[iOS] Stylus support

apple/Handlers/RNPanHandler.m

@@ -7,6 +7,7 @@
 //
 
 #import "RNPanHandler.h"
+#import "RNGHStylusData.h"
 
 #if TARGET_OS_OSX
 
@@ -31,6 +32,10 @@ @interface RNBetterPanGestureRecognizer : UIPanGestureRecognizer
 @property (nonatomic) CGFloat failOffsetYEnd;
 @property (nonatomic) CGFloat activateAfterLongPress;
 
+#if !TARGET_OS_OSX && !TARGET_OS_TV
+@property (atomic, readonly, strong) RNGHStylusData *stylusData;
+#endif
+
 - (id)initWithGestureHandler:(RNGestureHandler *)gestureHandler;
 
 @end
@@ -80,6 +85,28 @@ - (void)setMinimumNumberOfTouches:(NSUInteger)minimumNumberOfTouches
 }
 #endif
 
+#if !TARGET_OS_OSX && !TARGET_OS_TV
+- (void)tryUpdateStylusData:(UIEvent *)event
+{
+  UITouch *touch = [[event allTouches] anyObject];
+
+  if (touch.type != UITouchTypePencil) {
+    return;
+  } else if (_stylusData == nil) {
+    _stylusData = [[RNGHStylusData alloc] init];
+  }
+
+  _stylusData.altitudeAngle = touch.altitudeAngle;
+  _stylusData.azimuthAngle = [touch azimuthAngleInView:nil];
+  _stylusData.pressure = touch.force / touch.maximumPossibleForce;
+
+  CGPoint tilts = ghSpherical2tilt(_stylusData.altitudeAngle, _stylusData.azimuthAngle);
+
+  _stylusData.tiltX = tilts.x;
+  _stylusData.tiltY = tilts.y;
+}
+#endif
+
 - (void)activateAfterLongPress
 {
   self.state = UIGestureRecognizerStateBegan;
@@ -102,6 +129,8 @@ - (void)interactionsBegan:(NSSet *)touches withEvent:(UIEvent *)event
   } else {
     super.minimumNumberOfTouches = _realMinimumNumberOfTouches;
   }
+
+  [self tryUpdateStylusData:event];
 #endif
 
 #if TARGET_OS_OSX
@@ -150,17 +179,28 @@ - (void)interactionsMoved:(NSSet *)touches withEvent:(UIEvent *)event
       [self setTranslation:CGPointMake(0, 0) inView:self.view];
     }
   }
+
+  [self tryUpdateStylusData:event];
 #endif
 }
 
 - (void)interactionsEnded:(NSSet *)touches withEvent:(UIEvent *)event
 {
   [_gestureHandler.pointerTracker touchesEnded:touches withEvent:event];
+
+#if !TARGET_OS_TV && !TARGET_OS_OSX
+  [self tryUpdateStylusData:event];
+#endif
 }
 
 - (void)interactionsCancelled:(NSSet *)touches withEvent:(UIEvent *)event
 {
   [_gestureHandler.pointerTracker touchesCancelled:touches withEvent:event];
+
+#if !TARGET_OS_TV && !TARGET_OS_OSX
+  [self tryUpdateStylusData:event];
+#endif
+
   [self reset];
 }
 
@@ -224,6 +264,10 @@ - (void)reset
   self.enabled = YES;
   [super reset];
   [_gestureHandler reset];
+
+#if !TARGET_OS_TV && !TARGET_OS_OSX
+  _stylusData = nil;
+#endif
 }
 
