svg-filters: rework codegen

crates/svg-filters/src/codegen.rs

@@ -0,0 +1,229 @@
+use std::{
+    borrow::Cow,
+    cmp,
+    collections::{BTreeSet, HashMap, HashSet},
+};
+
+use indexmap::IndexMap;
+use petgraph::{
+    algo::toposort,
+    graph::DiGraph,
+    prelude::{EdgeIndex, NodeIndex},
+};
+use quick_xml::{events::attributes::Attribute, name::QName, ElementWriter};
+
+use crate::{
+    types::{
+        graph::{edge::Edge, FilterGraph},
+        nodes::{primitives::WriteElement, CommonAttrs},
+    },
+    Node,
+};
+
+use self::error::CodegenError;
+
+pub struct SvgDocument {
+    filters: HashMap<String, FilterGraph>,
+}
+
+impl SvgDocument {
+    pub fn new() -> Self {
+        Self {
+            filters: HashMap::new(),
+        }
+    }
+
+    #[allow(clippy::unwrap_used, reason = "we literally just did the insertion")]
+    pub fn create_filter(&mut self, id: impl ToString) -> &mut FilterGraph {
+        let filter = FilterGraph::new();
+
+        self.filters.insert(id.to_string(), filter);
+        self.filters.get_mut(&id.to_string()).unwrap()
+    }
+
+    pub fn generate_svg(&self) -> String {
+        let mut result = Vec::new();
+        let mut doc_writer = quick_xml::Writer::new_with_indent(&mut result, b' ', 4);
+
+        doc_writer
+            .create_element("svg")
+            .write_inner_content(|writer| {
+                self.filters
+                    .iter()
+                    .try_fold(writer, Self::gen_filter)
+                    .map(|_| {})
+            });
+
+        String::from_utf8_lossy(&result).to_string()
+    }
+
+    fn gen_filter<'w, 'r>(
+        writer: &'w mut quick_xml::Writer<&'r mut Vec<u8>>,
+        (id, graph): (&String, &FilterGraph),
+    ) -> Result<&'w mut quick_xml::Writer<&'r mut Vec<u8>>, CodegenError> {
+        writer
+            .create_element("filter")
+            .with_attribute(("id", id.as_str()))
+            .write_inner_content(|writer| Self::graph_to_svg(writer, graph))
+    }
+
+    fn graph_to_svg(
+        writer: &mut quick_xml::Writer<&mut Vec<u8>>,
+        graph: &FilterGraph,
+    ) -> Result<(), CodegenError> {
+        let sorted = toposort(&graph.dag, None).expect("no cycles allowed in a DAG");
+        sorted
+            .into_iter()
+            .filter_map(|node_idx| {
+                graph
+                    .dag
+                    .node_weight(node_idx)
+                    .and_then(|node| node.primitive())
+                    .map(|(primitive, common_attrs)| (node_idx, primitive, common_attrs))
+            })
+            .try_fold(writer, |writer, (node_idx, primitive, common_attrs)| {
+                let mut el_writer = primitive.element_writer(writer);
+                el_writer = input_attrs(node_idx, &graph.dag).write_into(el_writer);
+                el_writer = output_attrs(node_idx, &graph.dag).write_into(el_writer);
+                el_writer = Attrs::from(*common_attrs).write_into(el_writer);
+                el_writer.write_empty()
+            })?;
+
+        Ok(())
+    }
+}
+
+struct Attrs(IndexMap<String, String>);
+
+impl Attrs {
+    fn write_into<'w, 'b>(
+        self,
+        el_writer: ElementWriter<'w, &'b mut Vec<u8>>,
+    ) -> ElementWriter<'w, &'b mut Vec<u8>> {
+        let attrs = self.0.iter().map(|(k, v)| (k.as_str(), v.as_str()));
+        el_writer.with_attributes(attrs)
+    }
+}
+
+impl From<CommonAttrs> for Attrs {
+    fn from(value: CommonAttrs) -> Self {
+        let CommonAttrs {
+            x,
+            y,
+            width,
+            height,
