Add docs and CI

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: "cargo" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "daily"

.github/workflows/rust.yml

@@ -0,0 +1,35 @@
+name: Continuous integration
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust: [stable]
+
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v2
+
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          override: true
+
+      - name: Build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+
+      - name: Test
+        uses: actions-rs/cargo@v1
+        with:
+          command: test

Cargo.toml

@@ -1,8 +1,14 @@
 [package]
 name = "svg2pdf"
 version = "0.1.0"
+authors = ["Martin Haug <[email protected]>"]
 edition = "2018"
+description = "Convert SVG files to PDFs."
+repository = "https://github.com/typst/svg2pdf"
+readme = "README.md"
 license = "MIT OR Apache-2.0"
+categories = ["encoding", "graphics", "multimedia"]
+keywords = ["svg", "pdf", "vector-graphics", "conversion"]
 
 [features]
 default = ["png", "jpeg", "text", "system-fonts"]
@@ -14,5 +20,5 @@ system-fonts = ["usvg/system-fonts", "usvg/memmap-fonts"]
 [dependencies]
 image = { version = "0.23", default-features = false, optional = true }
 miniz_oxide = "0.4"
-pdf-writer = { git = "https://github.com/typst/pdf-writer", rev = "e1ec200" }
+pdf-writer = "0.4.1"
 usvg = { version = "0.19", default-features = false }

README.md

@@ -0,0 +1,63 @@
+# svg2pdf
+
+[![Build status](https://github.com/typst/svg2pdf/workflows/Continuous%20integration/badge.svg)](https://github.com/typst/svg2pdf/actions)
+[![Current crates.io release](https://img.shields.io/crates/v/svg2pdf)](https://crates.io/crates/svg2pdf)
+[![Documentation](https://img.shields.io/badge/docs.rs-svg2pdf-66c2a5?labelColor=555555&logoColor=white&logo=data:image/svg+xml;base64,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)](https://docs.rs/svg2pdf/)
+
+Convert SVG files to PDFs.
+
+This crate allows to convert static (i.e. non-interactive) SVG files to
+either standalone PDF files or Form XObjects that can be embedded in another
+PDF file and used just like images.
+
+The conversion will translate the SVG content to PDF without rasterizing it,
+so no quality is lost.
+
+## Example
+This example reads an SVG file and writes the corresponding PDF back to the disk.
+
+```rust
+let svg = std::fs::read_to_string("tests/example.svg").unwrap();
+
+// This can only fail if the SVG is malformed. This one is not.
+let pdf = svg2pdf::convert_str(&svg, svg2pdf::Options::default()).unwrap();
+
+// ... and now you have a Vec<u8> which you could write to a file or
+// transmit over the network!
+std::fs::write("target/example.pdf", pdf).unwrap();
+```
+
+## Supported features
+- Path drawing with fills and strokes
+- Gradients
+- Patterns
+- Clip paths
+- Masks
+- Transformation matrices
+- Respecting the `keepAspectRatio` attribute
+- Raster images and nested SVGs
+
+Filters are not currently supported and embedded raster images are not color
+managed. Instead, they use PDF's `DeviceRGB` color space.
+
+## Contributing
+We are looking forward to receiving your bugs and feature requests in the Issues
+tab. We would also be very happy to accept PRs for bug fixes, features, or
+refactorings!
+
+If you want to contribute but are uncertain where to start, yo could look into
+filters like `feBlend` and `feColorMatrix` that can be implemented with
+transparency groups and color spaces, respectively. We'd be happy to assist you
+with your PR's, so feel free to post Work in Progress PRs if marked as such.
+Please be kind to the maintainers and other contributors. If you feel that there
+are any problems, please feel free to reach out to us privately.
+
+Thanks to each and every prospective contributor for the effort you (plan to)
+invest in this project and for adopting it!
+
+## License
+svg2pdf is licensed under a MIT / Apache 2.0 dual license.
+
+Users and consumers of the library may choose which of those licenses they want
+to apply whereas contributors have to accept that their code is in compliance
+and distributed under the terms of both of these licenses.

