feat: add axis-aligned 3d camera views

2026-08-30 11:40:21 +09:00
parent 51c7bbd859
commit 2a2e192196
12 changed files with 619 additions and 61 deletions
@@ -0,0 +1,36 @@
+export const ORBIT_VIEW_DIRECTIONS = Object.freeze([
+  "iso",
+  "+x",
+  "-x",
+  "+y",
+  "-y",
+  "+z",
+  "-z",
+]);
+
+const ORBITS = Object.freeze({
+  iso: Object.freeze({
+    yaw: -Math.PI / 4,
+    pitch: Math.asin(1 / Math.sqrt(3)),
+  }),
+  "+x": Object.freeze({ yaw: -Math.PI / 2, pitch: 0 }),
+  "-x": Object.freeze({ yaw: Math.PI / 2, pitch: 0 }),
+  "+y": Object.freeze({ yaw: Math.PI, pitch: 0 }),
+  "-y": Object.freeze({ yaw: 0, pitch: 0 }),
+  "+z": Object.freeze({ yaw: 0, pitch: Math.PI / 2 }),
+  "-z": Object.freeze({ yaw: Math.PI, pitch: -Math.PI / 2 }),
+});
+
+/**
+ * Return the orthographic camera orbit for a view from the named axis toward
+ * the array origin. A fresh object prevents one view from mutating another.
+ */
+export function orbitForViewDirection(direction = "iso") {
+  const orbit = ORBITS[direction];
+  if (!orbit) {
+    throw new RangeError(
+      "view direction must be one of: " + ORBIT_VIEW_DIRECTIONS.join(", "),
+    );
+  }
+  return { ...orbit };
+}