+        } = value;
+        Self(IndexMap::from([
+            ("x".to_owned(), x.to_string()),
+            ("y".to_owned(), y.to_string()),
+            ("width".to_owned(), width.to_string()),
+            ("height".to_owned(), height.to_string()),
+        ]))
+    }
+}
+
+#[allow(
+    clippy::unwrap_used,
+    reason = "in all cases of use of unwrap, it's values we got from the graph so we know it's safe"
+)]
+fn input_attrs(node_idx: NodeIndex, g: &DiGraph<Node, Edge>) -> Attrs {
+    let inputs: Vec<NodeIndex> = g
+        .neighbors_directed(node_idx, petgraph::Direction::Incoming)
+        .collect();
+    let node = g.node_weight(node_idx).unwrap();
+
+    if node.input_count() as usize != inputs.len() {
+        todo!("proper error handling for wrong numbers of inputs")
+    }
+
+    let mut inputs = inputs
+        .into_iter()
+        .map(|input_idx| {
+            let edge_idx = g.find_edge(input_idx, node_idx).unwrap();
+            let edge = g.edge_weight(edge_idx).unwrap();
+            let input_node = g.node_weight(input_idx).unwrap();
+
+            (input_node, edge_idx, edge)
+        })
+        .collect::<Vec<(&Node, EdgeIndex, &Edge)>>();
+    inputs.sort_by(|a, b| a.2.cmp(b.2));
+
+    let mut uniq = BTreeSet::new();
+    let no_duplicates = inputs.iter().all(|(_, _, edge)| uniq.insert(edge));
+
+    if no_duplicates {
+        Attrs(
+            inputs
+                .into_iter()
+                .map(|(input, edge_idx, edge)| {
+                    let name = match input {
+                        Node::StdInput(s) => format!("{s:?}"),
+                        Node::Primitive { .. } => format_edge_idx(edge_idx),
+                    };
+                    (edge.to_string(), name)
+                })
+                .collect(),
+        )
+    } else {
+        todo!("better error handling for inputs with multiple values")
+    }
+}
+
+#[allow(
+    clippy::unwrap_used,
+    reason = "in all cases of use of unwrap, it's values we got from the graph so we know it's safe"
+)]
+fn output_attrs(node_idx: NodeIndex, g: &DiGraph<Node, Edge>) -> Attrs {
+    let outputs: Vec<NodeIndex> = g
+        .neighbors_directed(node_idx, petgraph::Direction::Outgoing)
+        .collect();
+
+    match outputs.len().cmp(&1) {
+        cmp::Ordering::Less => Attrs(IndexMap::new()),
+        cmp::Ordering::Equal => {
+            let output = outputs.first().unwrap();
+            let edge_idx = g.find_edge(node_idx, *output).unwrap();
+            Attrs(IndexMap::from([(
+                "result".to_string(),
+                format_edge_idx(edge_idx),
+            )]))
+        }
+        cmp::Ordering::Greater => todo!("better error handling for too many outputs"),
+    }
+}
+
+/// convenience method to avoid fuckups during future changes
+fn format_edge_idx(idx: EdgeIndex) -> String {
+    format!("edge{}", idx.index())
+}
+
+mod error {
+    use std::{error::Error, fmt::Display};
+
+    #[derive(Debug)]
+    pub enum CodegenError {
+        QuickXmlError(quick_xml::Error),
+    }
+
+    impl From<quick_xml::Error> for CodegenError {
+        fn from(value: quick_xml::Error) -> Self {
+            Self::QuickXmlError(value)
+        }
+    }
+
+    impl Display for CodegenError {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            match self {
+                CodegenError::QuickXmlError(e) => e.fmt(f),
+            }
+        }
+    }
+
+    impl Error for CodegenError {}
+}
+
+impl Default for SvgDocument {
+    fn default() -> Self {
+        Self::new()
+    }
+}

