// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <type_traits>

#include "flutter/flow/display_list.h"
#include "flutter/flow/display_list_canvas.h"
#include "flutter/flow/display_list_utils.h"

#include "third_party/skia/include/core/SkPath.h"
#include "third_party/skia/include/core/SkRSXform.h"
#include "third_party/skia/include/core/SkTextBlob.h"

namespace flutter {

const SkSamplingOptions DisplayList::NearestSampling =
    SkSamplingOptions(SkFilterMode::kNearest, SkMipmapMode::kNone);
const SkSamplingOptions DisplayList::LinearSampling =
    SkSamplingOptions(SkFilterMode::kLinear, SkMipmapMode::kNone);
const SkSamplingOptions DisplayList::MipmapSampling =
    SkSamplingOptions(SkFilterMode::kLinear, SkMipmapMode::kLinear);
const SkSamplingOptions DisplayList::CubicSampling =
    SkSamplingOptions(SkCubicResampler{1 / 3.0f, 1 / 3.0f});

// Most Ops can be bulk compared using memcmp because they contain
// only numeric values or constructs that are constructed from numeric
// values.
//
// Some contain sk_sp<> references which can also be bulk compared
// to see if they are pointing to the same reference. (Note that
// two sk_sp<> that refer to the same object are themselves ==.)
//
// Only a DLOp that wants to do a deep compare needs to override the
// DLOp::equals() method and return a value of kEqual or kNotEqual.
enum class DisplayListCompare {
  // The Op is deferring comparisons to a bulk memcmp performed lazily
  // across all bulk-comparable ops.
  kUseBulkCompare,

  // The Op provided a specific equals method that spotted a difference
  kNotEqual,

  // The Op provided a specific equals method that saw no differences
  kEqual,
};

#pragma pack(push, DLOp_Alignment, 8)

// Assuming a 64-bit platform (most of our platforms at this time?)
// the following comments are a "worst case" assessment of how well
// these structures pack into memory. They may be packed more tightly
// on some of the 32-bit platforms that we see in older phones.
//
// Struct allocation in the DL memory is aligned to a void* boundary
// which means that the minimum (aligned) struct size will be 8 bytes.
// The DLOp base uses 4 bytes so each Op-specific struct gets 4 bytes
// of data for "free" and works best when it packs well into an 8-byte
// aligned size.
struct DLOp {
  DisplayListOpType type : 8;
  uint32_t size : 24;

  DisplayListCompare equals(const DLOp* other) const {
    return DisplayListCompare::kUseBulkCompare;
  }
};

// 4 byte header + 4 byte payload packs into minimum 8 bytes
#define DEFINE_SET_BOOL_OP(name)                             \
  struct Set##name##Op final : DLOp {                        \
    static const auto kType = DisplayListOpType::kSet##name; \
                                                             \
    explicit Set##name##Op(bool value) : value(value) {}     \
                                                             \
    const bool value;                                        \
                                                             \
    void dispatch(Dispatcher& dispatcher) const {            \
      dispatcher.set##name(value);                           \
    }                                                        \
  };
DEFINE_SET_BOOL_OP(AntiAlias)
DEFINE_SET_BOOL_OP(Dither)
DEFINE_SET_BOOL_OP(InvertColors)
#undef DEFINE_SET_BOOL_OP

// 4 byte header + 4 byte payload packs into minimum 8 bytes
#define DEFINE_SET_ENUM_OP(name)                                        \
  struct SetStroke##name##Op final : DLOp {                             \
    static const auto kType = DisplayListOpType::kSetStroke##name;      \
                                                                        \
    explicit SetStroke##name##Op(SkPaint::name value) : value(value) {} \
                                                                        \
    const SkPaint::name value;                                          \
                                                                        \
    void dispatch(Dispatcher& dispatcher) const {                       \
      dispatcher.setStroke##name(value);                                \
    }                                                                   \
  };
DEFINE_SET_ENUM_OP(Cap)
DEFINE_SET_ENUM_OP(Join)
#undef DEFINE_SET_ENUM_OP

// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct SetStyleOp final : DLOp {
  static const auto kType = DisplayListOpType::kSetStyle;

  explicit SetStyleOp(SkPaint::Style style) : style(style) {}

  const SkPaint::Style style;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.setStyle(style); }
};
// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct SetStrokeWidthOp final : DLOp {
  static const auto kType = DisplayListOpType::kSetStrokeWidth;

  explicit SetStrokeWidthOp(SkScalar width) : width(width) {}

  const SkScalar width;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.setStrokeWidth(width);
  }
};
// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct SetStrokeMiterOp final : DLOp {
  static const auto kType = DisplayListOpType::kSetStrokeMiter;

  explicit SetStrokeMiterOp(SkScalar limit) : limit(limit) {}

  const SkScalar limit;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.setStrokeMiter(limit);
  }
};

// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct SetColorOp final : DLOp {
  static const auto kType = DisplayListOpType::kSetColor;

  explicit SetColorOp(SkColor color) : color(color) {}

  const SkColor color;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.setColor(color); }
};
// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct SetBlendModeOp final : DLOp {
  static const auto kType = DisplayListOpType::kSetBlendMode;

  explicit SetBlendModeOp(SkBlendMode mode) : mode(mode) {}

  const SkBlendMode mode;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.setBlendMode(mode); }
};

// Clear: 4 byte header + unused 4 byte payload uses 8 bytes
//        (4 bytes unused)
// Set: 4 byte header + an sk_sp (ptr) uses 16 bytes due to the
//      alignment of the ptr.
//      (4 bytes unused)
#define DEFINE_SET_CLEAR_SKREF_OP(name, field)                                 \
  struct Clear##name##Op final : DLOp {                                        \
    static const auto kType = DisplayListOpType::kClear##name;                 \
                                                                               \
    Clear##name##Op() {}                                                       \
                                                                               \
    void dispatch(Dispatcher& dispatcher) const {                              \
      dispatcher.set##name(nullptr);                                           \
    }                                                                          \
  };                                                                           \
  struct Set##name##Op final : DLOp {                                          \
    static const auto kType = DisplayListOpType::kSet##name;                   \
                                                                               \
    explicit Set##name##Op(sk_sp<Sk##name> field) : field(std::move(field)) {} \
                                                                               \
    sk_sp<Sk##name> field;                                                     \
                                                                               \
    void dispatch(Dispatcher& dispatcher) const {                              \
      dispatcher.set##name(field);                                             \
    }                                                                          \
  };
DEFINE_SET_CLEAR_SKREF_OP(Blender, blender)
DEFINE_SET_CLEAR_SKREF_OP(Shader, shader)
DEFINE_SET_CLEAR_SKREF_OP(ImageFilter, filter)
DEFINE_SET_CLEAR_SKREF_OP(ColorFilter, filter)
DEFINE_SET_CLEAR_SKREF_OP(MaskFilter, filter)
DEFINE_SET_CLEAR_SKREF_OP(PathEffect, effect)
#undef DEFINE_SET_CLEAR_SKREF_OP

// 4 byte header + 4 byte payload packs into minimum 8 bytes
// Note that the "blur style" is packed into the OpType to prevent
// needing an additional 8 bytes for a 4-value enum.
#define DEFINE_MASK_BLUR_FILTER_OP(name, style)                            \
  struct SetMaskBlurFilter##name##Op final : DLOp {                        \
    static const auto kType = DisplayListOpType::kSetMaskBlurFilter##name; \
                                                                           \
    explicit SetMaskBlurFilter##name##Op(SkScalar sigma) : sigma(sigma) {} \
                                                                           \
    SkScalar sigma;                                                        \
                                                                           \
    void dispatch(Dispatcher& dispatcher) const {                          \
      dispatcher.setMaskBlurFilter(style, sigma);                          \
    }                                                                      \
  };
DEFINE_MASK_BLUR_FILTER_OP(Normal, kNormal_SkBlurStyle)
DEFINE_MASK_BLUR_FILTER_OP(Solid, kSolid_SkBlurStyle)
DEFINE_MASK_BLUR_FILTER_OP(Inner, kInner_SkBlurStyle)
DEFINE_MASK_BLUR_FILTER_OP(Outer, kOuter_SkBlurStyle)
#undef DEFINE_MASK_BLUR_FILTER_OP

// 4 byte header + no payload uses minimum 8 bytes (4 bytes unused)
struct SaveOp final : DLOp {
  static const auto kType = DisplayListOpType::kSave;

