Merge "[CE] Extract transform computation logic to ProjectionSpace"

14 files changed, 290 insertions, 104 deletions

diff --git a/libs/ui/include/ui/Transform.h b/libs/ui/include/ui/Transform.h
index 9a434e541b..a197b3b20e 100644
--- a/libs/ui/include/ui/Transform.h
+++ b/libs/ui/include/ui/Transform.h
@@ -111,7 +111,7 @@ public:
     void dump(std::string& result, const char* name, const char* prefix = "") const;
     void dump(const char* name, const char* prefix = "") const;
 
-    static RotationFlags toRotationFlags(Rotation);
+    static constexpr RotationFlags toRotationFlags(Rotation);
 
 private:
     struct mat33 {
@@ -136,7 +136,7 @@ inline void PrintTo(const Transform& t, ::std::ostream* os) {
     *os << out;
 }
 
-inline Transform::RotationFlags Transform::toRotationFlags(Rotation rotation) {
+inline constexpr Transform::RotationFlags Transform::toRotationFlags(Rotation rotation) {
     switch (rotation) {
         case ROTATION_0:
             return ROT_0;
diff --git a/services/surfaceflinger/CompositionEngine/Android.bp b/services/surfaceflinger/CompositionEngine/Android.bp
index 4863297d82..57dc60bbac 100644
--- a/services/surfaceflinger/CompositionEngine/Android.bp
+++ b/services/surfaceflinger/CompositionEngine/Android.bp
@@ -95,8 +95,9 @@ cc_test {
         "tests/MockHWC2.cpp",
         "tests/MockHWComposer.cpp",
         "tests/MockPowerAdvisor.cpp",
-        "tests/OutputTest.cpp",
         "tests/OutputLayerTest.cpp",
+        "tests/OutputTest.cpp",
+        "tests/ProjectionSpaceTest.cpp",
         "tests/RenderSurfaceTest.cpp",
     ],
     static_libs: [
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
index 6552c5460a..fc1adccfb7 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
@@ -163,9 +163,8 @@ public:
     virtual void setCompositionEnabled(bool) = 0;
 
     // Sets the projection state to use
-    virtual void setProjection(const ui::Transform&, uint32_t orientation,
-                               const Rect& orientedDisplaySpaceRect,
-                               const Rect& layerStackSpaceRect, const Rect& displaySpaceRect) = 0;
+    virtual void setProjection(ui::Rotation orientation, const Rect& layerStackSpaceRect,
+                               const Rect& orientedDisplaySpaceRect) = 0;
     // Sets the bounds to use
     virtual void setDisplaySpaceSize(const ui::Size&) = 0;
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/ProjectionSpace.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/ProjectionSpace.h
index 9d15665af1..7ca91d86eb 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/ProjectionSpace.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/ProjectionSpace.h
@@ -38,14 +38,73 @@ struct ProjectionSpace {
 
     // Rect onto which content is projected.
     Rect content;
+
+    // The orientation of this space. This value is meaningful only in relation to the rotation
+    // of another projection space and it's used to determine the rotating transformation when
+    // mapping between the two.
+    // As a convention when using this struct orientation = 0 for the "oriented*" projection
+    // spaces. For example when the display is rotated 90 degress counterclockwise, the orientation
+    // of the display space will become 90, while  the orientation of the layer stack space will
+    // remain the same.
+    ui::Rotation orientation = ui::ROTATION_0;
+
+    // Returns a transform which maps this.content into destination.content
+    // and also rotates according to this.orientation and destination.orientation
+    ui::Transform getTransform(const ProjectionSpace& destination) const {
+        ui::Rotation rotation = destination.orientation - orientation;
+
+        // Compute a transformation which rotates the destination in a way it has the same
+        // orientation as us.
+        const uint32_t inverseRotationFlags = ui::Transform::toRotationFlags(-rotation);
+        ui::Transform inverseRotatingTransform;
+        inverseRotatingTransform.set(inverseRotationFlags, destination.bounds.width(),
+                                     destination.bounds.height());
+        // The destination content rotated so it has the same orientation as us.
+        Rect orientedDestContent = inverseRotatingTransform.transform(destination.content);
+
+        // Compute translation from the source content to (0, 0).
+        const float sourceX = content.left;
+        const float sourceY = content.top;
+        ui::Transform sourceTranslation;
+        sourceTranslation.set(-sourceX, -sourceY);
+
+        // Compute scaling transform which maps source content to destination content, assuming
+        // they are both at (0, 0).
+        ui::Transform scale;
+        const float scaleX = static_cast<float>(orientedDestContent.width()) / content.width();
+        const float scaleY = static_cast<float>(orientedDestContent.height()) / content.height();
+        scale.set(scaleX, 0, 0, scaleY);
+
+        // Compute translation from (0, 0) to the orientated destination content.
+        const float destX = orientedDestContent.left;
+        const float destY = orientedDestContent.top;
+        ui::Transform destTranslation;
+        destTranslation.set(destX, destY);
+
+        // Compute rotation transform.
+        const uint32_t orientationFlags = ui::Transform::toRotationFlags(rotation);
+        auto orientedDestWidth = destination.bounds.width();
+        auto orientedDestHeight = destination.bounds.height();
+        if (rotation == ui::ROTATION_90 || rotation == ui::ROTATION_270) {
+            std::swap(orientedDestWidth, orientedDestHeight);
+        }
+        ui::Transform rotationTransform;
+        rotationTransform.set(orientationFlags, orientedDestWidth, orientedDestHeight);
+
+        // The layerStackSpaceRect and orientedDisplaySpaceRect are both in the logical orientation.
+        // Apply the logical translation, scale to physical size, apply the
+        // physical translation and finally rotate to the physical orientation.
+        return rotationTransform * destTranslation * scale * sourceTranslation;
+    }
 };
 
