Back PaintRecord with PaintOpBuffer instead of SkPicture

cc/paint/paint_op_buffer.cc

+// Copyright 2017 The Chromium 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 "cc/paint/paint_op_buffer.h"
+
+#include "base/template_util.h"
+#include "cc/paint/display_item_list.h"
+#include "cc/paint/paint_record.h"
+#include "third_party/skia/include/core/SkAnnotation.h"
+
+namespace cc {
+
+#define TYPES(M)           \
+  M(AnnotateOp)            \
+  M(ClipPathOp)            \
+  M(ClipRectOp)            \
+  M(ClipRRectOp)           \
+  M(ConcatOp)              \
+  M(DrawArcOp)             \
+  M(DrawCircleOp)          \
+  M(DrawColorOp)           \
+  M(DrawDisplayItemListOp) \
+  M(DrawDRRectOp)          \
+  M(DrawImageOp)           \
+  M(DrawImageRectOp)       \
+  M(DrawIRectOp)           \
+  M(DrawLineOp)            \
+  M(DrawOvalOp)            \
+  M(DrawPathOp)            \
+  M(DrawPosTextOp)         \
+  M(DrawRecordOp)          \
+  M(DrawRectOp)            \
+  M(DrawRRectOp)           \
+  M(DrawTextOp)            \
+  M(DrawTextBlobOp)        \
+  M(NoopOp)                \
+  M(RestoreOp)             \
+  M(RotateOp)              \
+  M(SaveOp)                \
+  M(SaveLayerOp)           \
+  M(SaveLayerAlphaOp)      \
+  M(ScaleOp)               \
+  M(SetMatrixOp)           \
+  M(TranslateOp)
+
+// Helper template to share common code for RasterWithAlpha when paint ops
+// have or don't have PaintFlags.
+template <typename T, bool HasFlags>
+struct Rasterizer {
+  static void Raster(const T* op,
+                     SkCanvas* canvas,
+                     const SkMatrix& original_ctm) {
+    // Paint ops with kHasPaintFlags need to declare RasterWithPaintFlags
+    // otherwise, the paint op needs its own Raster function.  Without its
+    // own, this becomes an infinite loop as PaintOp::Raster calls itself.
+    static_assert(
+        !std::is_same<decltype(&PaintOp::Raster), decltype(&T::Raster)>::value,
+        "No Raster function");
+
+    op->Raster(canvas);
+  }
+  static void RasterWithAlpha(const T* op, SkCanvas* canvas, uint8_t alpha) {
+    DCHECK(T::kIsDrawOp);
+    // TODO(enne): is it ok to just drop the bounds here?
+    canvas->saveLayerAlpha(nullptr, alpha);
+    op->Raster(canvas);
+    canvas->restore();
+  }
+};
+
+template <typename T>
+struct Rasterizer<T, true> {
+  static void Raster(const T* op,
+                     SkCanvas* canvas,
+                     const SkMatrix& original_ctm) {
+    op->RasterWithFlags(canvas, op->flags);
+  }
+  static void RasterWithAlpha(const T* op, SkCanvas* canvas, uint8_t alpha) {
+    DCHECK(T::kIsDrawOp);
+    SkMatrix unused_matrix;
+    if (alpha == 255) {
+      Raster(op, canvas, unused_matrix);
+    } else if (op->flags.SupportsFoldingAlpha()) {
+      PaintFlags flags = op->flags;
+      flags.setAlpha(SkMulDiv255Round(flags.getAlpha(), alpha));
+      op->RasterWithFlags(canvas, flags);
+    } else {
+      canvas->saveLayerAlpha(nullptr, alpha);
+      op->RasterWithFlags(canvas, op->flags);
+      canvas->restore();
+    }
+  }
+};
+
+template <>
+struct Rasterizer<SetMatrixOp, false> {
+  static void Raster(const SetMatrixOp* op,
+                     SkCanvas* canvas,
+                     const SkMatrix& original_ctm) {
+    op->Raster(canvas, original_ctm);
+  }
+  static void RasterWithAlpha(const SetMatrixOp* op,
+                              SkCanvas* canvas,
+                              uint8_t alpha) {
+    NOTREACHED();
+  }
+};
+
+template <>
+struct Rasterizer<DrawRecordOp, false> {
+  static void Raster(const DrawRecordOp* op,
+                     SkCanvas* canvas,
+                     const SkMatrix& original_ctm) {
+    op->Raster(canvas);
+  }
+  static void RasterWithAlpha(const DrawRecordOp* op,
+                              SkCanvas* canvas,
+                              uint8_t alpha) {
+    // This looking into pictures optimization is done here instead of
+    // in the PaintOpBuffer::Raster function as DisplayItemList calls
+    // into RasterWithAlpha directly.
