Fix scrolling in WebKit

CoreGraphicsSPI.h

@@ -0,0 +1,9 @@
+// This file is part of Scroll Reverser <https://pilotmoon.com/scrollreverser/>
+// Licensed under Apache License v2.0 <http://www.apache.org/licenses/LICENSE-2.0>
+
+#ifndef CoreGraphicsSPI_h
+#define CoreGraphicsSPI_h
+
+IOHIDEventRef CGEventCopyIOHIDEvent(CGEventRef);
+
+#endif /* CoreGraphicsSPI_h */

IOKitSPI.h

@@ -0,0 +1,46 @@
+// This file is part of Scroll Reverser <https://pilotmoon.com/scrollreverser/>
+// Licensed under Apache License v2.0 <http://www.apache.org/licenses/LICENSE-2.0>
+
+#ifndef IOKitSPI_h
+#define IOKitSPI_h
+
+typedef struct __IOHIDEvent * IOHIDEventRef;
+
+enum {
+    kIOHIDEventTypeNULL,
+    kIOHIDEventTypeVendorDefined,
+    kIOHIDEventTypeKeyboard = 3,
+    kIOHIDEventTypeRotation = 5,
+    kIOHIDEventTypeScroll = 6,
+    kIOHIDEventTypeZoom = 8,
+    kIOHIDEventTypeDigitizer = 11,
+    kIOHIDEventTypeNavigationSwipe = 16,
+    kIOHIDEventTypeForce = 32,
+};
+typedef uint32_t IOHIDEventType;
+
+typedef uint32_t IOHIDEventField;
+typedef uint64_t IOHIDEventSenderID;
+
+
+enum {
+    kIOHIDEventScrollMomentumInterrupted = (1 << 4),
+};
+typedef uint8_t IOHIDEventScrollMomentumBits;
+
+#ifdef __LP64__
+typedef double IOHIDFloat;
+#else
+typedef float IOHIDFloat;
+#endif
+
+#define IOHIDEventFieldBase(type) (type << 16)
+
+#define kIOHIDEventFieldScrollBase IOHIDEventFieldBase(kIOHIDEventTypeScroll)
+static const IOHIDEventField kIOHIDEventFieldScrollX = (kIOHIDEventFieldScrollBase | 0);
+static const IOHIDEventField kIOHIDEventFieldScrollY = (kIOHIDEventFieldScrollBase | 1);
+
+IOHIDFloat IOHIDEventGetFloatValue(IOHIDEventRef, IOHIDEventField);
+void IOHIDEventSetFloatValue(IOHIDEventRef, IOHIDEventField, IOHIDFloat);
+
+#endif /* IOKitSPI_h */

MouseTap.m

@@ -78,6 +78,8 @@ static CGEventRef _callback(CGEventTapProxy proxy,
         }
         else if (type==(CGEventType)NSEventTypeScrollWheel)
         {
+            IOHIDEventRef const ioHidEventRef=CGEventCopyIOHIDEvent(eventRef);
+
             // is inverted from device? (1=natural scrolling, 0=classic scrolling)
             const BOOL invertedFromDevice=!![event isDirectionInvertedFromDevice];
             [tap->logger logBool:invertedFromDevice forKey:@"ifd"];
@@ -93,12 +95,20 @@ static CGEventRef _callback(CGEventTapProxy proxy,
             const int64_t point_axis2=CGEventGetIntegerValueField(eventRef, kCGScrollWheelEventPointDeltaAxis2);
             const double fixedpt_axis1=CGEventGetDoubleValueField(eventRef, kCGScrollWheelEventFixedPtDeltaAxis1);
             const double fixedpt_axis2=CGEventGetDoubleValueField(eventRef, kCGScrollWheelEventFixedPtDeltaAxis2);
+            IOHIDFloat iohid_axis1=0;
+            IOHIDFloat iohid_axis2=0;
+            if (ioHidEventRef) {
+                iohid_axis1=IOHIDEventGetFloatValue(ioHidEventRef, kIOHIDEventFieldScrollY);
+                iohid_axis2=IOHIDEventGetFloatValue(ioHidEventRef, kIOHIDEventFieldScrollX);
+            }
             [tap->logger logSignedInteger:axis1 forKey:@"y"];
             [tap->logger logSignedInteger:axis2 forKey:@"x"];
             [tap->logger logSignedInteger:point_axis1 forKey:@"y_pt"];
             [tap->logger logSignedInteger:point_axis2 forKey:@"x_pt"];
             [tap->logger logDouble:fixedpt_axis1 forKey:@"y_fp"];
             [tap->logger logDouble:fixedpt_axis2 forKey:@"x_fp"];
+            [tap->logger logDouble:iohid_axis1 forKey:@"y_iohid"];
+            [tap->logger logDouble:iohid_axis2 forKey:@"x_iohid"];
 