 } // namespace compositionengine
 
 inline std::string to_string(const android::compositionengine::ProjectionSpace& space) {
-    return android::base::StringPrintf("ProjectionSpace(bounds = %s, content = %s)",
-                                       to_string(space.bounds).c_str(),
-                                       to_string(space.content).c_str());
+    return android::base::
+            StringPrintf("ProjectionSpace(bounds = %s, content = %s, orientation = %s)",
+                         to_string(space.bounds).c_str(), to_string(space.content).c_str(),
+                         toCString(space.orientation));
 }
 
 // Defining PrintTo helps with Google Tests.
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
index e009894964..6fe93bfc20 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
@@ -38,9 +38,8 @@ public:
     bool isValid() const override;
     std::optional<DisplayId> getDisplayId() const override;
     void setCompositionEnabled(bool) override;
-    void setProjection(const ui::Transform&, uint32_t orientation,
-                       const Rect& orientedDisplaySpaceRect, const Rect& layerStackSpaceRect,
-                       const Rect& displaySpaceRect) override;
+    void setProjection(ui::Rotation orientation, const Rect& layerStackSpaceRect,
+                       const Rect& orientedDisplaySpaceRect) override;
     void setDisplaySpaceSize(const ui::Size&) override;
     void setLayerStackFilter(uint32_t layerStackId, bool isInternal) override;
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h
index 462d9525cc..f4d2b56d3a 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h
@@ -64,13 +64,11 @@ struct OutputCompositionState {
     uint32_t layerStackId{~0u};
 
     // The common space for all layers in the layer stack. layerStackSpace.content is the Rect
-    // which gets projected on the display. The content in this space is always in a single
-    // orientation.
+    // which gets projected on the display. The orientation of this space is always ROTATION_0.
     ProjectionSpace layerStackSpace;
 
     // Oriented physical display space. It will have the same size as displaySpace oriented to
-    // match the orientation of layerStackSpace. The content in this space is always in a single
-    // orientation.
+    // match the orientation of layerStackSpace. The orientation of this space is always ROTATION_0.
     ProjectionSpace orientedDisplaySpace;
 
     // The space of the physical display. It is as big as the currently active display mode. The
@@ -80,9 +78,6 @@ struct OutputCompositionState {
     // Transformation from layerStackSpace to displaySpace
     ui::Transform transform;
 
-    // The physical orientation of the display, expressed as ui::Transform orientation flags.
-    uint32_t orientation{0};
-
     // If true, RenderEngine filtering should be enabled
     bool needsFiltering{false};
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
index 5350611ae4..19025c1edc 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
@@ -36,8 +36,7 @@ public:
     MOCK_CONST_METHOD0(getDisplayId, std::optional<DisplayId>());
 
     MOCK_METHOD1(setCompositionEnabled, void(bool));
-    MOCK_METHOD5(setProjection,
-                 void(const ui::Transform&, uint32_t, const Rect&, const Rect&, const Rect&));
+    MOCK_METHOD3(setProjection, void(ui::Rotation, const Rect&, const Rect&));
     MOCK_METHOD1(setDisplaySpaceSize, void(const ui::Size&));
     MOCK_METHOD2(setLayerStackFilter, void(uint32_t, bool));
 
