1 files changed, 25 insertions, 0 deletions
diff --git a/public/bluebey-studio/src/main.js b/public/bluebey-studio/src/main.js
index 57f0140..fcee21d 100644
--- a/public/bluebey-studio/src/main.js
+++ b/public/bluebey-studio/src/main.js
@@ -1317,6 +1317,7 @@ async function init() {
     syncPanel: () => app.panel?.sync(),
     imageCanvas: (options) => captureImage(options),
     savePNG: (options = {}) => savePNG(options),
+    saveJPG: (options = {}) => saveJPG(options),
     copyPNG: () => copyPNG(),
     addGionStamp: (item) => addGionStamp(item),
     saveSettings: () => exporter.downloadText(JSON.stringify(state, null, 2), `bluebey-settings-${exporter.timestamp()}.json`),
@@ -2060,6 +2061,30 @@ async function init() {
     toast(`PNGを書き出しました（${result.width}×${result.height}）`);
   }
 
+  /**
+   * JPEG: the small-file export. JPEG has no alpha, so the picture is laid on the
+   * paper colour first - a transparent background would otherwise come out black.
+   * A photo backdrop is kept at the chosen scale/quality, which makes the file a
+   * fraction of the same PNG.
+   */
+  async function saveJPG({
+    scale = state.render.pngScale ?? 2,
+    quality = state.render.jpgQuality ?? 0.9,
+  } = {}) {
+    const result = await captureImage({ scale, transparent: false });
+    const out = document.createElement('canvas');
+    out.width = result.width;
+    out.height = result.height;
+    const ctx = out.getContext('2d');
+    ctx.fillStyle = state.render.paper || '#ffffff';
+    ctx.fillRect(0, 0, out.width, out.height);
+    ctx.drawImage(result.canvas, 0, 0);
+    const blob = await new Promise((resolve) => out.toBlob(resolve, 'image/jpeg', quality));
+    exporter.downloadBlob(blob, `bluebey-${exporter.timestamp()}.jpg`);
+    toast(`JPGを書き出しました（${result.width}×${result.height}・画質${Math.round(quality * 100)}%）`);
+    return { blob, width: result.width, height: result.height, quality };
+  }
+
   /** Hide the gizmo and helpers so they never end up in an export. */
   async function withHiddenHelpers(fn) {
     const wasVisible = rig.helper.visible;