Reland "display: Deduplicate display transform code with overlay transform code"

This is a reland of 4430b4c3

Original change's description:
> display: Deduplicate display transform code with overlay transform code
>
> Display rotation transforms are a subset of overlay transforms, so we can
> reuse OverlayTransformToTransform to compute display rotation matrices.
>
> Bug: 1019015
>
> Change-Id: I95d099323cb866ccc4b9cea404e1e6f8f2dfff65
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1913604
> Commit-Queue: Michael Spang <spang@chromium.org>
> Reviewed-by: Khushal <khushalsagar@chromium.org>
> Reviewed-by: Ken Buchanan <kenrb@chromium.org>
> Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
> Reviewed-by: Mitsuru Oshima (OOO - back on Dec 2nd) <oshima@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#717832}

TBR=oshima@chromium.org,sadrul@chromium.org,kenrb@chromium.org,kenrb@chromium.org

Bug: 1019015
Change-Id: I3eaa7819971e9ebd51329f22506cb6bb905d429a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1931131
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722643}

ash/display/window_tree_host_manager.cc

@@ -25,7 +25,6 @@
 #include "ash/shell_state.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/unified/unified_system_tray.h"
-#include "ash/utility/transformer_util.h"
 #include "ash/wm/window_util.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
@@ -48,6 +47,7 @@
 #include "ui/compositor/compositor_switches.h"
 #include "ui/display/display.h"
 #include "ui/display/display_layout.h"
+#include "ui/display/display_transform.h"
 #include "ui/display/manager/display_configurator.h"
 #include "ui/display/manager/display_layout_store.h"
 #include "ui/display/manager/display_manager.h"
@@ -86,7 +86,7 @@ void SetDisplayPropertiesOnHost(AshWindowTreeHost* ash_host,
   ash_host->SetRootWindowTransformer(std::move(transformer));
 
   host->SetDisplayTransformHint(
-      DisplayRotationToOverlayTransform(effective_rotation));
+      display::DisplayRotationToOverlayTransform(effective_rotation));
 
   // Just moving the display requires the full redraw.
   // chrome-os-partner:33558.

ash/utility/transformer_util.cc

@@ -6,7 +6,7 @@
 
 #include <cmath>
 
-#include "third_party/skia/include/core/SkMatrix44.h"
+#include "ui/display/display_transform.h"
 #include "ui/gfx/geometry/size_f.h"
 #include "ui/gfx/transform.h"
 
@@ -26,26 +26,8 @@ display::Display::Rotation RotationBetween(
 gfx::Transform CreateRotationTransform(display::Display::Rotation old_rotation,
                                        display::Display::Rotation new_rotation,
                                        const gfx::SizeF& size_to_rotate) {
-  gfx::Transform transform = display::Display::GetRotationTransform(
+  return display::CreateRotationTransform(
       RotationBetween(old_rotation, new_rotation), size_to_rotate);
-
-  return transform;
-}
-
-gfx::OverlayTransform DisplayRotationToOverlayTransform(
-    display::Display::Rotation rotation) {
-  switch (rotation) {
-    case display::Display::ROTATE_0:
-      return gfx::OVERLAY_TRANSFORM_NONE;
-    case display::Display::ROTATE_90:
-      return gfx::OVERLAY_TRANSFORM_ROTATE_90;
-    case display::Display::ROTATE_180:
-      return gfx::OVERLAY_TRANSFORM_ROTATE_180;
-    case display::Display::ROTATE_270:
-      return gfx::OVERLAY_TRANSFORM_ROTATE_270;
-  }
-  NOTREACHED();
-  return gfx::OVERLAY_TRANSFORM_NONE;
 }
 
 }  // namespace ash

ash/utility/transformer_util.h

@@ -7,7 +7,6 @@
 
 #include "ash/ash_export.h"
 #include "ui/display/display.h"
-#include "ui/gfx/overlay_transform.h"
 
 namespace gfx {
 class SizeF;
@@ -23,10 +22,6 @@ ASH_EXPORT gfx::Transform CreateRotationTransform(
     display::Display::Rotation new_rotation,
     const gfx::SizeF& size_to_rotate);
 
-// Maps display::Display::Rotation to gfx::OverlayTransform.
-ASH_EXPORT gfx::OverlayTransform DisplayRotationToOverlayTransform(
-    display::Display::Rotation rotation);
-
 }  // namespace ash
 
