Rasterise SVG with go-gfx/oksvg: clipPath, multi-set arcs

FIDELITY.md

@@ -4944,8 +4944,10 @@ dependency (BSD-3, "build from source").
 **What oksvg does / doesn't do (documented, not faked):** it handles the drawing
 subset above plus `currentColor` (we feed the element's computed CSS `color` via
 `ReadReplacingCurrentColor`, so `fill="currentColor"` logos take their real
-colour). It does **not** implement SVG `<filter>` effects, `<mask>`/`<clipPath>`
-compositing, `<pattern>` fills, embedded raster `<image>`, `<text>`/font shaping,
+colour). (Since the engine moved to the fleet fork `github.com/go-gfx/oksvg`,
+`<clipPath>` and the `clip-path` property are implemented, with `clip-rule`,
+and arc commands with several parameter sets are drawn correctly.) It does
+**not** implement SVG `<filter>` effects, `<mask>` compositing, `<pattern>` fills, embedded raster `<image>`, `<text>`/font shaping,
 CSS `<style>` selectors inside the SVG, or animation. Such features degrade to
 "drawn without them" or empty, never a crash.
 

README.md

@@ -171,7 +171,8 @@ PNGs, measured vs headless Chrome) is in [`FIDELITY.md`](FIDELITY.md) and
 - **Containers and shadow DOM**: `@container` size queries, and declarative
   shadow DOM (`<template shadowrootmode>`) with `<slot>` distribution.
 - **Images**: `<img>` over http(s) + `data:` (PNG/JPEG) and **SVG**
-  (oksvg/rasterx) via `<img *.svg>`, `data:image/svg+xml` and **inline `<svg>`**.
+  ([go-gfx/oksvg](https://github.com/go-gfx/oksvg), a fork of srwiley/oksvg
+  with `clipPath`, over rasterx) via `<img *.svg>`, `data:image/svg+xml` and **inline `<svg>`**.
 - **JavaScript**: page scripts run via [goja](https://github.com/dop251/goja)
   against a real DOM, with `fetch()`/XHR and read-back of real laid-out geometry
   (`getBoundingClientRect`, `offsetWidth/Height`, `getComputedStyle`). A

go.mod

@@ -7,13 +7,13 @@ require (
 	github.com/evanw/esbuild v0.28.2
 	github.com/go-browserhttp/browserhttp v0.2.0
 	github.com/go-gfx/gfx v0.35.0
+	github.com/go-gfx/oksvg v0.1.0
 	github.com/go-images/images v0.1.0
 	github.com/go-opentype/fonts v0.12.0
 	github.com/go-opentype/opentype v0.15.0
 	github.com/go-pdfkit/pdfkit v0.15.0
 	github.com/go-webengine/esbuildsandbox v0.1.0
 	github.com/go-widgets/painter v0.16.0
-	github.com/srwiley/oksvg v0.0.0-20221011165216-be6e8873101c
 	github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef
 	golang.org/x/image v0.46.0
 	golang.org/x/net v0.61.0