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index 816a09b05c..abb8769563 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -105,25 +105,34 @@ void Output::setCompositionEnabled(bool enabled) {
     dirtyEntireOutput();
 }
 
-void Output::setProjection(const ui::Transform& transform, uint32_t orientation,
-                           const Rect& orientedDisplaySpaceRect, const Rect& layerStackSpaceRect,
-                           const Rect& displaySpaceRect) {
+void Output::setProjection(ui::Rotation orientation, const Rect& layerStackSpaceRect,
+                           const Rect& orientedDisplaySpaceRect) {
     auto& outputState = editState();
-    outputState.transform = transform;
-    outputState.orientation = orientation;
-    outputState.displaySpace.content = displaySpaceRect;
+
+    outputState.displaySpace.orientation = orientation;
     // outputState.displaySpace.bounds should be already set from setDisplaySpaceSize().
-    outputState.orientedDisplaySpace.content = orientedDisplaySpaceRect;
 
+    // Compute the orientedDisplaySpace bounds
     ui::Size orientedSize = outputState.displaySpace.bounds.getSize();
-    if (orientation == ui::Transform::ROT_90 || orientation == ui::Transform::ROT_270) {
+    if (orientation == ui::ROTATION_90 || orientation == ui::ROTATION_270) {
         std::swap(orientedSize.width, orientedSize.height);
     }
     outputState.orientedDisplaySpace.bounds = Rect(orientedSize);
+    outputState.orientedDisplaySpace.content = orientedDisplaySpaceRect;
+
+    // Compute displaySpace.content
+    const uint32_t transformOrientationFlags = ui::Transform::toRotationFlags(orientation);
+    ui::Transform rotation;
+    if (transformOrientationFlags != ui::Transform::ROT_INVALID) {
+        const auto displaySize = outputState.displaySpace.bounds;
+        rotation.set(transformOrientationFlags, displaySize.width(), displaySize.height());
+    }
+    outputState.displaySpace.content = rotation.transform(orientedDisplaySpaceRect);
 
     outputState.layerStackSpace.content = layerStackSpaceRect;
     outputState.layerStackSpace.bounds = layerStackSpaceRect;
-    outputState.needsFiltering = transform.needsBilinearFiltering();
+    outputState.transform = outputState.layerStackSpace.getTransform(outputState.displaySpace);
+    outputState.needsFiltering = outputState.transform.needsBilinearFiltering();
 
     dirtyEntireOutput();
 }
@@ -870,7 +879,8 @@ std::optional<base::unique_fd> Output::composeSurfaces(
     renderengine::DisplaySettings clientCompositionDisplay;
     clientCompositionDisplay.physicalDisplay = outputState.displaySpace.content;
     clientCompositionDisplay.clip = outputState.layerStackSpace.content;
-    clientCompositionDisplay.orientation = outputState.orientation;
+    clientCompositionDisplay.orientation =
+            ui::Transform::toRotationFlags(outputState.displaySpace.orientation);
     clientCompositionDisplay.outputDataspace = mDisplayColorProfile->hasWideColorGamut()
             ? outputState.dataspace
             : ui::Dataspace::UNKNOWN;
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
index 0f536411a9..0faab6fbf4 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
@@ -133,7 +133,8 @@ FloatRect OutputLayer::calculateOutputSourceCrop() const {
          * the code below applies the primary display's inverse transform to the
          * buffer
          */
-        uint32_t invTransformOrient = outputState.orientation;
+        uint32_t invTransformOrient =
+                ui::Transform::toRotationFlags(outputState.displaySpace.orientation);
         // calculate the inverse transform
         if (invTransformOrient & HAL_TRANSFORM_ROT_90) {
             invTransformOrient ^= HAL_TRANSFORM_FLIP_V | HAL_TRANSFORM_FLIP_H;
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index d9fb0982f2..dcfc162922 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -21,6 +21,7 @@
 #include <compositionengine/mock/LayerFE.h>
 #include <compositionengine/mock/Output.h>
 #include <gtest/gtest.h>
+#include <log/log.h>
 
 #include "MockHWC2.h"
 #include "MockHWComposer.h"
@@ -55,6 +56,22 @@ MATCHER_P(ColorEq, expected, "") {
     return expected.r == arg.r && expected.g == arg.g && expected.b == arg.b && expected.a == arg.a;
 }
 
