bluebey-studio: ドラッグの役割を入れ替え、回転中心をぶるべーに固定

1 files changed, 14 insertions, 3 deletions

diff --git a/public/bluebey-studio/src/exporter.js b/public/bluebey-studio/src/exporter.js
index cc9c1ca..cad9ef0 100644
--- a/public/bluebey-studio/src/exporter.js
+++ b/public/bluebey-studio/src/exporter.js
@@ -10,13 +10,22 @@ import { roughenContours } from './handDrawn.js';
  */
 
 /** Render the current view into an offscreen 2D canvas at an arbitrary size. */
-export function renderStill(view, { width, height, background }) {
+export function renderStill(view, { width, height, background, viewOffset = null }) {
   const { renderer, scene, camera } = view;
   const previousAspect = camera.aspect;
+  // The live camera may already carry a projection shift (the pan). It is stored
+  // in CSS pixels against the viewport, so it has to be re-applied for the
+  // export's own pixel size - and restored afterwards.
+  const previousView = camera.view ? { ...camera.view } : null;
 
   renderer.setPixelRatio(1);
   renderer.setSize(width, height, false);
   camera.aspect = width / height;
+  if (viewOffset && (viewOffset.x || viewOffset.y)) {
+    camera.setViewOffset(width, height, -viewOffset.x * width, -viewOffset.y * height, width, height);
+  } else {
+    camera.clearViewOffset();
+  }
   camera.updateProjectionMatrix();
 
   applyBackground(renderer, background);
@@ -37,6 +46,8 @@ export function renderStill(view, { width, height, background }) {
   canvas.getContext('2d').drawImage(renderer.domElement, 0, 0);
 
   camera.aspect = previousAspect;
+  if (previousView) camera.view = previousView;
+  else camera.clearViewOffset();
   camera.updateProjectionMatrix();
   view.restore?.();
 
@@ -53,12 +64,12 @@ export function applyBackground(renderer, background) {
 }
 
 /** A PNG data URL of the current view, scaled up by `scale`. */
-export async function capturePNG(view, { scale = 2, background, width, height }) {
+export async function capturePNG(view, { scale = 2, background, width, height, viewOffset = null }) {
   const baseWidth = view.width || view.renderer.domElement.clientWidth || 1280;
   const baseHeight = view.height || view.renderer.domElement.clientHeight || 800;
   const outWidth = Math.min(8192, Math.max(64, Math.round((width ?? baseWidth) * scale)));
   const outHeight = Math.min(8192, Math.max(64, Math.round((height ?? baseHeight) * scale)));
-  const canvas = renderStill(view, { width: outWidth, height: outHeight, background });
+  const canvas = renderStill(view, { width: outWidth, height: outHeight, background, viewOffset });
   const blob = await canvasToBlob(canvas);
   return { blob, canvas, width: outWidth, height: outHeight };
 }