bluebey-studio: Shift+ドラッグの移動量が加速する不具合を修正

1 files changed, 11 insertions, 2 deletions

diff --git a/public/bluebey-studio/src/main.js b/public/bluebey-studio/src/main.js
index ac8c04b..063a6fc 100644
--- a/public/bluebey-studio/src/main.js
+++ b/public/bluebey-studio/src/main.js
@@ -2361,6 +2361,8 @@ async function init() {
         pan: event.shiftKey,
         x: event.clientX,
         y: event.clientY,
+        lastX: event.clientX,
+        lastY: event.clientY,
         root: [...root],
       };
       view.controls.enabled = false;
@@ -2376,11 +2378,18 @@ async function init() {
       if (modelDrag.pan) {
         // Shift+drag: move the camera's reference point (the same effect as the
         // two-finger drag on a phone). The character stays where it is.
+        // Use the step since the previous event, not the total from the press:
+        // pointermove fires many times per drag, so adding the total every time
+        // would make the pan accelerate.
+        const stepX = event.clientX - modelDrag.lastX;
+        const stepY = event.clientY - modelDrag.lastY;
+        modelDrag.lastX = event.clientX;
+        modelDrag.lastY = event.clientY;
         const right = new THREE.Vector3(1, 0, 0).applyQuaternion(view.camera.quaternion);
         const up = new THREE.Vector3(0, 1, 0).applyQuaternion(view.camera.quaternion);
         const move = new THREE.Vector3()
-          .addScaledVector(right, -dx * k)
-          .addScaledVector(up, dy * k);
+          .addScaledVector(right, -stepX * k)
+          .addScaledVector(up, stepY * k);
         view.target.add(move);
         for (const controls of Object.values(view.controlsMap ?? {})) controls.target.add(move);
         for (const cam of Object.values(view.cameras ?? {})) cam.position.add(move);