 #endif  // ASH_TRANSFORMER_UTIL_H_

chromecast/graphics/cast_window_manager_aura.cc

@@ -25,6 +25,7 @@
 #include "ui/base/ime/init/input_method_factory.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/display/display.h"
+#include "ui/display/display_transform.h"
 #include "ui/display/screen.h"
 #include "ui/ozone/public/ozone_platform.h"
 #include "ui/platform_window/platform_window_init_properties.h"
@@ -39,8 +40,8 @@ namespace {
 
 gfx::Transform GetPrimaryDisplayRotationTransform() {
   display::Display display = display::Screen::GetScreen()->GetPrimaryDisplay();
-  return display::Display::GetRotationTransform(display.rotation(),
-                                                gfx::SizeF(display.size()));
+  return display::CreateRotationTransform(display.rotation(),
+                                          gfx::SizeF(display.size()));
 }
 
 gfx::Rect GetPrimaryDisplayHostBounds() {

content/browser/renderer_host/compositor_impl_android.cc

@@ -77,6 +77,7 @@
 #include "third_party/skia/include/core/SkMallocPixelRef.h"
 #include "ui/android/window_android.h"
 #include "ui/display/display.h"
+#include "ui/display/display_transform.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/ca_layer_params.h"
 #include "ui/gfx/swap_result.h"
@@ -94,33 +95,6 @@ NOINLINE void FatalSurfaceFailure() {
   LOG(FATAL) << "Fatal surface initialization failure";
 }
 
-gfx::OverlayTransform RotationToDisplayTransform(
-    display::Display::Rotation rotation) {
-  // Note that the angle provided by |rotation| here is the opposite direction
-  // of the physical rotation of the device, which is the space in which the UI
-  // prepares the scene (see
-  // https://developer.android.com/reference/android/view/Display#getRotation()
-  // for details).
-  //
-  // The rotation which needs to be applied by the display compositor to allow
-  // the buffers produced by it to be used directly by the system compositor
-  // needs to be the inverse of this rotation. Since display::Rotation is in
-  // clockwise direction while gfx::OverlayTransform is anti-clockwise, directly
-  // mapping them below performs this inversion.
-  switch (rotation) {
-    case display::Display::ROTATE_0:
-      return gfx::OVERLAY_TRANSFORM_NONE;
-    case display::Display::ROTATE_90:
-      return gfx::OVERLAY_TRANSFORM_ROTATE_90;
-    case display::Display::ROTATE_180:
-      return gfx::OVERLAY_TRANSFORM_ROTATE_180;
-    case display::Display::ROTATE_270:
-      return gfx::OVERLAY_TRANSFORM_ROTATE_270;
-  }
-  NOTREACHED();
-  return gfx::OVERLAY_TRANSFORM_NONE;
-}
-
 gpu::SharedMemoryLimits GetCompositorContextSharedMemoryLimits(
     gfx::NativeWindow window) {
   const gfx::Size screen_size = display::Screen::GetScreen()
@@ -449,7 +423,7 @@ void CompositorImpl::CreateLayerTreeHost() {
   const auto& display_props =
       display::Screen::GetScreen()->GetDisplayNearestWindow(root_window_);
   host_->set_display_transform_hint(
-      RotationToDisplayTransform(display_props.rotation()));
+      display::DisplayRotationToOverlayTransform(display_props.rotation()));
 
   if (needs_animate_)
     host_->SetNeedsAnimate();
@@ -777,7 +751,7 @@ void CompositorImpl::OnDisplayMetricsChanged(const display::Display& display,
   if (changed_metrics &
       display::DisplayObserver::DisplayMetric::DISPLAY_METRIC_ROTATION) {
     host_->set_display_transform_hint(
-        RotationToDisplayTransform(display.rotation()));
+        display::DisplayRotationToOverlayTransform(display.rotation()));
   }
 }
 

ui/aura/test/test_screen.cc

@@ -13,6 +13,7 @@
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/ime/input_method.h"
+#include "ui/display/display_transform.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/native_widget_types.h"
@@ -117,8 +118,8 @@ void TestScreen::SetWorkAreaInsets(const gfx::Insets& insets) {
 
 gfx::Transform TestScreen::GetRotationTransform() const {
   display::Display display = GetPrimaryDisplay();
-  return display::Display::GetRotationTransform(display.rotation(),
-                                                gfx::SizeF(display.size()));
+  return display::CreateRotationTransform(display.rotation(),
+                                          gfx::SizeF(display.size()));
 }
 
 gfx::Transform TestScreen::GetUIScaleTransform() const {

ui/display/BUILD.gn

@@ -34,6 +34,8 @@ jumbo_component("display") {
     "display_observer.h",
     "display_switches.cc",
     "display_switches.h",
+    "display_transform.cc",
+    "display_transform.h",
     "screen.cc",
     "screen.h",
     "screen_base.cc",

ui/display/display.cc

@@ -285,34 +285,6 @@ int Display::PanelRotationAsDegree() const {
   return RotationToDegrees(panel_rotation_);
 }
 
