✨ viewBox fitting and resvg rendering

Cargo.toml

@@ -13,3 +13,7 @@ xmltree = "0.10.3"
 mustache = { git = "https://git.shadamethyst.xyz/adri326/rust-mustache.git" }
 clap = { version = "3.2", features = ["derive"] }
 mkdirp = "1.0.0"
+resvg = "0.23"
+usvg = "0.23"
+tiny-skia = "0.6"
+png = "0.17"

src/export.rs

@@ -0,0 +1,128 @@
+use usvg::{
+    Tree,
+    NodeExt,
+    Options,
+};
+use xmltree::{Element};
+use std::path::{PathBuf};
+use std::collections::HashSet;
+
+#[derive(Debug)]
+pub enum ExportError {
+    Xml(xmltree::Error),
+    XmlParse(xmltree::ParseError),
+    Usvg(usvg::Error),
+    Io(PathBuf, std::io::Error),
+    NoBBox,
+    Utf8(std::string::FromUtf8Error),
+    Encode(png::EncodingError),
+}
+
+impl From<xmltree::ParseError> for ExportError {
+    fn from(err: xmltree::ParseError) -> Self {
+        Self::XmlParse(err)
+    }
+}
+
+impl From<xmltree::Error> for ExportError {
+    fn from(err: xmltree::Error) -> Self {
+        Self::Xml(err)
+    }
+}
+
+impl From<usvg::Error> for ExportError {
+    fn from(err: usvg::Error) -> Self {
+        Self::Usvg(err)
+    }
+}
+
+impl From<std::string::FromUtf8Error> for ExportError {
+    fn from(err: std::string::FromUtf8Error) -> Self {
+        Self::Utf8(err)
+    }
+}
+
+impl From<png::EncodingError> for ExportError {
+    fn from(err: png::EncodingError) -> Self {
+        Self::Encode(err)
+    }
+}
+
+pub fn get_new_bbox(svg: &Tree) -> Option<(f64, f64, f64, f64)> {
+    let bbox = svg.root().calculate_bbox()?;
+    if bbox.width() > bbox.height() {
+        let y = bbox.y() - (bbox.width() - bbox.height()) / 2.0;
+
+        Some((bbox.x(), y, bbox.width(), bbox.width()))
+    } else {
+        let x = bbox.x() - (bbox.height() - bbox.width()) / 2.0;
+
+        Some((x, bbox.y(), bbox.height(), bbox.height()))
+    }
+}
+
+fn get_usvg(svg_str: &str) -> Result<usvg::Tree, usvg::Error> {
+    let usvg_options = Options::default();
+    Tree::from_str(svg_str, &usvg_options.to_ref())
+}
+
+fn get_xml(svg_str: &str) -> Result<Element, xmltree::ParseError> {
+    Element::parse(svg_str.as_bytes())
+}
+
+fn xml_to_str(svg_xml: &Element) -> Result<String, ExportError> {
+    let mut s: Vec<u8> = Vec::new();
+
+    svg_xml.write(&mut s)?;
+
+    Ok(String::from_utf8(s)?)
+}
+
+pub fn resize(svg_str: String) -> Result<String, ExportError> {
+    if let Some(new_bbox) = get_new_bbox(&get_usvg(&svg_str)?) {
+        let mut svg_xml = get_xml(&svg_str)?;
+        svg_xml.attributes.insert(
+            "viewBox".to_string(),
+            format!("{} {} {} {}", new_bbox.0, new_bbox.1, new_bbox.2, new_bbox.3),
+        );
+
+        xml_to_str(&svg_xml)
+    } else {
+        Err(ExportError::NoBBox)
+    }
+}
+
+pub fn export(
+    mut svg_str: String,
+    output_dir: &PathBuf,
+    output_name: String,
+    args: &super::Args,
+) -> Result<(), ExportError> {
+    if args.resize {
+        svg_str = resize(svg_str)?;
+    }
+
+    mkdirp::mkdirp(output_dir.join("vector")).unwrap();
+
+    let output = output_dir.join(&format!("vector/{}.svg", output_name));
+    std::fs::write(output.clone(), svg_str.clone()).map_err(|err| ExportError::Io(output, err))?;
+
+    let svg_usvg = get_usvg(&svg_str)?;
+    for resolution in args.dim.iter().copied().filter(|r| *r != 0).collect::<HashSet<_>>() {
+        mkdirp::mkdirp(output_dir.join(&format!("{}", resolution))).unwrap();
+        let output = output_dir.join(&format!("{}/{}.png", resolution, output_name));
+
+        let mut image = tiny_skia::Pixmap::new(resolution, resolution).unwrap();
+
+        resvg::render(
+            &svg_usvg,
+            usvg::FitTo::Width(resolution),
+            tiny_skia::Transform::identity(),
+            image.as_mut()
+        ).unwrap();
+
+        image.save_png(output)?;
+    }
+
+    Ok(())
+}

