Auto merge of #6280 - glennw:transform-transitions, r=nox

Also tidy up some of the ComputedMatrix code.

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5 files changed, 212 insertions, 71 deletions

diff --git a/components/layout/display_list_builder.rs b/components/layout/display_list_builder.rs
index f2cf382a23a..5491e9d0bc6 100644
--- a/components/layout/display_list_builder.rs
+++ b/components/layout/display_list_builder.rs
@@ -1163,16 +1163,13 @@ impl FragmentDisplayListBuilding for Fragment {
                 let matrix = match operation {
                     &transform::ComputedOperation::Rotate(ax, ay, az, theta) => {
                         let theta = f32::consts::PI_2 - theta.radians();
-                        let transform = Matrix4::create_rotation(ax, ay, az, theta);
-                        pre_transform.mul(&transform).mul(&post_transform)
+                        Matrix4::create_rotation(ax, ay, az, theta)
                     }
                     &transform::ComputedOperation::Perspective(d) => {
-                        let transform = Matrix4::create_perspective(d.to_f32_px());
-                        pre_transform.mul(&transform).mul(&post_transform)
+                        Matrix4::create_perspective(d.to_f32_px())
                     }
                     &transform::ComputedOperation::Scale(sx, sy, sz) => {
-                        let transform = Matrix4::create_scale(sx, sy, sz);
-                        pre_transform.mul(&transform).mul(&post_transform)
+                        Matrix4::create_scale(sx, sy, sz)
                     }
                     &transform::ComputedOperation::Translate(tx, ty, tz) => {
                         let tx = tx.to_au(border_box.size.width).to_f32_px();
@@ -1181,17 +1178,17 @@ impl FragmentDisplayListBuilding for Fragment {
                         Matrix4::create_translation(tx, ty, tz)
                     }
                     &transform::ComputedOperation::Matrix(m) => {
-                        let transform = m.to_gfx_matrix(&border_box.size);
-                        pre_transform.mul(&transform).mul(&post_transform)
+                        m.to_gfx_matrix()
                     }
                     &transform::ComputedOperation::Skew(sx, sy) => {
-                        let transform = Matrix4::create_skew(sx, sy);
-                        pre_transform.mul(&transform).mul(&post_transform)
+                        Matrix4::create_skew(sx, sy)
                     }
                 };
 
                 transform = transform.mul(&matrix);
             }
+
+            transform = pre_transform.mul(&transform).mul(&post_transform);
         }
 
         // FIXME(pcwalton): Is this vertical-writing-direction-safe?
diff --git a/components/layout/model.rs b/components/layout/model.rs
index 87e4d3cf3db..ad6dd66cf17 100644
--- a/components/layout/model.rs
+++ b/components/layout/model.rs
@@ -8,7 +8,7 @@
 
 use fragment::Fragment;
 
-use geom::{Matrix4, SideOffsets2D, Size2D};
+use geom::{Matrix4, SideOffsets2D};
 use std::cmp::{max, min};
 use std::fmt;
 use style::computed_values::transform::ComputedMatrix;
@@ -426,19 +426,16 @@ pub fn padding_from_style(style: &ComputedValues, containing_block_inline_size:
 }
 
 pub trait ToGfxMatrix {
-    fn to_gfx_matrix(&self, containing_size: &Size2D<Au>) -> Matrix4<f32>;
+    fn to_gfx_matrix(&self) -> Matrix4<f32>;
 }
 
