bluebey-studio: 縦書きの括弧「」『』［］（）などを90度回転に対応

縦書きでは開き括弧が下向き・閉じ括弧が上向きになるよう、括弧を90度回転（枠内は中央のまま）。canvasプレビューとSVG書き出しの両方。

1 files changed, 23 insertions, 8 deletions

diff --git a/public/bluebey-studio/src/caption.js b/public/bluebey-studio/src/caption.js
index df9c952..71759ea 100644
--- a/public/bluebey-studio/src/caption.js
+++ b/public/bluebey-studio/src/caption.js
@@ -101,21 +101,34 @@ const VERTICAL_OFFSETS = new Map();
 for (const ch of SMALL_KANA) VERTICAL_OFFSETS.set(ch, { dx: 0.12, dy: -0.12 });
 // 縦書きの句読点は、横書きの左下ではなく、字枠の右上に置く。
 for (const ch of HANGING_PUNCTUATION) VERTICAL_OFFSETS.set(ch, { dx: 0.68, dy: -0.55 });
-for (const ch of '「『（〔') VERTICAL_OFFSETS.set(ch, { dx: 0.14, dy: -0.12 });
-for (const ch of '」』）〕') VERTICAL_OFFSETS.set(ch, { dx: -0.14, dy: 0.12 });
 
 /**
  * Characters drawn turned a quarter turn when stacked, so they read the way
- * 縦書き sets them: the prolonged sound mark `ー` becomes an upright bar.
+ * 縦書き sets them: the prolonged sound mark `ー` becomes an upright bar, and the
+ * brackets `「」『』［］（）` turn so they open down the column.
  */
 const VERTICAL_ROTATED = new Set(['ー', '～', '〜', '―']);
+const VERTICAL_BRACKETS = new Set([
+  '「', '」', '『', '』', '（', '）', '［', '］', '【', '】', '〔', '〕', '〈', '〉', '《', '》',
+]);
 
 /**
  * How far a rotated glyph is nudged down inside its cell, in em. The rotated `ー`
- * is centred otherwise, which leaves it hugging the character above it.
+ * is centred otherwise, which leaves it hugging the character above it; the
+ * brackets stay centred.
  */
 const VERTICAL_ROTATED_DROP = 0.14;
 
+/**
+ * The downward nudge (em) for a glyph that is turned a quarter turn in 縦書き, or
+ * `null` when the glyph is drawn the ordinary way.
+ */
+function verticalRotation(ch) {
+  if (VERTICAL_ROTATED.has(ch)) return VERTICAL_ROTATED_DROP;
+  if (VERTICAL_BRACKETS.has(ch)) return 0;
+  return null;
+}
+
 /** Offset used for the characters that need no special placement. */
 const NO_OFFSET = Object.freeze({ dx: 0, dy: 0 });
 
@@ -426,9 +439,10 @@ function drawText(ctx, layout, state, font) {
       const x = left + (lines.length - 1 - i) * step;
       for (let j = 0; j < chars.length; j++) {
         const ch = chars[j];
-        if (VERTICAL_ROTATED.has(ch)) {
+        const drop = verticalRotation(ch);
+        if (drop !== null) {
           ctx.save();
-          ctx.translate(x + fontSize / 2, top + j * fontSize + fontSize / 2 + VERTICAL_ROTATED_DROP * fontSize);
+          ctx.translate(x + fontSize / 2, top + j * fontSize + fontSize / 2 + drop * fontSize);
           ctx.rotate(Math.PI / 2);
           ctx.textAlign = 'center';
           ctx.textBaseline = 'middle';
@@ -492,9 +506,10 @@ function liveText(state, layout, font, fill, places) {
       const x = left + (lines.length - 1 - i) * step;
       for (let j = 0; j < chars.length; j++) {
         const ch = chars[j];
-        if (VERTICAL_ROTATED.has(ch)) {
+        const drop = verticalRotation(ch);
+        if (drop !== null) {
           const cx = x + fontSize / 2;
-          const cy = top + j * fontSize + fontSize / 2 + VERTICAL_ROTATED_DROP * fontSize;
+          const cy = top + j * fontSize + fontSize / 2 + drop * fontSize;
           rotated.push(`<text ${base} text-anchor="middle" dy="0.36em"`
             + ` transform="rotate(90 ${formatNumber(cx, places)} ${formatNumber(cy, places)})"`
             + ` x="${formatNumber(cx, places)}" y="${formatNumber(cy, places)}">${escapeText(ch)}</text>`);