  SaveOp() {}

  void dispatch(Dispatcher& dispatcher) const { dispatcher.save(); }
};
// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct SaveLayerOp final : DLOp {
  static const auto kType = DisplayListOpType::kSaveLayer;

  explicit SaveLayerOp(bool with_paint) : with_paint(with_paint) {}

  bool with_paint;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.saveLayer(nullptr, with_paint);
  }
};
// 4 byte header + 20 byte payload packs evenly into 24 bytes
struct SaveLayerBoundsOp final : DLOp {
  static const auto kType = DisplayListOpType::kSaveLayerBounds;

  SaveLayerBoundsOp(SkRect rect, bool with_paint)
      : with_paint(with_paint), rect(rect) {}

  bool with_paint;
  const SkRect rect;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.saveLayer(&rect, with_paint);
  }
};
// 4 byte header + no payload uses minimum 8 bytes (4 bytes unused)
struct RestoreOp final : DLOp {
  static const auto kType = DisplayListOpType::kRestore;

  RestoreOp() {}

  void dispatch(Dispatcher& dispatcher) const { dispatcher.restore(); }
};

// 4 byte header + 8 byte payload uses 12 bytes but is rounded up to 16 bytes
// (4 bytes unused)
struct TranslateOp final : DLOp {
  static const auto kType = DisplayListOpType::kTranslate;

  TranslateOp(SkScalar tx, SkScalar ty) : tx(tx), ty(ty) {}

  const SkScalar tx;
  const SkScalar ty;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.translate(tx, ty); }
};
// 4 byte header + 8 byte payload uses 12 bytes but is rounded up to 16 bytes
// (4 bytes unused)
struct ScaleOp final : DLOp {
  static const auto kType = DisplayListOpType::kScale;

  ScaleOp(SkScalar sx, SkScalar sy) : sx(sx), sy(sy) {}

  const SkScalar sx;
  const SkScalar sy;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.scale(sx, sy); }
};
// 4 byte header + 4 byte payload packs into minimum 8 bytes
struct RotateOp final : DLOp {
  static const auto kType = DisplayListOpType::kRotate;

  explicit RotateOp(SkScalar degrees) : degrees(degrees) {}

  const SkScalar degrees;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.rotate(degrees); }
};
// 4 byte header + 8 byte payload uses 12 bytes but is rounded up to 16 bytes
// (4 bytes unused)
struct SkewOp final : DLOp {
  static const auto kType = DisplayListOpType::kSkew;

  SkewOp(SkScalar sx, SkScalar sy) : sx(sx), sy(sy) {}

  const SkScalar sx;
  const SkScalar sy;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.skew(sx, sy); }
};
// 4 byte header + 24 byte payload uses 28 bytes but is rounded up to 32 bytes
// (4 bytes unused)
struct Transform2DAffineOp final : DLOp {
  static const auto kType = DisplayListOpType::kTransform2DAffine;

  // clang-format off
  Transform2DAffineOp(SkScalar mxx, SkScalar mxy, SkScalar mxt,
                      SkScalar myx, SkScalar myy, SkScalar myt)
      : mxx(mxx), mxy(mxy), mxt(mxt), myx(myx), myy(myy), myt(myt) {}
  // clang-format on

  const SkScalar mxx, mxy, mxt;
  const SkScalar myx, myy, myt;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.transform2DAffine(mxx, mxy, mxt,  //
                                 myx, myy, myt);
  }
};
// 4 byte header + 64 byte payload uses 68 bytes which is rounded up to 72 bytes
// (4 bytes unused)
struct TransformFullPerspectiveOp final : DLOp {
  static const auto kType = DisplayListOpType::kTransformFullPerspective;

  // clang-format off
  TransformFullPerspectiveOp(
      SkScalar mxx, SkScalar mxy, SkScalar mxz, SkScalar mxt,
      SkScalar myx, SkScalar myy, SkScalar myz, SkScalar myt,
      SkScalar mzx, SkScalar mzy, SkScalar mzz, SkScalar mzt,
      SkScalar mwx, SkScalar mwy, SkScalar mwz, SkScalar mwt)
      : mxx(mxx), mxy(mxy), mxz(mxz), mxt(mxt),
        myx(myx), myy(myy), myz(myz), myt(myt),
        mzx(mzx), mzy(mzy), mzz(mzz), mzt(mzt),
        mwx(mwx), mwy(mwy), mwz(mwz), mwt(mwt) {}
  // clang-format on

  const SkScalar mxx, mxy, mxz, mxt;
  const SkScalar myx, myy, myz, myt;
  const SkScalar mzx, mzy, mzz, mzt;
  const SkScalar mwx, mwy, mwz, mwt;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.transformFullPerspective(mxx, mxy, mxz, mxt,  //
                                        myx, myy, myz, myt,  //
                                        mzx, mzy, mzz, mzt,  //
                                        mwx, mwy, mwz, mwt);
  }
};

// 4 byte header + 4 byte common payload packs into minimum 8 bytes
// SkRect is 16 more bytes, which packs efficiently into 24 bytes total
// SkRRect is 52 more bytes, which rounds up to 56 bytes (4 bytes unused)
//         which packs into 64 bytes total
// SkPath is 16 more bytes, which packs efficiently into 24 bytes total
//
// We could pack the clip_op and the bool both into the free 4 bytes after
// the header, but the Windows compiler keeps wanting to expand that
// packing into more bytes than needed (even when they are declared as
// packed bit fields!)
#define DEFINE_CLIP_SHAPE_OP(shapetype, clipop)                            \
  struct Clip##clipop##shapetype##Op final : DLOp {                        \
    static const auto kType = DisplayListOpType::kClip##clipop##shapetype; \
                                                                           \
    Clip##clipop##shapetype##Op(Sk##shapetype shape, bool is_aa)           \
        : is_aa(is_aa), shape(shape) {}                                    \
                                                                           \
    const bool is_aa;                                                      \
    const Sk##shapetype shape;                                             \
                                                                           \
    void dispatch(Dispatcher& dispatcher) const {                          \
      dispatcher.clip##shapetype(shape, SkClipOp::k##clipop, is_aa);       \
    }                                                                      \
  };
DEFINE_CLIP_SHAPE_OP(Rect, Intersect)
DEFINE_CLIP_SHAPE_OP(RRect, Intersect)
DEFINE_CLIP_SHAPE_OP(Rect, Difference)
DEFINE_CLIP_SHAPE_OP(RRect, Difference)
#undef DEFINE_CLIP_SHAPE_OP

#define DEFINE_CLIP_PATH_OP(clipop)                                      \
  struct Clip##clipop##PathOp final : DLOp {                             \
    static const auto kType = DisplayListOpType::kClip##clipop##Path;    \
                                                                         \
    Clip##clipop##PathOp(SkPath path, bool is_aa)                        \
        : is_aa(is_aa), path(path) {}                                    \
                                                                         \
    const bool is_aa;                                                    \
    const SkPath path;                                                   \
                                                                         \
    void dispatch(Dispatcher& dispatcher) const {                        \
      dispatcher.clipPath(path, SkClipOp::k##clipop, is_aa);             \
    }                                                                    \
                                                                         \
    DisplayListCompare equals(const Clip##clipop##PathOp* other) const { \
      return is_aa == other->is_aa && path == other->path                \
                 ? DisplayListCompare::kEqual                            \
                 : DisplayListCompare::kNotEqual;                        \
    }                                                                    \
  };
DEFINE_CLIP_PATH_OP(Intersect)
DEFINE_CLIP_PATH_OP(Difference)
#undef DEFINE_CLIP_PATH_OP

// 4 byte header + no payload uses minimum 8 bytes (4 bytes unused)
struct DrawPaintOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawPaint;

  DrawPaintOp() {}

  void dispatch(Dispatcher& dispatcher) const { dispatcher.drawPaint(); }
};
// 4 byte header + 8 byte payload uses 12 bytes but is rounded up to 16 bytes
// (4 bytes unused)
struct DrawColorOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawColor;

  DrawColorOp(SkColor color, SkBlendMode mode) : color(color), mode(mode) {}

  const SkColor color;
  const SkBlendMode mode;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawColor(color, mode);
  }
};