 - (void)updateHasCustomActivationCriteria
@@ -405,17 +449,23 @@ - (RNGestureHandlerEventExtraData *)eventExtraData:(NSPanGestureRecognizer *)rec
                                 withTranslation:[recognizer translationInView:recognizer.view.window.contentView]
                                    withVelocity:[recognizer velocityInView:recognizer.view.window.contentView]
                             withNumberOfTouches:1
-                                withPointerType:RNGestureHandlerMouse];
+                                withPointerType:RNGestureHandlerMouse
+                                 withStylusData:nil];
 }
 #else
 - (RNGestureHandlerEventExtraData *)eventExtraData:(UIPanGestureRecognizer *)recognizer
 {
-  return [RNGestureHandlerEventExtraData forPan:[recognizer locationInView:recognizer.view]
-                           withAbsolutePosition:[recognizer locationInView:recognizer.view.window]
-                                withTranslation:[recognizer translationInView:recognizer.view.window]
-                                   withVelocity:[recognizer velocityInView:recognizer.view.window]
-                            withNumberOfTouches:recognizer.numberOfTouches
-                                withPointerType:_pointerType];
+  RNBetterPanGestureRecognizer *panRecognizer = (RNBetterPanGestureRecognizer *)recognizer;
+
+  return [RNGestureHandlerEventExtraData
+                    forPan:[recognizer locationInView:recognizer.view]
+      withAbsolutePosition:[recognizer locationInView:recognizer.view.window]
+           withTranslation:[recognizer translationInView:recognizer.view.window]
+              withVelocity:[recognizer velocityInView:recognizer.view.window]
+       withNumberOfTouches:recognizer.numberOfTouches
+           withPointerType:_pointerType
+            withStylusData:[panRecognizer.stylusData toDictionary]]; // In Objective-C calling method on nil returns
+                                                                     // nil, therefore this line does not crash.
 }
 #endif
 

apple/RNGHStylusData.h

@@ -0,0 +1,77 @@
+//
+//  RNGHStylusData.h
+//  Pods
+//
+//  Created by Michał Bert on 18/09/2024.
+//
+
+#ifndef RNGHStylusData_h
+#define RNGHStylusData_h
+
+@interface RNGHStylusData : NSObject
+
+@property (atomic, assign) double tiltX;
+@property (atomic, assign) double tiltY;
+@property (atomic, assign) double altitudeAngle;
+@property (atomic, assign) double azimuthAngle;
+@property (atomic, assign) double pressure;
+
+- (NSDictionary *)toDictionary;
+
+@end
+
+static CGPoint ghSpherical2tilt(double altitudeAngle, double azimuthAngle)
+{
+  CGPoint tilts = {.x = 0.0, .y = 0.0};
+
+  const double radToDeg = 180 / M_PI;
+  const double eps = 0.000000001;
+
+  if (altitudeAngle < eps) {
+    // the pen is in the X-Y plane
+    if (azimuthAngle < eps || fabs(azimuthAngle - 2 * M_PI) < eps) {
+      // pen is on positive X axis
+      tilts.x = M_PI_2;
+    }
+    if (fabs(azimuthAngle - M_PI_2) < eps) {
+      // pen is on positive Y axis
+      tilts.y = M_PI_2;
+    }
+    if (fabs(azimuthAngle - M_PI) < eps) {
+      // pen is on negative X axis
+      tilts.x = -M_PI_2;
+    }
+    if (fabs(azimuthAngle - 3 * M_PI_2) < eps) {
+      // pen is on negative Y axis
+      tilts.y = -M_PI_2;
+    }
+    if (azimuthAngle > eps && fabs(azimuthAngle - M_PI_2) < eps) {
+      tilts.x = M_PI_2;
+      tilts.y = M_PI_2;
+    }
+    if (fabs(azimuthAngle - M_PI_2) > eps && fabs(azimuthAngle - M_PI) < eps) {
+      tilts.x = -M_PI_2;
+      tilts.y = M_PI_2;
+    }
+    if (azimuthAngle - M_PI > eps && fabs(azimuthAngle - 3 * M_PI_2) < eps) {
+      tilts.x = -M_PI_2;
+      tilts.y = -M_PI_2;
+    }
+    if (fabs(azimuthAngle - 3 * M_PI_2) > eps && fabs(azimuthAngle - 2 * M_PI) < eps) {
+      tilts.x = M_PI_2;
+      tilts.y = -M_PI_2;
+    }
+  } else {
+    const double tanAlt = tan(altitudeAngle);
+
+    tilts.x = atan(cos(azimuthAngle) / tanAlt);
+    tilts.y = atan(sin(azimuthAngle) / tanAlt);
+  }
+
+  tilts.x = round(tilts.x * radToDeg);
+  tilts.y = round(tilts.y * radToDeg);
+
+  return tilts;
+}
+
+#endif /* RNGHStylusData_h */

