadVertexBuffer->SetBufferType(BufferType::Vertex);

    ResourceViewDesc quadVertexViewDesc = {};
    quadVertexViewDesc.dimension = ResourceViewDimension::Buffer;
    quadVertexViewDesc.structureByteStride = quadVertexBufferDesc.stride;
    m_quadVertexBufferView =
        m_device->CreateVertexBufferView(m_quadVertexBuffer, quadVertexViewDesc);
    if (m_quadVertexBufferView == nullptr) {
        m_lastError = "Failed to create the D3D12 UI unit-quad vertex view.";
        DestroyResources();
        return false;
    }

    BufferDesc quadIndexBufferDesc = {};
    quadIndexBufferDesc.size = sizeof(kUnitQuadIndices);
    quadIndexBufferDesc.stride = static_cast<std::uint32_t>(sizeof(std::uint32_t));
    quadIndexBufferDesc.bufferType = static_cast<std::uint32_t>(BufferType::Index);
    m_quadIndexBuffer =
        m_device->CreateBuffer(quadIndexBufferDesc, kUnitQuadIndices, sizeof(kUnitQuadIndices));
    if (m_quadIndexBuffer == nullptr) {
        m_lastError = "Failed to create the D3D12 UI unit-quad index buffer.";
        DestroyResources();
        return false;
    }
    m_quadIndexBuffer->SetStride(quadIndexBufferDesc.stride);
    m_quadIndexBuffer->SetBufferType(BufferType::Index);

    ResourceViewDesc quadIndexViewDesc = {};
    quadIndexViewDesc.dimension = ResourceViewDimension::Buffer;
    quadIndexViewDesc.format = static_cast<std::uint32_t>(Format::R32_UInt);
    m_quadIndexBufferView =
        m_device->CreateIndexBufferView(m_quadIndexBuffer, quadIndexViewDesc);
    if (m_quadIndexBufferView == nullptr) {
        m_lastError = "Failed to create the D3D12 UI unit-quad index view.";
        DestroyResources();
        return false;
    }

    return true;
}

void D3D12UiRenderer::DestroyFrameResources(FrameResources& frameResources) {
    if (frameResources.primitiveInstanceBufferView != nullptr) {
        frameResources.primitiveInstanceBufferView->Shutdown();
        delete frameResources.primitiveInstanceBufferView;
        frameResources.primitiveInstanceBufferView = nullptr;
    }
    if (frameResources.primitiveInstanceBuffer != nullptr) {
        frameResources.primitiveInstanceBuffer->Shutdown();
        delete frameResources.primitiveInstanceBuffer;
        frameResources.primitiveInstanceBuffer = nullptr;
    }
    frameResources.primitiveInstanceCapacityBytes = 0u;
}

void D3D12UiRenderer::DestroyResources() {
    for (FrameResources& frameResources : m_frameResources) {
        DestroyFrameResources(frameResources);
    }

    if (m_quadIndexBufferView != nullptr) {
        m_quadIndexBufferView->Shutdown();
        delete m_quadIndexBufferView;
        m_quadIndexBufferView = nullptr;
    }
    if (m_quadIndexBuffer != nullptr) {
        m_quadIndexBuffer->Shutdown();
        delete m_quadIndexBuffer;
        m_quadIndexBuffer = nullptr;
    }
    if (m_quadVertexBufferView != nullptr) {
        m_quadVertexBufferView->Shutdown();
        delete m_quadVertexBufferView;
        m_quadVertexBufferView = nullptr;
    }
    if (m_quadVertexBuffer != nullptr) {
        m_quadVertexBuffer->Shutdown();
        delete m_quadVertexBuffer;
        m_quadVertexBuffer = nullptr;
    }
    if (m_primitivePipelineState != nullptr) {
        m_primitivePipelineState->Shutdown();
        delete m_primitivePipelineState;
        m_primitivePipelineState = nullptr;
    }
    if (m_samplerSet != nullptr) {
        m_samplerSet->Shutdown();
        delete m_samplerSet;
        m_samplerSet = nullptr;
    }
    if (m_samplerPool != nullptr) {
        m_samplerPool->Shutdown();
        delete m_samplerPool;
        m_samplerPool = nullptr;
    }
    if (m_sampler != nullptr) {
        m_sampler->Shutdown();
        delete m_sampler;
        m_sampler = nullptr;
    }
    if (m_constantSet != nullptr) {
        m_constantSet->Shutdown();
        delete m_constantSet;
        m_constantSet = nullptr;
    }
    if (m_constantPool != nullptr) {
        m_constantPool->Shutdown();
        delete m_constantPool;
        m_constantPool = nullptr;
    }
    if (m_pipelineLayout != nullptr) {
        m_pipelineLayout->Shutdown();
        delete m_pipelineLayout;
        m_pipelineLayout = nullptr;
    }