// The common data is a 4 byte header with an unused 4 bytes
// SkRect is 16 more bytes, using 20 bytes which rounds up to 24 bytes total
//        (4 bytes unused)
// SkOval is same as SkRect
// SkRRect is 52 more bytes, which packs efficiently into 56 bytes total
#define DEFINE_DRAW_1ARG_OP(op_name, arg_type, arg_name)                  \
  struct Draw##op_name##Op final : DLOp {                                 \
    static const auto kType = DisplayListOpType::kDraw##op_name;          \
                                                                          \
    explicit Draw##op_name##Op(arg_type arg_name) : arg_name(arg_name) {} \
                                                                          \
    const arg_type arg_name;                                              \
                                                                          \
    void dispatch(Dispatcher& dispatcher) const {                         \
      dispatcher.draw##op_name(arg_name);                                 \
    }                                                                     \
  };
DEFINE_DRAW_1ARG_OP(Rect, SkRect, rect)
DEFINE_DRAW_1ARG_OP(Oval, SkRect, oval)
DEFINE_DRAW_1ARG_OP(RRect, SkRRect, rrect)
#undef DEFINE_DRAW_1ARG_OP

// 4 byte header + 16 byte payload uses 20 bytes but is rounded up to 24 bytes
// (4 bytes unused)
struct DrawPathOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawPath;

  explicit DrawPathOp(SkPath path) : path(path) {}

  const SkPath path;

  void dispatch(Dispatcher& dispatcher) const { dispatcher.drawPath(path); }

  DisplayListCompare equals(const DrawPathOp* other) const {
    return path == other->path ? DisplayListCompare::kEqual
                               : DisplayListCompare::kNotEqual;
  }
};

// The common data is a 4 byte header with an unused 4 bytes
// 2 x SkPoint is 16 more bytes, using 20 bytes rounding up to 24 bytes total
//             (4 bytes unused)
// SkPoint + SkScalar is 12 more bytes, packing efficiently into 16 bytes total
// 2 x SkRRect is 104 more bytes, using 108 and rounding up to 112 bytes total
//             (4 bytes unused)
#define DEFINE_DRAW_2ARG_OP(op_name, type1, name1, type2, name2) \
  struct Draw##op_name##Op final : DLOp {                        \
    static const auto kType = DisplayListOpType::kDraw##op_name; \
                                                                 \
    Draw##op_name##Op(type1 name1, type2 name2)                  \
        : name1(name1), name2(name2) {}                          \
                                                                 \
    const type1 name1;                                           \
    const type2 name2;                                           \
                                                                 \
    void dispatch(Dispatcher& dispatcher) const {                \
      dispatcher.draw##op_name(name1, name2);                    \
    }                                                            \
  };
DEFINE_DRAW_2ARG_OP(Line, SkPoint, p0, SkPoint, p1)
DEFINE_DRAW_2ARG_OP(Circle, SkPoint, center, SkScalar, radius)
DEFINE_DRAW_2ARG_OP(DRRect, SkRRect, outer, SkRRect, inner)
#undef DEFINE_DRAW_2ARG_OP

// 4 byte header + 28 byte payload packs efficiently into 32 bytes
struct DrawArcOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawArc;

  DrawArcOp(SkRect bounds, SkScalar start, SkScalar sweep, bool center)
      : bounds(bounds), start(start), sweep(sweep), center(center) {}

  const SkRect bounds;
  const SkScalar start;
  const SkScalar sweep;
  const bool center;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawArc(bounds, start, sweep, center);
  }
};

// 4 byte header + 4 byte fixed payload packs efficiently into 8 bytes
// But then there is a list of points following the structure which
// is guaranteed to be a multiple of 8 bytes (SkPoint is 8 bytes)
// so this op will always pack efficiently
// The point type is packed into 3 different OpTypes to avoid expanding
// the fixed payload beyond the 8 bytes
#define DEFINE_DRAW_POINTS_OP(name, mode)                              \
  struct Draw##name##Op final : DLOp {                                 \
    static const auto kType = DisplayListOpType::kDraw##name;          \
                                                                       \
    explicit Draw##name##Op(uint32_t count) : count(count) {}          \
                                                                       \
    const uint32_t count;                                              \
                                                                       \
    void dispatch(Dispatcher& dispatcher) const {                      \
      const SkPoint* pts = reinterpret_cast<const SkPoint*>(this + 1); \
      dispatcher.drawPoints(SkCanvas::PointMode::mode, count, pts);    \
    }                                                                  \
  };
DEFINE_DRAW_POINTS_OP(Points, kPoints_PointMode);
DEFINE_DRAW_POINTS_OP(Lines, kLines_PointMode);
DEFINE_DRAW_POINTS_OP(Polygon, kPolygon_PointMode);
#undef DEFINE_DRAW_POINTS_OP

// 4 byte header + 12 byte payload packs efficiently into 16 bytes
struct DrawVerticesOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawVertices;

  DrawVerticesOp(sk_sp<SkVertices> vertices, SkBlendMode mode)
      : mode(mode), vertices(std::move(vertices)) {}

  const SkBlendMode mode;
  const sk_sp<SkVertices> vertices;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawVertices(vertices, mode);
  }
};

// 4 byte header + 36 byte payload packs efficiently into 40 bytes
#define DEFINE_DRAW_IMAGE_OP(name, with_attributes)                    \
  struct name##Op final : DLOp {                                       \
    static const auto kType = DisplayListOpType::k##name;              \
                                                                       \
    name##Op(const sk_sp<SkImage> image,                               \
             const SkPoint& point,                                     \
             const SkSamplingOptions& sampling)                        \
        : point(point), sampling(sampling), image(std::move(image)) {} \
                                                                       \
    const SkPoint point;                                               \
    const SkSamplingOptions sampling;                                  \
    const sk_sp<SkImage> image;                                        \
                                                                       \
    void dispatch(Dispatcher& dispatcher) const {                      \
      dispatcher.drawImage(image, point, sampling, with_attributes);   \
    }                                                                  \
  };
DEFINE_DRAW_IMAGE_OP(DrawImage, false)
DEFINE_DRAW_IMAGE_OP(DrawImageWithAttr, true)
#undef DEFINE_DRAW_IMAGE_OP

// 4 byte header + 68 byte payload packs efficiently into 72 bytes
struct DrawImageRectOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawImageRect;

  DrawImageRectOp(const sk_sp<SkImage> image,
                  const SkRect& src,
                  const SkRect& dst,
                  const SkSamplingOptions& sampling,
                  bool render_with_attributes,
                  SkCanvas::SrcRectConstraint constraint)
      : src(src),
        dst(dst),
        sampling(sampling),
        render_with_attributes(render_with_attributes),
        constraint(constraint),
        image(std::move(image)) {}

  const SkRect src;
  const SkRect dst;
  const SkSamplingOptions sampling;
  const bool render_with_attributes;
  const SkCanvas::SrcRectConstraint constraint;
  const sk_sp<SkImage> image;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawImageRect(image, src, dst, sampling, render_with_attributes,
                             constraint);
  }
};

// 4 byte header + 44 byte payload packs efficiently into 48 bytes
#define DEFINE_DRAW_IMAGE_NINE_OP(name, render_with_attributes)                \
  struct name##Op final : DLOp {                                               \
    static const auto kType = DisplayListOpType::k##name;                      \
                                                                               \
    name##Op(const sk_sp<SkImage> image,                                       \
             const SkIRect& center,                                            \
             const SkRect& dst,                                                \
             SkFilterMode filter)                                              \
        : center(center), dst(dst), filter(filter), image(std::move(image)) {} \
                                                                               \
    const SkIRect center;                                                      \
    const SkRect dst;                                                          \
    const SkFilterMode filter;                                                 \
    const sk_sp<SkImage> image;                                                \
                                                                               \
    void dispatch(Dispatcher& dispatcher) const {                              \
      dispatcher.drawImageNine(image, center, dst, filter,                     \
                               render_with_attributes);                        \
    }                                                                          \
  };
DEFINE_DRAW_IMAGE_NINE_OP(DrawImageNine, false)
DEFINE_DRAW_IMAGE_NINE_OP(DrawImageNineWithAttr, true)
#undef DEFINE_DRAW_IMAGE_NINE_OP

// 4 byte header + 60 byte payload packs evenly into 64 bytes
struct DrawImageLatticeOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawImageLattice;

