From 31b0a5ae76c8bc6aba3288246bb32fd8df41639c Mon Sep 17 00:00:00 2001
From: Nathan Adams <dinnerbone@dinnerbone.com>
Date: Wed, 20 May 2020 10:53:12 +0200
Subject: [PATCH] avm1: Implement gradient matrix types

---
 core/src/avm1/globals/matrix.rs     | 46 +++++++++++++++++++++++++++++
 core/src/avm1/globals/movie_clip.rs | 44 ++-------------------------
 2 files changed, 49 insertions(+), 41 deletions(-)

diff --git a/core/src/avm1/globals/matrix.rs b/core/src/avm1/globals/matrix.rs
index ebdc4ce89..ac679ab1f 100644
--- a/core/src/avm1/globals/matrix.rs
+++ b/core/src/avm1/globals/matrix.rs
@@ -16,6 +16,50 @@ pub fn value_to_matrix<'gc>(
     object_to_matrix(value.as_object()?, avm, context)
 }
 
+pub fn gradient_object_to_matrix<'gc>(
+    object: Object<'gc>,
+    avm: &mut Avm1<'gc>,
+    context: &mut UpdateContext<'_, 'gc, '_>,
+) -> Result<Matrix, Error> {
+    if object
+        .get("matrixType", avm, context)?
+        .resolve(avm, context)?
+        .coerce_to_string(avm, context)?
+        == "box"
+    {
+        let width = object
+            .get("w", avm, context)?
+            .resolve(avm, context)?
+            .as_number(avm, context)?;
+        let height = object
+            .get("h", avm, context)?
+            .resolve(avm, context)?
+            .as_number(avm, context)?;
+        let rotation = object
+            .get("r", avm, context)?
+            .resolve(avm, context)?
+            .as_number(avm, context)?;
+        let tx = object
+            .get("x", avm, context)?
+            .resolve(avm, context)?
+            .as_number(avm, context)?;
+        let ty = object
+            .get("y", avm, context)?
+            .resolve(avm, context)?
+            .as_number(avm, context)?;
+        Ok(Matrix::create_gradient_box(
+            width as f32,
+            height as f32,
+            rotation as f32,
+            Twips::from_pixels(tx),
+            Twips::from_pixels(ty),
+        ))
+    } else {
+        // TODO: You can apparently pass a 3x3 matrix here. Did anybody actually? How does it work?
+        object_to_matrix(object, avm, context)
+    }
+}
+
 pub fn object_to_matrix<'gc>(
     object: Object<'gc>,
     avm: &mut Avm1<'gc>,
@@ -53,6 +97,8 @@ pub fn object_to_matrix<'gc>(
     Ok(Matrix { a, b, c, d, tx, ty })
 }
 
+// We'll need this soon!
+#[allow(dead_code)]
 pub fn matrix_to_object<'gc>(
     matrix: Matrix,
     avm: &mut Avm1<'gc>,
diff --git a/core/src/avm1/globals/movie_clip.rs b/core/src/avm1/globals/movie_clip.rs
index d3cb8175e..8a9388985 100644
--- a/core/src/avm1/globals/movie_clip.rs
+++ b/core/src/avm1/globals/movie_clip.rs
@@ -1,6 +1,7 @@
 //! MovieClip prototype
 
 use crate::avm1::globals::display_object::{self, AVM_DEPTH_BIAS, AVM_MAX_DEPTH};
+use crate::avm1::globals::matrix::gradient_object_to_matrix;
 use crate::avm1::property::Attribute::*;
 use crate::avm1::return_value::ReturnValue;
 use crate::avm1::{Avm1, Error, Object, ScriptObject, TObject, UpdateContext, Value};
@@ -12,7 +13,7 @@ use crate::tag_utils::SwfSlice;
 use gc_arena::MutationContext;
 use swf::{
     FillStyle, Gradient, GradientInterpolation, GradientRecord, GradientSpread, LineCapStyle,
-    LineJoinStyle, LineStyle, Matrix, Twips,
+    LineJoinStyle, LineStyle, Twips,
 };
 
 /// Implements `MovieClip`
@@ -279,46 +280,7 @@ fn begin_gradient_fill<'gc>(
                 color: Color::from_rgb(rgb, (alpha / 100.0 * 255.0) as u8),
             });
         }
-        let matrix = if matrix_object
-            .get("matrixType", avm, context)?
-            .resolve(avm, context)?
-            .coerce_to_string(avm, context)?
-            == "box"
-        {
-            let width = matrix_object
-                .get("w", avm, context)?
-                .resolve(avm, context)?
-                .as_number(avm, context)?;
-            let height = matrix_object
-                .get("h", avm, context)?
-                .resolve(avm, context)?
-                .as_number(avm, context)?;
-            let tx = matrix_object
-                .get("x", avm, context)?
-                .resolve(avm, context)?
-                .as_number(avm, context)?
-                + width / 2.0;
-            let ty = matrix_object
-                .get("y", avm, context)?
-                .resolve(avm, context)?
-                .as_number(avm, context)?
-                + height / 2.0;
-            // TODO: This is wrong, doesn't account for rotations.
-            Matrix {
-                tx: Twips::from_pixels(tx),
-                ty: Twips::from_pixels(ty),
-                a: width as f32 / 1638.4,
-                d: height as f32 / 1638.4,
-                b: 0.0,
-                c: 0.0,
-            }
-        } else {
-            log::warn!(
-                "beginGradientFill() received unsupported matrix object {:?}",
-                matrix_object
-            );
-            return Ok(Value::Undefined.into());
-        };
+        let matrix = gradient_object_to_matrix(matrix_object, avm, context)?;
         let spread = match args
             .get(5)
             .and_then(|v| v.clone().coerce_to_string(avm, context).ok())