crates/svg-filters/src/lib.rs

@@ -1,6 +1,8 @@
 #![feature(lint_reasons)]
 
+pub mod codegen;
 pub mod types;
 pub use types::nodes::Node;
-pub use types::Edge;
-pub use types::Filter;
+
+#[cfg(test)]
+mod tests {}

crates/svg-filters/src/main.rs

@@ -1,11 +1,12 @@
+use std::hint::black_box;
+
 use svg_filters::{
-    types::nodes::{primitives::color_matrix::ColorMatrixType, standard_input::StandardInput},
-    Edge, Filter, Node,
+    codegen::SvgDocument,
+    types::{graph::edge::Edge, nodes::primitives::color_matrix::ColorMatrixType},
+    Node,
 };
 
 fn main() {
-    let mut filter = Filter::new();
-
     // <filter id="chromabb" >
     //   <feColorMatrix values="1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0" in="SourceGraphic" />
     //   <feOffset dx="25" dy="0" />
@@ -21,37 +22,42 @@ fn main() {
     //   <feComposite in="rb" in2="grn" operator="arithmetic" k2="1" k3="1" />
     // </filter>
 
-    let chan_r = filter.add_node(Node::color_matrix(ColorMatrixType::Matrix(Box::new([
+    let mut doc = SvgDocument::new();
+    let chromabb = doc.create_filter("chromabb_gen");
+
+    let chan_r = chromabb.add_node(Node::color_matrix(ColorMatrixType::Matrix(Box::new([
         1., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 1., 0.,
     ]))));
-    let chan_g = filter.add_node(Node::color_matrix(ColorMatrixType::Matrix(Box::new([
+    let chan_g = chromabb.add_node(Node::color_matrix(ColorMatrixType::Matrix(Box::new([
         0., 0., 0., 0., 0., 0., 1., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 1., 0.,
     ]))));
-    let chan_b = filter.add_node(Node::color_matrix(ColorMatrixType::Matrix(Box::new([
+    let chan_b = chromabb.add_node(Node::color_matrix(ColorMatrixType::Matrix(Box::new([
         0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 1., 0., 0., 0., 0., 0., 1., 0.,
     ]))));
 
-    let offset_r = filter.add_node(Node::offset(25., 0.));
-    let offset_b = filter.add_node(Node::offset(-25., 0.));
-    let blur_r = filter.add_node(Node::gaussian_blur_xy(5, 0));
-    let blur_b = filter.add_node(Node::gaussian_blur_xy(5, 0));
+    let offset_r = chromabb.add_node(Node::offset(25., 0.));
+    let offset_b = chromabb.add_node(Node::offset(-25., 0.));
+    let blur_r = chromabb.add_node(Node::gaussian_blur_xy(5, 0));
+    let blur_b = chromabb.add_node(Node::gaussian_blur_xy(5, 0));
 
-    let composite_rb = filter.add_node(Node::composite_arithmetic(0., 1., 1., 0.));
-    let composite_final = filter.add_node(Node::composite_arithmetic(0., 1., 1., 0.));
+    let composite_rb = chromabb.add_node(Node::composite_arithmetic(0., 1., 1., 0.));
+    let composite_final = chromabb.add_node(Node::composite_arithmetic(0., 1., 1., 0.));
 
-    filter.graph.extend_with_edges(&[
-        (filter.source_graphic(), chan_r, Edge::unnamed()),
-        (filter.source_graphic(), chan_b, Edge::unnamed()),
-        (filter.source_graphic(), chan_g, Edge::unnamed()),
-        (chan_r, offset_r, Edge::new("ro")),
-        (offset_r, blur_r, Edge::new("rob")),
-        (chan_b, offset_b, Edge::new("bo")),
-        (offset_b, blur_b, Edge::new("bob")),
-        (blur_r, composite_rb, Edge::new("robc").with_idx(0)),
-        (blur_b, composite_rb, Edge::new("bobc").with_idx(1)),
-        (composite_rb, composite_final, Edge::new("cf").with_idx(0)),
-        (chan_g, composite_final, Edge::new("gf").with_idx(1)),
+    chromabb.dag.extend_with_edges(&[
+        (chromabb.source_graphic(), chan_r),
+        (chromabb.source_graphic(), chan_b),
+        (chromabb.source_graphic(), chan_g),
+        (chan_r, offset_r),
+        (offset_r, blur_r),
+        (chan_b, offset_b),
+        (offset_b, blur_b),
+    ]);
+    chromabb.dag.extend_with_edges(&[
+        (blur_r, composite_rb, Edge::new(0)),
+        (blur_b, composite_rb, Edge::new(1)),
+        (composite_rb, composite_final, Edge::new(0)),
+        (chan_g, composite_final, Edge::new(1)),
     ]);
 
