thu0x31 · May 21, 2022 17:05 · May 21, 2022
diff --git a/arcFrom2Points.vfl b/arcFrom2Points.vfl
@@ -0,0 +1,50 @@
+
+function int[] arcFrom2Points(vector centerPos; float radius; int totalPoints;
+                                 vector startPos, endPos;
+                                 string direction) {
+
+    float threshold = 0.01;
+    if(radius < threshold) {
+        return{};
+    }
+
+    float TWO_PI = PI * 2;
+
+    vector v1 = normalize(startPos - centerPos);
+    vector v2 = normalize(endPos - centerPos);
+    float startRad = atan2(v1.z, v1.x);
+    // (atan2(v2.z, v2.x) - startRad) - (atan2(v1.z, v1.x) - startRad) ベクトルを{1,0,0}に初期化する
+    float rad = startRad*2 - atan2(v2.z, v2.x) - atan2(v1.z, v1.x);
+    if((rad < 0) && (direction == "Left")) {
+        rad += TWO_PI;
+    } else if((rad > 0) && (direction == "Right")) {
+        rad -= TWO_PI;
+    }
+
+    int points[];
+    for(int i = 0; i <= totalPoints; i++) {
+        vector pos = set(
+            centerPos.x + radius * cos(startRad - i * (rad/totalPoints)),
+            centerPos.y,
+            centerPos.z + radius * sin(startRad - i * (rad/totalPoints))
+        );
+        int pointN = addpoint(0, pos);
+        setpointattrib(0, "arcLength", pointN, rad*TWO_PI);
+        setpointattrib(0, "dictCenter", pointN, normalize(centerPos - pos));
+
+        if(direction == "Right") {
+            setpointattrib(0, "N", pointN, normalize(centerPos - pos));
+        }
+        if(direction == "Left") {
+            setpointattrib(0, "N", pointN, normalize(pos - centerPos));
+        }
+
+        push(points, pointN);
+    }
+
+    // debug 
+    // addprim(0, "polyline", addpoint(0, centerPos + v1 * radius), addpoint(0, centerPos));
+    // addprim(0, "polyline", addpoint(0, centerPos + v2 * radius), addpoint(0, centerPos));
+
+    return points;
+}