src/lib.rs

@@ -1,4 +1,39 @@
-//! Convert SVG files to PDFs.
+/*! Convert SVG files to PDFs.
+
+This crate allows to convert static (i.e. non-interactive) SVG files to
+either standalone PDF files or Form XObjects that can be embedded in another
+PDF file and used just like images.
+
+The conversion will translate the SVG content to PDF without rasterizing it,
+so no quality is lost.
+
+## Example
+This example reads an SVG file and writes the corresponding PDF back to the disk.
+
+```rust
+let svg = std::fs::read_to_string("tests/example.svg").unwrap();
+
+// This can only fail if the SVG is malformed. This one is not.
+let pdf = svg2pdf::convert_str(&svg, svg2pdf::Options::default()).unwrap();
+
+// ... and now you have a Vec<u8> which you could write to a file or
+// transmit over the network!
+std::fs::write("target/example.pdf", pdf).unwrap();
+```
+
+## Supported features
+- Path drawing with fills and strokes
+- Gradients
+- Patterns
+- Clip paths
+- Masks
+- Transformation matrices
+- Respecting the `keepAspectRatio` attribute
+- Raster images and nested SVGs
+
+Filters are not currently supported and embedded raster images are not color
+managed. Instead, they use PDF's `DeviceRGB` color space.
+*/
 
 use std::collections::HashMap;
 
@@ -258,12 +293,82 @@ pub fn convert_tree(tree: &Tree, options: Options) -> Vec<u8> {
 ///
 /// The resulting object can be used by registering a name and the `id` with a
 /// page's [`/XObject`](pdf_writer::writers::Resources::x_objects) resources
-/// dictionary and then invoking the [`/Do`](pdf_writer::Content::x_object)
+/// dictionary and then invoking the [`Do`](pdf_writer::Content::x_object)
 /// operator with the name in the page's content stream.
 ///
 /// As the conversion process may need to create multiple indirect objects in
 /// the PDF, this function allocates consecutive IDs starting at `id` for its
 /// objects and returns the next available ID for your future writing.
+///
+/// ## Example
+/// Write a PDF file with some text and an SVG graphic.
+///
+/// ```rust
+/// use svg2pdf;
+/// use pdf_writer::{Content, Finish, Name, PdfWriter, Rect, Ref, Str};
+///
+/// // Allocate the indirect reference IDs and names.
+/// let catalog_id = Ref::new(1);
+/// let page_tree_id = Ref::new(2);
+/// let page_id = Ref::new(3);
+/// let font_id = Ref::new(4);
+/// let content_id = Ref::new(5);
+/// let svg_id = Ref::new(6);
+/// let font_name = Name(b"F1");
+/// let svg_name = Name(b"S1");
+///
+/// // Start writing a PDF.
+/// let mut writer = PdfWriter::new();
+/// writer.catalog(catalog_id).pages(page_tree_id);
+/// writer.pages(page_tree_id).kids([page_id]).count(1);
+///
+/// // Set up a simple A4 page.
+/// let mut page = writer.page(page_id);
+/// page.media_box(Rect::new(0.0, 0.0, 595.0, 842.0));
+/// page.parent(page_tree_id);
+/// page.contents(content_id);
+///
+/// // Add the font and, more importantly, the SVG to the resource dictionary
+/// // so that it can be referenced in the content stream.
+/// let mut resources = page.resources();
+/// resources.x_objects().pair(svg_name, svg_id);
+/// resources.fonts().pair(font_name, font_id);
+/// resources.finish();
+/// page.finish();
+///
+/// // Set a predefined font, so we do not have to load anything extra.
+/// writer.type1_font(font_id).base_font(Name(b"Helvetica"));
+///
+/// // Let's add an SVG graphic to this file.
+/// // We need to load its source first and manually parse it into a usvg Tree.
+/// let svg = std::fs::read_to_string("tests/example.svg").unwrap();
+/// let tree = usvg::Tree::from_str(&svg, &usvg::Options::default().to_ref()).unwrap();
+///
+/// // Then, we will write it to the page as the 6th indirect object.
+/// //
+/// // This call allocates some indirect object reference IDs for itself. If we
+/// // wanted to write some more indirect objects afterwards, we could use the
+/// // return value as the next unused reference ID.
+/// svg2pdf::convert_tree_into(&tree, svg2pdf::Options::default(), &mut writer, svg_id);
+///
+/// // Write a content stream with some text and our SVG.
+/// let mut content = Content::new();
+/// content
+///     .begin_text()
+///     .set_font(font_name, 16.0)
+///     .next_line(108.0, 734.0)
+///     .show(Str(b"Look at my wonderful vector graphic!"))
+///     .end_text();
+///
+/// // Add our graphic.
+/// content
+///     .transform([300.0, 0.0, 0.0, 300.0, 147.5, 385.0])
+///     .x_object(svg_name);
+///
+/// // Write the file to the disk.
+/// writer.stream(content_id, &content.finish());
+/// std::fs::write("target/embedded.pdf", writer.finish()).unwrap();
+/// ```
 pub fn convert_tree_into(
     tree: &Tree,
     options: Options,