    m_samplerGpuHandle = {};
    m_device = nullptr;
    m_backendType = ::XCEngine::RHI::RHIType::D3D12;
    m_renderTargetFormat = Format::Unknown;
    m_renderTargetSampleCount = 1u;
    m_renderTargetSampleQuality = 0u;
}

bool D3D12UiRenderer::EnsureFrameBufferCapacity(
    std::uint32_t frameSlot,
    std::size_t primitiveInstanceBytes) {
    if (m_device == nullptr || frameSlot >= m_frameResources.size()) {
        return false;
    }

    FrameResources& frameResources = m_frameResources[frameSlot];
    auto ensureVertexBuffer =
        [&](std::size_t requiredBytes,
            std::uint64_t minimumBytes,
            std::uint32_t stride,
            ::XCEngine::RHI::RHIBuffer*& buffer,
            ::XCEngine::RHI::RHIResourceView*& bufferView,
            std::uint64_t& capacityBytes) -> bool {
            if (requiredBytes == 0u) {
                return true;
            }

            const std::uint64_t resolvedRequiredBytes =
                (std::max<std::uint64_t>)(static_cast<std::uint64_t>(requiredBytes), minimumBytes);
            if (buffer != nullptr && capacityBytes >= resolvedRequiredBytes) {
                return true;
            }

            if (bufferView != nullptr) {
                bufferView->Shutdown();
                delete bufferView;
                bufferView = nullptr;
            }
            if (buffer != nullptr) {
                buffer->Shutdown();
                delete buffer;
                buffer = nullptr;
            }

            capacityBytes = resolvedRequiredBytes;
            BufferDesc bufferDesc = {};
            bufferDesc.size = capacityBytes;
            bufferDesc.stride = stride;
            bufferDesc.bufferType = static_cast<std::uint32_t>(BufferType::Vertex);
            buffer = m_device->CreateBuffer(bufferDesc);
            if (buffer == nullptr) {
                capacityBytes = 0u;
                return false;
            }
            buffer->SetStride(bufferDesc.stride);
            buffer->SetBufferType(BufferType::Vertex);

            ResourceViewDesc viewDesc = {};
            viewDesc.dimension = ResourceViewDimension::Buffer;
            viewDesc.structureByteStride = bufferDesc.stride;
            bufferView = m_device->CreateVertexBufferView(buffer, viewDesc);
            if (bufferView == nullptr) {
                buffer->Shutdown();
                delete buffer;
                buffer = nullptr;
                capacityBytes = 0u;
                return false;
            }

            return true;
        };

    return ensureVertexBuffer(
               primitiveInstanceBytes,
               kMinDynamicInstanceBufferBytes,
               static_cast<std::uint32_t>(sizeof(UiPrimitiveInstance)),
               frameResources.primitiveInstanceBuffer,
               frameResources.primitiveInstanceBufferView,
               frameResources.primitiveInstanceCapacityBytes);
}

bool D3D12UiRenderer::BuildDrawBatches(
    const UIDrawData& drawData,
    const RenderSurface& surface,
    std::vector<UiPrimitiveInstance>& outPrimitiveInstances,
    std::vector<UiBatch>& outBatches) {
    outPrimitiveInstances.clear();
    outBatches.clear();

