Tag finger touches and stamp touch samples with their time

events.h

@@ -42,10 +42,11 @@ typedef struct {
   float scale, rotation; // Incremental scale factor and clockwise radians.
 } ax_gesture_t;
 
-enum { AX_POINTER_STYLUS = 1u << 0 };
+enum { AX_POINTER_STYLUS = 1u << 0, AX_POINTER_TOUCH = 1u << 1 };
 typedef struct {
-  uint32_t flags;   /**< AX_POINTER_STYLUS when the sample is a stylus / Apple Pencil. */
+  uint32_t flags;   /**< AX_POINTER_STYLUS for a stylus / Apple Pencil, AX_POINTER_TOUCH for a finger. */
   float altitude;   /**< Radians: 0 = parallel to the surface, π/2 = perpendicular. */
+  uint32_t time;    /**< Sample time in milliseconds for touch samples; 0 when unknown. */
 } ax_pointer_t;
 
 #endif

ios/ios_window.m

@@ -20,7 +20,10 @@ static ax_pointer_t ios_pointer(UITouch *touch) {
   if (touch.type == UITouchTypePencil) {
     p.flags = AX_POINTER_STYLUS;
     p.altitude = (float)touch.altitudeAngle;
+  } else if (touch.type == UITouchTypeDirect) {
+    p.flags = AX_POINTER_TOUCH;
   }
+  p.time = (uint32_t)(uint64_t)(touch.timestamp * 1000);
   return p;
 }