+    if (op->record->approximateOpCount() == 1) {
+      op->record->GetFirstOp()->RasterWithAlpha(canvas, alpha);
+      return;
+    }
+
+    canvas->saveLayerAlpha(nullptr, alpha);
+    op->Raster(canvas);
+    canvas->restore();
+  }
+};
+
+// TODO(enne): partially specialize RasterWithAlpha for draw color?
+
+static constexpr size_t kNumOpTypes =
+    static_cast<size_t>(PaintOpType::LastPaintOpType) + 1;
+
+// Verify that every op is in the TYPES macro.
+#define M(T) 1 +
+static_assert(kNumOpTypes == TYPES(M) 0, "Missing op in list");
+#undef M
+
+typedef void (*RasterFunction)(const PaintOp* op,
+                               SkCanvas* canvas,
+                               const SkMatrix& original_ctm);
+#define M(T)                                                              \
+  [](const PaintOp* op, SkCanvas* canvas, const SkMatrix& original_ctm) { \
+    Rasterizer<T, T::kHasPaintFlags>::Raster(static_cast<const T*>(op),   \
+                                             canvas, original_ctm);       \
+  },
+static const RasterFunction g_raster_functions[kNumOpTypes] = {TYPES(M)};
+#undef M
+
+typedef void (*RasterAlphaFunction)(const PaintOp* op,
+                                    SkCanvas* canvas,
+                                    uint8_t alpha);
+#define M(T) \
+  T::kIsDrawOp ? \
+  [](const PaintOp* op, SkCanvas* canvas, uint8_t alpha) { \
+    Rasterizer<T, T::kHasPaintFlags>::RasterWithAlpha( \
+        static_cast<const T*>(op), canvas, alpha); \
+  } : static_cast<RasterAlphaFunction>(nullptr),
+static const RasterAlphaFunction g_raster_alpha_functions[kNumOpTypes] = {
+    TYPES(M)};
+#undef M
+
+// Most state ops (matrix, clip, save, restore) have a trivial destructor.
+typedef void (*VoidFunction)(PaintOp* op);
+#define M(T)                                           \
+  !base::is_trivially_destructible<T>::value           \

[mtklein_C, 2017/04/05 15:26:43]

In retrospect, I'd bet this doesn't matter.  It's probably harmless to just call
all destructors if you want to cut a little complexity.

+      ? [](PaintOp* op) { static_cast<T*>(op)->~T(); } \
+      : static_cast<VoidFunction>(nullptr),
+static const VoidFunction g_destructor_functions[kNumOpTypes] = {TYPES(M)};
+#undef M
+
+#define M(T) T::kIsDrawOp,
+static bool g_is_draw_op[kNumOpTypes] = {TYPES(M)};
+#undef M
+
+#define M(T)                                         \
+  static_assert(sizeof(T) <= sizeof(LargestPaintOp), \
+                #T " must be no bigger than LargestPaintOp");
+TYPES(M);
+#undef M
+
+#undef TYPES
+
+SkRect PaintOp::kUnsetRect = {SK_ScalarInfinity, 0, 0, 0};
+
+void AnnotateOp::Raster(SkCanvas* canvas) const {
+  switch (annotation_type) {
+    case PaintCanvas::AnnotationType::URL:
+      SkAnnotateRectWithURL(canvas, rect, data.get());
+      break;
+    case PaintCanvas::AnnotationType::LINK_TO_DESTINATION:
+      SkAnnotateLinkToDestination(canvas, rect, data.get());
+      break;
+    case PaintCanvas::AnnotationType::NAMED_DESTINATION: {
+      SkPoint point = SkPoint::Make(rect.x(), rect.y());
+      SkAnnotateNamedDestination(canvas, point, data.get());
+      break;
