WebRenderTypes.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef GFX_WEBRENDERTYPES_H
#define GFX_WEBRENDERTYPES_H

#include "FrameMetrics.h"
#include "ImageTypes.h"
#include "mozilla/webrender/webrender_ffi.h"
#include "mozilla/Maybe.h"
#include "mozilla/gfx/Matrix.h"
#include "mozilla/gfx/Types.h"
#include "mozilla/gfx/Tools.h"
#include "mozilla/gfx/Rect.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Range.h"
#include "mozilla/Variant.h"
#include "Units.h"
#include "nsStyleConsts.h"

namespace mozilla {

namespace ipc {
class ByteBuf;
} // namespace ipc

namespace wr {

// Using uintptr_t in C++ code for "size" types seems weird, so let's use a
// better-sounding typedef. The name comes from the fact that we generally
// have to deal with uintptr_t because that's what rust's usize maps to.
typedef uintptr_t usize;

typedef wr::WrWindowId WindowId;
typedef wr::WrPipelineId PipelineId;
typedef wr::WrImageKey ImageKey;
typedef wr::WrFontKey FontKey;
typedef wr::WrFontInstanceKey FontInstanceKey;
typedef wr::WrEpoch Epoch;
typedef wr::WrExternalImageId ExternalImageId;
typedef wr::WrDebugFlags DebugFlags;

typedef mozilla::Maybe<mozilla::wr::IdNamespace> MaybeIdNamespace;
typedef mozilla::Maybe<mozilla::wr::WrImageMask> MaybeImageMask;
typedef Maybe<ExternalImageId> MaybeExternalImageId;

typedef Maybe<FontInstanceOptions> MaybeFontInstanceOptions;
typedef Maybe<FontInstancePlatformOptions> MaybeFontInstancePlatformOptions;

/* Generate a brand new window id and return it. */
WindowId NewWindowId();

inline DebugFlags NewDebugFlags(uint32_t aFlags) {
  DebugFlags flags;
  flags.mBits = aFlags;
  return flags;
}

inline Maybe<wr::ImageFormat>
SurfaceFormatToImageFormat(gfx::SurfaceFormat aFormat) {
  switch (aFormat) {
    case gfx::SurfaceFormat::R8G8B8X8:
    case gfx::SurfaceFormat::R8G8B8A8:
      // WebRender not support RGBA8 and RGBX8. Assert here.
      MOZ_ASSERT(false);
      return Nothing();
    case gfx::SurfaceFormat::B8G8R8X8:
      // TODO: WebRender will have a BGRA + opaque flag for this but does not
      // have it yet (cf. issue #732).
    case gfx::SurfaceFormat::B8G8R8A8:
      return Some(wr::ImageFormat::BGRA8);
    case gfx::SurfaceFormat::A8:
      return Some(wr::ImageFormat::R8);
    case gfx::SurfaceFormat::A16:
      return Some(wr::ImageFormat::R16);
    case gfx::SurfaceFormat::R8G8:
      return Some(wr::ImageFormat::RG8);
    case gfx::SurfaceFormat::UNKNOWN:
    default:
      return Nothing();
  }
}

inline gfx::SurfaceFormat
ImageFormatToSurfaceFormat(ImageFormat aFormat) {
  switch (aFormat) {
    case ImageFormat::BGRA8:
      return gfx::SurfaceFormat::B8G8R8A8;
    case ImageFormat::R8:
      return gfx::SurfaceFormat::A8;
    case ImageFormat::R16:
      return gfx::SurfaceFormat::A16;
    default:
      return gfx::SurfaceFormat::UNKNOWN;
  }
}

struct ImageDescriptor: public wr::WrImageDescriptor {
  // We need a default constructor for ipdl serialization.
  ImageDescriptor()
  {
    format = (ImageFormat)0;
    width = 0;
    height = 0;
    stride = 0;
    opacity = OpacityType::HasAlphaChannel;
  }

  ImageDescriptor(const gfx::IntSize& aSize, gfx::SurfaceFormat aFormat)
  {
    format = wr::SurfaceFormatToImageFormat(aFormat).value();
    width = aSize.width;
    height = aSize.height;
    stride = 0;
    opacity = gfx::IsOpaque(aFormat) ? OpacityType::Opaque
                                     : OpacityType::HasAlphaChannel;
  }