  DrawImageLatticeOp(const sk_sp<SkImage> image,
                     int x_count,
                     int y_count,
                     int cell_count,
                     const SkIRect& src,
                     const SkRect& dst,
                     SkFilterMode filter,
                     bool with_paint)
      : with_paint(with_paint),
        x_count(x_count),
        y_count(y_count),
        cell_count(cell_count),
        filter(filter),
        src(src),
        dst(dst),
        image(std::move(image)) {}

  const bool with_paint;
  const int x_count;
  const int y_count;
  const int cell_count;
  const SkFilterMode filter;
  const SkIRect src;
  const SkRect dst;
  const sk_sp<SkImage> image;

  void dispatch(Dispatcher& dispatcher) const {
    const int* xDivs = reinterpret_cast<const int*>(this + 1);
    const int* yDivs = reinterpret_cast<const int*>(xDivs + x_count);
    const SkColor* colors =
        (cell_count == 0) ? nullptr
                          : reinterpret_cast<const SkColor*>(yDivs + y_count);
    const SkCanvas::Lattice::RectType* types =
        (cell_count == 0)
            ? nullptr
            : reinterpret_cast<const SkCanvas::Lattice::RectType*>(colors +
                                                                   cell_count);
    dispatcher.drawImageLattice(
        image, {xDivs, yDivs, types, x_count, y_count, &src, colors}, dst,
        filter, with_paint);
  }
};

// 4 byte header + 36 byte common payload packs efficiently into 40 bytes
// Each of these is then followed by a number of lists.
// SkRSXform list is a multiple of 16 bytes so it is always packed well
// SkRect list is also a multiple of 16 bytes so it also packs well
// SkColor list only packs well if the count is even, otherwise there
// can be 4 unusued bytes at the end.
struct DrawAtlasBaseOp : DLOp {
  DrawAtlasBaseOp(const sk_sp<SkImage> atlas,
                  int count,
                  SkBlendMode mode,
                  const SkSamplingOptions& sampling,
                  bool has_colors,
                  bool render_with_attributes)
      : count(count),
        mode_index(static_cast<uint16_t>(mode)),
        has_colors(has_colors),
        render_with_attributes(render_with_attributes),
        sampling(sampling),
        atlas(std::move(atlas)) {}

  const int count;
  const uint16_t mode_index;
  const uint8_t has_colors;
  const uint8_t render_with_attributes;
  const SkSamplingOptions sampling;
  const sk_sp<SkImage> atlas;
};

// Packs as efficiently into 40 bytes as per DrawAtlasBaseOp
// with array data following the struct also as per DrawAtlasBaseOp
struct DrawAtlasOp final : DrawAtlasBaseOp {
  static const auto kType = DisplayListOpType::kDrawAtlas;

  DrawAtlasOp(const sk_sp<SkImage> atlas,
              int count,
              SkBlendMode mode,
              const SkSamplingOptions& sampling,
              bool has_colors,
              bool render_with_attributes)
      : DrawAtlasBaseOp(atlas,
                        count,
                        mode,
                        sampling,
                        has_colors,
                        render_with_attributes) {}

  void dispatch(Dispatcher& dispatcher) const {
    const SkRSXform* xform = reinterpret_cast<const SkRSXform*>(this + 1);
    const SkRect* tex = reinterpret_cast<const SkRect*>(xform + count);
    const SkColor* colors =
        has_colors ? reinterpret_cast<const SkColor*>(tex + count) : nullptr;
    const SkBlendMode mode = static_cast<SkBlendMode>(mode_index);
    dispatcher.drawAtlas(atlas, xform, tex, colors, count, mode, sampling,
                         nullptr, render_with_attributes);
  }
};

// Packs efficiently into the same 40 bytes as DrawAtlasBaseOp plus
// an additional 16 bytes for the cull rect resulting in a total
// of 56 bytes for the Culled drawAtlas.
// Also with array data following the struct as per DrawAtlasBaseOp
struct DrawAtlasCulledOp final : DrawAtlasBaseOp {
  static const auto kType = DisplayListOpType::kDrawAtlasCulled;

  DrawAtlasCulledOp(const sk_sp<SkImage> atlas,
                    int count,
                    SkBlendMode mode,
                    const SkSamplingOptions& sampling,
                    bool has_colors,
                    const SkRect& cull_rect,
                    bool render_with_attributes)
      : DrawAtlasBaseOp(atlas,
                        count,
                        mode,
                        sampling,
                        has_colors,
                        render_with_attributes),
        cull_rect(cull_rect) {}

  const SkRect cull_rect;

  void dispatch(Dispatcher& dispatcher) const {
    const SkRSXform* xform = reinterpret_cast<const SkRSXform*>(this + 1);
    const SkRect* tex = reinterpret_cast<const SkRect*>(xform + count);
    const SkColor* colors =
        has_colors ? reinterpret_cast<const SkColor*>(tex + count) : nullptr;
    const SkBlendMode mode = static_cast<SkBlendMode>(mode_index);
    dispatcher.drawAtlas(atlas, xform, tex, colors, count, mode, sampling,
                         &cull_rect, render_with_attributes);
  }
};

// 4 byte header + 12 byte payload packs evenly into 16 bytes
struct DrawSkPictureOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawSkPicture;

  DrawSkPictureOp(sk_sp<SkPicture> picture, bool render_with_attributes)
      : render_with_attributes(render_with_attributes),
        picture(std::move(picture)) {}

  const bool render_with_attributes;
  const sk_sp<SkPicture> picture;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawPicture(picture, nullptr, render_with_attributes);
  }
};

// 4 byte header + 52 byte payload packs evenly into 56 bytes
struct DrawSkPictureMatrixOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawSkPictureMatrix;

  DrawSkPictureMatrixOp(sk_sp<SkPicture> picture,
                        const SkMatrix matrix,
                        bool render_with_attributes)
      : render_with_attributes(render_with_attributes),
        picture(std::move(picture)),
        matrix(matrix) {}

  const bool render_with_attributes;
  const sk_sp<SkPicture> picture;
  const SkMatrix matrix;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawPicture(picture, &matrix, render_with_attributes);
  }
};

// 4 byte header + ptr aligned payload uses 12 bytes rounde up to 16
// (4 bytes unused)
struct DrawDisplayListOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawDisplayList;

  explicit DrawDisplayListOp(const sk_sp<DisplayList> display_list)
      : display_list(std::move(display_list)) {}

  sk_sp<DisplayList> display_list;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawDisplayList(display_list);
  }
};

// 4 byte header + 8 payload bytes + an aligned pointer take 24 bytes
// (4 unused to align the pointer)
struct DrawTextBlobOp final : DLOp {
  static const auto kType = DisplayListOpType::kDrawTextBlob;

  DrawTextBlobOp(const sk_sp<SkTextBlob> blob, SkScalar x, SkScalar y)
      : x(x), y(y), blob(std::move(blob)) {}

  const SkScalar x;
  const SkScalar y;
  const sk_sp<SkTextBlob> blob;

  void dispatch(Dispatcher& dispatcher) const {
    dispatcher.drawTextBlob(blob, x, y);
  }
};

// 4 byte header + 28 byte payload packs evenly into 32 bytes
#define DEFINE_DRAW_SHADOW_OP(name, transparent_occluder)                 \
  struct Draw##name##Op final : DLOp {                                    \
    static const auto kType = DisplayListOpType::kDraw##name;             \
                                                                          \
    Draw##name##Op(const SkPath& path,                                    \
                   SkColor color,                                         \
                   SkScalar elevation,                                    \
                   SkScalar dpr)                                          \
        : color(color), elevation(elevation), dpr(dpr), path(path) {}     \
                                                                          \
    const SkColor color;                                                  \
    const SkScalar elevation;                                             \
    const SkScalar dpr;                                                   \
    const SkPath path;                                                    \
                                                                          \
    void dispatch(Dispatcher& dispatcher) const {                         \
      dispatcher.drawShadow(path, color, elevation, transparent_occluder, \
                            dpr);                                         \
    }                                                                     \
  };
DEFINE_DRAW_SHADOW_OP(Shadow, false)
DEFINE_DRAW_SHADOW_OP(ShadowTransparentOccluder, true)
#undef DEFINE_DRAW_SHADOW_OP