-    println!("{}", filter.to_svg())
+    black_box(doc.generate_svg());
 }

crates/svg-filters/src/types.rs

@@ -1,250 +1,70 @@
-use core::panic;
-use std::{
-    borrow::Cow,
-    collections::{HashMap, HashSet},
-    fmt::Debug,
-    io::BufWriter,
-    primitive,
-};
-
-use petgraph::{
-    adj::EdgeIndex,
-    algo::{toposort, DfsSpace},
-    data::{Build, DataMap},
-    graph::DiGraph,
-    graphmap::DiGraphMap,
-    prelude::NodeIndex,
-    visit::NodeIndexable,
-};
-use quick_xml::{events::attributes::Attribute, name::QName, ElementWriter, Error};
-
 pub mod length;
 pub mod nodes;
 
-use crate::types::nodes::primitives::color_matrix::{ColorMatrix, ColorMatrixType};
+// pub mod old;
 
-use self::{
-    length::{Coordinate, Length},
-    nodes::{
-        primitives::{FePrimitive, WriteElement},
-        Node,
-    },
-};
+pub mod graph {
+    use std::iter::Iterator;
 
-#[derive(Debug)]
-pub struct Filter<'a> {
-    pub graph: DiGraph<Node, Edge<'a>>,
-    source_graphic_idx: NodeIndex,
-}
+    use petgraph::{data::Build, prelude::*};
 
-impl Filter<'_> {
-    pub fn new() -> Self {
-        let mut graph = DiGraph::new();
-        let source_graphic_idx = graph.add_node(Node::StdInput(
-            nodes::standard_input::StandardInput::SourceGraphic,
-        ));
+    use crate::Node;
 
-        Self {
-            graph,
-            source_graphic_idx,
+    use self::edge::Edge;
+
+    use super::nodes::standard_input::StandardInput;
+
+    #[derive(Debug)]
+    pub struct FilterGraph {
+        pub dag: DiGraph<Node, Edge>,
+        source_graphic_idx: NodeIndex,
+    }
+
+    impl FilterGraph {
+        pub fn new() -> Self {
+            let mut dag = DiGraph::new();
+            let source_graphic_idx = dag.add_node(Node::StdInput(StandardInput::SourceGraphic));
+
+            Self {
+                dag,
+                source_graphic_idx,
+            }
+        }
+
+        pub fn add_node(&mut self, node: Node) -> NodeIndex {
+            self.dag.add_node(node)
+        }
+
+        pub fn source_graphic(&self) -> NodeIndex {
+            self.source_graphic_idx
         }
     }
 