+ui::Rotation toRotation(uint32_t rotationFlag) {
+    switch (rotationFlag) {
+        case ui::Transform::RotationFlags::ROT_0:
+            return ui::ROTATION_0;
+        case ui::Transform::RotationFlags::ROT_90:
+            return ui::ROTATION_90;
+        case ui::Transform::RotationFlags::ROT_180:
+            return ui::ROTATION_180;
+        case ui::Transform::RotationFlags::ROT_270:
+            return ui::ROTATION_270;
+        default:
+            LOG_FATAL("Unexpected rotation flag %d", rotationFlag);
+            return ui::Rotation(-1);
+    }
+}
+
 struct OutputLayerTest : public testing::Test {
     struct OutputLayer final : public impl::OutputLayer {
         OutputLayer(const compositionengine::Output& output, sp<compositionengine::LayerFE> layerFE)
@@ -209,7 +226,7 @@ TEST_F(OutputLayerSourceCropTest, calculateOutputSourceCropWorksWithATransformed
 
         mLayerFEState.geomBufferUsesDisplayInverseTransform = entry.bufferInvDisplay;
         mLayerFEState.geomBufferTransform = entry.buffer;
-        mOutputState.orientation = entry.display;
+        mOutputState.displaySpace.orientation = toRotation(entry.display);
 
         EXPECT_THAT(calculateOutputSourceCrop(), entry.expected) << "entry " << i;
     }
@@ -358,7 +375,7 @@ TEST_F(OutputLayerTest, calculateOutputRelativeBufferTransformTestsNeeded) {
 
         mLayerFEState.geomLayerTransform.set(entry.layer, 1920, 1080);
         mLayerFEState.geomBufferTransform = entry.buffer;
-        mOutputState.orientation = entry.display;
+        mOutputState.displaySpace.orientation = toRotation(entry.display);
         mOutputState.transform = ui::Transform{entry.display};
 
         const auto actual = mOutputLayer.calculateOutputRelativeBufferTransform(entry.display);
@@ -470,7 +487,7 @@ TEST_F(OutputLayerTest,
 
         mLayerFEState.geomLayerTransform.set(entry.layer, 1920, 1080);
         mLayerFEState.geomBufferTransform = entry.buffer;
-        mOutputState.orientation = entry.display;
+        mOutputState.displaySpace.orientation = toRotation(entry.display);
         mOutputState.transform = ui::Transform{entry.display};
 
         const auto actual = mOutputLayer.calculateOutputRelativeBufferTransform(entry.internal);
@@ -853,7 +870,7 @@ TEST_F(OutputLayerTest, displayInstallOrientationBufferTransformSetTo90) {
     // This test simulates a scenario where displayInstallOrientation is set to
     // ROT_90. This only has an effect on the transform; orientation stays 0 (see
     // DisplayDevice::setProjection).
-    mOutputState.orientation = TR_IDENT;
+    mOutputState.displaySpace.orientation = ui::ROTATION_0;
     mOutputState.transform = ui::Transform{TR_ROT_90};
     // Buffers are pre-rotated based on the transform hint (ROT_90); their
     // geomBufferTransform is set to the inverse transform.
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index 23efd2dc18..c01f3e00a2 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -236,19 +236,15 @@ TEST_F(OutputTest, setCompositionEnabledSetsDisabledAndDirtiesEntireOutput) {
  */
 
 TEST_F(OutputTest, setProjectionTriviallyWorks) {
-    const ui::Transform transform{ui::Transform::ROT_180};
-    const int32_t orientation = 123;
+    const ui::Rotation orientation = ui::ROTATION_90;
     const Rect frame{1, 2, 3, 4};
     const Rect viewport{5, 6, 7, 8};
-    const Rect destinationClip{13, 14, 15, 16};
 
-    mOutput->setProjection(transform, orientation, frame, viewport, destinationClip);
+    mOutput->setProjection(orientation, viewport, frame);
 
-    EXPECT_THAT(mOutput->getState().transform, transform);
-    EXPECT_EQ(orientation, mOutput->getState().orientation);
+    EXPECT_EQ(orientation, mOutput->getState().displaySpace.orientation);
     EXPECT_EQ(frame, mOutput->getState().orientedDisplaySpace.content);
     EXPECT_EQ(viewport, mOutput->getState().layerStackSpace.content);
-    EXPECT_EQ(destinationClip, mOutput->getState().displaySpace.content);
 }
 