apple/RNGHStylusData.m

@@ -0,0 +1,37 @@
+//
+//  RNGHStylusData.m
+//  DoubleConversion
+//
+//  Created by Michał Bert on 18/09/2024.
+//
+
+#import "RNGHStylusData.h"
+#import <Foundation/Foundation.h>
+
+@implementation RNGHStylusData
+
+- (instancetype)init
+{
+  if (self = [super init]) {
+    self.tiltX = 0;
+    self.tiltY = 0;
+    self.altitudeAngle = M_PI_2;
+    self.azimuthAngle = 0;
+    self.pressure = 0;
+  }
+
+  return self;
+}
+
+- (NSDictionary *)toDictionary
+{
+  return @{
+    @"tiltX" : @(_tiltX),
+    @"tiltY" : @(_tiltY),
+    @"altitudeAngle" : @(_altitudeAngle),
+    @"azimuthAngle" : @(_azimuthAngle),
+    @"pressure" : @(_pressure),
+  };
+}
+
+@end

apple/RNGestureHandlerEvents.h

@@ -2,6 +2,7 @@
 
 #import <Foundation/Foundation.h>
 
+#import "RNGHStylusData.h"
 #import "RNGHTouchEventType.h"
 #import "RNGHUIKit.h"
 #import "RNGestureHandlerState.h"
@@ -29,7 +30,8 @@
                            withTranslation:(CGPoint)translation
                               withVelocity:(CGPoint)velocity
                        withNumberOfTouches:(NSUInteger)numberOfTouches
-                           withPointerType:(NSInteger)pointerType;
+                           withPointerType:(NSInteger)pointerType
+                            withStylusData:(NSDictionary *)stylusData;
 + (RNGestureHandlerEventExtraData *)forForce:(CGFloat)force
                                  forPosition:(CGPoint)position
                         withAbsolutePosition:(CGPoint)absolutePosition

apple/RNGestureHandlerEvents.m

@@ -63,8 +63,9 @@ + (RNGestureHandlerEventExtraData *)forPan:(CGPoint)position
                               withVelocity:(CGPoint)velocity
                        withNumberOfTouches:(NSUInteger)numberOfTouches
                            withPointerType:(NSInteger)pointerType
+                            withStylusData:(NSDictionary *)stylusData
 {
-  return [[RNGestureHandlerEventExtraData alloc] initWithData:@{
+  NSMutableDictionary *data = [@{
     @"x" : @(position.x),
     @"y" : @(position.y),
     @"absoluteX" : @(absolutePosition.x),
@@ -74,8 +75,15 @@ + (RNGestureHandlerEventExtraData *)forPan:(CGPoint)position
     @"velocityX" : SAFE_VELOCITY(velocity.x),
     @"velocityY" : SAFE_VELOCITY(velocity.y),
     @"numberOfPointers" : @(numberOfTouches),
-    @"pointerType" : @(pointerType)
-  }];
+    @"pointerType" : @(pointerType),
+  } mutableCopy];
+
+  // Add the stylusData to the dictionary only if necessary
+  if (stylusData != nil) {
+    data[@"stylusData"] = stylusData;
+  }
+
+  return [[RNGestureHandlerEventExtraData alloc] initWithData:data];
 }
 
 + (RNGestureHandlerEventExtraData *)forForce:(CGFloat)force