ui/compositor/dip_util.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/compositor/dip_util.h"
   6
   7 #include "base/command_line.h"
   8 #include "cc/layers/layer.h"
   9 #include "ui/compositor/compositor.h"
  10 #include "ui/compositor/compositor_switches.h"
  11 #include "ui/compositor/layer.h"
  12 #include "ui/gfx/display.h"
  13 #include "ui/gfx/geometry/safe_integer_conversions.h"
  14 #include "ui/gfx/point.h"
  15 #include "ui/gfx/point_conversions.h"
  16 #include "ui/gfx/rect.h"
  17 #include "ui/gfx/rect_conversions.h"
  18 #include "ui/gfx/size.h"
  19 #include "ui/gfx/size_conversions.h"
  20
  21 namespace ui {
  22
  23 float GetDeviceScaleFactor(const Layer* layer) {
  24   return layer->device_scale_factor();
  25 }
  26
  27 gfx::Point ConvertPointToDIP(const Layer* layer,
  28                              const gfx::Point& point_in_pixel) {
  29   return gfx::ToFlooredPoint(
  30       gfx::ScalePoint(point_in_pixel, 1.0f / GetDeviceScaleFactor(layer)));
  31 }
  32
  33 gfx::PointF ConvertPointToDIP(const Layer* layer,
  34                               const gfx::PointF& point_in_pixel) {
  35   return gfx::ScalePoint(point_in_pixel, 1.0f / GetDeviceScaleFactor(layer));
  36 }
  37
  38 gfx::Size ConvertSizeToDIP(const Layer* layer,
  39                            const gfx::Size& size_in_pixel) {
  40   return gfx::ToFlooredSize(
  41       gfx::ScaleSize(size_in_pixel, 1.0f / GetDeviceScaleFactor(layer)));
  42 }
  43
  44 gfx::Rect ConvertRectToDIP(const Layer* layer,
  45                            const gfx::Rect& rect_in_pixel) {
  46   float scale = 1.0f / GetDeviceScaleFactor(layer);
  47   return gfx::ToFlooredRectDeprecated(gfx::ScaleRect(rect_in_pixel, scale));
  48 }
  49
  50 gfx::Point ConvertPointToPixel(const Layer* layer,
  51                                const gfx::Point& point_in_dip) {
  52   return gfx::ToFlooredPoint(
  53       gfx::ScalePoint(point_in_dip, GetDeviceScaleFactor(layer)));
  54 }
  55
  56 gfx::Size ConvertSizeToPixel(const Layer* layer,
  57                              const gfx::Size& size_in_dip) {
  58   return gfx::ToFlooredSize(
  59       gfx::ScaleSize(size_in_dip, GetDeviceScaleFactor(layer)));
  60 }
  61
  62 gfx::Rect ConvertRectToPixel(const Layer* layer,
  63                              const gfx::Rect& rect_in_dip) {
  64   float scale = GetDeviceScaleFactor(layer);
  65   // Use ToEnclosingRect() to ensure we paint all the possible pixels
  66   // touched. ToEnclosingRect() floors the origin, and ceils the max
  67   // coordinate. To do otherwise (such as flooring the size) potentially
  68   // results in rounding down and not drawing all the pixels that are
  69   // touched.
  70   return gfx::ToEnclosingRect(
  71       gfx::RectF(gfx::ScalePoint(rect_in_dip.origin(), scale),
  72                  gfx::ScaleSize(rect_in_dip.size(), scale)));
  73 }
  74
  75 #if !defined(NDEBUG)
  76 namespace {
  77
  78 void CheckSnapped(float snapped_position) {
  79   const float kEplison = 0.0001f;
  80   float diff = std::abs(snapped_position - static_cast<int>(snapped_position));
  81   DCHECK_LT(diff, kEplison);
  82 }
  83
  84 }  // namespace
  85 #endif
  86
  87 void SnapLayerToPhysicalPixelBoundary(ui::Layer* snapped_layer,
  88                                       ui::Layer* layer_to_snap) {
  89   DCHECK_NE(snapped_layer, layer_to_snap);
  90   DCHECK(snapped_layer);
  91   DCHECK(snapped_layer->Contains(layer_to_snap));
  92
  93   gfx::Point view_offset_dips = layer_to_snap->GetTargetBounds().origin();
  94   ui::Layer::ConvertPointToLayer(
  95       layer_to_snap->parent(), snapped_layer, &view_offset_dips);
  96   gfx::PointF view_offset = view_offset_dips;
  97
  98   float scale_factor = GetDeviceScaleFactor(layer_to_snap);
  99   view_offset.Scale(scale_factor);
 100   gfx::PointF view_offset_snapped(gfx::ToRoundedInt(view_offset.x()),
 101                                   gfx::ToRoundedInt(view_offset.y()));
 102
 103   gfx::Vector2dF fudge = view_offset_snapped - view_offset;
 104   fudge.Scale(1.0 / scale_factor);
 105   layer_to_snap->SetSubpixelPositionOffset(fudge);
 106 #if !defined(NDEBUG)
 107   gfx::Point p;
 108   Layer::ConvertPointToLayer(layer_to_snap->parent(), snapped_layer, &p);
 109   cc::Layer* cc_layer = layer_to_snap->cc_layer();
 110   gfx::PointF origin = cc_layer->position();
 111   CheckSnapped((p.x() + origin.x()) * scale_factor);
 112   CheckSnapped((p.y() + origin.y()) * scale_factor);
 113 #endif
 114 }
 115
 116 }  // namespace ui