 /*
@@ -2783,8 +2779,8 @@ struct OutputComposeSurfacesTest : public testing::Test {
         mOutput.mState.orientedDisplaySpace.content = kDefaultOutputFrame;
         mOutput.mState.layerStackSpace.content = kDefaultOutputViewport;
         mOutput.mState.displaySpace.content = kDefaultOutputDestinationClip;
-        mOutput.mState.transform = ui::Transform{kDefaultOutputOrientation};
-        mOutput.mState.orientation = kDefaultOutputOrientation;
+        mOutput.mState.transform = ui::Transform{kDefaultOutputOrientationFlags};
+        mOutput.mState.displaySpace.orientation = kDefaultOutputOrientation;
         mOutput.mState.dataspace = kDefaultOutputDataspace;
         mOutput.mState.colorTransformMatrix = kDefaultColorTransformMat;
         mOutput.mState.isSecure = false;
@@ -2819,7 +2815,9 @@ struct OutputComposeSurfacesTest : public testing::Test {
     // Call this member function to start using the mini-DSL defined above.
     [[nodiscard]] auto verify() { return ExecuteState::make(this); }
 
-    static constexpr uint32_t kDefaultOutputOrientation = TR_IDENT;
+    static constexpr ui::Rotation kDefaultOutputOrientation = ui::ROTATION_0;
+    static constexpr uint32_t kDefaultOutputOrientationFlags =
+            ui::Transform::toRotationFlags(kDefaultOutputOrientation);
     static constexpr ui::Dataspace kDefaultOutputDataspace = ui::Dataspace::UNKNOWN;
     static constexpr ui::Dataspace kExpensiveOutputDataspace = ui::Dataspace::DISPLAY_P3;
     static constexpr float kDefaultMaxLuminance = 0.9f;
@@ -3116,7 +3114,7 @@ TEST_F(OutputComposeSurfacesTest_UsesExpectedDisplaySettings, forHdrMixedComposi
             .andIfSkipColorTransform(false)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace, mat4(),
-                                            Region::INVALID_REGION, kDefaultOutputOrientation})
+                                            Region::INVALID_REGION, kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3127,7 +3125,7 @@ TEST_F(OutputComposeSurfacesTest_UsesExpectedDisplaySettings, forNonHdrMixedComp
             .andIfSkipColorTransform(false)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace, mat4(),
-                                            Region::INVALID_REGION, kDefaultOutputOrientation})
+                                            Region::INVALID_REGION, kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3139,7 +3137,7 @@ TEST_F(OutputComposeSurfacesTest_UsesExpectedDisplaySettings, forHdrOnlyClientCo
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace,
                                             kDefaultColorTransformMat, Region::INVALID_REGION,
-                                            kDefaultOutputOrientation})
+                                            kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3151,7 +3149,7 @@ TEST_F(OutputComposeSurfacesTest_UsesExpectedDisplaySettings, forNonHdrOnlyClien
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace,
                                             kDefaultColorTransformMat, Region::INVALID_REGION,
-                                            kDefaultOutputOrientation})
+                                            kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3163,7 +3161,7 @@ TEST_F(OutputComposeSurfacesTest_UsesExpectedDisplaySettings,
             .andIfSkipColorTransform(true)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace, mat4(),
-                                            Region::INVALID_REGION, kDefaultOutputOrientation})
+                                            Region::INVALID_REGION, kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3409,8 +3407,9 @@ struct GenerateClientCompositionRequestsTest_ThreeLayers
         mOutput.mState.orientedDisplaySpace.content = kDisplayFrame;
         mOutput.mState.layerStackSpace.content = kDisplayViewport;
         mOutput.mState.displaySpace.content = kDisplayDestinationClip;
-        mOutput.mState.transform = ui::Transform{kDisplayOrientation};
-        mOutput.mState.orientation = kDisplayOrientation;
+        mOutput.mState.transform =
+                ui::Transform{ui::Transform::toRotationFlags(kDisplayOrientation)};
+        mOutput.mState.displaySpace.orientation = kDisplayOrientation;
         mOutput.mState.needsFiltering = false;
         mOutput.mState.isSecure = false;
 
@@ -3434,7 +3433,7 @@ struct GenerateClientCompositionRequestsTest_ThreeLayers
         EXPECT_CALL(mOutput, getOutputLayerCount()).WillRepeatedly(Return(mLayers.size()));
     }
 