#pragma pack(pop, DLOp_Alignment)

void DisplayList::ComputeBounds() {
  DisplayListBoundsCalculator calculator(&bounds_cull_);
  Dispatch(calculator);
  bounds_ = calculator.bounds();
}

void DisplayList::Dispatch(Dispatcher& dispatcher,
                           uint8_t* ptr,
                           uint8_t* end) const {
  while (ptr < end) {
    auto op = reinterpret_cast<const DLOp*>(ptr);
    ptr += op->size;
    FML_DCHECK(ptr <= end);
    switch (op->type) {
#define DL_OP_DISPATCH(name)                                \
  case DisplayListOpType::k##name:                          \
    static_cast<const name##Op*>(op)->dispatch(dispatcher); \
    break;

      FOR_EACH_DISPLAY_LIST_OP(DL_OP_DISPATCH)

#undef DL_OP_DISPATCH

      default:
        FML_DCHECK(false);
        return;
    }
  }
}

static void DisposeOps(uint8_t* ptr, uint8_t* end) {
  while (ptr < end) {
    auto op = reinterpret_cast<const DLOp*>(ptr);
    ptr += op->size;
    FML_DCHECK(ptr <= end);
    switch (op->type) {
#define DL_OP_DISPOSE(name)                            \
  case DisplayListOpType::k##name:                     \
    if (!std::is_trivially_destructible_v<name##Op>) { \
      static_cast<const name##Op*>(op)->~name##Op();   \
    }                                                  \
    break;

      FOR_EACH_DISPLAY_LIST_OP(DL_OP_DISPOSE)

#undef DL_OP_DISPOSE

      default:
        FML_DCHECK(false);
        return;
    }
  }
}

static bool CompareOps(uint8_t* ptrA,
                       uint8_t* endA,
                       uint8_t* ptrB,
                       uint8_t* endB) {
  // These conditions are checked by the caller...
  FML_DCHECK((endA - ptrA) == (endB - ptrB));
  FML_DCHECK(ptrA != ptrB);
  uint8_t* bulkStartA = ptrA;
  uint8_t* bulkStartB = ptrB;
  while (ptrA < endA && ptrB < endB) {
    auto opA = reinterpret_cast<const DLOp*>(ptrA);
    auto opB = reinterpret_cast<const DLOp*>(ptrB);
    if (opA->type != opB->type || opA->size != opB->size) {
      return false;
    }
    ptrA += opA->size;
    ptrB += opB->size;
    FML_DCHECK(ptrA <= endA);
    FML_DCHECK(ptrB <= endB);
    DisplayListCompare result;
    switch (opA->type) {
#define DL_OP_EQUALS(name)                              \
  case DisplayListOpType::k##name:                      \
    result = static_cast<const name##Op*>(opA)->equals( \
        static_cast<const name##Op*>(opB));             \
    break;

      FOR_EACH_DISPLAY_LIST_OP(DL_OP_EQUALS)

#undef DL_OP_EQUALS

      default:
        FML_DCHECK(false);
        return false;
    }
    switch (result) {
      case DisplayListCompare::kNotEqual:
        return false;
      case DisplayListCompare::kUseBulkCompare:
        break;
      case DisplayListCompare::kEqual:
        // Check if we have a backlog of bytes to bulk compare and then
        // reset the bulk compare pointers to the address following this op
        auto bulkBytes = reinterpret_cast<const uint8_t*>(opA) - bulkStartA;
        if (bulkBytes > 0) {
          if (memcmp(bulkStartA, bulkStartB, bulkBytes) != 0) {
            return false;
          }
        }
        bulkStartA = ptrA;
        bulkStartB = ptrB;
        break;
    }
  }
  if (ptrA != endA || ptrB != endB) {
    return false;
  }
  if (bulkStartA < ptrA) {
    // Perform a final bulk compare if we have remaining bytes waiting
    if (memcmp(bulkStartA, bulkStartB, ptrA - bulkStartA) != 0) {
      return false;
    }
  }
  return true;
}

void DisplayList::RenderTo(SkCanvas* canvas) const {
  DisplayListCanvasDispatcher dispatcher(canvas);
  Dispatch(dispatcher);
}

bool DisplayList::Equals(const DisplayList& other) const {
  if (byte_count_ != other.byte_count_ || op_count_ != other.op_count_) {
    return false;
  }
  uint8_t* ptr = storage_.get();
  uint8_t* o_ptr = other.storage_.get();
  if (ptr == o_ptr) {
    return true;
  }
  return CompareOps(ptr, ptr + byte_count_, o_ptr, o_ptr + other.byte_count_);
}

DisplayList::DisplayList(uint8_t* ptr,
                         size_t byte_count,
                         int op_count,
                         size_t nested_byte_count,
                         int nested_op_count,
                         const SkRect& cull_rect)
    : storage_(ptr),
      byte_count_(byte_count),
      op_count_(op_count),
      nested_byte_count_(nested_byte_count),
      nested_op_count_(nested_op_count),
      bounds_({0, 0, -1, -1}),
      bounds_cull_(cull_rect) {
  static std::atomic<uint32_t> nextID{1};
  do {
    unique_id_ = nextID.fetch_add(+1, std::memory_order_relaxed);
  } while (unique_id_ == 0);
}

DisplayList::~DisplayList() {
  uint8_t* ptr = storage_.get();
  DisposeOps(ptr, ptr + byte_count_);
}

#define DL_BUILDER_PAGE 4096

// CopyV(dst, src,n, src,n, ...) copies any number of typed srcs into dst.
static void CopyV(void* dst) {}

template <typename S, typename... Rest>
static void CopyV(void* dst, const S* src, int n, Rest&&... rest) {
  FML_DCHECK(((uintptr_t)dst & (alignof(S) - 1)) == 0)
      << "Expected " << dst << " to be aligned for at least " << alignof(S)
      << " bytes.";
  sk_careful_memcpy(dst, src, n * sizeof(S));
  CopyV(SkTAddOffset<void>(dst, n * sizeof(S)), std::forward<Rest>(rest)...);
}

template <typename T, typename... Args>
void* DisplayListBuilder::Push(size_t pod, int op_inc, Args&&... args) {
  size_t size = SkAlignPtr(sizeof(T) + pod);
  FML_DCHECK(size < (1 << 24));
  if (used_ + size > allocated_) {
    static_assert(SkIsPow2(DL_BUILDER_PAGE),
                  "This math needs updating for non-pow2.");
    // Next greater multiple of DL_BUILDER_PAGE.
    allocated_ = (used_ + size + DL_BUILDER_PAGE) & ~(DL_BUILDER_PAGE - 1);
    storage_.realloc(allocated_);
    FML_DCHECK(storage_.get());
    memset(storage_.get() + used_, 0, allocated_ - used_);
  }
  FML_DCHECK(used_ + size <= allocated_);
  auto op = reinterpret_cast<T*>(storage_.get() + used_);
  used_ += size;
  new (op) T{std::forward<Args>(args)...};
  op->type = T::kType;
  op->size = size;
  op_count_ += op_inc;
  return op + 1;
}

sk_sp<DisplayList> DisplayListBuilder::Build() {
  while (save_level_ > 0) {
    restore();
  }
  size_t bytes = used_;
  int count = op_count_;
  size_t nested_bytes = nested_bytes_;
  int nested_count = nested_op_count_;
  used_ = allocated_ = op_count_ = 0;
  nested_bytes_ = nested_op_count_ = 0;
  storage_.realloc(bytes);
  return sk_sp<DisplayList>(new DisplayList(storage_.release(), bytes, count,
                                            nested_bytes, nested_count,
                                            cull_rect_));
}

DisplayListBuilder::DisplayListBuilder(const SkRect& cull_rect)
    : cull_rect_(cull_rect) {}

