Donner SVG v0.5.0

Major release adding a software rendering backend, complete text rendering, all 17 SVG filter primitives, and a CLI tool — while maintaining the existing Skia backend.

Highlights

• <text> support — Full <text>, <tspan>, and <textPath> support with per-character
  positioning, text-anchor, text-decoration, and all baseline properties. Fonts are loaded from
  @font-face rules (TTF, OTF, WOFF, WOFF2). An optional HarfBuzz tier (--config=text-full)
  adds complex script shaping.
• <filter> support — all 17 SVG filter primitives — feGaussianBlur, feColorMatrix,
  feComposite, feBlend, feTurbulence, feConvolveMatrix, feDiffuseLighting, feSpecularLighting,
  feDisplacementMap, feComponentTransfer, feMorphology, feFlood, feOffset, feMerge, feTile,
  feImage, feDropShadow. Float-precision pipeline with SIMD (NEON) optimizations. CSS shorthand
  filter functions (blur(), brightness(), drop-shadow(), etc.) also supported.
• tiny-skia software renderer — A new default rendering backend written in C++ that requires no
  external GPU libraries. Achieves performance within 1.5x of Skia across all rendering operations.
  The Skia backend remains available as a build option. A vectorized WASM SIMD128 backend ships
  alongside the existing ARM NEON / x86 AVX2 / scalar paths and is selected automatically when
  Donner is compiled with Emscripten's -msimd128.
• donner-svg CLI tool — Render SVGs to PNG, preview in the terminal, or interactively
  inspect elements with mouse selection.
• WebAssembly build — Donner's renderer and parser now build through the Emscripten toolchain
  via bazel build --config=wasm //..., with an examples/svg_viewer demo that parses and
  renders SVGs entirely in the browser using ImGui + emscripten-glfw.
• Donner Editor — A new in-tree SVG editor lives under donner/editor/, shipping both as a
  native desktop application and as a WebAssembly edition that runs entirely in the browser.
• .svgz support — SVGParser auto-detects the gzip magic bytes and decompresses .svgz
  input transparently, so gzipped SVG files load without any extra ceremony at the call site.

What's Changed

• Renderer architecture — Abstract RendererInterface with RendererDriver traversal,
  enabling backend-agnostic rendering. Both Skia and tiny-skia implement the same interface.
• Incremental invalidation — Dirty flags on DOM mutations with O(1) fast path for unchanged
  documents. StyleSystem performs selective per-entity recomputation.
• External SVG references — <image> and <use> elements can reference external .svg files
  with sandboxed resource loading.
• <clipPath> <use> support — <use> children inside <clipPath> now resolve correctly.
• transform-origin presentation attribute — Accepted as both a presentation attribute
  and a CSS property, with the single-keyword grammar (top/bottom/left/right/center)
  parsed per the spec.
• XML entity support — Custom <!ENTITY> declarations in doctypes are now parsed by default.
• XML parser conformance — Name token validation per XML 1.0 spec.
• CSS Color 4 — Full CSS Color 4 parsing plus color-profile aliases and modern color
  function grammar. Hex colors, rgb()/rgba(), hsl()/hsla(), hwb(), lab(), lch(),
  oklab(), oklch(), and color() all round-trip through the parser.
• Unified parser diagnostics — ParseDiagnostic replaces ParseError, carries a
  DiagnosticSeverity and half-open SourceRange, and routes non-fatal warnings through
  a lazy-evaluated ParseWarningSink. Clang/rustc-style source-context rendering via
  DiagnosticRenderer.
• CMake support — Full CMake build for both Skia and tiny-skia backends with feature toggles
  for text, WOFF2, and filters.
• Fuzzing — Continuous fuzzing harness with Docker support; all parser surfaces fuzz-tested.
• 81.7% line coverage across production code (84.0% function coverage, 73.4% branch
  coverage).

Fixes and Internals

• CompileTimeMap 32-bit correctness fix — The compile-time perfect-hash map used for CSS
  named colors, presentation attributes, and shape property tables was silently broken on
  32-bit targets: the splitmix64 finalizer performed a >> 33 shift on std::size_t, which is
  undefined behavior when size_t is 32 bits. The hash has been reworked to use explicit
  uint64_t arithmetic. Native builds (where size_t is already 64-bit) are unaffected, but
  WebAssembly builds now produce correct lookups for every property map.
• Modular EnTT headers — Switched from the monolithic entt.hpp amalgamation to the
  modular EnTT headers, improving clean-build compile time and making incremental rebuilds
  after ECS-adjacent edits measurably cheaper.
• resvg test suite upgraded — Upgraded the vendored resvg-test-suite snapshot and
  reworked the skip mechanism to carry a reason string per skipped test, which made it
  straightforward to enable another wave of previously-skipped cases.
• Filter-function CSS shorthand — 30 additional filter: blur() / brightness() /
  drop-shadow() / ... resvg tests now pass.

Breaking API Changes

v0.5 includes a substantial API refactor to prepare for future GPU rendering and to unify parser
error reporting. Callers upgrading from v0.1 will need to update the following:

