Align Stroke inside or outside on live type (#2294)

The characters' stroke takes Align Stroke like an object stroke: CharStyle
keeps stroke_align (written only when not centred), stroke.set and
text.setRangeStyle strokeOptions apply align to type, and the Stroke panel
enables the buttons for type. Canvas, PDF and EPS draw it around the glyphs
through stroke_layer(); SVG keeps the text live and writes the aligned
stroke on the glyph outlines, clipped or masked. Type's visual bounds grow
with its character strokes.

crates/render/src/tests_charstroke.rs

@@ -81,3 +81,25 @@ fn character_and_object_strokes_on_type_are_dashed() {
     let p = half.pixel(x0, (y0 + y1) / 2);
     assert!(p[0] > 90 && p[0] < 200, "a half-opaque stroke is grey: {p:?}");
 }
+
+/// Align Stroke on live type: an outside character stroke paints its whole weight around the
+/// glyphs and leaves them unpainted, an inside one stays within them, as on paths.
+#[test]
+fn aligned_character_strokes_keep_to_their_side_of_the_glyphs() {
+    use vectorcraft_doc::StrokeAlign;
+    let glyph = ink(&render_text("I", CharStyle::default(), vec![]));
+    let reach = |b: (u32, u32, u32, u32)| {
+        let d = |a: u32, b: u32| a as i64 - b as i64;
+        d(glyph.0, b.0).max(d(glyph.1, b.1)).max(d(b.2, glyph.2)).max(d(b.3, glyph.3))
+    };
+    let style = |align| CharStyle { fill: Paint::None, stroke_align: align, ..stroked(LineJoin::Round) };
+    let centre = render_text("I", style(StrokeAlign::Center), vec![]);
+    let outside = render_text("I", style(StrokeAlign::Outside), vec![]);
+    let inside = render_text("I", style(StrokeAlign::Inside), vec![]);
+    assert!((7..=9).contains(&reach(ink(&centre))), "centred: half the weight past the glyph, {:?}", ink(&centre));
+    assert!((15..=17).contains(&reach(ink(&outside))), "outside: the whole weight past the glyph, {:?}", ink(&outside));
+    assert!(reach(ink(&inside)) <= 0, "inside: within the glyph, {:?}", ink(&inside));
+    let mid = ((glyph.0 + glyph.2) / 2, (glyph.1 + glyph.3) / 2);
+    assert!(!dark(&outside, mid.0, mid.1), "an outside stroke leaves the glyph itself unpainted");
+    assert!(dark(&inside, mid.0, mid.1), "an inside stroke paints into the glyph");
+}