+    }
+  }
+}
+
+void ClipPathOp::Raster(SkCanvas* canvas) const {
+  canvas->clipPath(path, op, antialias);
+}
+
+void ClipRectOp::Raster(SkCanvas* canvas) const {
+  canvas->clipRect(rect, op, antialias);
+}
+
+void ClipRRectOp::Raster(SkCanvas* canvas) const {
+  canvas->clipRRect(rrect, op, antialias);
+}
+
+void ConcatOp::Raster(SkCanvas* canvas) const {
+  canvas->concat(matrix);
+}
+
+void DrawArcOp::RasterWithFlags(SkCanvas* canvas,
+                                const PaintFlags& flags) const {
+  canvas->drawArc(oval, start_angle, sweep_angle, use_center, ToSkPaint(flags));
+}
+
+void DrawCircleOp::RasterWithFlags(SkCanvas* canvas,
+                                   const PaintFlags& flags) const {
+  canvas->drawCircle(cx, cy, radius, ToSkPaint(flags));
+}
+
+void DrawColorOp::Raster(SkCanvas* canvas) const {
+  canvas->drawColor(color, mode);
+}
+
+void DrawDisplayItemListOp::Raster(SkCanvas* canvas) const {
+  list->Raster(canvas, nullptr);
+}
+
+void DrawDRRectOp::RasterWithFlags(SkCanvas* canvas,
+                                   const PaintFlags& flags) const {
+  canvas->drawDRRect(outer, inner, ToSkPaint(flags));
+}
+
+void DrawImageOp::RasterWithFlags(SkCanvas* canvas,
+                                  const PaintFlags& flags) const {
+  canvas->drawImage(image.get(), left, top, ToSkPaint(&flags));
+}
+
+void DrawImageRectOp::RasterWithFlags(SkCanvas* canvas,
+                                      const PaintFlags& flags) const {
+  // TODO(enne): Probably PaintCanvas should just use the skia enum directly.
+  SkCanvas::SrcRectConstraint skconstraint =
+      static_cast<SkCanvas::SrcRectConstraint>(constraint);
+  canvas->drawImageRect(image.get(), src, dst, ToSkPaint(&flags), skconstraint);
+}
+
+void DrawIRectOp::RasterWithFlags(SkCanvas* canvas,
+                                  const PaintFlags& flags) const {
+  canvas->drawIRect(rect, ToSkPaint(flags));
+}
+
+void DrawLineOp::RasterWithFlags(SkCanvas* canvas,
+                                 const PaintFlags& flags) const {
+  canvas->drawLine(x0, y0, x1, y1, ToSkPaint(flags));
+}
+
+void DrawOvalOp::RasterWithFlags(SkCanvas* canvas,
+                                 const PaintFlags& flags) const {
+  canvas->drawOval(oval, ToSkPaint(flags));
+}
+
+void DrawPathOp::RasterWithFlags(SkCanvas* canvas,
+                                 const PaintFlags& flags) const {
+  canvas->drawPath(path, ToSkPaint(flags));
+}
+
+void DrawPosTextOp::RasterWithFlags(SkCanvas* canvas,
+                                    const PaintFlags& flags) const {
+  canvas->drawPosText(paint_op_data(this), bytes, paint_op_array<SkPoint>(this),
+                      ToSkPaint(flags));
+}
+
+void DrawRecordOp::Raster(SkCanvas* canvas) const {
+  record->playback(canvas);
+}
+
+void DrawRectOp::RasterWithFlags(SkCanvas* canvas,
+                                 const PaintFlags& flags) const {
+  canvas->drawRect(rect, ToSkPaint(flags));
+}
+
+void DrawRRectOp::RasterWithFlags(SkCanvas* canvas,
+                                  const PaintFlags& flags) const {
+  canvas->drawRRect(rrect, ToSkPaint(flags));
+}
+
+void DrawTextOp::RasterWithFlags(SkCanvas* canvas,
