initial migration to TS

frontend/src/angleMeasureGeometry.ts

@@ -0,0 +1,77 @@
+function clamp01(value) {
+  return Math.max(0, Math.min(1, Number(value) || 0));
+}
+
+export function round3(value) {
+  return Number.parseFloat(Number(value).toFixed(3));
+}
+
+export function getAngleLabelBasePosition(x1, y1, xm, ym, x2, y2) {
+  const va = { x: Number(x1) - Number(xm), y: Number(y1) - Number(ym) };
+  const vb = { x: Number(x2) - Number(xm), y: Number(y2) - Number(ym) };
+  const lenA = Math.hypot(va.x, va.y);
+  const lenB = Math.hypot(vb.x, vb.y);
+
+  if (lenA <= 1e-6 || lenB <= 1e-6) {
+    return { x: clamp01(xm), y: clamp01(Number(ym) - 0.14) };
+  }
+
+  const unit = {
+    x: (va.x / lenA) + (vb.x / lenB),
+    y: (va.y / lenA) + (vb.y / lenB),
+  };
+  const unitLength = Math.hypot(unit.x, unit.y);
+  const bisector = unitLength <= 1e-6
+    ? { x: 0, y: -1 }
+    : { x: unit.x / unitLength, y: unit.y / unitLength };
+
+  return {
+    x: clamp01(Number(xm) + bisector.x * 0.14),
+    y: clamp01(Number(ym) + bisector.y * 0.14),
+  };
+}
+
+export function getAngleLabelPosition(points, labelDx = 0, labelDy = 0) {
+  const base = getAngleLabelBasePosition(points.x1, points.y1, points.xm, points.ym, points.x2, points.y2);
+  return {
+    x: clamp01(base.x + (Number(labelDx) || 0)),
+    y: clamp01(base.y + (Number(labelDy) || 0)),
+  };
+}
+
+export function moveAngleWidget(points, dx, dy) {
+  const nextDx = Number(dx) || 0;
+  const nextDy = Number(dy) || 0;
+  const xs = [points.x1, points.xm, points.x2];
+  const ys = [points.y1, points.ym, points.y2];
+  const minX = Math.min(...xs);
+  const maxX = Math.max(...xs);
+  const minY = Math.min(...ys);
+  const maxY = Math.max(...ys);
+  const clampedDx = Math.max(-minX, Math.min(1 - maxX, nextDx));
+  const clampedDy = Math.max(-minY, Math.min(1 - maxY, nextDy));
+
+  return {
+    x1: round3(clamp01(points.x1 + clampedDx)),
+    y1: round3(clamp01(points.y1 + clampedDy)),
+    xm: round3(clamp01(points.xm + clampedDx)),
+    ym: round3(clamp01(points.ym + clampedDy)),
+    x2: round3(clamp01(points.x2 + clampedDx)),
+    y2: round3(clamp01(points.y2 + clampedDy)),
+  };
+}
+
+export function measureAngleDegrees(x1, y1, xm, ym, x2, y2) {
+  const ax = Number(x1) - Number(xm);
+  const ay = Number(y1) - Number(ym);
+  const bx = Number(x2) - Number(xm);
+  const by = Number(y2) - Number(ym);
+  const lenA = Math.hypot(ax, ay);
+  const lenB = Math.hypot(bx, by);
+
+  if (lenA <= 1e-12 || lenB <= 1e-12) return 0;
+
+  const cosTheta = ((ax * bx) + (ay * by)) / (lenA * lenB);
+  const clamped = Math.max(-1, Math.min(1, cosTheta));
+  return Math.acos(clamped) * (180 / Math.PI);
+}