 impl ToGfxMatrix for ComputedMatrix {
-    fn to_gfx_matrix(&self, containing_size: &Size2D<Au>) -> Matrix4<f32> {
+    fn to_gfx_matrix(&self) -> Matrix4<f32> {
         Matrix4 {
             m11: self.m11 as f32, m12: self.m12 as f32, m13: self.m13 as f32, m14: self.m14 as f32,
             m21: self.m21 as f32, m22: self.m22 as f32, m23: self.m23 as f32, m24: self.m24 as f32,
             m31: self.m31 as f32, m32: self.m32 as f32, m33: self.m33 as f32, m34: self.m34 as f32,
-            m41: self.m41.to_au(containing_size.width).to_f32_px(),
-            m42: self.m42.to_au(containing_size.height).to_f32_px(),
-            m43: self.m43 as f32,
-            m44: self.m44 as f32
+            m41: self.m41 as f32, m42: self.m42 as f32, m43: self.m43 as f32, m44: self.m44 as f32
         }
     }
 }
diff --git a/components/style/animation.rs b/components/style/animation.rs
index d8652b3ea0e..cecf676c5e5 100644
--- a/components/style/animation.rs
+++ b/components/style/animation.rs
@@ -17,7 +17,11 @@ use properties::longhands::text_shadow::computed_value::TextShadow;
 use properties::longhands::text_shadow::computed_value::T as TextShadowList;
 use properties::longhands::background_position::computed_value::T as BackgroundPosition;
 use properties::longhands::transition_property;
-use values::computed::{LengthOrPercentageOrAuto, LengthOrPercentageOrNone, LengthOrPercentage, Length, Time};
+use properties::longhands::transform::computed_value::ComputedMatrix;
+use properties::longhands::transform::computed_value::ComputedOperation as TransformOperation;
+use properties::longhands::transform::computed_value::T as TransformList;
+use values::computed::{Angle, LengthOrPercentageOrAuto, LengthOrPercentageOrNone};
+use values::computed::{LengthAndPercentage, LengthOrPercentage, Length, Time};
 use values::CSSFloat;
 use cssparser::{RGBA, Color};
 
@@ -92,6 +96,10 @@ impl PropertyAnimation {
                             AnimatedProperty::TextShadow(old_style.get_effects().text_shadow.clone(),
                                                          new_style.get_effects().text_shadow.clone())
                         }
+                        TransitionProperty::Transform => {
+                            AnimatedProperty::Transform(old_style.get_effects().transform.clone(),
+                                                        new_style.get_effects().transform.clone())
+                        }
                     }
                 }
         }
@@ -220,6 +228,7 @@ impl PropertyAnimation {
             [TextIndent; mutate_inheritedtext; text_indent],
             [TextShadow; mutate_effects; text_shadow],
             [Top; mutate_positionoffsets; top],
+            [Transform; mutate_effects; transform],
             [VerticalAlign; mutate_box; vertical_align],
             [Visibility; mutate_inheritedbox; visibility],
             [Width; mutate_box; width],
@@ -274,6 +283,7 @@ enum AnimatedProperty {
     TextIndent(LengthOrPercentage, LengthOrPercentage),
     TextShadow(TextShadowList, TextShadowList),
     Top(LengthOrPercentageOrAuto, LengthOrPercentageOrAuto),
+    Transform(TransformList, TransformList),
     VerticalAlign(VerticalAlign, VerticalAlign),
     Visibility(Visibility, Visibility),
     Width(LengthOrPercentageOrAuto, LengthOrPercentageOrAuto),
@@ -329,6 +339,7 @@ impl AnimatedProperty {
             AnimatedProperty::Visibility(ref a, ref b) => a == b,
             AnimatedProperty::WordSpacing(ref a, ref b) => a == b,
             AnimatedProperty::ZIndex(ref a, ref b) => a == b,
+            AnimatedProperty::Transform(ref a, ref b) => a == b,
         }
     }
 }
@@ -495,6 +506,17 @@ impl Interpolate for LengthOrPercentage {
     }
 }
 
+impl Interpolate for LengthAndPercentage {
+    #[inline]
+    fn interpolate(&self, other: &LengthAndPercentage, time: f32)
+                   -> Option<LengthAndPercentage> {
+        Some(LengthAndPercentage {
+            length: self.length.interpolate(&other.length, time).unwrap(),
+            percentage: self.percentage.interpolate(&other.percentage, time).unwrap(),
+        })
+    }
+}
+
 impl Interpolate for LengthOrPercentageOrAuto {
     #[inline]
     fn interpolate(&self, other: &LengthOrPercentageOrAuto, time: f32)
@@ -670,6 +692,159 @@ impl Interpolate for TextShadowList {
     }
 }
 