    if (!EnsureWhiteTexture()) {
        return false;
    }

    const auto renderArea = surface.GetRenderArea();
    const Rect fullScissor = {
        renderArea.x,
        renderArea.y,
        renderArea.x + renderArea.width,
        renderArea.y + renderArea.height
    };
    const FloatRect fullRect = {
        static_cast<float>(fullScissor.left),
        static_cast<float>(fullScissor.top),
        static_cast<float>(fullScissor.right),
        static_cast<float>(fullScissor.bottom)
    };

    const float dpiScale = ClampDpiScale(m_dpiScale);
    const std::uint64_t currentFrameId = ++m_compiledDrawListFrameCounter;
    const D3D12_GPU_DESCRIPTOR_HANDLE whiteTextureHandle = {
        static_cast<UINT64>(m_whiteTexture.nativeHandle)
    };
    const float zeroAux[4] = { 0.0f, 0.0f, 0.0f, 0.0f };

    auto buildCompiledDrawList =
        [&](const UIDrawList& drawList,
            std::vector<UiPrimitiveInstance>& compiledInstances,
            std::vector<UiBatch>& compiledBatches) {
            compiledInstances.clear();
            compiledBatches.clear();

            std::vector<ClipState> localClipStack = {};
            localClipStack.push_back({ fullScissor, fullRect });

            auto appendAxisAlignedPrimitive =
                [&](const FloatRect& rect,
                    const UIPoint& uvMin,
                    const UIPoint& uvMax,
                    const UIColor& color,
                    const UIColor& secondaryColor,
                    UiPrimitiveKind primitiveKind,
                    float radius,
                    float thickness,
                    float gradientDirection,
                    D3D12_GPU_DESCRIPTOR_HANDLE textureHandle,
                    const Rect& scissor) {
                    if (IsEmptyRect(rect) || textureHandle.ptr == 0u || IsEmptyScissor(scissor)) {
                        return;
                    }

                    AppendPrimitiveInstance(
                        compiledInstances,
                        compiledBatches,
                        FloatPoint{ rect.left, rect.top },
                        FloatPoint{ rect.right - rect.left, 0.0f },
                        FloatPoint{ 0.0f, rect.bottom - rect.top },
                        uvMin,
                        uvMax,
                        color,
                        secondaryColor,
                        primitiveKind,
                        radius,
                        thickness,
                        gradientDirection,
                        zeroAux,
                        zeroAux,
                        textureHandle,
                        scissor);
                };

            auto appendOrientedPrimitive =
                [&](const FloatPoint& origin,
                    const FloatPoint& axisX,
                    const FloatPoint& axisY,
                    const UIColor& color,
                    UiPrimitiveKind primitiveKind,
                    float radius,
                    float thickness,
                    D3D12_GPU_DESCRIPTOR_HANDLE textureHandle,
                    const Rect& scissor) {
                    if (textureHandle.ptr == 0u || IsEmptyScissor(scissor)) {
                        return;
                    }

                    AppendPrimitiveInstance(
                        compiledInstances,
                        compiledBatches,
                        origin,
                        axisX,
                        axisY,
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        color,
                        color,
                        primitiveKind,
                        radius,
                        thickness,
                        0.0f,
                        zeroAux,
                        zeroAux,
                        textureHandle,
                        scissor);
                };

            auto appendTrianglePrimitive =
                [&](const FloatPoint& p0,
                    const FloatPoint& p1,
                    const FloatPoint& p2,
                    const UIColor& color,
                    D3D12_GPU_DESCRIPTOR_HANDLE textureHandle,
                    const Rect& scissor) {
                    if (textureHandle.ptr == 0u || IsEmptyScissor(scissor)) {
                        return;
                    }

                    const float minX = (std::min)({ p0.x, p1.x, p2.x });
                    const float minY = (std::min)({ p0.y, p1.y, p2.y });
                    const float maxX = (std::max)({ p0.x, p1.x, p2.x });
                    const float maxY = (std::max)({ p0.y, p1.y, p2.y });
                    if (maxX <= minX || maxY <= minY) {
                        return;
                    }

                    const FloatPoint origin = { minX, minY };
                    const FloatPoint axisX = { maxX - minX, 0.0f };
                    const FloatPoint axisY = { 0.0f, maxY - minY };
                    const float triangleAux0[4] = {
                        p0.x - origin.x,
                        p0.y - origin.y,
                        p1.x - origin.x,
                        p1.y - origin.y
                    };
                    const float triangleAux1[4] = {
                        p2.x - origin.x,
                        p2.y - origin.y,
                        0.0f,
                        0.0f
                    };

