diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.cpp b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
index 51a1c39..afbec99 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
@@ -142,12 +142,14 @@
     hoveringIdBits.clear();
     touchingIdBits.clear();
     canceledIdBits.clear();
+    validIdBits.clear();
 }
 
 void CookedPointerData::copyFrom(const CookedPointerData& other) {
     pointerCount = other.pointerCount;
     hoveringIdBits = other.hoveringIdBits;
     touchingIdBits = other.touchingIdBits;
+    validIdBits = other.validIdBits;
 
     for (uint32_t i = 0; i < pointerCount; i++) {
         pointerProperties[i].copyFrom(other.pointerProperties[i]);
@@ -288,12 +290,14 @@
         const PointerProperties& pointerProperties =
                 mLastCookedState.cookedPointerData.pointerProperties[i];
         const PointerCoords& pointerCoords = mLastCookedState.cookedPointerData.pointerCoords[i];
-        dump += StringPrintf(INDENT4 "[%d]: id=%d, x=%0.3f, y=%0.3f, pressure=%0.3f, "
-                                     "touchMajor=%0.3f, touchMinor=%0.3f, toolMajor=%0.3f, "
-                                     "toolMinor=%0.3f, "
+        dump += StringPrintf(INDENT4 "[%d]: id=%d, x=%0.3f, y=%0.3f, dx=%0.3f, dy=%0.3f, "
+                                     "pressure=%0.3f, touchMajor=%0.3f, touchMinor=%0.3f, "
+                                     "toolMajor=%0.3f, toolMinor=%0.3f, "
                                      "orientation=%0.3f, tilt=%0.3f, distance=%0.3f, "
                                      "toolType=%d, isHovering=%s\n",
                              i, pointerProperties.id, pointerCoords.getX(), pointerCoords.getY(),
+                             pointerCoords.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X),
+                             pointerCoords.getAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y),
                              pointerCoords.getAxisValue(AMOTION_EVENT_AXIS_PRESSURE),
                              pointerCoords.getAxisValue(AMOTION_EVENT_AXIS_TOUCH_MAJOR),
                              pointerCoords.getAxisValue(AMOTION_EVENT_AXIS_TOUCH_MINOR),
@@ -2270,15 +2274,26 @@
             out.setAxisValue(AMOTION_EVENT_AXIS_TOOL_MINOR, toolMinor);
         }
 
+        // Write output relative fieldis if applicable.
+        uint32_t id = in.id;
+        if (mSource == AINPUT_SOURCE_TOUCHPAD &&
+            mLastCookedState.cookedPointerData.hasPointerCoordsForId(id)) {
+            const PointerCoords& p = mLastCookedState.cookedPointerData.pointerCoordsForId(id);
+            float dx = xTransformed - p.getAxisValue(AMOTION_EVENT_AXIS_X);
+            float dy = yTransformed - p.getAxisValue(AMOTION_EVENT_AXIS_Y);
+            out.setAxisValue(AMOTION_EVENT_AXIS_RELATIVE_X, dx);
+            out.setAxisValue(AMOTION_EVENT_AXIS_RELATIVE_Y, dy);
+        }
+
         // Write output properties.
         PointerProperties& properties = mCurrentCookedState.cookedPointerData.pointerProperties[i];
-        uint32_t id = in.id;
         properties.clear();
         properties.id = id;
         properties.toolType = in.toolType;
 
-        // Write id index.
+        // Write id index and mark id as valid.
         mCurrentCookedState.cookedPointerData.idToIndex[id] = i;
+        mCurrentCookedState.cookedPointerData.validIdBits.markBit(id);
     }
 }
 
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.h b/services/inputflinger/reader/mapper/TouchInputMapper.h
index 94486a6..df6581d 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.h
@@ -103,7 +103,7 @@
     uint32_t pointerCount;
     PointerProperties pointerProperties[MAX_POINTERS];
     PointerCoords pointerCoords[MAX_POINTERS];
-    BitSet32 hoveringIdBits, touchingIdBits, canceledIdBits;
+    BitSet32 hoveringIdBits, touchingIdBits, canceledIdBits, validIdBits;
     uint32_t idToIndex[MAX_POINTER_ID + 1];
 
     CookedPointerData();
@@ -129,6 +129,8 @@
     inline bool isTouching(uint32_t pointerIndex) const {
         return touchingIdBits.hasBit(pointerProperties[pointerIndex].id);
     }
+
+    inline bool hasPointerCoordsForId(uint32_t id) const { return validIdBits.hasBit(id); }
 };
 
 class TouchInputMapper : public InputMapper {