+                                 const PaintFlags& flags) const {
+  canvas->drawText(paint_op_data(this), bytes, x, y, ToSkPaint(flags));
+}
+
+void DrawTextBlobOp::RasterWithFlags(SkCanvas* canvas,
+                                     const PaintFlags& flags) const {
+  canvas->drawTextBlob(blob.get(), x, y, ToSkPaint(flags));
+}
+
+void RestoreOp::Raster(SkCanvas* canvas) const {
+  canvas->restore();
+}
+
+void RotateOp::Raster(SkCanvas* canvas) const {
+  canvas->rotate(degrees);
+}
+
+void SaveOp::Raster(SkCanvas* canvas) const {
+  canvas->save();
+}
+
+void SaveLayerOp::RasterWithFlags(SkCanvas* canvas,
+                                  const PaintFlags& flags) const {
+  // See PaintOp::kUnsetRect
+  bool unset = bounds.left() == SK_ScalarInfinity;
+
+  canvas->saveLayer(unset ? nullptr : &bounds, ToSkPaint(&flags));
+}
+
+void SaveLayerAlphaOp::Raster(SkCanvas* canvas) const {
+  // See PaintOp::kUnsetRect
+  bool unset = bounds.left() == SK_ScalarInfinity;
+  canvas->saveLayerAlpha(unset ? nullptr : &bounds, alpha);
+}
+
+void ScaleOp::Raster(SkCanvas* canvas) const {
+  canvas->scale(sx, sy);
+}
+
+void SetMatrixOp::Raster(SkCanvas* canvas, const SkMatrix& original_ctm) const {
+  canvas->setMatrix(SkMatrix::Concat(original_ctm, matrix));
+}
+
+void TranslateOp::Raster(SkCanvas* canvas) const {
+  canvas->translate(dx, dy);
+}
+
+bool PaintOp::IsDrawOp() const {
+  return g_is_draw_op[type];
+}
+
+void PaintOp::Raster(SkCanvas* canvas, const SkMatrix& original_ctm) const {
+  g_raster_functions[type](this, canvas, original_ctm);
+}
+
+void PaintOp::RasterWithAlpha(SkCanvas* canvas, uint8_t alpha) const {
+  g_raster_alpha_functions[type](this, canvas, alpha);
+}
+
+DrawDisplayItemListOp::DrawDisplayItemListOp(
+    scoped_refptr<DisplayItemList> list)
+    : list(list) {}
+
+int ClipPathOp::CountSlowPaths() const {
+  return antialias && !path.isConvex() ? 1 : 0;
+}
+
+int DrawLineOp::CountSlowPaths() const {
+  if (const SkPathEffect* effect = flags.getPathEffect()) {
+    SkPathEffect::DashInfo info;
+    SkPathEffect::DashType dashType = effect->asADash(&info);
+    if (flags.getStrokeCap() != PaintFlags::kRound_Cap &&
+        dashType == SkPathEffect::kDash_DashType && info.fCount == 2) {
+      // The PaintFlags will count this as 1, so uncount that here as
+      // this kind of line is special cased and not slow.
+      return -1;
+    }
+  }
+  return 0;
+}
+
+int DrawPathOp::CountSlowPaths() const {
+  // TODO(enne): It's not the best to have these Skia details exposed here,
+  // but hopefully the veto is shortlived and this can go away.
+  if (flags.isAntiAlias() && !path.isConvex()) {
+    PaintFlags::Style paintStyle = flags.getStyle();
+    const SkRect& pathBounds = path.getBounds();
+    if (paintStyle == PaintFlags::kStroke_Style &&
+        flags.getStrokeWidth() == 0) {
+      // AA hairline concave path is not slow.
+    } else if (paintStyle == PaintFlags::kFill_Style &&
+               pathBounds.width() < 64.f && pathBounds.height() < 64.f &&
+               !path.isVolatile()) {
+      // AADF eligible concave path is not slow.