  ImageDescriptor(const gfx::IntSize& aSize, uint32_t aByteStride, gfx::SurfaceFormat aFormat)
  {
    format = wr::SurfaceFormatToImageFormat(aFormat).value();
    width = aSize.width;
    height = aSize.height;
    stride = aByteStride;
    opacity = gfx::IsOpaque(aFormat) ? OpacityType::Opaque
                                     : OpacityType::HasAlphaChannel;
  }

  ImageDescriptor(const gfx::IntSize& aSize,
                  uint32_t aByteStride,
                  gfx::SurfaceFormat aFormat,
                  OpacityType aOpacity)
  {
    format = wr::SurfaceFormatToImageFormat(aFormat).value();
    width = aSize.width;
    height = aSize.height;
    stride = aByteStride;
    opacity = aOpacity;
  }

};

// Whenever possible, use wr::WindowId instead of manipulating uint64_t.
inline uint64_t AsUint64(const WindowId& aId) {
  return static_cast<uint64_t>(aId.mHandle);
}

// Whenever possible, use wr::ImageKey instead of manipulating uint64_t.
inline uint64_t AsUint64(const ImageKey& aId) {
  return (static_cast<uint64_t>(aId.mNamespace.mHandle) << 32)
        + static_cast<uint64_t>(aId.mHandle);
}

inline ImageKey AsImageKey(const uint64_t& aId) {
  ImageKey imageKey;
  imageKey.mNamespace.mHandle = aId >> 32;
  imageKey.mHandle = aId;
  return imageKey;
}

// Whenever possible, use wr::FontKey instead of manipulating uint64_t.
inline uint64_t AsUint64(const FontKey& aId) {
  return (static_cast<uint64_t>(aId.mNamespace.mHandle) << 32)
        + static_cast<uint64_t>(aId.mHandle);
}

inline FontKey AsFontKey(const uint64_t& aId) {
  FontKey fontKey;
  fontKey.mNamespace.mHandle = aId >> 32;
  fontKey.mHandle = aId;
  return fontKey;
}

// Whenever possible, use wr::FontInstanceKey instead of manipulating uint64_t.
inline uint64_t AsUint64(const FontInstanceKey& aId) {
  return (static_cast<uint64_t>(aId.mNamespace.mHandle) << 32)
        + static_cast<uint64_t>(aId.mHandle);
}

inline FontInstanceKey AsFontInstanceKey(const uint64_t& aId) {
  FontInstanceKey instanceKey;
  instanceKey.mNamespace.mHandle = aId >> 32;
  instanceKey.mHandle = aId;
  return instanceKey;
}

// Whenever possible, use wr::PipelineId instead of manipulating uint64_t.
inline uint64_t AsUint64(const PipelineId& aId) {
  return (static_cast<uint64_t>(aId.mNamespace) << 32)
        + static_cast<uint64_t>(aId.mHandle);
}

inline PipelineId AsPipelineId(const uint64_t& aId) {
  PipelineId pipeline;
  pipeline.mNamespace = aId >> 32;
  pipeline.mHandle = aId;
  return pipeline;
}

inline mozilla::layers::LayersId AsLayersId(const PipelineId& aId) {
  return mozilla::layers::LayersId { AsUint64(aId) };
}

inline PipelineId AsPipelineId(const mozilla::layers::LayersId& aId) {
  return AsPipelineId(uint64_t(aId));
}

inline ImageRendering ToImageRendering(gfx::SamplingFilter aFilter)
{
  return aFilter == gfx::SamplingFilter::POINT ? ImageRendering::Pixelated
                                               : ImageRendering::Auto;
}

static inline FontRenderMode ToFontRenderMode(gfx::AntialiasMode aMode, bool aPermitSubpixelAA = true)
{
  switch (aMode) {
    case gfx::AntialiasMode::NONE:
      return FontRenderMode::Mono;
    case gfx::AntialiasMode::GRAY:
      return FontRenderMode::Alpha;
    case gfx::AntialiasMode::SUBPIXEL:
    default:
      return aPermitSubpixelAA ? FontRenderMode::Subpixel : FontRenderMode::Alpha;
  }
}