-    static constexpr uint32_t kDisplayOrientation = TR_IDENT;
+    static constexpr ui::Rotation kDisplayOrientation = ui::ROTATION_0;
     static constexpr ui::Dataspace kDisplayDataspace = ui::Dataspace::UNKNOWN;
 
     static const Rect kDisplayFrame;
@@ -3918,14 +3917,14 @@ TEST_F(GenerateClientCompositionRequestsTest, handlesLandscapeModeSplitScreenReq
     const Rect kPortraitFrame(0, 0, 1000, 2000);
     const Rect kPortraitViewport(0, 0, 2000, 1000);
     const Rect kPortraitDestinationClip(0, 0, 1000, 2000);
-    const uint32_t kPortraitOrientation = TR_ROT_90;
+    const ui::Rotation kPortraitOrientation = ui::ROTATION_90;
     constexpr ui::Dataspace kOutputDataspace = ui::Dataspace::DISPLAY_P3;
 
     mOutput.mState.orientedDisplaySpace.content = kPortraitFrame;
     mOutput.mState.layerStackSpace.content = kPortraitViewport;
     mOutput.mState.displaySpace.content = kPortraitDestinationClip;
-    mOutput.mState.transform = ui::Transform{kPortraitOrientation};
-    mOutput.mState.orientation = kPortraitOrientation;
+    mOutput.mState.transform = ui::Transform{ui::Transform::toRotationFlags(kPortraitOrientation)};
+    mOutput.mState.displaySpace.orientation = kPortraitOrientation;
     mOutput.mState.needsFiltering = false;
     mOutput.mState.isSecure = true;
 