-// static
-gfx::Transform Display::GetRotationTransform(Rotation rotation,
-                                             const gfx::SizeF& size) {
-  // NB: Using gfx::Transform::Rotate() introduces very small errors here
-  // which are later exacerbated by use of gfx::EnclosingRect() in
-  // WindowTreeHost::GetTransformedRootWindowBoundsInPixels().
-  const gfx::Transform rotate_90(0.f, -1.f, 0.f, 0.f,  //
-                                 1.f, 0.f, 0.f, 0.f,   //
-                                 0.f, 0.f, 1.f, 0.f,   //
-                                 0.f, 0.f, 0.f, 1.f);
-  const gfx::Transform rotate_180 = rotate_90 * rotate_90;
-  const gfx::Transform rotate_270 = rotate_180 * rotate_90;
-  gfx::Transform translation;
-  switch (rotation) {
-    case display::Display::ROTATE_0:
-      return translation;
-    case display::Display::ROTATE_90:
-      translation.Translate(size.height(), 0);
-      return translation * rotate_90;
-    case display::Display::ROTATE_180:
-      translation.Translate(size.width(), size.height());
-      return translation * rotate_180;
-    case display::Display::ROTATE_270:
-      translation.Translate(0, size.width());
-      return translation * rotate_270;
-  }
-}
-
 gfx::Insets Display::GetWorkAreaInsets() const {
   return gfx::Insets(work_area_.y() - bounds_.y(), work_area_.x() - bounds_.x(),
                      bounds_.bottom() - work_area_.bottom(),

ui/display/display.h

@@ -13,8 +13,6 @@
 #include "ui/display/types/display_constants.h"
 #include "ui/gfx/color_space.h"
 #include "ui/gfx/geometry/rect.h"
-#include "ui/gfx/geometry/size_f.h"
-#include "ui/gfx/transform.h"
 
 namespace display {
 
@@ -167,11 +165,6 @@ class DISPLAY_EXPORT Display final {
   void set_panel_rotation(Rotation rotation) { panel_rotation_ = rotation; }
   int PanelRotationAsDegree() const;
 
-  // Returns an exact matrix representation of the transform that corrects for
-  // the display's rotation.
-  static gfx::Transform GetRotationTransform(Rotation rotation,
-                                             const gfx::SizeF& size);
-
   TouchSupport touch_support() const { return touch_support_; }
   void set_touch_support(TouchSupport support) { touch_support_ = support; }
 

ui/display/display_transform.cc

+// Copyright 2019 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 "ui/display/display_transform.h"
+
+#include "ui/gfx/overlay_transform_utils.h"
+
+namespace display {
+
+gfx::Transform CreateRotationTransform(display::Display::Rotation rotation,
+                                       const gfx::SizeF& size_to_rotate) {
+  return OverlayTransformToTransform(
+      DisplayRotationToOverlayTransform(rotation), size_to_rotate);
+}
+
+gfx::OverlayTransform DisplayRotationToOverlayTransform(
+    display::Display::Rotation rotation) {
+  // Note that the angle provided by |rotation| here is the opposite direction
+  // of the physical rotation of the device, which is the space in which the UI
+  // prepares the scene (see
+  // https://developer.android.com/reference/android/view/Display#getRotation()
+  // for details).
+  //
+  // The rotation which needs to be applied by the display compositor to allow
+  // the buffers produced by it to be used directly by the system compositor
+  // needs to be the inverse of this rotation. Since display::Rotation is in
+  // clockwise direction while gfx::OverlayTransform is anti-clockwise, directly
+  // mapping them below performs this inversion.
+  switch (rotation) {
+    case display::Display::ROTATE_0:
+      return gfx::OVERLAY_TRANSFORM_NONE;
+    case display::Display::ROTATE_90:
+      return gfx::OVERLAY_TRANSFORM_ROTATE_90;
+    case display::Display::ROTATE_180:
+      return gfx::OVERLAY_TRANSFORM_ROTATE_180;
+    case display::Display::ROTATE_270:
+      return gfx::OVERLAY_TRANSFORM_ROTATE_270;
+  }
+  NOTREACHED();
+  return gfx::OVERLAY_TRANSFORM_NONE;
+}
+
+}  // namespace display

ui/display/display_transform.h

+// Copyright 2019 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_DISPLAY_DISPLAY_TRANSFORM_H_
+#define UI_DISPLAY_DISPLAY_TRANSFORM_H_
+
+#include "ui/display/display.h"
+#include "ui/display/display_export.h"
+#include "ui/gfx/overlay_transform.h"
+
+namespace gfx {
+class SizeF;
+class Transform;
+}  // namespace gfx
+
+namespace display {
+
+// Creates an exact gfx::Transform for a rotation.
+DISPLAY_EXPORT gfx::Transform CreateRotationTransform(
+    display::Display::Rotation rotation,
+    const gfx::SizeF& size_to_rotate);
+
+// Maps display::Display::Rotation to gfx::OverlayTransform.
+DISPLAY_EXPORT gfx::OverlayTransform DisplayRotationToOverlayTransform(
+    display::Display::Rotation rotation);
+
+}  // namespace display
+
+#endif  // UI_DISPLAY_DISPLAY_TRANSFORM_H_

ui/gfx/OWNERS

@@ -23,6 +23,11 @@ per-file screen*=oshima@chromium.org
 # Canvas painting.
 per-file canvas*=danakj@chromium.org
 
+# Overlay transforms.
+per-file overlay*=alexst@chromium.org
+per-file overlay*=khushalsagar@chromium.org
+per-file overlay*=spang@chromium.org
+
 # Transform, interpolated transform and transform util.
 per-file transform*=danakj@chromium.org
 per-file transform*=vollick@chromium.org