DisplayListBuilder::~DisplayListBuilder() {
  uint8_t* ptr = storage_.get();
  if (ptr) {
    DisposeOps(ptr, ptr + used_);
  }
}

void DisplayListBuilder::onSetAntiAlias(bool aa) {
  Push<SetAntiAliasOp>(0, 0, current_anti_alias_ = aa);
}
void DisplayListBuilder::onSetDither(bool dither) {
  Push<SetDitherOp>(0, 0, current_dither_ = dither);
}
void DisplayListBuilder::onSetInvertColors(bool invert) {
  Push<SetInvertColorsOp>(0, 0, current_invert_colors_ = invert);
}
void DisplayListBuilder::onSetStrokeCap(SkPaint::Cap cap) {
  Push<SetStrokeCapOp>(0, 0, current_stroke_cap_ = cap);
}
void DisplayListBuilder::onSetStrokeJoin(SkPaint::Join join) {
  Push<SetStrokeJoinOp>(0, 0, current_stroke_join_ = join);
}
void DisplayListBuilder::onSetStyle(SkPaint::Style style) {
  Push<SetStyleOp>(0, 0, current_style_ = style);
}
void DisplayListBuilder::onSetStrokeWidth(SkScalar width) {
  Push<SetStrokeWidthOp>(0, 0, current_stroke_width_ = width);
}
void DisplayListBuilder::onSetStrokeMiter(SkScalar limit) {
  Push<SetStrokeMiterOp>(0, 0, current_stroke_miter_ = limit);
}
void DisplayListBuilder::onSetColor(SkColor color) {
  Push<SetColorOp>(0, 0, current_color_ = color);
}
void DisplayListBuilder::onSetBlendMode(SkBlendMode mode) {
  current_blender_ = nullptr;
  Push<SetBlendModeOp>(0, 0, current_blend_mode_ = mode);
}
void DisplayListBuilder::onSetBlender(sk_sp<SkBlender> blender) {
  // setBlender(nullptr) should be redirected to setBlendMode(SrcOver)
  // by the set method, if not then the following is inefficient but works
  FML_DCHECK(blender);
  SkPaint p;
  p.setBlender(blender);
  if (p.asBlendMode()) {
    setBlendMode(p.asBlendMode().value());
  } else {
    // |current_blender_| supersedes any value of |current_blend_mode_|
    (current_blender_ = blender)  //
        ? Push<SetBlenderOp>(0, 0, std::move(blender))
        : Push<ClearBlenderOp>(0, 0);
  }
}
void DisplayListBuilder::onSetShader(sk_sp<SkShader> shader) {
  (current_shader_ = shader)  //
      ? Push<SetShaderOp>(0, 0, std::move(shader))
      : Push<ClearShaderOp>(0, 0);
}
void DisplayListBuilder::onSetImageFilter(sk_sp<SkImageFilter> filter) {
  (current_image_filter_ = filter)  //
      ? Push<SetImageFilterOp>(0, 0, std::move(filter))
      : Push<ClearImageFilterOp>(0, 0);
}
void DisplayListBuilder::onSetColorFilter(sk_sp<SkColorFilter> filter) {
  (current_color_filter_ = filter)  //
      ? Push<SetColorFilterOp>(0, 0, std::move(filter))
      : Push<ClearColorFilterOp>(0, 0);
}
void DisplayListBuilder::onSetPathEffect(sk_sp<SkPathEffect> effect) {
  (current_path_effect_ = effect)  //
      ? Push<SetPathEffectOp>(0, 0, std::move(effect))
      : Push<ClearPathEffectOp>(0, 0);
}
void DisplayListBuilder::onSetMaskFilter(sk_sp<SkMaskFilter> filter) {
  current_mask_sigma_ = kInvalidSigma;
  (current_mask_filter_ = filter)  //
      ? Push<SetMaskFilterOp>(0, 0, std::move(filter))
      : Push<ClearMaskFilterOp>(0, 0);
}
void DisplayListBuilder::onSetMaskBlurFilter(SkBlurStyle style,
                                             SkScalar sigma) {
  // Valid sigma is checked by setMaskBlurFilter
  FML_DCHECK(mask_sigma_valid(sigma));
  current_mask_filter_ = nullptr;
  current_mask_style_ = style;
  current_mask_sigma_ = sigma;
  switch (style) {
    case kNormal_SkBlurStyle:
      Push<SetMaskBlurFilterNormalOp>(0, 0, sigma);
      break;
    case kSolid_SkBlurStyle:
      Push<SetMaskBlurFilterSolidOp>(0, 0, sigma);
      break;
    case kOuter_SkBlurStyle:
      Push<SetMaskBlurFilterOuterOp>(0, 0, sigma);
      break;
    case kInner_SkBlurStyle:
      Push<SetMaskBlurFilterInnerOp>(0, 0, sigma);
      break;
  }
}

void DisplayListBuilder::setAttributesFromPaint(
    const SkPaint& paint,
    const DisplayListAttributeFlags flags) {
  if (flags.applies_anti_alias()) {
    setAntiAlias(paint.isAntiAlias());
  }
  if (flags.applies_dither()) {
    setDither(paint.isDither());
  }
  if (flags.applies_alpha_or_color()) {
    setColor(paint.getColor());
  }
  if (flags.applies_blend()) {
    skstd::optional<SkBlendMode> mode_optional = paint.asBlendMode();
    if (mode_optional) {
      setBlendMode(mode_optional.value());
    } else {
      setBlender(sk_ref_sp(paint.getBlender()));
    }
  }
  if (flags.applies_style()) {
    setStyle(paint.getStyle());
  }
  if (flags.is_stroked(paint.getStyle())) {
    setStrokeWidth(paint.getStrokeWidth());
    setStrokeMiter(paint.getStrokeMiter());
    setStrokeCap(paint.getStrokeCap());
    setStrokeJoin(paint.getStrokeJoin());
  }
  if (flags.applies_shader()) {
    setShader(sk_ref_sp(paint.getShader()));
  }
  if (flags.applies_color_filter()) {
    // invert colors is a Flutter::Paint thing, not an SkPaint thing
    // we must clear it because it is a second potential color filter
    // that is composed with the paint's color filter.
    setInvertColors(false);
    setColorFilter(sk_ref_sp(paint.getColorFilter()));
  }
  if (flags.applies_image_filter()) {
    setImageFilter(sk_ref_sp(paint.getImageFilter()));
  }
  if (flags.applies_path_effect()) {
    setPathEffect(sk_ref_sp(paint.getPathEffect()));
  }
  if (flags.applies_mask_filter()) {
    setMaskFilter(sk_ref_sp(paint.getMaskFilter()));
  }
}

void DisplayListBuilder::save() {
  save_level_++;
  Push<SaveOp>(0, 1);
}
void DisplayListBuilder::restore() {
  if (save_level_ > 0) {
    Push<RestoreOp>(0, 1);
    save_level_--;
  }
}
void DisplayListBuilder::saveLayer(const SkRect* bounds,
                                   bool restore_with_paint) {
  save_level_++;
  bounds  //
      ? Push<SaveLayerBoundsOp>(0, 1, *bounds, restore_with_paint)
      : Push<SaveLayerOp>(0, 1, restore_with_paint);
}

void DisplayListBuilder::translate(SkScalar tx, SkScalar ty) {
  if (SkScalarIsFinite(tx) && SkScalarIsFinite(ty) &&
      (tx != 0.0 || ty != 0.0)) {
    Push<TranslateOp>(0, 1, tx, ty);
  }
}
void DisplayListBuilder::scale(SkScalar sx, SkScalar sy) {
  if (SkScalarIsFinite(sx) && SkScalarIsFinite(sy) &&
      (sx != 1.0 || sy != 1.0)) {
    Push<ScaleOp>(0, 1, sx, sy);
  }
}
void DisplayListBuilder::rotate(SkScalar degrees) {
  if (SkScalarMod(degrees, 360.0) != 0.0) {
    Push<RotateOp>(0, 1, degrees);
  }
}
void DisplayListBuilder::skew(SkScalar sx, SkScalar sy) {
  if (SkScalarIsFinite(sx) && SkScalarIsFinite(sy) &&
      (sx != 0.0 || sy != 0.0)) {
    Push<SkewOp>(0, 1, sx, sy);
  }
}