diff --git a/services/surfaceflinger/CompositionEngine/tests/ProjectionSpaceTest.cpp b/services/surfaceflinger/CompositionEngine/tests/ProjectionSpaceTest.cpp
new file mode 100644
index 0000000000..704f5a8c07
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/tests/ProjectionSpaceTest.cpp
@@ -0,0 +1,144 @@
+/*
+ * 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 <compositionengine/ProjectionSpace.h>
+#include <gtest/gtest.h>
+
+namespace android::compositionengine {
+namespace {
+
+// Returns a rectangular strip along the side of the given rect pointed by
+// rotation. E.g. if rotation is ROTATION_0, the srip will be along the top
+// side, if it is ROTATION_90 the stip will be along the right wall.
+// One of the dimensions of the strip will be 0 and the other one will match
+// the length of the corresponding side.
+// The strip will be contained inside the given rect.
+Rect getSideStrip(const Rect& rect, ui::Rotation rotation) {
+    int width, height;
+    if (rotation == ui::ROTATION_90 || rotation == ui::ROTATION_270) {
+        width = 0;
+        height = rect.height();
+    } else {
+        width = rect.width();
+        height = 0;
+    }
+
+    if (rotation == ui::ROTATION_0 || rotation == ui::ROTATION_270) {
+        return Rect(rect.left, rect.top, rect.left + width, rect.top + height);
+    }
+
+    if (rotation == ui::ROTATION_90) {
+        return Rect(rect.right, rect.top, rect.right + width, rect.top + height);
+    }
+
+    if (rotation == ui::ROTATION_180) {
+        return Rect(rect.left, rect.bottom, rect.left + width, rect.bottom + height);
+    }
+
+    return Rect::INVALID_RECT;
+}
+} // namespace
+
+TEST(ProjectionSpaceTest, getTransformToSelfIsIdentity) {
+    ProjectionSpace space;
+    space.content = Rect(100, 200);
+    space.bounds = Rect(100, 200);
+
+    const ui::Transform identity;
+    for (int rotation = 0; rotation <= 3; rotation++) {
+        space.orientation = ui::Rotation(rotation);
+        EXPECT_EQ(space.getTransform(space), identity);
+    }
+}
+
+TEST(ProjectionSpaceTest, getTransformWhenTranslationIsNeeded) {
+    ProjectionSpace source;
+    source.content = Rect(10, 10, 20, 20);
+    source.bounds = Rect(100, 200);
+
+    ProjectionSpace dest;
+    dest.content = Rect(10, 20, 30, 20);
+    dest.bounds = source.bounds;
+
+    const auto transform = source.getTransform(dest);
+    EXPECT_EQ(transform.transform(source.content), dest.content);
+}
+
+TEST(ProjectionSpaceTest, getTransformWhenScaleIsNeeded) {
+    ProjectionSpace source;
+    source.content = Rect(0, 0, 20, 20);
+    source.bounds = Rect(100, 200);
+
+    ProjectionSpace dest;
+    dest.content = Rect(0, 0, 40, 30);
+    dest.bounds = source.bounds;
+
+    const auto transform = source.getTransform(dest);
+    EXPECT_EQ(transform.transform(source.content), dest.content);
+}
+
+TEST(ProjectionSpaceTest, getSideStripTest) {
+    const Rect rect(10, 20, 40, 100);
+    EXPECT_EQ(getSideStrip(rect, ui::ROTATION_0), Rect(10, 20, 40, 20));
+    EXPECT_EQ(getSideStrip(rect, ui::ROTATION_90), Rect(40, 20, 40, 100));
+    EXPECT_EQ(getSideStrip(rect, ui::ROTATION_180), Rect(10, 100, 40, 100));
+    EXPECT_EQ(getSideStrip(rect, ui::ROTATION_270), Rect(10, 20, 10, 100));
+}
+
+void testTransform(const ProjectionSpace& source, const ProjectionSpace& dest) {
+    const auto transform = source.getTransform(dest);
+    EXPECT_EQ(transform.transform(source.content), dest.content)
+            << "Source content doesn't map to dest content when projecting " << to_string(source)
+            << " onto " << to_string(dest);
+
+    // We take a strip at the top (according to the orientation) of each
+    // content rect and verify that transform maps between them. This way we
+    // verify that the transform is rotating properly.
+    // In the following example the strip is marked with asterisks:
+    //
+    //      *******                +-------*
+    //      |     |                |       *
+    //      |     |                |       *
+    //      +-----+                +-------*
+    // source(ROTATION_0)      dest (ROTATION_90)
+    const auto sourceStrip = getSideStrip(source.content, source.orientation);
+    const auto destStrip = getSideStrip(dest.content, dest.orientation);
+    ASSERT_NE(sourceStrip, Rect::INVALID_RECT);
+    ASSERT_NE(destStrip, Rect::INVALID_RECT);
+    const auto mappedStrip = transform.transform(sourceStrip);
+    EXPECT_EQ(mappedStrip, destStrip)
+            << to_string(sourceStrip) << " maps to " << to_string(mappedStrip) << " instead of "
+            << to_string(destStrip) << " when projecting " << to_string(source) << " onto "
+            << to_string(dest);
+}
+
+TEST(ProjectionSpaceTest, getTransformWithOrienations) {
+    ProjectionSpace source;
+    source.bounds = Rect(12, 13, 678, 789);
+    source.content = Rect(40, 50, 234, 343);
+    ProjectionSpace dest;
+    dest.bounds = Rect(17, 18, 879, 564);
+    dest.content = Rect(43, 52, 432, 213);
+
+    for (int sourceRot = 0; sourceRot <= 3; sourceRot++) {
+        source.orientation = ui::Rotation(sourceRot);
+        for (int destRot = 0; destRot <= 3; destRot++) {
+            dest.orientation = ui::Rotation(destRot);
+            testTransform(source, dest);
+        }
+    }
+}
+
+} // namespace android::compositionengine
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index b53f88de58..7df9b766bd 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -163,6 +163,10 @@ void DisplayDevice::setProjection(ui::Rotation orientation, Rect layerStackSpace
                                   Rect orientedDisplaySpaceRect) {
     mOrientation = orientation;
 
+    if (isPrimary()) {
+        sPrimaryDisplayRotationFlags = ui::Transform::toRotationFlags(orientation);
+    }
+
     const Rect& displayBounds = getCompositionDisplay()->getState().displaySpace.bounds;
     const int displayWidth = displayBounds.width();
     const int displayHeight = displayBounds.height();
@@ -184,52 +188,11 @@ void DisplayDevice::setProjection(ui::Rotation orientation, Rect layerStackSpace
         }
     }
 
