Change force to be Option<f32> instead of f32 (#3240)

crates/eframe/src/web/input.rs

@@ -68,7 +68,7 @@ pub fn push_touches(runner: &mut AppRunner, phase: egui::TouchPhase, event: &web
                 id: egui::TouchId::from(touch.identifier()),
                 phase,
                 pos: pos_from_touch(canvas_origin, &touch),
-                force: touch.force(),
+                force: Some(touch.force()),
             });
         }
     }

crates/egui-winit/src/lib.rs

@@ -441,7 +441,7 @@ impl State {
                             id: egui::TouchId(0),
                             phase: egui::TouchPhase::Start,
                             pos,
-                            force: 0.0,
+                            force: None,
                         });
                     } else {
                         self.any_pointer_button_down = false;
@@ -453,7 +453,7 @@ impl State {
                             id: egui::TouchId(0),
                             phase: egui::TouchPhase::End,
                             pos,
-                            force: 0.0,
+                            force: None,
                         });
                     };
                 }
@@ -479,7 +479,7 @@ impl State {
                     id: egui::TouchId(0),
                     phase: egui::TouchPhase::Move,
                     pos: pos_in_points,
-                    force: 0.0,
+                    force: None,
                 });
             }
         } else {
@@ -505,13 +505,13 @@ impl State {
                 touch.location.y as f32 / self.pixels_per_point(),
             ),
             force: match touch.force {
-                Some(winit::event::Force::Normalized(force)) => force as f32,
+                Some(winit::event::Force::Normalized(force)) => Some(force as f32),
                 Some(winit::event::Force::Calibrated {
                     force,
                     max_possible_force,
                     ..
-                }) => (force / max_possible_force) as f32,
-                None => 0_f32,
+                }) => Some((force / max_possible_force) as f32),
+                None => None,
             },
         });
         // If we're not yet translating a touch or we're translating this very

crates/egui/src/data/input.rs

@@ -274,10 +274,10 @@ pub enum Event {
         /// Position of the touch (or where the touch was last detected)
         pos: Pos2,
 
-        /// Describes how hard the touch device was pressed. May always be `0` if the platform does
+        /// Describes how hard the touch device was pressed. May always be `None` if the platform does
         /// not support pressure sensitivity.
         /// The value is in the range from 0.0 (no pressure) to 1.0 (maximum pressure).
-        force: f32,
+        force: Option<f32>,
     },
 
     /// A raw mouse wheel event as sent by the backend (minus the z coordinate),

crates/egui/src/input_state/touch_state.rs

@@ -118,7 +118,7 @@ struct ActiveTouch {
     ///
     /// Note that a value of 0.0 either indicates a very light touch, or it means that the device
     /// is not capable of measuring the touch force.
-    force: f32,
+    force: Option<f32>,
 }
 
 impl TouchState {
@@ -249,7 +249,7 @@ impl TouchState {
 
             // first pass: calculate force and center of touch positions:
             for touch in self.active_touches.values() {
-                state.avg_force += touch.force;
+                state.avg_force += touch.force.unwrap_or(0.0);
                 state.avg_pos.x += touch.pos.x;
                 state.avg_pos.y += touch.pos.y;
             }