                    AppendPrimitiveInstance(
                        compiledInstances,
                        compiledBatches,
                        origin,
                        axisX,
                        axisY,
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        color,
                        color,
                        UiPrimitiveKind::TriangleFill,
                        0.0f,
                        0.0f,
                        0.0f,
                        triangleAux0,
                        triangleAux1,
                        textureHandle,
                        scissor);
                };

            for (const UIDrawCommand& command : drawList.GetCommands()) {
                if (localClipStack.empty()) {
                    localClipStack.push_back({ fullScissor, fullRect });
                }

                if (command.type == UIDrawCommandType::PushClipRect) {
                    FloatRect clipRect = ToPixelRect(command.rect, dpiScale);
                    clipRect = command.intersectWithCurrentClip
                        ? IntersectFloatRect(localClipStack.back().rect, clipRect)
                        : IntersectFloatRect(fullRect, clipRect);
                    ClipState clipState = {};
                    clipState.rect = clipRect;
                    clipState.scissor = ClampScissor(clipRect, fullScissor);
                    localClipStack.push_back(clipState);
                    continue;
                }

                if (command.type == UIDrawCommandType::PopClipRect) {
                    if (localClipStack.size() > 1u) {
                        localClipStack.pop_back();
                    }
                    continue;
                }

                const ClipState currentClip = localClipStack.back();
                if (IsEmptyScissor(currentClip.scissor)) {
                    continue;
                }

                switch (command.type) {
                case UIDrawCommandType::FilledRect: {
                    appendAxisAlignedPrimitive(
                        ToPixelRect(command.rect, dpiScale),
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        command.color,
                        command.color,
                        UiPrimitiveKind::RectFill,
                        command.rounding * dpiScale,
                        0.0f,
                        0.0f,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::FilledRectLinearGradient: {
                    appendAxisAlignedPrimitive(
                        ToPixelRect(command.rect, dpiScale),
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        command.color,
                        command.secondaryColor,
                        UiPrimitiveKind::RectFill,
                        command.rounding * dpiScale,
                        0.0f,
                        command.gradientDirection == UILinearGradientDirection::Vertical
                            ? 1.0f
                            : 0.0f,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::RectOutline: {
                    const FloatRect rect = ToPixelRect(command.rect, dpiScale);
                    const float thickness =
                        (command.thickness > 0.0f ? command.thickness : 1.0f) * dpiScale;
                    const float halfThickness = thickness * 0.5f;
                    appendAxisAlignedPrimitive(
                        FloatRect{
                            rect.left - halfThickness,
                            rect.top - halfThickness,
                            rect.right + halfThickness,
                            rect.bottom + halfThickness
                        },
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        command.color,
                        command.color,
                        UiPrimitiveKind::RectOutline,
                        command.rounding * dpiScale + halfThickness,
                        thickness,
                        0.0f,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::Line: {
                    const FloatPoint start = ToPixelPoint(command.position, dpiScale);
                    const FloatPoint end = ToPixelPoint(command.uvMin, dpiScale);
                    const float dx = end.x - start.x;
                    const float dy = end.y - start.y;
                    const float length = std::sqrt(dx * dx + dy * dy);
                    if (length <= 0.0f) {
                        break;
                    }

                    const float thickness =
                        (command.thickness > 0.0f ? command.thickness : 1.0f) * dpiScale;
                    const float halfThickness = thickness * 0.5f;
                    const float nx = -dy / length;
                    const float ny = dx / length;
                    appendOrientedPrimitive(
                        FloatPoint{ start.x + nx * halfThickness, start.y + ny * halfThickness },
                        FloatPoint{ dx, dy },
                        FloatPoint{ -nx * thickness, -ny * thickness },
                        command.color,
                        UiPrimitiveKind::RectFill,
                        0.0f,
                        0.0f,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::FilledTriangle: {
                    appendTrianglePrimitive(
                        ToPixelPoint(command.position, dpiScale),
                        ToPixelPoint(command.uvMin, dpiScale),
                        ToPixelPoint(command.uvMax, dpiScale),
                        command.color,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::FilledCircle: {
                    const FloatPoint center = ToPixelPoint(command.position, dpiScale);
                    const float radius = command.radius * dpiScale;
                    if (radius <= 0.0f) {
                        break;
                    }