// clang-format off

// 2x3 2D affine subset of a 4x4 transform in row major order
void DisplayListBuilder::transform2DAffine(
    SkScalar mxx, SkScalar mxy, SkScalar mxt,
    SkScalar myx, SkScalar myy, SkScalar myt) {
  if (SkScalarsAreFinite(mxx, myx) &&
      SkScalarsAreFinite(mxy, myy) &&
      SkScalarsAreFinite(mxt, myt) &&
      !(mxx == 1 && mxy == 0 && mxt == 0 &&
        myx == 0 && myy == 1 && myt == 0)) {
    Push<Transform2DAffineOp>(0, 1,
                              mxx, mxy, mxt,
                              myx, myy, myt);
  }
}
// full 4x4 transform in row major order
void DisplayListBuilder::transformFullPerspective(
    SkScalar mxx, SkScalar mxy, SkScalar mxz, SkScalar mxt,
    SkScalar myx, SkScalar myy, SkScalar myz, SkScalar myt,
    SkScalar mzx, SkScalar mzy, SkScalar mzz, SkScalar mzt,
    SkScalar mwx, SkScalar mwy, SkScalar mwz, SkScalar mwt) {
  if (                        mxz == 0 &&
                              myz == 0 &&
      mzx == 0 && mzy == 0 && mzz == 1 && mzt == 0 &&
      mwx == 0 && mwy == 0 && mwz == 0 && mwt == 1) {
    transform2DAffine(mxx, mxy, mxt,
                      myx, myy, myt);
  } else if (SkScalarsAreFinite(mxx, mxy) && SkScalarsAreFinite(mxz, mxt) &&
             SkScalarsAreFinite(myx, myy) && SkScalarsAreFinite(myz, myt) &&
             SkScalarsAreFinite(mzx, mzy) && SkScalarsAreFinite(mzz, mzt) &&
             SkScalarsAreFinite(mwx, mwy) && SkScalarsAreFinite(mwz, mwt)) {
    Push<TransformFullPerspectiveOp>(0, 1,
                                     mxx, mxy, mxz, mxt,
                                     myx, myy, myz, myt,
                                     mzx, mzy, mzz, mzt,
                                     mwx, mwy, mwz, mwt);
  }
}

// clang-format on

void DisplayListBuilder::clipRect(const SkRect& rect,
                                  SkClipOp clip_op,
                                  bool is_aa) {
  clip_op == SkClipOp::kIntersect  //
      ? Push<ClipIntersectRectOp>(0, 1, rect, is_aa)
      : Push<ClipDifferenceRectOp>(0, 1, rect, is_aa);
}
void DisplayListBuilder::clipRRect(const SkRRect& rrect,
                                   SkClipOp clip_op,
                                   bool is_aa) {
  if (rrect.isRect()) {
    clipRect(rrect.rect(), clip_op, is_aa);
  } else {
    clip_op == SkClipOp::kIntersect  //
        ? Push<ClipIntersectRRectOp>(0, 1, rrect, is_aa)
        : Push<ClipDifferenceRRectOp>(0, 1, rrect, is_aa);
  }
}
void DisplayListBuilder::clipPath(const SkPath& path,
                                  SkClipOp clip_op,
                                  bool is_aa) {
  if (!path.isInverseFillType()) {
    SkRect rect;
    if (path.isRect(&rect)) {
      this->clipRect(rect, clip_op, is_aa);
      return;
    }
    SkRRect rrect;
    if (path.isOval(&rect)) {
      rrect.setOval(rect);
      this->clipRRect(rrect, clip_op, is_aa);
      return;
    }
    if (path.isRRect(&rrect)) {
      this->clipRRect(rrect, clip_op, is_aa);
      return;
    }
  }
  clip_op == SkClipOp::kIntersect  //
      ? Push<ClipIntersectPathOp>(0, 1, path, is_aa)
      : Push<ClipDifferencePathOp>(0, 1, path, is_aa);
}

void DisplayListBuilder::drawPaint() {
  Push<DrawPaintOp>(0, 1);
}
void DisplayListBuilder::drawColor(SkColor color, SkBlendMode mode) {
  Push<DrawColorOp>(0, 1, color, mode);
}
void DisplayListBuilder::drawLine(const SkPoint& p0, const SkPoint& p1) {
  Push<DrawLineOp>(0, 1, p0, p1);
}
void DisplayListBuilder::drawRect(const SkRect& rect) {
  Push<DrawRectOp>(0, 1, rect);
}
void DisplayListBuilder::drawOval(const SkRect& bounds) {
  Push<DrawOvalOp>(0, 1, bounds);
}
void DisplayListBuilder::drawCircle(const SkPoint& center, SkScalar radius) {
  Push<DrawCircleOp>(0, 1, center, radius);
}
void DisplayListBuilder::drawRRect(const SkRRect& rrect) {
  if (rrect.isRect()) {
    drawRect(rrect.rect());
  } else if (rrect.isOval()) {
    drawOval(rrect.rect());
  } else {
    Push<DrawRRectOp>(0, 1, rrect);
  }
}
void DisplayListBuilder::drawDRRect(const SkRRect& outer,
                                    const SkRRect& inner) {
  Push<DrawDRRectOp>(0, 1, outer, inner);
}
void DisplayListBuilder::drawPath(const SkPath& path) {
  Push<DrawPathOp>(0, 1, path);
}

void DisplayListBuilder::drawArc(const SkRect& bounds,
                                 SkScalar start,
                                 SkScalar sweep,
                                 bool useCenter) {
  Push<DrawArcOp>(0, 1, bounds, start, sweep, useCenter);
}
void DisplayListBuilder::drawPoints(SkCanvas::PointMode mode,
                                    uint32_t count,
                                    const SkPoint pts[]) {
  void* data_ptr;
  FML_DCHECK(count < kMaxDrawPointsCount);
  int bytes = count * sizeof(SkPoint);
  switch (mode) {
    case SkCanvas::PointMode::kPoints_PointMode:
      data_ptr = Push<DrawPointsOp>(bytes, 1, count);
      break;
    case SkCanvas::PointMode::kLines_PointMode:
      data_ptr = Push<DrawLinesOp>(bytes, 1, count);
      break;
    case SkCanvas::PointMode::kPolygon_PointMode:
      data_ptr = Push<DrawPolygonOp>(bytes, 1, count);
      break;
    default:
      FML_DCHECK(false);
      return;
  }
  CopyV(data_ptr, pts, count);
}
void DisplayListBuilder::drawVertices(const sk_sp<SkVertices> vertices,
                                      SkBlendMode mode) {
  Push<DrawVerticesOp>(0, 1, std::move(vertices), mode);
}

void DisplayListBuilder::drawImage(const sk_sp<SkImage> image,
                                   const SkPoint point,
                                   const SkSamplingOptions& sampling,
                                   bool render_with_attributes) {
  render_with_attributes
      ? Push<DrawImageWithAttrOp>(0, 1, std::move(image), point, sampling)
      : Push<DrawImageOp>(0, 1, std::move(image), point, sampling);
}
void DisplayListBuilder::drawImageRect(const sk_sp<SkImage> image,
                                       const SkRect& src,
                                       const SkRect& dst,
                                       const SkSamplingOptions& sampling,
                                       bool render_with_attributes,
                                       SkCanvas::SrcRectConstraint constraint) {
  Push<DrawImageRectOp>(0, 1, std::move(image), src, dst, sampling,
                        render_with_attributes, constraint);
}
void DisplayListBuilder::drawImageNine(const sk_sp<SkImage> image,
                                       const SkIRect& center,
                                       const SkRect& dst,
                                       SkFilterMode filter,
                                       bool render_with_attributes) {
  render_with_attributes
      ? Push<DrawImageNineWithAttrOp>(0, 1, std::move(image), center, dst,
                                      filter)
      : Push<DrawImageNineOp>(0, 1, std::move(image), center, dst, filter);
}
void DisplayListBuilder::drawImageLattice(const sk_sp<SkImage> image,
                                          const SkCanvas::Lattice& lattice,
                                          const SkRect& dst,
                                          SkFilterMode filter,
                                          bool render_with_attributes) {
  int xDivCount = lattice.fXCount;
  int yDivCount = lattice.fYCount;
  FML_DCHECK((lattice.fRectTypes == nullptr) || (lattice.fColors != nullptr));
  int cellCount = lattice.fRectTypes && lattice.fColors
                      ? (xDivCount + 1) * (yDivCount + 1)
                      : 0;
  size_t bytes =
      (xDivCount + yDivCount) * sizeof(int) +
      cellCount * (sizeof(SkColor) + sizeof(SkCanvas::Lattice::RectType));
  SkIRect src = lattice.fBounds ? *lattice.fBounds : image->bounds();
  void* pod = this->Push<DrawImageLatticeOp>(
      bytes, 1, std::move(image), xDivCount, yDivCount, cellCount, src, dst,
      filter, render_with_attributes);
  CopyV(pod, lattice.fXDivs, xDivCount, lattice.fYDivs, yDivCount,
        lattice.fColors, cellCount, lattice.fRectTypes, cellCount);
}
void DisplayListBuilder::drawAtlas(const sk_sp<SkImage> atlas,
                                   const SkRSXform xform[],
                                   const SkRect tex[],
                                   const SkColor colors[],
                                   int count,
                                   SkBlendMode mode,
                                   const SkSamplingOptions& sampling,
                                   const SkRect* cull_rect,
                                   bool render_with_attributes) {
  int bytes = count * (sizeof(SkRSXform) + sizeof(SkRect));
  void* data_ptr;
  if (colors != nullptr) {
    bytes += count * sizeof(SkColor);
    if (cull_rect != nullptr) {
      data_ptr = Push<DrawAtlasCulledOp>(bytes, 1, std::move(atlas), count,
                                         mode, sampling, true, *cull_rect,
                                         render_with_attributes);
    } else {
      data_ptr = Push<DrawAtlasOp>(bytes, 1, std::move(atlas), count, mode,
                                   sampling, true, render_with_attributes);
    }
    CopyV(data_ptr, xform, count, tex, count, colors, count);
  } else {
    if (cull_rect != nullptr) {
      data_ptr = Push<DrawAtlasCulledOp>(bytes, 1, std::move(atlas), count,
                                         mode, sampling, false, *cull_rect,
                                         render_with_attributes);
    } else {
      data_ptr = Push<DrawAtlasOp>(bytes, 1, std::move(atlas), count, mode,
                                   sampling, false, render_with_attributes);
    }
    CopyV(data_ptr, xform, count, tex, count);
  }
}

