Added RectExt::bbox_transform.

6 files changed, 44 insertions, 14 deletions

diff --git a/src/backend_cairo/mask.rs b/src/backend_cairo/mask.rs
index 7b364f5..6a93dc9 100644
--- a/src/backend_cairo/mask.rs
+++ b/src/backend_cairo/mask.rs
@@ -30,7 +30,7 @@ pub fn apply(
         mask_cr.set_matrix(sub_cr.get_matrix());
 
         let r = if mask.units == usvg::Units::ObjectBoundingBox {
-            mask.rect.transform(usvg::Transform::from_bbox(bbox))
+            mask.rect.bbox_transform(bbox)
         } else {
             mask.rect
         };
diff --git a/src/backend_cairo/pattern.rs b/src/backend_cairo/pattern.rs
index 9b81b5e..96a8b6a 100644
--- a/src/backend_cairo/pattern.rs
+++ b/src/backend_cairo/pattern.rs
@@ -24,7 +24,7 @@ pub fn apply(
     cr: &cairo::Context,
 ) {
     let r = if pattern.units == usvg::Units::ObjectBoundingBox {
-        pattern.rect.transform(usvg::Transform::from_bbox(bbox))
+        pattern.rect.bbox_transform(bbox)
     } else {
         pattern.rect
     };
diff --git a/src/backend_qt/mask.rs b/src/backend_qt/mask.rs
index febe82b..46d20d9 100644
--- a/src/backend_qt/mask.rs
+++ b/src/backend_qt/mask.rs
@@ -27,7 +27,7 @@ pub fn apply(
         mask_p.set_transform(&sub_p.get_transform());
 
         let r = if mask.units == usvg::Units::ObjectBoundingBox {
-            mask.rect.transform(usvg::Transform::from_bbox(bbox))
+            mask.rect.bbox_transform(bbox)
         } else {
             mask.rect
         };
diff --git a/src/backend_qt/pattern.rs b/src/backend_qt/pattern.rs
index 2401cbf..f609e95 100644
--- a/src/backend_qt/pattern.rs
+++ b/src/backend_qt/pattern.rs
@@ -20,7 +20,7 @@ pub fn apply(
     brush: &mut qt::Brush,
 ) {
     let r = if pattern.units == usvg::Units::ObjectBoundingBox {
-        pattern.rect.transform(usvg::Transform::from_bbox(bbox))
+        pattern.rect.bbox_transform(bbox)
     } else {
         pattern.rect
     };
diff --git a/src/backend_utils/filter.rs b/src/backend_utils/filter.rs
index 11b850e..12f9366 100644
--- a/src/backend_utils/filter.rs
+++ b/src/backend_utils/filter.rs
@@ -610,12 +610,17 @@ fn calc_subregion<T: ImageExt>(
         usvg::FilterKind::FeImage(..) => {
             // `feImage` uses the object bbox.
             if filter.primitive_units == usvg::Units::ObjectBoundingBox {
-                return Rect::new(
-                    bbox.x + bbox.width * primitive.x.unwrap_or(0.0),
-                    bbox.y + bbox.height * primitive.y.unwrap_or(0.0),
-                    bbox.width * primitive.width.unwrap_or(1.0),
-                    bbox.height * primitive.height.unwrap_or(1.0),
-                ).transform(*ts).to_screen_rect();
+                // TODO: wrong
+                let ts_bbox = Rect::new(ts.e, ts.f, ts.a, ts.d);
+
+                let r = Rect::new(
+                    primitive.x.unwrap_or(0.0),
+                    primitive.y.unwrap_or(0.0),
+                    primitive.width.unwrap_or(1.0),
+                    primitive.height.unwrap_or(1.0),
+                );
+
+                return r.bbox_transform(bbox).bbox_transform(ts_bbox).to_screen_rect();
             } else {
                 filter_region
             }
@@ -631,9 +636,8 @@ fn calc_subregion<T: ImageExt>(
             primitive.width.unwrap_or(1.0),
             primitive.height.unwrap_or(1.0),
         );
-        let ts = usvg::Transform::from_bbox(subregion_bbox);
 
-        region.to_rect().transform(ts)
+        region.to_rect().bbox_transform(subregion_bbox)
     } else {
         let (dx, dy) = ts.get_translate();
         let (sx, sy) = ts.get_scale();
diff --git a/src/geom.rs b/src/geom.rs
index cccd26e..cf61bc9 100644
--- a/src/geom.rs
+++ b/src/geom.rs
@@ -97,12 +97,15 @@ fn size_scale(s1: ScreenSize, s2: ScreenSize, expand: bool) -> ScreenSize {
 pub trait RectExt {
     /// Creates a new `Rect` for bounding box calculation.
     ///
-    /// Shorthand for `Rect::from_xywh(f64::MAX, f64::MAX, 1.0, 1.0)`.
+    /// Shorthand for `Rect::new(f64::MAX, f64::MAX, 1.0, 1.0)`.
     fn new_bbox() -> Self;
 
-    /// Expands the `Rect` to the specified size.
+    /// Expands the `Rect` to the provided size.
     fn expand(&mut self, r: Rect);
 
+    /// Transforms the `Rect` using the provided `bbox`.
+    fn bbox_transform(&self, bbox: Rect) -> Self;
+
     /// Returns rect's size in screen units.
     fn to_screen_size(&self) -> ScreenSize;
 
@@ -132,6 +135,15 @@ impl RectExt for Rect {
         }
     }
 
+    fn bbox_transform(&self, bbox: Rect) -> Self {
+        let x = self.x * bbox.width + bbox.x;
+        let y = self.y * bbox.height + bbox.y;
+        let w = self.width * bbox.width;
+        let h = self.height * bbox.height;
+
+        Self::new(x, y, w, h)
+    }
+
     fn to_screen_size(&self) -> ScreenSize {
         self.size().to_screen_size()
     }
@@ -245,3 +257,17 @@ impl From<(i32, i32, u32, u32)> for ScreenRect {
 fn f64_min(v1: f64, v2: f64) -> f64 {
     if v1 < v2 { v1 } else { v2 }
 }
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use usvg::FuzzyEq;
+
+    #[test]
+    fn bbox_transform_1() {
+        let r = Rect::new(10.0, 20.0, 30.0, 40.0);
+        assert!(r.bbox_transform(Rect::new(0.2, 0.3, 0.4, 0.5))
+                 .fuzzy_eq(&Rect::new(4.2, 10.3, 12.0, 20.0)));
+    }
+}