static inline MixBlendMode ToMixBlendMode(gfx::CompositionOp compositionOp)
{
  switch (compositionOp)
  {
      case gfx::CompositionOp::OP_MULTIPLY:
        return MixBlendMode::Multiply;
      case gfx::CompositionOp::OP_SCREEN:
        return MixBlendMode::Screen;
      case gfx::CompositionOp::OP_OVERLAY:
        return MixBlendMode::Overlay;
      case gfx::CompositionOp::OP_DARKEN:
        return MixBlendMode::Darken;
      case gfx::CompositionOp::OP_LIGHTEN:
        return MixBlendMode::Lighten;
      case gfx::CompositionOp::OP_COLOR_DODGE:
        return MixBlendMode::ColorDodge;
      case gfx::CompositionOp::OP_COLOR_BURN:
        return MixBlendMode::ColorBurn;
      case gfx::CompositionOp::OP_HARD_LIGHT:
        return MixBlendMode::HardLight;
      case gfx::CompositionOp::OP_SOFT_LIGHT:
        return MixBlendMode::SoftLight;
      case gfx::CompositionOp::OP_DIFFERENCE:
        return MixBlendMode::Difference;
      case gfx::CompositionOp::OP_EXCLUSION:
        return MixBlendMode::Exclusion;
      case gfx::CompositionOp::OP_HUE:
        return MixBlendMode::Hue;
      case gfx::CompositionOp::OP_SATURATION:
        return MixBlendMode::Saturation;
      case gfx::CompositionOp::OP_COLOR:
        return MixBlendMode::Color;
      case gfx::CompositionOp::OP_LUMINOSITY:
        return MixBlendMode::Luminosity;
      default:
        return MixBlendMode::Normal;
  }
}

static inline wr::ColorF ToColorF(const gfx::Color& color)
{
  wr::ColorF c;
  c.r = color.r;
  c.g = color.g;
  c.b = color.b;
  c.a = color.a;
  return c;
}

static inline wr::ColorU ToColorU(const gfx::Color& color)
{
  wr::ColorU c;
  c.r = uint8_t(color.r * 255.0f);
  c.g = uint8_t(color.g * 255.0f);
  c.b = uint8_t(color.b * 255.0f);
  c.a = uint8_t(color.a * 255.0f);
  return c;
}

static inline wr::LayoutPoint ToLayoutPoint(const mozilla::LayoutDevicePoint& point)
{
  wr::LayoutPoint p;
  p.x = point.x;
  p.y = point.y;
  return p;
}

static inline wr::LayoutPoint ToLayoutPoint(const mozilla::LayoutDeviceIntPoint& point)
{
  return ToLayoutPoint(LayoutDevicePoint(point));
}

static inline wr::LayoutPoint ToRoundedLayoutPoint(const mozilla::LayoutDevicePoint& point)
{
  mozilla::LayoutDevicePoint rounded = point;
  rounded.Round();
  return ToLayoutPoint(rounded);
}

static inline wr::WorldPoint ToWorldPoint(const mozilla::ScreenPoint& point)
{
  wr::WorldPoint p;
  p.x = point.x;
  p.y = point.y;
  return p;
}

static inline wr::LayoutVector2D ToLayoutVector2D(const mozilla::LayoutDevicePoint& point)
{
  wr::LayoutVector2D p;
  p.x = point.x;
  p.y = point.y;
  return p;
}

static inline wr::LayoutVector2D ToLayoutVector2D(const mozilla::LayoutDeviceIntPoint& point)
{
  return ToLayoutVector2D(LayoutDevicePoint(point));
}

static inline wr::LayoutRect ToLayoutRect(const mozilla::LayoutDeviceRect& rect)
{
  wr::LayoutRect r;
  r.origin.x = rect.X();
  r.origin.y = rect.Y();
  r.size.width = rect.Width();
  r.size.height = rect.Height();
  return r;
}

static inline wr::LayoutRect ToLayoutRect(const gfx::Rect& rect)
{
  wr::LayoutRect r;
  r.origin.x = rect.X();
  r.origin.y = rect.Y();
  r.size.width = rect.Width();
  r.size.height = rect.Height();
  return r;
}

static inline wr::DeviceUintRect ToDeviceUintRect(const mozilla::ImageIntRect& rect)
{
  wr::DeviceUintRect r;
  r.origin.x = rect.X();
  r.origin.y = rect.Y();
  r.size.width = rect.Width();
  r.size.height = rect.Height();
  return r;
}

static inline wr::LayoutRect ToLayoutRect(const mozilla::LayoutDeviceIntRect& rect)
{
  return ToLayoutRect(IntRectToRect(rect));
}

static inline wr::LayoutRect ToRoundedLayoutRect(const mozilla::LayoutDeviceRect& aRect) {
  auto rect = aRect;
  rect.Round();
  return wr::ToLayoutRect(rect);
}