void DisplayListBuilder::drawPicture(const sk_sp<SkPicture> picture,
                                     const SkMatrix* matrix,
                                     bool render_with_attributes) {
  matrix  //
      ? Push<DrawSkPictureMatrixOp>(0, 1, std::move(picture), *matrix,
                                    render_with_attributes)
      : Push<DrawSkPictureOp>(0, 1, std::move(picture), render_with_attributes);
  // The non-nested op count accumulated in the |Push| method will include
  // this call to |drawPicture| for non-nested op count metrics.
  // But, for nested op count metrics we want the |drawPicture| call itself
  // to be transparent. So we subtract 1 from our accumulated nested count to
  // balance out against the 1 that was accumulated into the regular count.
  // This behavior is identical to the way SkPicture computes nested op counts.
  nested_op_count_ += picture->approximateOpCount(true) - 1;
  nested_bytes_ += picture->approximateBytesUsed();
}
void DisplayListBuilder::drawDisplayList(
    const sk_sp<DisplayList> display_list) {
  Push<DrawDisplayListOp>(0, 1, std::move(display_list));
  // The non-nested op count accumulated in the |Push| method will include
  // this call to |drawDisplayList| for non-nested op count metrics.
  // But, for nested op count metrics we want the |drawDisplayList| call itself
  // to be transparent. So we subtract 1 from our accumulated nested count to
  // balance out against the 1 that was accumulated into the regular count.
  // This behavior is identical to the way SkPicture computes nested op counts.
  nested_op_count_ += display_list->op_count(true) - 1;
  nested_bytes_ += display_list->bytes(true);
}
void DisplayListBuilder::drawTextBlob(const sk_sp<SkTextBlob> blob,
                                      SkScalar x,
                                      SkScalar y) {
  Push<DrawTextBlobOp>(0, 1, std::move(blob), x, y);
}
void DisplayListBuilder::drawShadow(const SkPath& path,
                                    const SkColor color,
                                    const SkScalar elevation,
                                    bool transparent_occluder,
                                    SkScalar dpr) {
  transparent_occluder  //
      ? Push<DrawShadowTransparentOccluderOp>(0, 1, path, color, elevation, dpr)
      : Push<DrawShadowOp>(0, 1, path, color, elevation, dpr);
}

// clang-format off
// Flags common to all primitives that apply colors
#define PAINT_FLAGS (kUsesDither_ |      \
                     kUsesColor_ |       \
                     kUsesAlpha_ |       \
                     kUsesBlend_ |       \
                     kUsesShader_ |      \
                     kUsesColorFilter_ | \
                     kUsesImageFilter_)

// Flags common to all primitives that stroke or fill
#define STROKE_OR_FILL_FLAGS (kIsDrawnGeometry_ | \
                              kUsesAntiAlias_ |   \
                              kUsesMaskFilter_ |  \
                              kUsesPathEffect_)

// Flags common to primitives that stroke geometry
#define STROKE_FLAGS (kIsStrokedGeometry_ | \
                      kUsesAntiAlias_ |     \
                      kUsesMaskFilter_ |    \
                      kUsesPathEffect_)

// Flags common to primitives that render an image with paint attributes
#define IMAGE_FLAGS_BASE (kIsNonGeometric_ |  \
                          kUsesAlpha_ |       \
                          kUsesDither_ |      \
                          kUsesBlend_ |       \
                          kUsesColorFilter_ | \
                          kUsesImageFilter_)
// clang-format on

const DisplayListAttributeFlags DisplayListOpFlags::kSaveLayerFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags DisplayListOpFlags::kSaveLayerWithPaintFlags =
    DisplayListAttributeFlags(kIsNonGeometric_ |   //
                              kUsesAlpha_ |        //
                              kUsesBlend_ |        //
                              kUsesColorFilter_ |  //
                              kUsesImageFilter_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawColorFlags =
    DisplayListAttributeFlags(kFloodsSurface_ | kIgnoresPaint_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawPaintFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | kFloodsSurface_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawHVLineFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_FLAGS | kMayHaveCaps_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawLineFlags =
    kDrawHVLineFlags.with(kMayHaveDiagonalCaps_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawRectFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS |
                              kMayHaveJoins_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawOvalFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawCircleFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawRRectFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawDRRectFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawPathFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS |
                              kMayHaveCaps_ | kMayHaveDiagonalCaps_ |
                              kMayHaveJoins_ | kMayHaveAcuteJoins_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawArcNoCenterFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS |
                              kMayHaveCaps_ | kMayHaveDiagonalCaps_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawArcWithCenterFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS |
                              kMayHaveJoins_ | kMayHaveAcuteJoins_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawPointsAsPointsFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_FLAGS |  //
                              kMayHaveCaps_ | kButtCapIsSquare_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawPointsAsLinesFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_FLAGS |  //
                              kMayHaveCaps_ | kMayHaveDiagonalCaps_);

// Polygon mode just draws (count-1) separate lines, no joins
const DisplayListAttributeFlags DisplayListOpFlags::kDrawPointsAsPolygonFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_FLAGS |  //
                              kMayHaveCaps_ | kMayHaveDiagonalCaps_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawVerticesFlags =
    DisplayListAttributeFlags(kIsNonGeometric_ |   //
                              kUsesDither_ |       //
                              kUsesAlpha_ |        //
                              kUsesShader_ |       //
                              kUsesBlend_ |        //
                              kUsesColorFilter_ |  //
                              kUsesImageFilter_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawImageFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawImageWithPaintFlags =
    DisplayListAttributeFlags(IMAGE_FLAGS_BASE |  //
                              kUsesAntiAlias_ | kUsesMaskFilter_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawImageRectFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags
    DisplayListOpFlags::kDrawImageRectWithPaintFlags =
        DisplayListAttributeFlags(IMAGE_FLAGS_BASE |  //
                                  kUsesAntiAlias_ | kUsesMaskFilter_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawImageNineFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags
    DisplayListOpFlags::kDrawImageNineWithPaintFlags =
        DisplayListAttributeFlags(IMAGE_FLAGS_BASE);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawImageLatticeFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags
    DisplayListOpFlags::kDrawImageLatticeWithPaintFlags =
        DisplayListAttributeFlags(IMAGE_FLAGS_BASE);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawAtlasFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawAtlasWithPaintFlags =
    DisplayListAttributeFlags(IMAGE_FLAGS_BASE);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawPictureFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawPictureWithPaintFlags =
    kSaveLayerWithPaintFlags;

const DisplayListAttributeFlags DisplayListOpFlags::kDrawDisplayListFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawTextBlobFlags =
    DisplayListAttributeFlags(PAINT_FLAGS | STROKE_OR_FILL_FLAGS |
                              kMayHaveJoins_)
        .without(kUsesAntiAlias_);

const DisplayListAttributeFlags DisplayListOpFlags::kDrawShadowFlags =
    DisplayListAttributeFlags(kIgnoresPaint_);

#undef PAINT_FLAGS
#undef STROKE_OR_FILL_FLAGS
#undef STROKE_FLAGS
#undef IMAGE_FLAGS_BASE

}  // namespace flutter