Implement `vector` pipeline in `iced_tiny_skia`

5 files changed, 182 insertions, 8 deletions

diff --git a/tiny_skia/Cargo.toml b/tiny_skia/Cargo.toml
index 647ec12a..69197589 100644
--- a/tiny_skia/Cargo.toml
+++ b/tiny_skia/Cargo.toml
@@ -5,7 +5,7 @@ edition = "2021"
 
 [features]
 image = ["iced_graphics/image"]
-svg = []
+svg = ["resvg"]
 geometry = ["iced_graphics/geometry"]
 
 [dependencies]
@@ -34,3 +34,7 @@ default-features = false
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies.twox-hash]
 version = "1.6.1"
 features = ["std"]
+
+[dependencies.resvg]
+version = "0.29"
+optional = true
diff --git a/tiny_skia/src/backend.rs b/tiny_skia/src/backend.rs
index d894ab95..3c2a97b9 100644
--- a/tiny_skia/src/backend.rs
+++ b/tiny_skia/src/backend.rs
@@ -14,6 +14,9 @@ pub struct Backend {
 
     #[cfg(feature = "image")]
     raster_pipeline: crate::raster::Pipeline,
+
+    #[cfg(feature = "svg")]
+    vector_pipeline: crate::vector::Pipeline,
 }
 
 impl Backend {
@@ -25,6 +28,9 @@ impl Backend {
 
             #[cfg(feature = "image")]
             raster_pipeline: crate::raster::Pipeline::new(),
+
+            #[cfg(feature = "svg")]
+            vector_pipeline: crate::vector::Pipeline::new(),
         }
     }
 
@@ -78,7 +84,10 @@ impl Backend {
             );
         }
 
-        self.text_pipeline.end_frame();
+        self.text_pipeline.trim_cache();
+
+        #[cfg(feature = "svg")]
+        self.vector_pipeline.trim_cache();
     }
 
     fn draw_primitive(
@@ -181,8 +190,18 @@ impl Backend {
                     clip_bounds.map(|_| clip_mask as &_),
                 );
             }
-            Primitive::Svg { .. } => {
-                // TODO
+            #[cfg(feature = "svg")]
+            Primitive::Svg {
+                handle,
+                bounds,
+                color: _, // TODO: Implement color filter
+            } => {
+                self.vector_pipeline.draw(
+                    handle,
+                    (*bounds + translation) * scale_factor,
+                    pixels,
+                    clip_bounds.map(|_| clip_mask as &_),
+                );
             }
             Primitive::Fill {
                 path,
@@ -518,9 +537,8 @@ impl backend::Image for Backend {
 impl backend::Svg for Backend {
     fn viewport_dimensions(
         &self,
-        _handle: &crate::core::svg::Handle,
+        handle: &crate::core::svg::Handle,
     ) -> Size<u32> {
-        // TODO
-        Size::new(0, 0)
+        self.vector_pipeline.viewport_dimensions(handle)
     }
 }
diff --git a/tiny_skia/src/lib.rs b/tiny_skia/src/lib.rs
index d03bdcc2..83baef1c 100644
--- a/tiny_skia/src/lib.rs
+++ b/tiny_skia/src/lib.rs
@@ -7,6 +7,9 @@ mod text;
 #[cfg(feature = "image")]
 mod raster;
 
+#[cfg(feature = "svg")]
+mod vector;
+
 #[cfg(feature = "geometry")]
 pub mod geometry;
 
diff --git a/tiny_skia/src/text.rs b/tiny_skia/src/text.rs
index c4edadb3..bfe5da9d 100644
--- a/tiny_skia/src/text.rs
+++ b/tiny_skia/src/text.rs
@@ -143,7 +143,7 @@ impl Pipeline {
         });
     }
 