-    pub fn add_node(&mut self, node: Node) -> NodeIndex {
-        self.graph.add_node(node)
-    }
-
-    pub fn source_graphic(&self) -> NodeIndex {
-        self.source_graphic_idx
-    }
-
-    pub fn to_svg(&self) -> String {
-        let mut result = Vec::new();
-        // let mut doc_writer = quick_xml::Writer::new(&mut result);
-        let mut doc_writer = quick_xml::Writer::new_with_indent(&mut result, b' ', 2);
-
-        doc_writer
-            .create_element("filter")
-            .with_attribute(("id", "chromabb_gen"))
-            .write_inner_content(|writer| {
-                let mut dfs_space = DfsSpace::new(&self.graph);
-                let sorted =
-                    toposort(&self.graph, Some(&mut dfs_space)).expect("No cycles! Bad user!");
-
-                let v = sorted
-                    .into_iter()
-                    .filter_map(|node_idx| {
-                        let node = self
-                            .graph
-                            .node_weight(node_idx)
-                            .expect("toposorting will not return invalid indices");
-
-                        if let Node::Primitive {
-                            primitive,
-                            common_attrs,
-                        } = node
-                        {
-                            Some((node_idx, primitive, common_attrs))
-                        } else {
-                            None
-                        }
-                    })
-                    .try_fold(writer, |acc, (node_idx, primitive, common_attrs)| {
-                        let mut el_writer = primitive.element_writer(&mut *acc);
-                        el_writer = create_input_attr(
-                            &self.graph,
-                            el_writer,
-                            node_idx,
-                            self.graph
-                                .node_weight(node_idx)
-                                .expect("cannot get invalid node_idx from toposort")
-                                .input_count(),
-                        );
-                        create_output_attr(&self.graph, el_writer, node_idx).write_empty()
-                    })
-                    .map(|_| ());
-
-                Ok::<(), Error>(())
-            })
-            .expect("shouldnt fail to write or something");
-        String::from_utf8_lossy(&result).to_string()
-    }
-}
-
-impl Default for Filter<'_> {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct Edge<'a> {
-    pub edge_type: EdgeType<'a>,
-    /// the index of the `in` attribute on the target element
-    /// if None, just `in`
-    pub in_idx: Option<u8>,
-}
-
-impl<'a> Edge<'a> {
-    pub fn new(name: &'a str) -> Self {
-        Self {
-            edge_type: EdgeType::Named(name),
-            in_idx: None,
+    pub mod edge {
+        #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+        pub struct Edge {
+            input_idx: u8,
         }
-    }
 
-    #[must_use]
-    pub fn with_idx(mut self, idx: u8) -> Self {
-        self.in_idx = Some(idx);
-        self
-    }
-
-    pub fn unnamed() -> Self {
-        Self {
-            edge_type: EdgeType::Unnamed,
-            in_idx: None,
+        impl Edge {
+            pub fn new(input_idx: u8) -> Self {
+                Self { input_idx }
+            }
         }
-    }
-}
 
-impl Default for Edge<'_> {
-    fn default() -> Self {
-        Self::unnamed()
-    }
-}
+        impl Default for Edge {
+            fn default() -> Self {
+                Self { input_idx: 0 }
+            }
+        }
 