static inline wr::LayoutRect IntersectLayoutRect(const wr::LayoutRect& aRect,
                                                 const wr::LayoutRect& aOther)
{
  wr::LayoutRect r;
  r.origin.x = std::max(aRect.origin.x, aOther.origin.x);
  r.origin.y = std::max(aRect.origin.y, aOther.origin.y);
  r.size.width = std::min(aRect.origin.x + aRect.size.width,
                          aOther.origin.x + aOther.size.width) - r.origin.x;
  r.size.height = std::min(aRect.origin.y + aRect.size.height,
                           aOther.origin.y + aOther.size.height) - r.origin.y;
  if (r.size.width < 0 || r.size.height < 0) {
    r.size.width = 0;
    r.size.height = 0;
  }
  return r;
}

static inline wr::LayoutSize ToLayoutSize(const mozilla::LayoutDeviceSize& size)
{
  wr::LayoutSize ls;
  ls.width = size.width;
  ls.height = size.height;
  return ls;
}

static inline wr::ComplexClipRegion ToComplexClipRegion(const gfx::RoundedRect& rect)
{
  wr::ComplexClipRegion ret;
  ret.rect               = ToLayoutRect(rect.rect);
  ret.radii.top_left     = ToLayoutSize(LayoutDeviceSize::FromUnknownSize(rect.corners.radii[mozilla::eCornerTopLeft]));
  ret.radii.top_right    = ToLayoutSize(LayoutDeviceSize::FromUnknownSize(rect.corners.radii[mozilla::eCornerTopRight]));
  ret.radii.bottom_left  = ToLayoutSize(LayoutDeviceSize::FromUnknownSize(rect.corners.radii[mozilla::eCornerBottomLeft]));
  ret.radii.bottom_right = ToLayoutSize(LayoutDeviceSize::FromUnknownSize(rect.corners.radii[mozilla::eCornerBottomRight]));
  ret.mode = wr::ClipMode::Clip;
  return ret;
}

static inline wr::ComplexClipRegion SimpleRadii(const wr::LayoutRect& aRect, float aRadii)
{
  wr::ComplexClipRegion ret;
  wr::LayoutSize radii { aRadii, aRadii };
  ret.rect = aRect;
  ret.radii.top_left = radii;
  ret.radii.top_right = radii;
  ret.radii.bottom_left = radii;
  ret.radii.bottom_right = radii;
  ret.mode = wr::ClipMode::Clip;
  return ret;
}

static inline wr::LayoutSize ToLayoutSize(const mozilla::LayoutDeviceIntSize& size)
{
  return ToLayoutSize(LayoutDeviceSize(size));
}

template<class S, class T>
static inline wr::LayoutTransform ToLayoutTransform(const gfx::Matrix4x4Typed<S, T>& m)
{
  wr::LayoutTransform transform;
  transform.m11 = m._11;
  transform.m12 = m._12;
  transform.m13 = m._13;
  transform.m14 = m._14;
  transform.m21 = m._21;
  transform.m22 = m._22;
  transform.m23 = m._23;
  transform.m24 = m._24;
  transform.m31 = m._31;
  transform.m32 = m._32;
  transform.m33 = m._33;
  transform.m34 = m._34;
  transform.m41 = m._41;
  transform.m42 = m._42;
  transform.m43 = m._43;
  transform.m44 = m._44;
  return transform;
}

static inline wr::BorderStyle ToBorderStyle(const uint8_t& style)
{
  switch (style) {
  case NS_STYLE_BORDER_STYLE_NONE:
    return wr::BorderStyle::None;
  case NS_STYLE_BORDER_STYLE_SOLID:
    return wr::BorderStyle::Solid;
  case NS_STYLE_BORDER_STYLE_DOUBLE:
    return wr::BorderStyle::Double;
  case NS_STYLE_BORDER_STYLE_DOTTED:
    return wr::BorderStyle::Dotted;
  case NS_STYLE_BORDER_STYLE_DASHED:
    return wr::BorderStyle::Dashed;
  case NS_STYLE_BORDER_STYLE_HIDDEN:
    return wr::BorderStyle::Hidden;
  case NS_STYLE_BORDER_STYLE_GROOVE:
    return wr::BorderStyle::Groove;
  case NS_STYLE_BORDER_STYLE_RIDGE:
    return wr::BorderStyle::Ridge;
  case NS_STYLE_BORDER_STYLE_INSET:
    return wr::BorderStyle::Inset;
  case NS_STYLE_BORDER_STYLE_OUTSET:
    return wr::BorderStyle::Outset;
  default:
    MOZ_ASSERT(false);
  }
  return wr::BorderStyle::None;
}

