core: Fix stageX and stageY getters for MouseEvent

These getters were previously calling `local_to_global`
with the unused localX/localY coordinate set to 0. Howver,
`local_to_global` does a matrix multiplication, which in general
will depend on both the x and y values. This was causing the getters
to return incorrect results when any of the `transform.matrix` values
included a non-diagonal matrix.

We now call `local_to_transform` with the real `localX` and `localY`
values.

core/src/avm2/globals/flash/events/mouse_event.rs

@@ -17,11 +17,18 @@ pub fn get_stage_x<'gc>(
                 .get_public_property("localX", activation)?
                 .coerce_to_number(activation)?;
 
-            if local_x.is_nan() {
+            let local_y = this
+                .get_public_property("localY", activation)?
+                .coerce_to_number(activation)?;
+
+            if local_x.is_nan() || local_y.is_nan() {
                 return Ok(Value::Number(local_x));
             } else if let Some(target) = evt.target().and_then(|t| t.as_display_object()) {
-                let as_twips = Twips::from_pixels(local_x);
-                let xformed = target.local_to_global((as_twips, Twips::ZERO)).0;
+                let x_as_twips = Twips::from_pixels(local_x);
+                let y_as_twips = Twips::from_pixels(local_y);
+                // `local_to_global` does a matrix multiplication, which in general
+                // depends on both the x and y coordinates.
+                let xformed = target.local_to_global((x_as_twips, y_as_twips)).0;
 
                 return Ok(Value::Number(xformed.to_pixels()));
             } else {
@@ -41,15 +48,22 @@ pub fn get_stage_y<'gc>(
 ) -> Result<Value<'gc>, Error<'gc>> {
     if let Some(this) = this {
         if let Some(evt) = this.as_event() {
+            let local_x = this
+                .get_public_property("localX", activation)?
+                .coerce_to_number(activation)?;
+
             let local_y = this
                 .get_public_property("localY", activation)?
                 .coerce_to_number(activation)?;
 
-            if local_y.is_nan() {
+            if local_x.is_nan() || local_y.is_nan() {
                 return Ok(Value::Number(local_y));
             } else if let Some(target) = evt.target().and_then(|t| t.as_display_object()) {
-                let as_twips = Twips::from_pixels(local_y);
-                let xformed = target.local_to_global((Twips::ZERO, as_twips)).1;
+                let x_as_twips = Twips::from_pixels(local_x);
+                let y_as_twips = Twips::from_pixels(local_y);
+                // `local_to_global` does a matrix multiplication, which in general
+                // depends on both the x and y coordinates.
+                let xformed = target.local_to_global((x_as_twips, y_as_twips)).1;
 
                 return Ok(Value::Number(xformed.to_pixels()));
             } else {

tests/tests/swfs/avm2/mouseevent_stagexy/Test.as

@@ -26,11 +26,28 @@
 }
 
 import flash.events.MouseEvent;
+import flash.geom.Matrix;
 
 function assert_event(evt: MouseEvent) {
-	trace("/// evt.stageX");
-	trace(evt.stageX);
-
-	trace("/// evt.stageY");
-	trace(evt.stageY);
+	trace("/// evt.localX = " + evt.localX + " evt.localY = " + evt.localY + " evt.stageX = " + evt.stageX + " evt.stageY = " + evt.stageY);
+	
+	evt.localX = 1;
+	evt.localY = 2;
+	
+	trace("/// set localX=1 localY=2")
+	
+	trace("/// evt.localX = " + evt.localX + " evt.localY = " + evt.localY + " evt.stageX = " + evt.stageX + " evt.stageY = " + evt.stageY);
+	
+	trace("/// modified target.x and target.y")
+	
+	evt.target.x = 100;
+	evt.target.y = 100;
+	
+	trace("/// evt.localX = " + evt.localX + " evt.localY = " + evt.localY + " evt.stageX = " + evt.stageX + " evt.stageY = " + evt.stageY);
+	
+	trace("/// modified target.transform.matrix")
+	
+	evt.target.transform.matrix = new Matrix(1, 2, 3, 4, 5, 6);
+	
+	trace("/// evt.localX = " + evt.localX + " evt.localY = " + evt.localY + " evt.stageX = " + evt.stageX + " evt.stageY = " + evt.stageY);
 }

tests/tests/swfs/avm2/mouseevent_stagexy/output.txt

@@ -1,23 +1,35 @@
 /// (dispatching MouseEvent at 5.0, 1.5...)
-/// evt.stageX
-5
-/// evt.stageY
-1.5
+/// evt.localX = 5 evt.localY = 1.5 evt.stageX = 5 evt.stageY = 1.5
+/// set localX=1 localY=2
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 1 evt.stageY = 2
+/// modified target.x and target.y
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 101 evt.stageY = 102
+/// modified target.transform.matrix
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 12 evt.stageY = 16
 /// (dispatching MouseEvent at 5.0, 1.5...)
-/// evt.stageX
-37
-/// evt.stageY
-17.5
+/// evt.localX = 5 evt.localY = 1.5 evt.stageX = 41.5 evt.stageY = 32
+/// set localX=1 localY=2
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 39 evt.stageY = 26
+/// modified target.x and target.y
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 107 evt.stageY = 110
+/// modified target.transform.matrix
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 12 evt.stageY = 16
 ///this.addChild(this.te);
 /// (dispatching MouseEvent at 5.0, 1.5...)
-/// evt.stageX
-37
-/// evt.stageY
-17.5
+/// evt.localX = 5 evt.localY = 1.5 evt.stageX = 14.5 evt.stageY = 22
+/// set localX=1 localY=2
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 12 evt.stageY = 16
+/// modified target.x and target.y
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 107 evt.stageY = 110
+/// modified target.transform.matrix
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 12 evt.stageY = 16
 ///this.scaleX = 0.5
 ///this.scaleY = 0.25
 /// (dispatching MouseEvent at 5.0, 1.5...)
-/// evt.stageX
-18.5
-/// evt.stageY
-4.4
+/// evt.localX = 5 evt.localY = 1.5 evt.stageX = 7.25 evt.stageY = 5.5
+/// set localX=1 localY=2
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 6 evt.stageY = 4
+/// modified target.x and target.y
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 53.5 evt.stageY = 27.5
+/// modified target.transform.matrix
+/// evt.localX = 1 evt.localY = 2 evt.stageX = 6 evt.stageY = 4