-    ui::Transform logicalTranslation, physicalTranslation, scale;
-    const float sourceWidth = layerStackSpaceRect.width();
-    const float sourceHeight = layerStackSpaceRect.height();
-    const float destWidth = orientedDisplaySpaceRect.width();
-    const float destHeight = orientedDisplaySpaceRect.height();
-    if (sourceWidth != destWidth || sourceHeight != destHeight) {
-        const float scaleX = destWidth / sourceWidth;
-        const float scaleY = destHeight / sourceHeight;
-        scale.set(scaleX, 0, 0, scaleY);
-    }
-
-    const float sourceX = layerStackSpaceRect.left;
-    const float sourceY = layerStackSpaceRect.top;
-    const float destX = orientedDisplaySpaceRect.left;
-    const float destY = orientedDisplaySpaceRect.top;
-    logicalTranslation.set(-sourceX, -sourceY);
-    physicalTranslation.set(destX, destY);
-
     // We need to take care of display rotation for globalTransform for case if the panel is not
     // installed aligned with device orientation.
     const auto transformOrientation = orientation + mPhysicalOrientation;
-    const uint32_t transformOrientationFlags = ui::Transform::toRotationFlags(transformOrientation);
-    ui::Transform rotation;
-    if (transformOrientationFlags != ui::Transform::ROT_INVALID) {
-        rotation.set(transformOrientationFlags, displayWidth, displayHeight);
-    }
-
-    // The layerStackSpaceRect and orientedDisplaySpaceRect are both in the logical orientation.
-    // Apply the logical translation, scale to physical size, apply the
-    // physical translation and finally rotate to the physical orientation.
-    ui::Transform globalTransform = rotation * physicalTranslation * scale * logicalTranslation;
-
-    Rect displaySpaceRect = globalTransform.transform(layerStackSpaceRect);
-    if (displaySpaceRect.isEmpty()) {
-        displaySpaceRect = displayBounds;
-    }
-    // Make sure the displaySpaceRect is contained in the display bounds
-    displaySpaceRect.intersect(displayBounds, &displaySpaceRect);
-
-    if (isPrimary()) {
-        sPrimaryDisplayRotationFlags = ui::Transform::toRotationFlags(orientation);
-    }
-
-    getCompositionDisplay()->setProjection(globalTransform, transformOrientationFlags,
-                                           orientedDisplaySpaceRect, layerStackSpaceRect,
-                                           displaySpaceRect);
+    getCompositionDisplay()->setProjection(transformOrientation, layerStackSpaceRect,
+                                           orientedDisplaySpaceRect);
 }
 
 ui::Transform::RotationFlags DisplayDevice::getPrimaryDisplayRotationFlags() {
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
index b42d9de9b7..b750d6b39b 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
@@ -1481,7 +1481,7 @@ public:
         EXPECT_EQ(ui::Transform(TRANSFORM_FLAGS_ROT_0, mHardwareDisplaySize.width,
                                 mHardwareDisplaySize.height),
                   compositionState.transform);
-        EXPECT_EQ(TRANSFORM_FLAGS_ROT_0, compositionState.orientation);
+        EXPECT_EQ(ui::ROTATION_0, compositionState.displaySpace.orientation);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.displaySpace.content);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.orientedDisplaySpace.content);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.layerStackSpace.content);
@@ -1493,7 +1493,7 @@ public:
         EXPECT_EQ(ui::Transform(TRANSFORM_FLAGS_ROT_90, mHardwareDisplaySize.width,
                                 mHardwareDisplaySize.height),
                   compositionState.transform);
-        EXPECT_EQ(TRANSFORM_FLAGS_ROT_90, compositionState.orientation);
+        EXPECT_EQ(ui::ROTATION_90, compositionState.displaySpace.orientation);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.displaySpace.content);
         // For 90, the orientedDisplaySpaceRect and layerStackSpaceRect have the hardware display
         // size width and height swapped
@@ -1508,7 +1508,7 @@ public:
         EXPECT_EQ(ui::Transform(TRANSFORM_FLAGS_ROT_180, mHardwareDisplaySize.width,
                                 mHardwareDisplaySize.height),
                   compositionState.transform);
-        EXPECT_EQ(TRANSFORM_FLAGS_ROT_180, compositionState.orientation);
+        EXPECT_EQ(ui::ROTATION_180, compositionState.displaySpace.orientation);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.orientedDisplaySpace.content);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.layerStackSpace.content);
         EXPECT_EQ(false, compositionState.needsFiltering);
@@ -1519,7 +1519,7 @@ public:
         EXPECT_EQ(ui::Transform(TRANSFORM_FLAGS_ROT_270, mHardwareDisplaySize.width,
                                 mHardwareDisplaySize.height),
                   compositionState.transform);
-        EXPECT_EQ(TRANSFORM_FLAGS_ROT_270, compositionState.orientation);
+        EXPECT_EQ(ui::ROTATION_270, compositionState.displaySpace.orientation);
         EXPECT_EQ(Rect(mHardwareDisplaySize), compositionState.displaySpace.content);
         // For 270, the orientedDisplaySpaceRect and layerStackSpaceRect have the hardware display
         // size width and height swapped