+    } else {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+AnnotateOp::AnnotateOp(PaintCanvas::AnnotationType annotation_type,
+                       const SkRect& rect,
+                       sk_sp<SkData> data)
+    : annotation_type(annotation_type), rect(rect), data(data) {}
+
+AnnotateOp::~AnnotateOp() = default;
+
+DrawDisplayItemListOp::~DrawDisplayItemListOp() = default;
+
+DrawImageOp::DrawImageOp(sk_sp<const SkImage> image,
+                         SkScalar left,
+                         SkScalar top,
+                         const PaintFlags* flags)
+    : image(std::move(image)), left(left), top(top) {
+  if (flags)
+    this->flags = *flags;
+}
+
+DrawImageOp::~DrawImageOp() = default;
+
+DrawImageRectOp::DrawImageRectOp(sk_sp<const SkImage> image,
+                                 const SkRect& src,
+                                 const SkRect& dst,
+                                 const PaintFlags* flags,
+                                 PaintCanvas::SrcRectConstraint constraint)
+    : image(image), src(src), dst(dst), constraint(constraint) {
+  if (flags)
+    this->flags = *flags;
+}
+
+DrawImageRectOp::~DrawImageRectOp() = default;
+
+DrawPosTextOp::DrawPosTextOp(size_t bytes,
+                             size_t count,
+                             const PaintFlags& flags)
+    : PaintOpWithDataArray(bytes, count), flags(flags) {}
+
+DrawPosTextOp::~DrawPosTextOp() = default;
+
+DrawRecordOp::DrawRecordOp(sk_sp<const PaintRecord> record) : record(record) {}
+
+DrawRecordOp::~DrawRecordOp() = default;
+
+DrawTextBlobOp::DrawTextBlobOp(sk_sp<SkTextBlob> blob,
+                               SkScalar x,
+                               SkScalar y,
+                               const PaintFlags& flags)
+    : blob(blob), x(x), y(y), flags(flags) {}
+
+DrawTextBlobOp::~DrawTextBlobOp() = default;
+
+PaintOpBuffer::PaintOpBuffer() : cull_rect_(SkRect::MakeEmpty()) {}
+
+PaintOpBuffer::PaintOpBuffer(const SkRect& cull_rect) : cull_rect_(cull_rect) {}
+
+PaintOpBuffer::~PaintOpBuffer() {
+  Reset();
+}
+
+void PaintOpBuffer::Reset() {
+  for (auto* op : Iterator(this)) {
+    auto func = g_destructor_functions[op->type];
+    if (func)
+      func(op);
+  }
+
+  // Leave data_ allocated, reserved_ unchanged.
+  used_ = 0;
+  op_count_ = 0;
+  num_slow_paths_ = 0;
+}
+
+void PaintOpBuffer::playback(SkCanvas* canvas) const {
+  // TODO(enne): a PaintRecord that contains a SetMatrix assumes that the
+  // SetMatrix is local to that PaintRecord itself.  Said differently, if you
+  // translate(x, y), then draw a paint record with a SetMatrix(identity),
+  // the translation should be preserved instead of clobbering the top level
+  // transform.  This could probably be done more efficiently.
+  SkMatrix original = canvas->getTotalMatrix();
+
+  for (Iterator iter(this); iter; ++iter) {
+    // Optimize out save/restores or save/draw/restore that can be a single
+    // draw.  See also: similar code in SkRecordOpts and cc's DisplayItemList.
+    // TODO(enne): consider making this recursive?
+    const PaintOp* op = *iter;
+    if (op->GetType() == PaintOpType::SaveLayerAlpha) {
+      const PaintOp* second = iter.peek1();
+      if (second) {
+        if (second->GetType() == PaintOpType::Restore) {
+          ++iter;
+          continue;
+        }
+        if (second->IsDrawOp()) {
+          const PaintOp* third = iter.peek2();
+          if (third && third->GetType() == PaintOpType::Restore) {
+            const SaveLayerAlphaOp* save_op =
+                static_cast<const SaveLayerAlphaOp*>(op);
+            second->RasterWithAlpha(canvas, save_op->alpha);
+            ++iter;
+            ++iter;
+            continue;
+          }
+        }
+      }
+    }
+    // TODO(enne): skip SaveLayer followed by restore with nothing in
+    // between, however SaveLayer with image filters on it (or maybe
+    // other PaintFlags options) are not a noop.  Figure out what these
+    // are so we can skip them correctly.
+
+    op->Raster(canvas, original);
+  }
+}
+
+void PaintOpBuffer::playback(SkCanvas* canvas,
+                             SkPicture::AbortCallback* callback) const {
+  // The abort callback is only used for analysis, in general, so
+  // this playback code can be more straightforward and not do the
+  // optimizations in the other function.
+  if (!callback) {
+    playback(canvas);
+    return;
+  }
+
+  SkMatrix original = canvas->getTotalMatrix();
+
+  // TODO(enne): ideally callers would just iterate themselves and we
+  // can remove the entire notion of an abort callback.
+  for (auto* op : Iterator(this)) {
+    op->Raster(canvas, original);
+    if (callback && callback->abort())
+      return;
+  }
+}
+
+}  // namespace cc