+/// Check if it's possible to do a direct numerical interpolation
+/// between these two transform lists.
+/// http://dev.w3.org/csswg/css-transforms/#transform-transform-animation
+fn can_interpolate_list(from_list: &Vec<TransformOperation>,
+                        to_list: &Vec<TransformOperation>) -> bool {
+    // Lists must be equal length
+    if from_list.len() != to_list.len() {
+        return false;
+    }
+
+    // Each transform operation must match primitive type in other list
+    for (from, to) in from_list.iter().zip(to_list.iter()) {
+        match (from, to) {
+            (&TransformOperation::Matrix(..), &TransformOperation::Matrix(..)) |
+            (&TransformOperation::Skew(..), &TransformOperation::Skew(..)) |
+            (&TransformOperation::Translate(..), &TransformOperation::Translate(..)) |
+            (&TransformOperation::Scale(..), &TransformOperation::Scale(..)) |
+            (&TransformOperation::Rotate(..), &TransformOperation::Rotate(..)) |
+            (&TransformOperation::Perspective(..), &TransformOperation::Perspective(..)) => {}
+            _ => {
+                return false;
+            }
+        }
+    }
+
+    true
+}
+
+/// Interpolate two transform lists.
+/// http://dev.w3.org/csswg/css-transforms/#interpolation-of-transforms
+fn interpolate_transform_list(from_list: &Vec<TransformOperation>,
+                              to_list: &Vec<TransformOperation>,
+                              time: f32) -> TransformList {
+    let mut result = vec!();
+
+    if can_interpolate_list(from_list, to_list) {
+        for (from, to) in from_list.iter().zip(to_list.iter()) {
+            match (from, to) {
+                (&TransformOperation::Matrix(from),
+                 &TransformOperation::Matrix(_to)) => {
+                    // TODO(gw): Implement matrix decomposition and interpolation
+                    result.push(TransformOperation::Matrix(from));
+                }
+                (&TransformOperation::Skew(fx, fy),
+                 &TransformOperation::Skew(tx, ty)) => {
+                    let ix = fx.interpolate(&tx, time).unwrap();
+                    let iy = fy.interpolate(&ty, time).unwrap();
+                    result.push(TransformOperation::Skew(ix, iy));
+                }
+                (&TransformOperation::Translate(fx, fy, fz),
+                 &TransformOperation::Translate(tx, ty, tz)) => {
+                    let ix = fx.interpolate(&tx, time).unwrap();
+                    let iy = fy.interpolate(&ty, time).unwrap();
+                    let iz = fz.interpolate(&tz, time).unwrap();
+                    result.push(TransformOperation::Translate(ix, iy, iz));
+                }
+                (&TransformOperation::Scale(fx, fy, fz),
+                 &TransformOperation::Scale(tx, ty, tz)) => {
+                    let ix = fx.interpolate(&tx, time).unwrap();
+                    let iy = fy.interpolate(&ty, time).unwrap();
+                    let iz = fz.interpolate(&tz, time).unwrap();
+                    result.push(TransformOperation::Scale(ix, iy, iz));
+                }
+                (&TransformOperation::Rotate(fx, fy, fz, fa),
+                 &TransformOperation::Rotate(_tx, _ty, _tz, _ta)) => {
+                    // TODO(gw): Implement matrix decomposition and interpolation
+                    result.push(TransformOperation::Rotate(fx, fy, fz, fa));
+                }
+                (&TransformOperation::Perspective(fd),
+                 &TransformOperation::Perspective(_td)) => {
+                    // TODO(gw): Implement matrix decomposition and interpolation
+                    result.push(TransformOperation::Perspective(fd));
+                }
+                _ => {
+                    // This should be unreachable due to the can_interpolate_list() call.
+                    unreachable!();
+                }
+            }
+        }
+    } else {
+        // TODO(gw): Implement matrix decomposition and interpolation
+        result.push_all(from_list);
+    }
+
+    Some(result)
+}
+
+/// Build an equivalent 'identity transform function list' based
+/// on an existing transform list.
+/// http://dev.w3.org/csswg/css-transforms/#none-transform-animation
+fn build_identity_transform_list(list: &Vec<TransformOperation>) -> Vec<TransformOperation> {
+    let mut result = vec!();
+
+    for operation in list {
+        match operation {
+            &TransformOperation::Matrix(..) => {
+                let identity = ComputedMatrix::identity();
+                result.push(TransformOperation::Matrix(identity));
+            }
+            &TransformOperation::Skew(..) => {
+                result.push(TransformOperation::Skew(0.0, 0.0));
+            }
+            &TransformOperation::Translate(..) => {
+                result.push(TransformOperation::Translate(LengthAndPercentage::zero(),
+                                                          LengthAndPercentage::zero(),
+                                                          Au(0)));
+            }
+            &TransformOperation::Scale(..) => {
+                result.push(TransformOperation::Scale(1.0, 1.0, 1.0));
+            }
+            &TransformOperation::Rotate(..) => {
+                result.push(TransformOperation::Rotate(0.0, 0.0, 1.0, Angle(0.0)));
+            }
+            &TransformOperation::Perspective(..) => {
+                // http://dev.w3.org/csswg/css-transforms/#identity-transform-function
+                let identity = ComputedMatrix::identity();
+                result.push(TransformOperation::Matrix(identity));
+            }
+        }
+    }
+
+    result
+}
+
+impl Interpolate for TransformList {
+    #[inline]
+    fn interpolate(&self, other: &TransformList, time: f32) -> Option<TransformList> {
+        // http://dev.w3.org/csswg/css-transforms/#interpolation-of-transforms
+        let result = match (self, other) {
+            (&Some(ref from_list), &Some(ref to_list)) => {
+                // Two lists of transforms
+                interpolate_transform_list(from_list, &to_list, time)
+            }
+            (&Some(ref from_list), &None) => {
+                // http://dev.w3.org/csswg/css-transforms/#none-transform-animation
+                let to_list = build_identity_transform_list(from_list);
+                interpolate_transform_list(from_list, &to_list, time)
+            }
+            (&None, &Some(ref to_list)) => {
+                // http://dev.w3.org/csswg/css-transforms/#none-transform-animation
+                let from_list = build_identity_transform_list(to_list);
+                interpolate_transform_list(&from_list, to_list, time)
+            }
+            (&None, &None) => {
+                // http://dev.w3.org/csswg/css-transforms/#none-none-animation
+                None
+            }
+        };
+
+        Some(result)
+    }
+}
+
 /// Accesses an element of an array, "wrapping around" using modular arithmetic. This is needed
 /// to handle values of differing lengths according to CSS-TRANSITIONS § 2.
 pub trait GetMod {
diff --git a/components/style/properties.mako.rs b/components/style/properties.mako.rs
index ca4af9f18ff..5bc292e85b3 100644
--- a/components/style/properties.mako.rs
+++ b/components/style/properties.mako.rs
@@ -3131,17 +3131,24 @@ pub mod longhands {
         pub mod computed_value {
             use values::CSSFloat;
             use values::computed;
-            use values::specified;
 
