fix: ctx.filter should store in state and be able to save/restore

__test__/filter.spec.ts

@@ -110,6 +110,16 @@ test('filter-combine-contrast-brightness', async (t) => {
   await snapshotImage(t)
 })
 
+test('filter-save-restore', async (t) => {
+  const { ctx } = t.context
+  ctx.filter = 'none'
+  ctx.save()
+  ctx.filter = 'invert(100%)'
+  ctx.restore()
+  ctx.drawImage(await createImage('filter-invert.jpeg'), 0, 0)
+  await snapshotImage(t)
+})
+
 async function createImage(name: string) {
   const i = new Image()
   i.src = await fs.readFile(join(__dirname, 'fixtures', name))

skia-c/skia_c.cpp

@@ -1331,6 +1331,12 @@ extern "C"
     }
   }
 
+  void skiac_image_filter_ref(skiac_image_filter *c_image_filter)
+  {
+    auto image_filter = IMAGE_FILTER_CAST;
+    image_filter->ref();
+  }
+
   void skiac_image_filter_destroy(skiac_image_filter *c_image_filter)
   {
     auto image_filter = IMAGE_FILTER_CAST;

src/ctx.rs

@@ -49,8 +49,6 @@ pub struct Context {
   pub height: u32,
   pub color_space: ColorSpace,
   pub stream: Option<SkWMemoryStream>,
-  pub filter: Option<ImageFilter>,
-  filters_string: String,
 }
 
 impl Context {
@@ -267,8 +265,6 @@ impl Context {
       height,
       color_space,
       stream: Some(stream),
-      filter: None,
-      filters_string: "none".to_owned(),
     })
   }
 
@@ -291,8 +287,6 @@ impl Context {
       height,
       color_space,
       stream: None,
-      filter: None,
-      filters_string: "none".to_owned(),
     })
   }
 
@@ -571,21 +565,21 @@ impl Context {
       .ok_or_else(|| SkError::Generic("Make line dash path effect failed".to_string()))?;
       paint.set_path_effect(&path_effect);
     }
-    if let Some(f) = &self.filter {
+    if let Some(f) = &self.state.filter {
       paint.set_image_filter(f);
     }
     Ok(paint)
   }
 
   pub fn set_filter(&mut self, filter_str: &str) -> result::Result<(), SkError> {
     if filter_str.trim() == "none" {
-      self.filters_string = "none".to_owned();
-      self.filter = None;
+      self.state.filters_string = "none".to_owned();
+      self.state.filter = None;
     } else {
       let (_, filters) =
         css_filter(filter_str).map_err(|e| SkError::StringToFillRuleError(format!("{}", e)))?;
-      self.filter = css_filters_to_image_filter(filters);
-      self.filters_string = filter_str.to_owned();
+      self.state.filter = css_filters_to_image_filter(filters);
+      self.state.filters_string = filter_str.to_owned();
     }
     Ok(())
   }
@@ -623,7 +617,7 @@ impl Context {
       .ok_or_else(|| SkError::Generic("Make line dash path effect failed".to_string()))?;
       paint.set_path_effect(&path_effect);
     }
-    if let Some(f) = &self.filter {
+    if let Some(f) = &self.state.filter {
       paint.set_image_filter(f);
     }
     Ok(paint)
@@ -2005,7 +1999,9 @@ fn set_filter(ctx: CallContext) -> Result<JsUndefined> {
 fn get_filter(ctx: CallContext) -> Result<JsString> {
   let this = ctx.this_unchecked::<JsObject>();
   let context_2d = ctx.env.unwrap::<Context>(&this)?;
-  ctx.env.create_string(context_2d.filters_string.as_str())
+  ctx
+    .env
+    .create_string(context_2d.state.filters_string.as_str())
 }
 
 #[js_function]

src/sk.rs

@@ -760,6 +760,8 @@ mod ffi {
       c_image_filter: *mut skiac_image_filter,
     ) -> *mut skiac_image_filter;
 
+    pub fn skiac_image_filter_ref(image_filter: *mut skiac_image_filter);
+
     pub fn skiac_image_filter_destroy(image_filter: *mut skiac_image_filter);
 
     pub fn skiac_sk_data_destroy(c_data: *mut skiac_data);
@@ -3143,6 +3145,15 @@ impl Drop for MaskFilter {
 #[derive(Debug)]
 pub struct ImageFilter(pub(crate) *mut ffi::skiac_image_filter);
 
+impl Clone for ImageFilter {
+  fn clone(&self) -> Self {
+    unsafe {
+      ffi::skiac_image_filter_ref(self.0);
+    };
+    Self(self.0)
+  }
+}
+
 impl ImageFilter {
   pub fn make_drop_shadow_only(
     dx: f32,

src/state.rs

@@ -1,6 +1,6 @@
 use cssparser::RGBA;
 
-use crate::sk::Matrix;
+use crate::sk::{ImageFilter, Matrix};
 
 use super::{
   font::Font,
@@ -30,6 +30,8 @@ pub struct Context2dRenderingState {
   pub text_baseline: TextBaseline,
   pub text_direction: TextDirection,
   pub transform: Matrix,
+  pub filter: Option<ImageFilter>,
+  pub filters_string: String,
 }
 
 impl Default for Context2dRenderingState {
@@ -57,6 +59,8 @@ impl Default for Context2dRenderingState {
       text_baseline: TextBaseline::default(),
       text_direction: TextDirection::default(),
       transform: Matrix::identity(),
+      filter: None,
+      filters_string: "none".to_owned(),
     }
   }
 }