MotionEvent: Rotate relative axes according to window orientation

We rotate the X and Y coordinates of MotionEvents when the window
transform also contains a rotation. This means we should rotate the
relative axes (AXIS_RELATIVE_{X,Y}) as well, making sure not to
translate these relative values.

Bug: 179274888
Test: libinput_tests
Test: manual with test app
Change-Id: I8c716b14ee2b3cd5362f4e9f1554ee37d6875c2d
diff --git a/libs/input/tests/InputEvent_test.cpp b/libs/input/tests/InputEvent_test.cpp
index 97fe9c1..cfb5986 100644
--- a/libs/input/tests/InputEvent_test.cpp
+++ b/libs/input/tests/InputEvent_test.cpp
@@ -636,13 +636,16 @@
     ASSERT_NEAR(originalRawY, event.getRawY(0), 0.001);
 }
 
-MotionEvent createTouchDownEvent(int x, int y, ui::Transform transform) {
+MotionEvent createTouchDownEvent(float x, float y, float dx, float dy,
+                                 const ui::Transform& transform) {
     std::vector<PointerProperties> pointerProperties;
     pointerProperties.push_back(PointerProperties{/* id */ 0, AMOTION_EVENT_TOOL_TYPE_FINGER});
     std::vector<PointerCoords> pointerCoords;
     pointerCoords.emplace_back().clear();
     pointerCoords.back().setAxisValue(AMOTION_EVENT_AXIS_X, x);
     pointerCoords.back().setAxisValue(AMOTION_EVENT_AXIS_Y, y);
+    pointerCoords.back().setAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, dx);
+    pointerCoords.back().setAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, dy);
     nsecs_t eventTime = systemTime(SYSTEM_TIME_MONOTONIC);
     MotionEvent event;
     event.initialize(InputEvent::nextId(), /* deviceId */ 1, AINPUT_SOURCE_TOUCHSCREEN,
@@ -661,26 +664,36 @@
     ui::Transform identity;
     ui::Transform xform(ui::Transform::ROT_90, 800, 400);
     xform.set(xform.tx() + 20, xform.ty() + 40);
-    MotionEvent event = createTouchDownEvent(60, 100, xform);
+    MotionEvent event = createTouchDownEvent(60, 100, 42, 96, xform);
     ASSERT_EQ(700, event.getRawX(0));
     ASSERT_EQ(60, event.getRawY(0));
     ASSERT_NE(event.getRawX(0), event.getX(0));
     ASSERT_NE(event.getRawY(0), event.getY(0));
+    // Relative values should be rotated but not translated.
+    ASSERT_EQ(-96, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0));
+    ASSERT_EQ(42, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0));
 
-    MotionEvent changedEvent = createTouchDownEvent(60, 100, identity);
+    MotionEvent changedEvent = createTouchDownEvent(60, 100, 42, 96, identity);
     const std::array<float, 9> rowMajor{xform[0][0], xform[1][0], xform[2][0],
                                         xform[0][1], xform[1][1], xform[2][1],
                                         xform[0][2], xform[1][2], xform[2][2]};
     changedEvent.applyTransform(rowMajor);
 
     // transformContent effectively rotates the raw coordinates, so those should now include
-    // both rotation AND offset
+    // both rotation AND offset.
     ASSERT_EQ(720, changedEvent.getRawX(0));
     ASSERT_EQ(100, changedEvent.getRawY(0));
+    // Relative values should be rotated but not translated.
+    ASSERT_EQ(-96, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0));
+    ASSERT_EQ(42, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0));
 
-    // The transformed output should be the same then
+    // The transformed output should be the same then.
     ASSERT_NEAR(event.getX(0), changedEvent.getX(0), 0.001);
     ASSERT_NEAR(event.getY(0), changedEvent.getY(0), 0.001);
+    ASSERT_NEAR(event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0),
+                changedEvent.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0), 0.001);
+    ASSERT_NEAR(event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0),
+                changedEvent.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0), 0.001);
 }
 
 TEST_F(MotionEventTest, NonPointerSourcesAreNotTranslated) {
@@ -691,7 +704,7 @@
         // Create a rotate-90 transform with an offset (like a window which isn't fullscreen).
         ui::Transform xform(ui::Transform::ROT_90, 800, 400);
         xform.set(xform.tx() + 20, xform.ty() + 40);
-        MotionEvent event = createTouchDownEvent(60, 100, xform);
+        MotionEvent event = createTouchDownEvent(60, 100, 42, 96, xform);
         event.setSource(source);
 
         // Since this event comes from a non-pointer source, it should include rotation but not
@@ -708,11 +721,14 @@
         // Make sure raw is raw regardless of transform translation.
         ui::Transform xform;
         xform.set(20, 40);
-        MotionEvent event = createTouchDownEvent(60, 100, xform);
+        MotionEvent event = createTouchDownEvent(60, 100, 42, 96, xform);
         ASSERT_EQ(60, event.getRawX(0));
         ASSERT_EQ(100, event.getRawY(0));
         ASSERT_NE(event.getRawX(0), event.getX(0));
         ASSERT_NE(event.getRawY(0), event.getY(0));
+        // Relative values should not be modified.
+        ASSERT_EQ(42, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0));
+        ASSERT_EQ(96, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0));
     }
 
     // Next check that getRaw contains rotation (for compatibility) but otherwise is still
@@ -721,29 +737,38 @@
         // Create a rotate-90 transform with an offset (like a window which isn't fullscreen).
         ui::Transform xform(ui::Transform::ROT_90, 800, 400);
         xform.set(xform.tx() + 20, xform.ty() + 40);
-        MotionEvent event = createTouchDownEvent(60, 100, xform);
+        MotionEvent event = createTouchDownEvent(60, 100, 42, 96, xform);
         ASSERT_EQ(700, event.getRawX(0));
         ASSERT_EQ(60, event.getRawY(0));
         ASSERT_NE(event.getRawX(0), event.getX(0));
         ASSERT_NE(event.getRawY(0), event.getY(0));
+        // Relative values should be rotated but not translated.
+        ASSERT_EQ(-96, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0));
+        ASSERT_EQ(42, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0));
     }
 
     {
         // Same as above, but check rotate-180.
         ui::Transform xform(ui::Transform::ROT_180, 400, 800);
         xform.set(xform.tx() + 20, xform.ty() + 40);
-        MotionEvent event = createTouchDownEvent(60, 100, xform);
+        MotionEvent event = createTouchDownEvent(60, 100, 42, 96, xform);
         ASSERT_EQ(340, event.getRawX(0));
         ASSERT_EQ(700, event.getRawY(0));
+        // Relative values should be rotated but not translated.
+        ASSERT_EQ(-42, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0));
+        ASSERT_EQ(-96, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0));
     }
 
     {
         // Same as above, but check rotate-270.
         ui::Transform xform(ui::Transform::ROT_270, 800, 400);
         xform.set(xform.tx() + 20, xform.ty() + 40);
-        MotionEvent event = createTouchDownEvent(60, 100, xform);
+        MotionEvent event = createTouchDownEvent(60, 100, 42, 96, xform);
         ASSERT_EQ(100, event.getRawX(0));
         ASSERT_EQ(340, event.getRawY(0));
+        // Relative values should be rotated but not translated.
+        ASSERT_EQ(96, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, 0));
+        ASSERT_EQ(-42, event.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, 0));
     }
 }