-    pub fn end_frame(&mut self) {
+    pub fn trim_cache(&mut self) {
         self.system
             .as_mut()
             .unwrap()
diff --git a/tiny_skia/src/vector.rs b/tiny_skia/src/vector.rs
new file mode 100644
index 00000000..fd9cfdc5
--- /dev/null
+++ b/tiny_skia/src/vector.rs
@@ -0,0 +1,149 @@
+use crate::core::svg::{Data, Handle};
+use crate::core::{Rectangle, Size};
+
+use resvg::usvg;
+use rustc_hash::{FxHashMap, FxHashSet};
+
+use std::cell::RefCell;
+use std::collections::hash_map;
+use std::fs;
+
+pub struct Pipeline {
+    cache: RefCell<Cache>,
+}
+
+impl Pipeline {
+    pub fn new() -> Self {
+        Self {
+            cache: RefCell::new(Cache::default()),
+        }
+    }
+
+    pub fn viewport_dimensions(&self, handle: &Handle) -> Size<u32> {
+        self.cache
+            .borrow_mut()
+            .viewport_dimensions(handle)
+            .unwrap_or(Size::new(0, 0))
+    }
+
+    pub fn draw(
+        &mut self,
+        handle: &Handle,
+        bounds: Rectangle,
+        pixels: &mut tiny_skia::PixmapMut<'_>,
+        clip_mask: Option<&tiny_skia::ClipMask>,
+    ) {
+        if let Some(image) = self
+            .cache
+            .borrow_mut()
+            .draw(handle, Size::new(bounds.width as u32, bounds.height as u32))
+        {
+            pixels.draw_pixmap(
+                bounds.x as i32,
+                bounds.y as i32,
+                image,
+                &tiny_skia::PixmapPaint::default(),
+                tiny_skia::Transform::identity(),
+                clip_mask,
+            );
+        }
+    }
+
+    pub fn trim_cache(&mut self) {
+        self.cache.borrow_mut().trim();
+    }
+}
+
+#[derive(Default)]
+struct Cache {
+    trees: FxHashMap<u64, Option<resvg::usvg::Tree>>,
+    tree_hits: FxHashSet<u64>,
+    rasters: FxHashMap<(u64, Size<u32>), tiny_skia::Pixmap>,
+    raster_hits: FxHashSet<(u64, Size<u32>)>,
+}
+
+impl Cache {
+    fn load(&mut self, handle: &Handle) -> Option<&usvg::Tree> {
+        let id = handle.id();
+
+        if let hash_map::Entry::Vacant(entry) = self.trees.entry(id) {
+            let svg = match handle.data() {
+                Data::Path(path) => {
+                    fs::read_to_string(path).ok().and_then(|contents| {
+                        usvg::Tree::from_str(
+                            &contents,
+                            &usvg::Options::default(),
+                        )
+                        .ok()
+                    })
+                }
+                Data::Bytes(bytes) => {
+                    usvg::Tree::from_data(bytes, &usvg::Options::default()).ok()
+                }
+            };
+
+            entry.insert(svg);
+        }
+
+        self.tree_hits.insert(id);
+        self.trees.get(&id).unwrap().as_ref()
+    }
+
+    fn viewport_dimensions(&mut self, handle: &Handle) -> Option<Size<u32>> {
+        let tree = self.load(handle)?;
+
+        Some(Size::new(
+            tree.size.width() as u32,
+            tree.size.height() as u32,
+        ))
+    }
+
+    fn draw(
+        &mut self,
+        handle: &Handle,
+        size: Size<u32>,
+    ) -> Option<tiny_skia::PixmapRef<'_>> {
+        if size.width == 0 || size.height == 0 {
+            return None;
+        }
+
+        let id = handle.id();
+
+        if !self.rasters.contains_key(&(id, size)) {
+            let tree = self.load(handle)?;
+
+            let mut image = tiny_skia::Pixmap::new(size.width, size.height)?;
+
+            resvg::render(
+                tree,
+                if size.width > size.height {
+                    usvg::FitTo::Width(size.width)
+                } else {
+                    usvg::FitTo::Height(size.height)
+                },
+                tiny_skia::Transform::default(),
+                image.as_mut(),
+            )?;
+
+            // Swap R and B channels for `softbuffer` presentation
+            for pixel in bytemuck::cast_slice_mut::<u8, u32>(image.data_mut()) {
+                *pixel = *pixel & 0xFF00FF00
+                    | ((0x000000FF & *pixel) << 16)
+                    | ((0x00FF0000 & *pixel) >> 16);
+            }
+
+            self.rasters.insert((id, size), image);
+        }
+
+        self.raster_hits.insert((id, size));
+        self.rasters.get(&(id, size)).map(tiny_skia::Pixmap::as_ref)
+    }
+
+    fn trim(&mut self) {
+        self.trees.retain(|key, _| self.tree_hits.contains(key));
+        self.rasters.retain(|key, _| self.raster_hits.contains(key));
+
+        self.tree_hits.clear();
+        self.raster_hits.clear();
+    }
+}