                    appendAxisAlignedPrimitive(
                        FloatRect{
                            center.x - radius,
                            center.y - radius,
                            center.x + radius,
                            center.y + radius
                        },
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        command.color,
                        command.color,
                        UiPrimitiveKind::CircleFill,
                        radius,
                        0.0f,
                        0.0f,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::CircleOutline: {
                    const FloatPoint center = ToPixelPoint(command.position, dpiScale);
                    const float thickness =
                        (command.thickness > 0.0f ? command.thickness : 1.0f) * dpiScale;
                    const float radius = command.radius * dpiScale;
                    const float outerRadius = radius + thickness * 0.5f;
                    if (outerRadius <= 0.0f) {
                        break;
                    }

                    appendAxisAlignedPrimitive(
                        FloatRect{
                            center.x - outerRadius,
                            center.y - outerRadius,
                            center.x + outerRadius,
                            center.y + outerRadius
                        },
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        command.color,
                        command.color,
                        UiPrimitiveKind::CircleOutline,
                        radius,
                        thickness,
                        0.0f,
                        whiteTextureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::Text: {
                    if (command.text.empty()) {
                        break;
                    }

                    const CachedTextRun* textRun =
                        ResolveTextRun(command.text, command.fontSize, currentFrameId);
                    if (textRun == nullptr ||
                        !textRun->hasPixels ||
                        textRun->textureHandle.ptr == 0u ||
                        textRun->width <= 0.0f ||
                        textRun->height <= 0.0f) {
                        break;
                    }

                    const FloatPoint position = ToPixelPoint(command.position, dpiScale);
                    appendAxisAlignedPrimitive(
                        FloatRect{
                            position.x + textRun->offsetX,
                            position.y + textRun->offsetY,
                            position.x + textRun->offsetX + textRun->width,
                            position.y + textRun->offsetY + textRun->height
                        },
                        UIPoint(0.0f, 0.0f),
                        UIPoint(1.0f, 1.0f),
                        command.color,
                        command.color,
                        UiPrimitiveKind::Textured,
                        0.0f,
                        0.0f,
                        0.0f,
                        textRun->textureHandle,
                        currentClip.scissor);
                    break;
                }
                case UIDrawCommandType::Image: {
                    if (!command.texture.IsValid()) {
                        break;
                    }

                    appendAxisAlignedPrimitive(
                        ToPixelRect(command.rect, dpiScale),
                        command.uvMin,
                        command.uvMax,
                        command.color,
                        command.color,
                        UiPrimitiveKind::Textured,
                        0.0f,
                        0.0f,
                        0.0f,
                        D3D12_GPU_DESCRIPTOR_HANDLE{
                            static_cast<UINT64>(command.texture.nativeHandle)
                        },
                        currentClip.scissor);
                    break;
                }
                default:
                    break;
                }
            }

            return true;
        };

    auto appendCompiledDrawList =
        [&](const CompiledDrawList& compiled) {
            if (compiled.batches.empty()) {
                return;
            }

            const std::uint32_t baseInstance =
                static_cast<std::uint32_t>(outPrimitiveInstances.size());

            if (!compiled.instances.empty()) {
                outPrimitiveInstances.insert(
                    outPrimitiveInstances.end(),
                    compiled.instances.begin(),
                    compiled.instances.end());
            }

            for (const UiBatch& batch : compiled.batches) {
                AppendBatch(
                    outBatches,
                    baseInstance + batch.firstInstance,
                    batch.instanceCount,
                    batch.textureHandle,
                    batch.scissorRect);
            }
        };

    const std::uint32_t renderWidth = renderArea.width > 0 ? renderArea.width : 0u;
    const std::uint32_t renderHeight = renderArea.height > 0 ? renderArea.height : 0u;
    const int dpiScaleMilli =
        static_cast<int>(std::lround(dpiScale * 1000.0f));

    for (const UIDrawList& drawList : drawData.GetDrawLists()) {
        if (drawList.Empty()) {
            continue;
        }

