[SF] Extract {Display|Layer}RenderArea to separate files

This CL also fixes incorrect sampling bounds in RegionSamplingThread,
caused by ag/11837111.

Bug: 158599281
Test: atest libsurfaceflinger_unittest
Test: take a screenshot from launcher
Test: take a screenshot from YouTube while playing a video
Change-Id: I7e7777071e91a833a7bad4bd77e9d0c989fea9b7
diff --git a/services/surfaceflinger/DisplayRenderArea.cpp b/services/surfaceflinger/DisplayRenderArea.cpp
new file mode 100644
index 0000000..7cd283d
--- /dev/null
+++ b/services/surfaceflinger/DisplayRenderArea.cpp
@@ -0,0 +1,154 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "DisplayRenderArea.h"
+#include "DisplayDevice.h"
+
+namespace android {
+namespace {
+
+RenderArea::RotationFlags applyDeviceOrientation(RenderArea::RotationFlags rotation,
+                                                 const DisplayDevice& display) {
+    uint32_t inverseRotate90 = 0;
+    uint32_t inverseReflect = 0;
+
+    // Reverse the logical orientation.
+    ui::Rotation logicalOrientation = display.getOrientation();
+    if (logicalOrientation == ui::Rotation::Rotation90) {
+        logicalOrientation = ui::Rotation::Rotation270;
+    } else if (logicalOrientation == ui::Rotation::Rotation270) {
+        logicalOrientation = ui::Rotation::Rotation90;
+    }
+
+    const ui::Rotation orientation = display.getPhysicalOrientation() + logicalOrientation;
+
+    switch (orientation) {
+        case ui::ROTATION_0:
+            return rotation;
+
+        case ui::ROTATION_90:
+            inverseRotate90 = ui::Transform::ROT_90;
+            inverseReflect = ui::Transform::ROT_180;
+            break;
+
+        case ui::ROTATION_180:
+            inverseReflect = ui::Transform::ROT_180;
+            break;
+
+        case ui::ROTATION_270:
+            inverseRotate90 = ui::Transform::ROT_90;
+            break;
+    }
+
+    const uint32_t rotate90 = rotation & ui::Transform::ROT_90;
+    uint32_t reflect = rotation & ui::Transform::ROT_180;
+
+    // Apply reflection for double rotation.
+    if (rotate90 & inverseRotate90) {
+        reflect = ~reflect & ui::Transform::ROT_180;
+    }
+
+    return static_cast<RenderArea::RotationFlags>((rotate90 ^ inverseRotate90) |
+                                                  (reflect ^ inverseReflect));
+}
+
+} // namespace
+
+std::unique_ptr<RenderArea> DisplayRenderArea::create(wp<const DisplayDevice> displayWeak,
+                                                      const Rect& sourceCrop, ui::Size reqSize,
+                                                      ui::Dataspace reqDataSpace,
+                                                      RotationFlags rotation,
+                                                      bool allowSecureLayers) {
+    if (auto display = displayWeak.promote()) {
+        // Using new to access a private constructor.
+        return std::unique_ptr<DisplayRenderArea>(
+                new DisplayRenderArea(std::move(display), sourceCrop, reqSize, reqDataSpace,
+                                      rotation, allowSecureLayers));
+    }
+    return nullptr;
+}
+
+DisplayRenderArea::DisplayRenderArea(sp<const DisplayDevice> display, const Rect& sourceCrop,
+                                     ui::Size reqSize, ui::Dataspace reqDataSpace,
+                                     RotationFlags rotation, bool allowSecureLayers)
+      : RenderArea(reqSize, CaptureFill::OPAQUE, reqDataSpace, display->getViewport(),
+                   applyDeviceOrientation(rotation, *display)),
+        mDisplay(std::move(display)),
+        mSourceCrop(sourceCrop),
+        mAllowSecureLayers(allowSecureLayers) {}
+
+const ui::Transform& DisplayRenderArea::getTransform() const {
+    return mTransform;
+}
+
+Rect DisplayRenderArea::getBounds() const {
+    return mDisplay->getBounds();
+}
+
+int DisplayRenderArea::getHeight() const {
+    return mDisplay->getHeight();
+}
+
+int DisplayRenderArea::getWidth() const {
+    return mDisplay->getWidth();
+}
+
+bool DisplayRenderArea::isSecure() const {
+    return mAllowSecureLayers && mDisplay->isSecure();
+}
+
+sp<const DisplayDevice> DisplayRenderArea::getDisplayDevice() const {
+    return mDisplay;
+}
+
+bool DisplayRenderArea::needsFiltering() const {
+    // check if the projection from the logical render area
+    // to the physical render area requires filtering
+    const Rect& sourceCrop = getSourceCrop();
+    int width = sourceCrop.width();
+    int height = sourceCrop.height();
+    if (getRotationFlags() & ui::Transform::ROT_90) {
+        std::swap(width, height);
+    }
+    return width != getReqWidth() || height != getReqHeight();
+}
+
+Rect DisplayRenderArea::getSourceCrop() const {
+    // use the projected display viewport by default.
+    if (mSourceCrop.isEmpty()) {
+        return mDisplay->getSourceClip();
+    }
+
+    // If there is a source crop provided then it is assumed that the device
+    // was in portrait orientation. This may not logically be true, so
+    // correct for the orientation error by undoing the rotation
+
+    ui::Rotation logicalOrientation = mDisplay->getOrientation();
+    if (logicalOrientation == ui::Rotation::Rotation90) {
+        logicalOrientation = ui::Rotation::Rotation270;
+    } else if (logicalOrientation == ui::Rotation::Rotation270) {
+        logicalOrientation = ui::Rotation::Rotation90;
+    }
+
+    const auto flags = ui::Transform::toRotationFlags(logicalOrientation);
+    int width = mDisplay->getSourceClip().getWidth();
+    int height = mDisplay->getSourceClip().getHeight();
+    ui::Transform rotation;
+    rotation.set(flags, width, height);
+    return rotation.transform(mSourceCrop);
+}
+
+} // namespace android
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