             #[derive(Clone, Copy, Debug, PartialEq)]
             pub struct ComputedMatrix {
                 pub m11: CSSFloat, pub m12: CSSFloat, pub m13: CSSFloat, pub m14: CSSFloat,
                 pub m21: CSSFloat, pub m22: CSSFloat, pub m23: CSSFloat, pub m24: CSSFloat,
                 pub m31: CSSFloat, pub m32: CSSFloat, pub m33: CSSFloat, pub m34: CSSFloat,
-                pub m41: computed::LengthAndPercentage,
-                pub m42: computed::LengthAndPercentage,
-                pub m43: CSSFloat,
-                pub m44: CSSFloat,
+                pub m41: CSSFloat, pub m42: CSSFloat, pub m43: CSSFloat, pub m44: CSSFloat,
+            }
+
+            impl ComputedMatrix {
+                pub fn identity() -> ComputedMatrix {
+                    ComputedMatrix {
+                        m11: 1.0, m12: 0.0, m13: 0.0, m14: 0.0,
+                        m21: 0.0, m22: 1.0, m23: 0.0, m24: 0.0,
+                        m31: 0.0, m32: 0.0, m33: 1.0, m34: 0.0,
+                        m41: 0.0, m42: 0.0, m43: 0.0, m44: 1.0
+                    }
+                }
             }
 