static inline wr::BorderSide ToBorderSide(const gfx::Color& color, const uint8_t& style)
{
  wr::BorderSide bs;
  bs.color = ToColorF(color);
  bs.style = ToBorderStyle(style);
  return bs;
}

static inline wr::BorderRadius EmptyBorderRadius()
{
  wr::BorderRadius br;
  PodZero(&br);
  return br;
}

static inline wr::BorderRadius ToBorderRadius(const mozilla::LayoutDeviceSize& topLeft,
                                              const mozilla::LayoutDeviceSize& topRight,
                                              const mozilla::LayoutDeviceSize& bottomLeft,
                                              const mozilla::LayoutDeviceSize& bottomRight)
{
  wr::BorderRadius br;
  br.top_left = ToLayoutSize(topLeft);
  br.top_right = ToLayoutSize(topRight);
  br.bottom_left = ToLayoutSize(bottomLeft);
  br.bottom_right = ToLayoutSize(bottomRight);
  return br;
}

static inline wr::LayoutSideOffsets ToBorderWidths(float top, float right, float bottom, float left)
{
  wr::LayoutSideOffsets bw;
  bw.top = top;
  bw.right = right;
  bw.bottom = bottom;
  bw.left = left;
  return bw;
}

static inline wr::SideOffsets2D<uint32_t> ToSideOffsets2D_u32(uint32_t top, uint32_t right, uint32_t bottom, uint32_t left)
{
  SideOffsets2D<uint32_t> offset;
  offset.top = top;
  offset.right = right;
  offset.bottom = bottom;
  offset.left = left;
  return offset;
}

static inline wr::SideOffsets2D<float> ToSideOffsets2D_f32(float top, float right, float bottom, float left)
{
  SideOffsets2D<float> offset;
  offset.top = top;
  offset.right = right;
  offset.bottom = bottom;
  offset.left = left;
  return offset;
}

static inline wr::RepeatMode ToRepeatMode(mozilla::StyleBorderImageRepeat repeatMode)
{
  switch (repeatMode) {
  case mozilla::StyleBorderImageRepeat::Stretch:
    return wr::RepeatMode::Stretch;
  case mozilla::StyleBorderImageRepeat::Repeat:
    return wr::RepeatMode::Repeat;
  case mozilla::StyleBorderImageRepeat::Round:
    return wr::RepeatMode::Round;
  case mozilla::StyleBorderImageRepeat::Space:
    return wr::RepeatMode::Space;
  default:
    MOZ_ASSERT(false);
  }

  return wr::RepeatMode::Stretch;
}

template<class S, class T>
static inline wr::WrTransformProperty ToWrTransformProperty(uint64_t id,
                                                            const gfx::Matrix4x4Typed<S, T>& transform)
{
  wr::WrTransformProperty prop;
  prop.id = id;
  prop.transform = ToLayoutTransform(transform);
  return prop;
}

static inline wr::WrOpacityProperty ToWrOpacityProperty(uint64_t id, const float opacity)
{
  wr::WrOpacityProperty prop;
  prop.id = id;
  prop.opacity = opacity;
  return prop;
}

// Whenever possible, use wr::ExternalImageId instead of manipulating uint64_t.
inline uint64_t AsUint64(const ExternalImageId& aId) {
  return static_cast<uint64_t>(aId.mHandle);
}

static inline ExternalImageId ToExternalImageId(uint64_t aID)
{
  ExternalImageId Id;
  Id.mHandle = aID;
  return Id;
}

static inline wr::WrExternalImage RawDataToWrExternalImage(const uint8_t* aBuff,
                                                           size_t size)
{
  return wr::WrExternalImage {
    wr::WrExternalImageType::RawData,
    0, 0.0f, 0.0f, 0.0f, 0.0f,
    aBuff, size
  };
}

static inline wr::WrExternalImage NativeTextureToWrExternalImage(uint32_t aHandle,
                                                                 float u0, float v0,
                                                                 float u1, float v1)
{
  return wr::WrExternalImage {
    wr::WrExternalImageType::NativeTexture,
    aHandle, u0, v0, u1, v1,
    nullptr, 0
  };
}