go.sum

@@ -22,6 +22,8 @@ github.com/go-crdt/crdt v0.57.0 h1:sNLDTVCEnSb20gm77BUuYav8dzj5krmly/z9O7eRMCo=
 github.com/go-crdt/crdt v0.57.0/go.mod h1:zdVTTDLGV5JYAoTJDqCivcAT+/B5gGebDsVd8QNZpVs=
 github.com/go-gfx/gfx v0.35.0 h1:AaXMxDMxNB1hROxzx+3EoO06KxsrQUvnw/10olmSgVo=
 github.com/go-gfx/gfx v0.35.0/go.mod h1:qIZS9u2+VnBk5CX7o4f/fQ5uD8c+mPFTtAPE85s8V90=
+github.com/go-gfx/oksvg v0.1.0 h1:gK9AJ948GoKapOPikT391sD95YVnaNLq2PcvedDGxPo=
+github.com/go-gfx/oksvg v0.1.0/go.mod h1:ap7jj7yma4qOcwiAFzPMC9/eODo7Q2nt71DkEZlHA0k=
 github.com/go-icons/iconoir v0.3.0 h1:kHG2sU5IsCvtBS1JICuXgfFo5f8UfwY1m7KYMVy97CI=
 github.com/go-icons/iconoir v0.3.0/go.mod h1:lPh5OuzVQ+rR4qDPGgAdSRUhnCbHeCAX70HDdwp8/RI=
 github.com/go-images/gif v0.2.0 h1:8Xl4Nan+PvyqH4wPre7wJUH61T2eJKOKonFKOdMdpkU=
@@ -74,8 +76,6 @@ github.com/sergeymakinen/go-bmp v1.0.0 h1:SdGTzp9WvCV0A1V0mBeaS7kQAwNLdVJbmHlqNW
 github.com/sergeymakinen/go-bmp v1.0.0/go.mod h1:/mxlAQZRLxSvJFNIEGGLBE/m40f3ZnUifpgVDlcUIEY=
 github.com/sergeymakinen/go-ico v1.0.0 h1:uL3khgvKkY6WfAetA+RqsguClBuu7HpvBB/nq/Jvr80=
 github.com/sergeymakinen/go-ico v1.0.0/go.mod h1:wQ47mTczswBO5F0NoDt7O0IXgnV4Xy3ojrroMQzyhUk=
-github.com/srwiley/oksvg v0.0.0-20221011165216-be6e8873101c h1:km8GpoQut05eY3GiYWEedbTT0qnSxrCjsVbb7yKY1KE=
-github.com/srwiley/oksvg v0.0.0-20221011165216-be6e8873101c/go.mod h1:cNQ3dwVJtS5Hmnjxy6AgTPd0Inb3pW05ftPSX7NZO7Q=
 github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef h1:Ch6Q+AZUxDBCVqdkI8FSpFyZDtCVBc2VmejdNrm5rRQ=
 github.com/srwiley/rasterx v0.0.0-20220730225603-2ab79fcdd4ef/go.mod h1:nXTWP6+gD5+LUJ8krVhhoeHjvHTutPxMYl5SvkcnJNE=
 github.com/tannevaled/gobig2 v0.2.0 h1:yx97/ltljALrIWDFVqHjPUIjAp3bfUUhH8Z8UROvNLc=

svg.go

@@ -12,7 +12,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/srwiley/oksvg"
+	"github.com/go-gfx/oksvg"
 	"github.com/srwiley/rasterx"
 
 	"github.com/go-webengine/engine/css"

svg_clip_test.go

@@ -0,0 +1,30 @@
+// Copyright (c) the go-webengine/engine authors.
+// SPDX-License-Identifier: BSD-3-Clause
+
+package engine
+
+import (
+	"image/color"
+	"testing"
+)
+
+// TestRasterizeSVGClipPath: an SVG clipPath is honoured (the rasteriser is
+// go-gfx/oksvg, which implements it; srwiley/oksvg dropped the property).
+func TestRasterizeSVGClipPath(t *testing.T) {
+	src := `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
+<defs><clipPath id="c"><circle cx="50" cy="50" r="30"/></clipPath></defs>
+<rect width="100" height="100" fill="#ff0000" clip-path="url(#c)"/></svg>`
+	img, ok := RasterizeSVG([]byte(src), 100, 100, "")
+	if !ok {
+		t.Fatal("not rasterised")
+	}
+	alpha := func(x, y int) uint8 { return color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA).A }
+	if a := alpha(50, 50); a != 255 {
+		t.Errorf("inside the clip: alpha %d", a)
+	}
+	for _, p := range [][2]int{{5, 5}, {95, 5}, {50, 90}} {
+		if a := alpha(p[0], p[1]); a != 0 {
+			t.Errorf("outside the clip at %v: alpha %d", p, a)
+		}
+	}
+}

svg_test.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/srwiley/oksvg"
+	"github.com/go-gfx/oksvg"
 
 	"github.com/go-webengine/engine/css"
 	"github.com/go-webengine/engine/dom"