Implements core logic for Pixel Canvas

ui/compositor/paint_context.h

 // Copyright 2015 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.
 
 #ifndef UI_COMPOSITOR_PAINT_CONTEXT_H_
 #define UI_COMPOSITOR_PAINT_CONTEXT_H_
 
 #include <memory>
 
 #include "base/logging.h"
@@ skipping 11 matching lines @@
 class CompositingRecorder;
 class PaintRecorder;
 class TransformRecorder;
 
 class COMPOSITOR_EXPORT PaintContext {
  public:
   // Construct a PaintContext that may only re-paint the area in the
   // |invalidation|.
   PaintContext(cc::DisplayItemList* list,
                float device_scale_factor,
-               const gfx::Rect& invalidation);
+               const gfx::Rect& invalidation,
+               bool is_pixel_canvas);
 
   // Clone a PaintContext with an additional |offset|.
   PaintContext(const PaintContext& other, const gfx::Vector2d& offset);
 
   // Clone a PaintContext that has no consideration for invalidation.
   enum CloneWithoutInvalidation {
     CLONE_WITHOUT_INVALIDATION,
   };
   PaintContext(const PaintContext& other, CloneWithoutInvalidation c);
 
   ~PaintContext();
 
   // When true, IsRectInvalid() can be called, otherwise its result would be
   // invalid.
   bool CanCheckInvalid() const { return !invalidation_.IsEmpty(); }
 
+  float device_scale_factor() const { return device_scale_factor_; }

[danakj, 2017/07/25 17:58:56]

Can you document these accessors?

[malaykeshav, 2017/07/25 22:57:58]

Done

+  bool is_pixel_canvas() const { return is_pixel_canvas_; }
+
   // When true, the |bounds| touches an invalidated area, so should be
   // re-painted. When false, re-painting can be skipped. Bounds should be in
   // the local space with offsets up to the painting root in the PaintContext.
   bool IsRectInvalid(const gfx::Rect& bounds) const {
     DCHECK(CanCheckInvalid());
     return invalidation_.Intersects(bounds + offset_);
   }
 
 #if DCHECK_IS_ON()
   void Visited(void* visited) const {
@@ skipping 28 matching lines @@
   cc::DisplayItemList* list_;
   // The device scale of the frame being painted. Used to determine which bitmap
   // resources to use in the frame.
   float device_scale_factor_;
   // Invalidation in the space of the paint root (ie the space of the layer
   // backing the paint taking place).
   gfx::Rect invalidation_;
   // Offset from the PaintContext to the space of the paint root and the
   // |invalidation_|.
   gfx::Vector2d offset_;
+  // If enabled, the paint commands are recorded at pixel size.
+  bool is_pixel_canvas_;

[danakj, 2017/07/25 17:58:56]

const

[malaykeshav, 2017/07/25 22:57:58]

Done

 
 #if DCHECK_IS_ON()
   // Used to verify that the |invalidation_| is only used to compare against
   // rects in the same space.
   mutable void* root_visited_;
   // Used to verify that paint recorders are not nested. True while a paint
   // recorder is active.
   mutable bool inside_paint_recorder_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(PaintContext);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_PAINT_CONTEXT_H_