static inline wr::WrExternalImage InvalidToWrExternalImage()
{
  return wr::WrExternalImage {
    wr::WrExternalImageType::Invalid,
    0, 0, 0, 0, 0,
    nullptr, 0
  };
}

inline wr::ByteSlice RangeToByteSlice(mozilla::Range<uint8_t> aRange) {
  return wr::ByteSlice { aRange.begin().get(), aRange.length() };
}

inline mozilla::Range<const uint8_t> ByteSliceToRange(wr::ByteSlice aWrSlice) {
  return mozilla::Range<const uint8_t>(aWrSlice.buffer, aWrSlice.len);
}

inline mozilla::Range<uint8_t> MutByteSliceToRange(wr::MutByteSlice aWrSlice) {
  return mozilla::Range<uint8_t>(aWrSlice.buffer, aWrSlice.len);
}

void Assign_WrVecU8(wr::WrVecU8& aVec, mozilla::ipc::ByteBuf&& aOther);

template<typename T>
struct Vec;

template<>
struct Vec<uint8_t> {
  wr::WrVecU8 inner;
  Vec() {
    SetEmpty();
  }
  Vec(Vec&) = delete;
  Vec(Vec&& src) {
    inner = src.inner;
    src.SetEmpty();
  }

  explicit Vec(mozilla::ipc::ByteBuf&& aSrc) {
    Assign_WrVecU8(inner, std::move(aSrc));
  }

  Vec&
  operator=(Vec&& src) {
    inner = src.inner;
    src.SetEmpty();
    return *this;
  }

  wr::WrVecU8
  Extract() {
    wr::WrVecU8 ret = inner;
    SetEmpty();
    return ret;
  }

  void
  SetEmpty() {
    inner.data = (uint8_t*)1;
    inner.capacity = 0;
    inner.length = 0;
  }

  size_t Length() { return inner.length; }

  void PushBytes(Range<uint8_t> aBytes)
  {
    wr_vec_u8_push_bytes(&inner, RangeToByteSlice(aBytes));
  }

  ~Vec() {
    if (inner.data) {
      wr_vec_u8_free(inner);
    }
  }
};

struct ByteBuffer
{
  ByteBuffer(size_t aLength, uint8_t* aData)
    : mLength(aLength)
    , mData(aData)
    , mOwned(false)
  {}

  // XXX: this is a bit of hack that assumes
  // the allocators are the same
  explicit ByteBuffer(VecU8&& vec)
  {
    if (vec.inner.capacity) {
      mLength = vec.inner.length;
      mData = vec.inner.data;
      vec.inner.data = nullptr;
      vec.inner.capacity = 0;
      mOwned = true;
    } else {
      mOwned = false;
      mData = nullptr;
      mLength = 0;
    }
  }

  ByteBuffer(ByteBuffer&& aFrom)
  : mLength(aFrom.mLength)
  , mData(aFrom.mData)
  , mOwned(aFrom.mOwned)
  {
    aFrom.mLength = 0;
    aFrom.mData = nullptr;
    aFrom.mOwned = false;
  }

  ByteBuffer(ByteBuffer& aFrom)
  : mLength(aFrom.mLength)
  , mData(aFrom.mData)
  , mOwned(aFrom.mOwned)
  {
    aFrom.mLength = 0;
    aFrom.mData = nullptr;
    aFrom.mOwned = false;
  }


  ByteBuffer()
    : mLength(0)
    , mData(nullptr)
    , mOwned(false)
  {}

  bool
  Allocate(size_t aLength)
  {
    MOZ_ASSERT(mData == nullptr);
    mData = (uint8_t*)malloc(aLength);
    if (!mData) {
      return false;
    }
    mLength = aLength;
    mOwned = true;
    return true;
  }