        CompiledDrawListKey key = {};
        key.contentHash = BuildDrawListContentHash(drawList);
        key.renderWidth = renderWidth;
        key.renderHeight = renderHeight;
        key.dpiScaleMilli = dpiScaleMilli;

        auto found = m_compiledDrawListCache.find(key);
        if (found == m_compiledDrawListCache.end()) {
            CompiledDrawList compiled = {};
            if (!buildCompiledDrawList(
                    drawList,
                    compiled.instances,
                    compiled.batches)) {
                return false;
            }

            compiled.lastUsedFrame = currentFrameId;
            const auto [insertedIt, inserted] =
                m_compiledDrawListCache.emplace(key, std::move(compiled));
            (void)inserted;
            found = insertedIt;
        } else {
            found->second.lastUsedFrame = currentFrameId;
        }

        appendCompiledDrawList(found->second);
    }

    constexpr std::size_t kCompiledDrawListCacheMaxEntries = 256u;
    constexpr std::uint64_t kCompiledDrawListCacheRetentionFrames = 240u;
    if (m_compiledDrawListCache.size() > kCompiledDrawListCacheMaxEntries) {
        const std::uint64_t pruneBeforeFrame =
            currentFrameId > kCompiledDrawListCacheRetentionFrames
                ? currentFrameId - kCompiledDrawListCacheRetentionFrames
                : 0u;
        for (auto it = m_compiledDrawListCache.begin();
             it != m_compiledDrawListCache.end();) {
            if (it->second.lastUsedFrame <= pruneBeforeFrame) {
                it = m_compiledDrawListCache.erase(it);
            } else {
                ++it;
            }
        }
    }

    PruneTextRunCache(currentFrameId);

    return true;
}

bool D3D12UiRenderer::Render(
    const UIDrawData& drawData,
    const RenderContext& renderContext,
    const RenderSurface& surface) {
    if (m_windowRenderer == nullptr ||
        m_textureHost == nullptr ||
        m_textSystem == nullptr) {
        m_lastError = "Render requires an initialized D3D12 UI renderer.";
        return false;
    }

    if (!renderContext.IsValid() || renderContext.commandList == nullptr) {
        m_lastError = "Render requires a valid D3D12 render context.";
        return false;
    }

    if (!::XCEngine::Rendering::HasSingleColorAttachment(surface) ||
        surface.GetColorAttachments().empty() ||
        surface.GetColorAttachments()[0] == nullptr) {
        m_lastError = "Render requires a valid single-color render surface.";
        return false;
    }

    if (!EnsureInitialized(renderContext, surface)) {
        if (m_lastError.empty()) {
            m_lastError = "Failed to initialize the D3D12 UI renderer resources.";
        }
        return false;
    }

    m_textureHost->BeginFrame(m_windowRenderer->GetActiveFrameSlot());

    std::vector<UiPrimitiveInstance> primitiveInstances = {};
    std::vector<UiBatch> batches = {};
    if (!BuildDrawBatches(drawData, surface, primitiveInstances, batches)) {
        if (m_lastError.empty()) {
            m_lastError = "Failed to build the D3D12 UI draw batches.";
        }
        return false;
    }

    if (batches.empty()) {
        m_lastError.clear();
        return true;
    }

    const std::uint32_t frameSlot = m_windowRenderer->GetActiveFrameSlot();
    if (!EnsureFrameBufferCapacity(
            frameSlot,
            primitiveInstances.size() * sizeof(UiPrimitiveInstance))) {
        m_lastError = "Failed to allocate the D3D12 UI dynamic buffers.";
        return false;
    }