             #[derive(Clone, Debug, PartialEq)]
@@ -3152,30 +3159,14 @@ pub mod longhands {
                           computed::LengthAndPercentage,
                           computed::Length),
                 Scale(CSSFloat, CSSFloat, CSSFloat),
-                Rotate(CSSFloat, CSSFloat, CSSFloat, specified::Angle),
+                Rotate(CSSFloat, CSSFloat, CSSFloat, computed::Angle),
                 Perspective(computed::Length),
             }
 
             pub type T = Option<Vec<ComputedOperation>>;
         }
 
-        #[derive(Clone, Debug, PartialEq)]
-        pub struct SpecifiedMatrix {
-            m11: CSSFloat, m12: CSSFloat, m13: CSSFloat, m14: CSSFloat,
-            m21: CSSFloat, m22: CSSFloat, m23: CSSFloat, m24: CSSFloat,
-            m31: CSSFloat, m32: CSSFloat, m33: CSSFloat, m34: CSSFloat,
-            m41: specified::LengthAndPercentage,
-            m42: specified::LengthAndPercentage,
-            m43: specified::Length,
-            m44: CSSFloat,
-        }
-
-        impl ToCss for SpecifiedMatrix {
-            fn to_css<W>(&self, _: &mut W) -> fmt::Result where W: fmt::Write {
-                // TODO(pcwalton)
-                Ok(())
-            }
-        }
+        pub use self::computed_value::ComputedMatrix as SpecifiedMatrix;
 
         fn parse_two_lengths_or_percentages(input: &mut Parser)
                                             -> Result<(specified::LengthAndPercentage,
@@ -3259,19 +3250,12 @@ pub mod longhands {
                             if values.len() != 6 {
                                 return Err(())
                             }
-                            let (tx, ty, tz) =
-                                (specified::Length::Absolute(Au::from_f32_px(values[4])),
-                                 specified::Length::Absolute(Au::from_f32_px(values[5])),
-                                 specified::Length::Absolute(Au(0)));
-                            let (tx, ty) =
-                                (specified::LengthAndPercentage::from_length(tx),
-                                 specified::LengthAndPercentage::from_length(ty));
                             result.push(SpecifiedOperation::Matrix(
                                     SpecifiedMatrix {
                                         m11: values[0], m12: values[1], m13: 0.0, m14: 0.0,
                                         m21: values[2], m22: values[3], m23: 0.0, m24: 0.0,
                                         m31:       0.0, m32:       0.0, m33: 1.0, m34: 0.0,
-                                        m41:        tx, m42:        ty, m43:  tz, m44: 1.0
+                                        m41: values[4], m42: values[5], m43: 0.0, m44: 1.0
                                     }));
                             Ok(())
                         }))
@@ -3284,19 +3268,12 @@ pub mod longhands {
                             if values.len() != 16 {
                                 return Err(())
                             }
-                            let (tx, ty, tz) =
-                                (specified::Length::Absolute(Au::from_f32_px(values[12])),
-                                 specified::Length::Absolute(Au::from_f32_px(values[13])),
-                                 specified::Length::Absolute(Au::from_f32_px(values[14])));
-                            let (tx, ty) =
-                                (specified::LengthAndPercentage::from_length(tx),
-                                 specified::LengthAndPercentage::from_length(ty));
                             result.push(SpecifiedOperation::Matrix(
                                     SpecifiedMatrix {
                                         m11: values[ 0], m12: values[ 1], m13: values[ 2], m14: values[ 3],
                                         m21: values[ 4], m22: values[ 5], m23: values[ 6], m24: values[ 7],
                                         m31: values[ 8], m32: values[ 9], m33: values[10], m34: values[11],
-                                        m41:         tx, m42:         ty, m43:         tz, m44: values[15]
+                                        m41: values[12], m42: values[13], m43: values[14], m44: values[15]
                                     }));
                             Ok(())
                         }))
@@ -3490,21 +3467,12 @@ pub mod longhands {
                 for operation in self.0.iter() {
                     match *operation {
                         SpecifiedOperation::Matrix(ref matrix) => {
-                            let m = computed_value::ComputedMatrix {
-                                m11: matrix.m11, m12: matrix.m12, m13: matrix.m13, m14: matrix.m14,
-                                m21: matrix.m21, m22: matrix.m22, m23: matrix.m23, m24: matrix.m24,
-                                m31: matrix.m31, m32: matrix.m32, m33: matrix.m33, m34: matrix.m34,
-                                m41: matrix.m41.to_computed_value(context),
-                                m42: matrix.m42.to_computed_value(context),
-                                m43: matrix.m43.to_computed_value(context).to_f32_px(),
-                                m44: matrix.m44
-                            };
-                            result.push(computed_value::ComputedOperation::Matrix(m));
+                            result.push(computed_value::ComputedOperation::Matrix(*matrix));
                         }
                         SpecifiedOperation::Translate(ref tx, ref ty, ref tz) => {
                             result.push(computed_value::ComputedOperation::Translate(tx.to_computed_value(context),
-                                                                                    ty.to_computed_value(context),
-                                                                                    tz.to_computed_value(context)));
+                                                                                     ty.to_computed_value(context),
+                                                                                     tz.to_computed_value(context)));
                         }
                         SpecifiedOperation::Scale(sx, sy, sz) => {
                             result.push(computed_value::ComputedOperation::Scale(sx, sy, sz));
@@ -4023,6 +3991,7 @@ pub mod longhands {
                 TextIndent,
                 TextShadow,
                 Top,
+                Transform,
                 VerticalAlign,
                 Visibility,
                 Width,
@@ -4030,7 +3999,7 @@ pub mod longhands {
                 ZIndex,
             }
 