-#[derive(Debug, Clone)]
-pub enum EdgeType<'a> {
-    Named(&'a str),
-    /// For standard inputs such as SourceGraphic etc., which we'll just be representing as nodes for simplicity
-    Unnamed,
-}
-
-fn create_input_attr<'w, 'b>(
-    g: &'_ DiGraph<Node, Edge<'_>>,
-    mut el_writer: ElementWriter<'w, &'b mut Vec<u8>>,
-    node_idx: NodeIndex,
-    input_count: u8,
-) -> ElementWriter<'w, &'b mut Vec<u8>> {
-    let inputs = g
-        .neighbors_directed(node_idx, petgraph::Direction::Incoming)
-        .collect::<Vec<NodeIndex>>();
-
-    if inputs.len() != input_count as usize {
-        // TODO: better error handling
-        panic!("input couns didnt match");
-    }
-
-    inputs
-        .into_iter()
-        .enumerate()
-        .fold(el_writer, |el_writer, (i, incoming_idx)| {
-            let incoming_node = g.node_weight(incoming_idx).expect("cannot fail here");
-
-            // find incoming edge and get weight
-            let Edge { edge_type, in_idx } = g
-                .edge_weight(
-                    g.find_edge(incoming_idx, node_idx)
-                        .expect("there should always be an edge"),
-                )
-                .expect("once again, should always exist");
-
-            let in_attr_name = match in_idx {
-                None | Some(0) => "in".to_owned(),
-                Some(n) => format!("in{}", n + 1),
-            };
-
-            let v = match incoming_node {
-                Node::StdInput(std_in) => format!("{std_in:?}"),
-                Node::Primitive { .. } => {
-                    if let EdgeType::Named(name) = edge_type {
-                        (*name).to_owned()
-                    } else {
-                        panic!(
-                            "unnamed edges should not be used for connections between primitives"
-                        )
-                    }
+        impl ToString for Edge {
+            fn to_string(&self) -> String {
+                match self.input_idx {
+                    0 => "in".to_owned(),
+                    n => format!("in{}", n + 1),
                 }
-            };
-
-            el_writer.with_attribute((in_attr_name.as_str(), v.as_str()))
-        })
-}
-
-#[allow(clippy::unwrap_used, reason = "all unwraps are for finding on options")]
-fn create_output_attr<'w, 'b>(
-    g: &'_ DiGraph<Node, Edge<'_>>,
-    mut el_writer: ElementWriter<'w, &'b mut Vec<u8>>,
-    node_idx: NodeIndex,
-) -> ElementWriter<'w, &'b mut Vec<u8>> {
-    let output = g
-        .neighbors_directed(node_idx, petgraph::Direction::Outgoing)
-        .map(|neighbor_idx| {
-            let edge_idx = g.find_edge(node_idx, neighbor_idx).unwrap();
-
-            let Edge {
-                edge_type: EdgeType::Named(name),
-                ..
-            } = g.edge_weight(edge_idx).unwrap()
-            else {
-                panic!("Unnamed edge used for connection between primitives");
-            };
-            *name
-        })
-        .collect::<HashSet<&str>>();
-
-    if output.is_empty() {
-        el_writer
-    } else if output.len() == 1 {
-        el_writer.with_attribute(Attribute {
-            key: QName(b"result"),
-            value: Cow::from(
-                (*output.into_iter().collect::<Vec<&str>>().first().unwrap())
-                    .to_string()
-                    .into_bytes(),
-            ),
-        })
-    } else {
-        panic!("Can't have more then one named output: {output:?}")
+            }
+        }
     }
 }

crates/svg-filters/src/types/length.rs

@@ -1,8 +1,17 @@
-#[derive(Default, Debug)]
+use std::fmt::Display;
+
+#[derive(Default, Debug, Clone, Copy)]
 pub struct Length(f32, Unit);
+
+impl Display for Length {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}{}", self.0, self.1)
+    }
+}
+
 pub type Coordinate = Length;
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone, Copy)]
 pub enum Unit {
     #[default]
     None,
@@ -15,3 +24,19 @@ pub enum Unit {
     Pt,
     Pc,
 }
+
+impl Display for Unit {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Unit::None => f.write_str(""),
+            Unit::Em => f.write_str("em"),
+            Unit::Ex => f.write_str("ex"),
+            Unit::Px => f.write_str("px"),
+            Unit::In => f.write_str("in"),
+            Unit::Cm => f.write_str("cm"),
+            Unit::Mm => f.write_str("mm"),
+            Unit::Pt => f.write_str("pt"),
+            Unit::Pc => f.write_str("pc"),
+        }
+    }
+}

crates/svg-filters/src/types/nodes.rs

@@ -34,12 +34,12 @@ impl Default for Node {
     }
 }
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone, Copy)]
 pub(crate) struct CommonAttrs {
-    x: Coordinate,
-    y: Coordinate,
-    width: Length,
-    height: Length,
+    pub x: Coordinate,
+    pub y: Coordinate,
+    pub width: Length,
+    pub height: Length,
 }
 
 impl Node {
@@ -50,6 +50,18 @@ impl Node {
         }
     }
 
+    pub fn primitive(&self) -> Option<(&FePrimitive, &CommonAttrs)> {
+        if let Node::Primitive {
+            primitive,
+            common_attrs,
+        } = self
+        {
+            Some((primitive, common_attrs))
+        } else {
+            None
+        }
+    }
+
     pub fn input_count(&self) -> u8 {
         match self {
             Node::Primitive {