    FrameResources& frameResources = m_frameResources[frameSlot];
    if (!primitiveInstances.empty() && frameResources.primitiveInstanceBuffer != nullptr) {
        frameResources.primitiveInstanceBuffer->SetData(
            primitiveInstances.data(),
            primitiveInstances.size() * sizeof(UiPrimitiveInstance));
    }

    const auto renderArea = surface.GetRenderArea();
    UiConstants constants = {};
    constants.invViewportSize[0] =
        renderArea.width > 0 ? 1.0f / static_cast<float>(renderArea.width) : 0.0f;
    constants.invViewportSize[1] =
        renderArea.height > 0 ? 1.0f / static_cast<float>(renderArea.height) : 0.0f;
    m_constantSet->WriteConstant(0u, &constants, sizeof(constants));

    auto* d3d12CommandList =
        static_cast<D3D12CommandList*>(renderContext.commandList);
    auto* renderTarget = surface.GetColorAttachments()[0];
    RHICommandList* commandList = renderContext.commandList;
    commandList->SetRenderTargets(1u, &renderTarget, nullptr);
    commandList->SetViewport(Viewport{
        static_cast<float>(renderArea.x),
        static_cast<float>(renderArea.y),
        static_cast<float>(renderArea.width),
        static_cast<float>(renderArea.height),
        0.0f,
        1.0f
    });
    commandList->SetScissorRect(Rect{
        renderArea.x,
        renderArea.y,
        renderArea.x + renderArea.width,
        renderArea.y + renderArea.height
    });
    commandList->SetPrimitiveTopology(PrimitiveTopology::TriangleList);

    ::XCEngine::RHI::RHIDescriptorSet* constantSets[] = { m_constantSet };
    commandList->SetGraphicsDescriptorSets(0u, 1u, constantSets, m_pipelineLayout);

    auto* textureHeap = m_windowRenderer->GetTextureDescriptorAllocator().GetDescriptorHeap();
    auto* samplerHeap = static_cast<D3D12DescriptorHeap*>(m_samplerPool)->GetDescriptorHeap();
    ID3D12DescriptorHeap* descriptorHeaps[] = { textureHeap, samplerHeap };
    d3d12CommandList->SetDescriptorHeaps(2u, descriptorHeaps);

    const auto* pipelineLayout =
        static_cast<const ::XCEngine::RHI::D3D12PipelineLayout*>(m_pipelineLayout);
    const std::uint32_t textureRootIndex =
        pipelineLayout->GetShaderResourceTableRootParameterIndex(1u);
    const std::uint32_t samplerRootIndex =
        pipelineLayout->GetSamplerTableRootParameterIndex(2u);

    if (m_primitivePipelineState == nullptr ||
        m_quadVertexBufferView == nullptr ||
        m_quadIndexBufferView == nullptr ||
        frameResources.primitiveInstanceBufferView == nullptr) {
        m_lastError = "D3D12 UI primitive rendering resources are unavailable.";
        return false;
    }

    commandList->SetPipelineState(m_primitivePipelineState);
    const std::uint64_t primitiveVertexOffsets[] = { 0u, 0u };
    const std::uint32_t primitiveVertexStrides[] = {
        static_cast<std::uint32_t>(sizeof(UiQuadVertex)),
        static_cast<std::uint32_t>(sizeof(UiPrimitiveInstance))
    };
    ::XCEngine::RHI::RHIResourceView* primitiveVertexViews[] = {
        m_quadVertexBufferView,
        frameResources.primitiveInstanceBufferView
    };
    commandList->SetVertexBuffers(
        0u,
        2u,
        primitiveVertexViews,
        primitiveVertexOffsets,
        primitiveVertexStrides);
    commandList->SetIndexBuffer(m_quadIndexBufferView, 0u);

    for (const UiBatch& batch : batches) {
        commandList->SetScissorRect(batch.scissorRect);
        d3d12CommandList->SetGraphicsRootDescriptorTable(
            textureRootIndex,
            batch.textureHandle);
        d3d12CommandList->SetGraphicsRootDescriptorTable(
            samplerRootIndex,
            m_samplerGpuHandle);
        commandList->DrawIndexed(
            static_cast<std::uint32_t>(sizeof(kUnitQuadIndices) / sizeof(kUnitQuadIndices[0])),
            batch.instanceCount,
            0u,
            0,
            batch.firstInstance);
    }

    m_lastError.clear();
    return true;
}

} // namespace XCEngine::UI::Editor::Host