src/main.rs

@@ -8,35 +8,45 @@ use parse::*;
 pub mod template;
 use template::*;
 
+pub mod export;
+use export::*;
+
 fn main() {
     let args = Args::parse();
 
-    let species = Arc::new(load_species(args.decl).unwrap());
+    let species = Arc::new(load_species(args.decl.clone()).unwrap());
     let context = RenderingContext::new(species);
 
-    let output_dir = args.output_dir.unwrap_or(PathBuf::from("output/vector/"));
-
-    mkdirp::mkdirp(output_dir.clone()).unwrap();
+    let output_dir = args.output_dir.clone().unwrap_or(PathBuf::from("output/"));
 
     if args.names.is_empty() {
         for name in context.species().variants.keys() {
-            generate_variant(&context, name, &output_dir);
+            generate_variant(&context, name, &output_dir, &args);
         }
     } else {
         for name in args.names.iter() {
-            generate_variant(&context, name, &output_dir);
+            generate_variant(&context, name, &output_dir, &args);
         }
     }
 }
 
-fn generate_variant(context: &RenderingContext, name: &str, output_dir: &PathBuf) {
+fn generate_variant(context: &RenderingContext, name: &str, output_dir: &PathBuf, args: &Args) {
     if let Some(path) = context.species().variants.get(name) {
         match context.compile(path).and_then(|template| {
             template.render_data_to_string(&context.get_data())
         }) {
-            Ok(rendered) => {
-                let output = output_dir.join(&format!("{}_{}.svg", context.species().name, name));
-                std::fs::write(output, rendered).unwrap();
+            Ok(svg) => {
+                match export(
+                    svg,
+                    output_dir,
+                    format!("{}_{}", context.species().name, name),
+                    args
+                ) {
+                    Ok(_) => {}
+                    Err(err) => {
+                        eprintln!("Error while rendering {}: {:?}", name, err);
+                    }
+                }
             }
             Err(err) => {
                 eprintln!("Error while rendering {}: {}", name, err);
@@ -49,7 +59,7 @@ fn generate_variant(context: &RenderingContext, name: &str, output_dir: &PathBuf
 
 #[derive(Parser, Debug)]
 #[clap(author, version, about, long_about = None)]
-struct Args {
+pub struct Args {
     /// A folder containing the declaration from which the emotes should be generated
     #[clap(short, long, value_parser)]
     decl: PathBuf,
@@ -58,6 +68,14 @@ struct Args {
     #[clap(value_parser)]
     names: Vec<String>,
 
+    /// Automatically resize the SVG's viewBox, defaults to true
+    #[clap(short, long, value_parser, default_value = "true")]
+    resize: bool,
+
+    /// Dimension to export the images as; can be specified multiple times
+    #[clap(long, value_parser)]
+    dim: Vec<u32>,
+
     /// Output directory
     #[clap(short, long, value_parser)]
     output_dir: Option<PathBuf>,