             // get source pid
             const uint64_t pid=CGEventGetIntegerValueField(eventRef, kCGEventSourceUnixProcessID);
@@ -197,11 +207,21 @@ This is because setting DeltaAxis causes macos to internally modify PointDeltaAx
             if (!discreteAdjust&&vmul!=1) { // vertical - only set these if not doing discrete adjust
                 CGEventSetDoubleValueField(eventRef, kCGScrollWheelEventFixedPtDeltaAxis1, fixedpt_axis1*vmul);
                 CGEventSetIntegerValueField(eventRef, kCGScrollWheelEventPointDeltaAxis1, point_axis1*vmul);
+                if (ioHidEventRef) {
+                    IOHIDEventSetFloatValue(ioHidEventRef, kIOHIDEventFieldScrollY, iohid_axis1*vmul);
+                }
             }
             if (hmul!=1) { // horizontal
                 CGEventSetIntegerValueField(eventRef, kCGScrollWheelEventDeltaAxis2, axis2*hmul);
                 CGEventSetDoubleValueField(eventRef, kCGScrollWheelEventFixedPtDeltaAxis2, fixedpt_axis2*hmul);
                 CGEventSetIntegerValueField(eventRef, kCGScrollWheelEventPointDeltaAxis2, point_axis2*hmul);
+                if (ioHidEventRef) {
+                    IOHIDEventSetFloatValue(ioHidEventRef, kIOHIDEventFieldScrollX, iohid_axis2*vmul);
+                }
+            }
+
+            if (ioHidEventRef) {
+                CFRelease(ioHidEventRef);
             }
         }
         else

ScrollReverser.xcodeproj/project.pbxproj

@@ -169,6 +169,8 @@
 		88AC80572405185D00063181 /* es */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.strings; name = es; path = resources/es.lproj/Localizable.strings; sourceTree = "<group>"; };
 		8D1107310486CEB800E47090 /* ScrollReverser-Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; path = "ScrollReverser-Info.plist"; sourceTree = "<group>"; };
 		8D1107320486CEB800E47090 /* Scroll Reverser (Dev).app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = "Scroll Reverser (Dev).app"; sourceTree = BUILT_PRODUCTS_DIR; };
+		B7CF5D6627BFAB8400E09485 /* IOKitSPI.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = IOKitSPI.h; sourceTree = "<group>"; };
+		B7CF5D6727BFACD800E09485 /* CoreGraphicsSPI.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CoreGraphicsSPI.h; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -302,6 +304,8 @@
 			isa = PBXGroup;
 			children = (
 				256AC3F00F4B6AF500CF3369 /* Scroll_Inverter_Prefix.pch */,
+				B7CF5D6627BFAB8400E09485 /* IOKitSPI.h */,
+				B7CF5D6727BFACD800E09485 /* CoreGraphicsSPI.h */,
 				29B97316FDCFA39411CA2CEA /* main.m */,
 			);
 			name = "Other Sources";

Scroll_Inverter_Prefix.pch

@@ -4,6 +4,8 @@
 
 #ifdef __OBJC__
     #import <Cocoa/Cocoa.h>
+    #import "IOKitSPI.h"
+    #import "CoreGraphicsSPI.h"
 
 #if !defined(DEBUG)
     #define NSLog(...)