improve miter

packages/element/src/shape.ts

@@ -1258,6 +1258,7 @@ const getSvgPathFromPoints = (
 
 const FIXED_FREEDRAW_MIN_SMOOTH_ALIGNMENT = 0.6;
 const FIXED_FREEDRAW_MIN_SMOOTH_SEGMENT_LENGTH = 0.2;
+const FIXED_FREEDRAW_MIN_CORNER_ALIGNMENT = -0.25;
 const FIXED_FREEDRAW_MIN_CORNER_ROUNDING = 0.75;
 const FIXED_FREEDRAW_MAX_CORNER_ROUNDING = 6;
 const FIXED_FREEDRAW_CORNER_ROUNDING_FACTOR = 0.35;
@@ -1310,7 +1311,10 @@ const getFixedFreeDrawRoundedCorner = (
     (previousDeltaX * nextDeltaX + previousDeltaY * nextDeltaY) /
     (previousSegmentLength * nextSegmentLength);
 
-  if (alignment >= FIXED_FREEDRAW_MIN_SMOOTH_ALIGNMENT) {
+  if (
+    alignment >= FIXED_FREEDRAW_MIN_SMOOTH_ALIGNMENT ||
+    alignment <= FIXED_FREEDRAW_MIN_CORNER_ALIGNMENT
+  ) {
     return null;
   }
 

packages/element/tests/shape.test.ts

@@ -43,6 +43,19 @@ describe("freedraw stroke shape", () => {
     expect(path).toBe("M0,0 L8.5,0 Q10,0 10,1.5 L10,10 ");
   });
 
+  it("does not round fixed stroke hairpin turns", () => {
+    const element = API.createElement({
+      type: "freedraw",
+      strokeShape: "fixed",
+      strokeWidth: 1,
+      points: [pointFrom(0, 0), pointFrom(10, 0), pointFrom(9, 1)],
+    });
+
+    const [path] = ShapeCache.generateElementShape(element, null);
+
+    expect(path).toBe("M0,0 L10,0 L9,1 ");
+  });
+
   it("smooths dense fixed stroke points without dropping them", () => {
     const element = API.createElement({
       type: "freedraw",