[librsvg] drawing_ctx: pass SharedImageSurface as param to run_filter

[Paolo Borelli <pborelli src gnome org>]

commit 2fe7c1ecff4393de51fe1dd85e14b965343986f4
Author: Paolo Borelli <pborelli gnome org>
Date:   Sat Jan 11 00:43:37 2020 +0100

    drawing_ctx: pass SharedImageSurface as param to run_filter

 rsvg_internals/src/drawing_ctx.rs | 29 ++++++++++++++++++-----------
 rsvg_internals/src/filters/mod.rs | 12 ++++--------
 2 files changed, 22 insertions(+), 19 deletions(-)
---
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index 8409f3f2..f7cbbe9d 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -520,11 +520,18 @@ impl DrawingCtx {
                     // Filter
 
                     let source_surface = if let Some(filter_uri) = filter {
-                        let child_surface =
-                            cairo::ImageSurface::try_from(dc.cr.get_target()).unwrap();
-                        let img_surface =
-                            dc.run_filter(filter_uri, node, values, &child_surface, bbox)?;
-                        // turn into a Surface
+                        // The target surface has multiple references.
+                        // We need to copy it to a new surface to have a unique
+                        // reference to be able to safely access the pixel data.
+                        let child_surface = SharedImageSurface::copy_from_surface(
+                            &cairo::ImageSurface::try_from(dc.cr.get_target()).unwrap(),
+                        )?;
+
+                        let img_surface = dc
+                            .run_filter(filter_uri, node, values, child_surface, bbox)?
+                            .into_image_surface()?;
+
+                        // turn ImageSurface into a Surface
                         (*img_surface).clone()
                     } else {
                         dc.cr.get_target()
@@ -666,9 +673,9 @@ impl DrawingCtx {
         filter_uri: &Fragment,
         node: &RsvgNode,
         values: &ComputedValues,
-        child_surface: &cairo::ImageSurface,
+        child_surface: SharedImageSurface,
         node_bbox: BoundingBox,
-    ) -> Result<cairo::ImageSurface, RenderingError> {
+    ) -> Result<SharedImageSurface, RenderingError> {
         match self.acquire_node(filter_uri, &[NodeType::Filter]) {
             Ok(acquired) => {
                 let filter_node = acquired.get();
@@ -690,10 +697,10 @@ impl DrawingCtx {
 
                 // Non-existing filters must act as null filters (that is, an
                 // empty surface is returned).
-                Ok(cairo::ImageSurface::create(
-                    cairo::Format::ARgb32,
-                    child_surface.get_width(),
-                    child_surface.get_height(),
+                Ok(SharedImageSurface::empty(
+                    child_surface.width(),
+                    child_surface.height(),
+                    child_surface.surface_type(),
                 )?)
             }
         }
diff --git a/rsvg_internals/src/filters/mod.rs b/rsvg_internals/src/filters/mod.rs
index d3c3ca0f..b627fb27 100644
--- a/rsvg_internals/src/filters/mod.rs
+++ b/rsvg_internals/src/filters/mod.rs
@@ -239,18 +239,14 @@ impl Deref for PrimitiveWithInput {
 pub fn render(
     filter_node: &RsvgNode,
     computed_from_node_being_filtered: &ComputedValues,
-    source: &cairo::ImageSurface,
+    source_surface: SharedImageSurface,
     draw_ctx: &mut DrawingCtx,
     node_bbox: BoundingBox,
-) -> Result<cairo::ImageSurface, RenderingError> {
+) -> Result<SharedImageSurface, RenderingError> {
     let filter_node = &*filter_node;
     assert_eq!(filter_node.borrow().get_type(), NodeType::Filter);
     assert!(!filter_node.borrow().is_in_error());
 
-    // The source surface has multiple references. We need to copy it to a new surface to have a
-    // unique reference to be able to safely access the pixel data.
-    let source_surface = SharedImageSurface::copy_from_surface(source)?;
-
     let mut filter_ctx = FilterContext::new(
         filter_node,
         computed_from_node_being_filtered,
@@ -262,7 +258,7 @@ pub fn render(
     // If paffine is non-invertible, we won't draw anything. Also bbox combining in bounds
     // computations will panic due to non-invertible martrix.
     if filter_ctx.paffine().try_invert().is_err() {
-        return Ok(filter_ctx.into_output()?.into_image_surface()?);
+        return Ok(filter_ctx.into_output()?);
     }
 
     let primitives = filter_node
@@ -327,7 +323,7 @@ pub fn render(
         );
     }
 
-    Ok(filter_ctx.into_output()?.into_image_surface()?)
+    Ok(filter_ctx.into_output()?)
 }
 
 impl From<ColorInterpolationFilters> for SurfaceType {