• Transform → Transform2, Box → Box2 — 2D math types are renamed to make room for
  future 3D variants. No compatibility aliases are provided; callers must update to the new
  names (and the Transform2f/Transform2d/Box2d shorthand typedefs).
• PathSpline replaced by immutable Path + PathBuilder — The mutable PathSpline class
  is removed. Paths are now constructed via PathBuilder and consumed as immutable Path
  values. Path exposes geometric queries (bounds, transformedBounds, pathLength,
  pointAt, tangentAt, normalAt, strokeMiterBounds, isInside, isOnPath, vertices)
  and conversions (cubicToQuadratic, toMonotonic, flatten, strokeToFill). PathBuilder
  supports native QuadTo and full SVG Appendix F.6 arc decomposition.
• BezierUtils — New public utility with EvalQuadratic/Cubic, SplitQuadratic/Cubic,
  ApproximateCubicWithQuadratics, QuadraticYExtrema/CubicYExtrema, and
  QuadraticBounds/CubicBounds.
• FillRule moved from donner::svg to donner — Now lives in the base namespace since
  it is shared across the path and rendering layers.
• PathParser emits native QuadTo — Previously quadratic segments were degree-elevated to
  cubics. Consumers that assumed only cubic segments will need to handle QuadTo as well.
• Unified parser diagnostics (ParseError → ParseDiagnostic) — All parser APIs now return
  ParseDiagnostic instead of ParseError. Diagnostics carry a DiagnosticSeverity
  (Error/Warning), a reason string, and a half-open SourceRange (replacing the previous
  single FileOffset). Use ParseDiagnostic::Error() / ParseDiagnostic::Warning() factories
  to construct them.
• ParseWarningSink — Parser entry points now accept a ParseWarningSink& for collecting
  non-fatal warnings, replacing std::vector<ParseError>* out-parameters. The sink uses lazy
  factory-callable evaluation, so warning construction is zero-cost when no sink is attached.
  A new DiagnosticRenderer produces clang/rustc-style output with source context and
  caret/tilde indicators.

Full Changelog: v0.1.2...v0.5.0

What's Included

• donner-svg, a CLI tool for rendering and previewing SVG files.
• An embeddable C++ API for parsing, inspecting, modifying, and rendering SVGs.

ParseResult<SVGDocument> maybeDocument = SVGParser::ParseSVG(fileData);
if (maybeDocument.hasError()) {
  std::cerr << "Parse Error: " << maybeDocument.error() << "\n";
  std::abort();
}

Renderer renderer;
renderer.draw(maybeDocument.result());

const bool success = renderer.save("output.png");

To use the CLI tool:

# Render to PNG
donner-svg input.svg --output output.png

# Show a terminal preview
donner-svg input.svg --preview

# Interactive terminal mode with mouse selection
donner-svg input.svg --interactive

Or when building from source:

bazel run //donner/svg/tool -- input.svg --output output.png

Donner SVG v0.1.2

This release provides an embeddable SVG2 library, which includes CSS3 with a Skia-based renderer.

Large portions of the SVG2 static spec are implemented, including all shapes, markers, gradients, <use>, etc. Text is not yet implemented but is planned for v0.2.0.

What's Changed

• Add support for the <symbol> element.
• Experimentally support XML <!ENTITY ...> references in the doctype (behind the off-by-default enableExperimental Option).
• Various dependency updates.

Full Changelog: v0.1.1...v0.1.2

What's Included

• svg_to_png, which is a standalone tool to render an SVG using Donner.
• An embeddable C++ API that allows rendering and manulating SVGs.

ParseResult<SVGDocument> maybeDocument = SVGParser::ParseSVG(fileData);
if (maybeDocument.hasError()) {
  std::cerr << "Parse Error: " << maybeDocument.error() << "\n";
  std::abort();
}

RendererSkia renderer;
renderer.draw(maybeDocument.result());

const bool success = renderer.save("output.png");

To use svg_to_png:

./svg_to_png donner_splash.svg

Or when building from source:

bazel run --run_under="cd $PWD &&" //examples:svg_to_png -- donner_splash.svg

Donner SVG v0.1.1

This release provides an embeddable SVG2 library, which includes CSS3 with a Skia-based renderer.

Large portions of the SVG2 static spec are implemented, including all shapes, markers, gradients, <use>, etc. Text is not yet implemented but is planned for v0.2.0.

What's Changed

• Improve error handling in svg_to_png app.
• Fixed SVGElement::tryCast and SVGElement::isa with intermediate classes like SVGGraphicsElement
• Always build Skia optimized, even in debug builds.
• Fixed source offsets for namespace mismatch errors in XML.
• Remove dependency on absl, replace absl::from_chars with a hand-rolled float parser.
• Various dependency updates.

Full Changelog: v0.1.0...v0.1.1

What's Included

• svg_to_png, which is a standalone tool to render an SVG using Donner.
• An embeddable C++ API that allows rendering and manulating SVGs.

ParseResult<SVGDocument> maybeDocument = SVGParser::ParseSVG(fileData);
if (maybeDocument.hasError()) {
  std::cerr << "Parse Error: " << maybeDocument.error() << "\n";
  std::abort();
}

RendererSkia renderer;
renderer.draw(maybeDocument.result());

const bool success = renderer.save("output.png");

To use svg_to_png:

./svg_to_png donner_splash.svg

Or when building from source:

bazel run --run_under="cd $PWD &&" //examples:svg_to_png -- donner_splash.svg

Donner SVG v0.1.0

Donner SVG's first release!

This release provides an embeddable SVG2 library, which includes CSS3 with a Skia-based renderer.

Large portions of the SVG2 static spec are implemented, including all shapes, markers, gradients, <use>, etc. Text is not yet implemented but is planned for v0.2.0.

Included in the release are:

• svg_to_png, which is a standalone tool to render an SVG using Donner.
• An embeddable C++ API that allows rendering and manulating SVGs.

ParseResult<SVGDocument> maybeDocument = SVGParser::ParseSVG(fileData);
if (maybeDocument.hasError()) {
  std::cerr << "Parse Error: " << maybeDocument.error() << "\n";
  std::abort();
}

RendererSkia renderer;
renderer.draw(maybeDocument.result());

const bool success = renderer.save("output.png");

To use svg_to_png:

./svg_to_png donner_splash.svg

Or when building from source:

bazel run --run_under="cd $PWD &&" //examples:svg_to_png -- donner_splash.svg