-            pub static ALL_TRANSITION_PROPERTIES: [TransitionProperty; 44] = [
+            pub static ALL_TRANSITION_PROPERTIES: [TransitionProperty; 45] = [
                 TransitionProperty::BackgroundColor,
                 TransitionProperty::BackgroundPosition,
                 TransitionProperty::BorderBottomColor,
@@ -4070,6 +4039,7 @@ pub mod longhands {
                 TransitionProperty::TextIndent,
                 TransitionProperty::TextShadow,
                 TransitionProperty::Top,
+                TransitionProperty::Transform,
                 TransitionProperty::VerticalAlign,
                 TransitionProperty::Visibility,
                 TransitionProperty::Width,
@@ -4120,6 +4090,7 @@ pub mod longhands {
                         TransitionProperty::TextIndent => dest.write_str("text-indent"),
                         TransitionProperty::TextShadow => dest.write_str("text-shadow"),
                         TransitionProperty::Top => dest.write_str("top"),
+                        TransitionProperty::Transform => dest.write_str("transform"),
                         TransitionProperty::VerticalAlign => dest.write_str("vertical-align"),
                         TransitionProperty::Visibility => dest.write_str("visibility"),
                         TransitionProperty::Width => dest.write_str("width"),
@@ -4196,6 +4167,7 @@ pub mod longhands {
                 "text-indent" => Ok(TransitionProperty::TextIndent),
                 "text-shadow" => Ok(TransitionProperty::TextShadow),
                 "top" => Ok(TransitionProperty::Top),
+                "transform" => Ok(TransitionProperty::Transform),
                 "vertical-align" => Ok(TransitionProperty::VerticalAlign),
                 "visibility" => Ok(TransitionProperty::Visibility),
                 "width" => Ok(TransitionProperty::Width),
diff --git a/components/style/values.rs b/components/style/values.rs
index 992ee08a79d..fde7f715689 100644
--- a/components/style/values.rs
+++ b/components/style/values.rs
@@ -888,7 +888,7 @@ pub mod specified {
 }
 
 pub mod computed {
-    pub use super::specified::{BorderStyle, Time};
+    pub use super::specified::{Angle, BorderStyle, Time};
     use super::specified::{AngleOrCorner};
     use super::{specified, CSSFloat};
     pub use cssparser::Color as CSSColor;