  ~ByteBuffer()
  {
    if (mData && mOwned) {
      free(mData);
    }
  }

  const Range<uint8_t> AsSlice() const { return Range<uint8_t>(mData, mLength); }

  Range<uint8_t> AsSlice() { return Range<uint8_t>(mData, mLength); }

  bool operator==(const ByteBuffer& other) const {
    return mLength == other.mLength &&
          !(memcmp(mData, other.mData, mLength));
  }

  size_t mLength;
  uint8_t* mData;
  bool mOwned;
};

struct BuiltDisplayList {
  wr::VecU8 dl;
  wr::BuiltDisplayListDescriptor dl_desc;
};

static inline wr::WrFilterOpType ToWrFilterOpType(uint32_t type) {
  switch (type) {
    case NS_STYLE_FILTER_BLUR:
      return wr::WrFilterOpType::Blur;
    case NS_STYLE_FILTER_BRIGHTNESS:
      return wr::WrFilterOpType::Brightness;
    case NS_STYLE_FILTER_CONTRAST:
      return wr::WrFilterOpType::Contrast;
    case NS_STYLE_FILTER_GRAYSCALE:
      return wr::WrFilterOpType::Grayscale;
    case NS_STYLE_FILTER_HUE_ROTATE:
      return wr::WrFilterOpType::HueRotate;
    case NS_STYLE_FILTER_INVERT:
      return wr::WrFilterOpType::Invert;
    case NS_STYLE_FILTER_OPACITY:
      return wr::WrFilterOpType::Opacity;
    case NS_STYLE_FILTER_SATURATE:
      return wr::WrFilterOpType::Saturate;
    case NS_STYLE_FILTER_SEPIA:
      return wr::WrFilterOpType::Sepia;
    case NS_STYLE_FILTER_DROP_SHADOW:
      return wr::WrFilterOpType::DropShadow;
  }
  MOZ_ASSERT_UNREACHABLE("Tried to convert unknown filter type.");
  return wr::WrFilterOpType::Grayscale;
}

// Corresponds to an "internal" webrender clip id. That is, a
// ClipId::Clip(x,pipeline_id) maps to a WrClipId{x}. We use a struct wrapper
// instead of a typedef so that this is a distinct type from ids generated
// by scroll and position:sticky nodes and the compiler will catch accidental
// conversions between them.
struct WrClipId {
  size_t id;

  bool operator==(const WrClipId& other) const {
    return id == other.id;
  }

  bool operator!=(const WrClipId& other) const {
    return !(*this == other);
  }

  static WrClipId RootScrollNode();

  // Helper struct that allows this class to be used as a key in
  // std::unordered_map like so:
  //   std::unordered_map<WrClipId, ValueType, WrClipId::HashFn> myMap;
  struct HashFn {
    std::size_t operator()(const WrClipId& aKey) const
    {
      return std::hash<size_t>{}(aKey.id);
    }
  };
};

// Corresponds to a clip id for a clip chain in webrender. Similar to
// WrClipId but a separate struct so we don't get them mixed up in C++.
struct WrClipChainId {
  uint64_t id;

  bool operator==(const WrClipChainId& other) const {
    return id == other.id;
  }
};

enum class WebRenderError : int8_t {
  INITIALIZE = 0,
  MAKE_CURRENT,
  RENDER,

  Sentinel /* this must be last for serialization purposes. */
};

static inline wr::WrYuvColorSpace ToWrYuvColorSpace(YUVColorSpace aYUVColorSpace) {
  switch (aYUVColorSpace) {
    case YUVColorSpace::BT601:
      return wr::WrYuvColorSpace::Rec601;
    case YUVColorSpace::BT709:
      return wr::WrYuvColorSpace::Rec709;
    default:
      MOZ_ASSERT_UNREACHABLE("Tried to convert invalid YUVColorSpace.");
  }
  return wr::WrYuvColorSpace::Rec601;
}

static inline wr::WrColorDepth ToWrColorDepth(gfx::ColorDepth aColorDepth) {
  switch (aColorDepth) {
    case gfx::ColorDepth::COLOR_8:
      return wr::WrColorDepth::Color8;
    case gfx::ColorDepth::COLOR_10:
      return wr::WrColorDepth::Color10;
    case gfx::ColorDepth::COLOR_12:
      return wr::WrColorDepth::Color12;
    case gfx::ColorDepth::COLOR_16:
      return wr::WrColorDepth::Color16;
    default:
      MOZ_ASSERT_UNREACHABLE("Tried to convert invalid color depth value.");
  }
  return wr::WrColorDepth::Color8;
}

static inline wr::SyntheticItalics DegreesToSyntheticItalics(float aDegrees) {
  wr::SyntheticItalics synthetic_italics;
  synthetic_italics.angle = int16_t(std::min(std::max(aDegrees, -89.0f), 89.0f) * 256.0f);
  return synthetic_italics;
}

} // namespace wr
} // namespace mozilla

#endif /* GFX_WEBRENDERTYPES_H */