1 files changed, 140 insertions, 0 deletions
diff --git a/src/client/util/bezierFit.ts b/src/client/util/bezierFit.ts
index d6f3f2340..e2055887d 100644
--- a/src/client/util/bezierFit.ts
+++ b/src/client/util/bezierFit.ts
@@ -586,6 +586,146 @@ export function FitOneCurve(d: Point[], tHat1?: Point, tHat2?: Point) {
     return { finalCtrls, error };
 }
 
+// alpha determines how far away the tangents are, or the "tightness" of the bezier
+export function GenerateControlPoints(coordinates: Point[], alpha = 0.1) {
+    const firstEnd = coordinates.length ? [coordinates[0], coordinates[0]] : [];
+    const lastEnd = coordinates.length ? [coordinates.lastElement(), coordinates.lastElement()] : [];
+    const points: Point[] = coordinates.slice(1, coordinates.length - 1).flatMap((pt, index, inkData) => {
+        const prevPt: Point = index === 0 ? firstEnd[0] : inkData[index - 1];
+        const nextPt: Point = index === inkData.length - 1 ? lastEnd[0] : inkData[index + 1];
+        if (prevPt.X === nextPt.X) {
+            const verticalDist = nextPt.Y - prevPt.Y;
+            return [{ X: pt.X, Y: pt.Y - alpha * verticalDist }, pt, pt, { X: pt.X, Y: pt.Y + alpha * verticalDist }];
+        } else if (prevPt.Y === nextPt.Y) {
+            const horizDist = nextPt.X - prevPt.X;
+            return [{ X: pt.X - alpha * horizDist, Y: pt.Y }, pt, pt, { X: pt.X + alpha * horizDist, Y: pt.Y }];
+        }
+        // tangent vectors between the adjacent points
+        const tanX = nextPt.X - prevPt.X;
+        const tanY = nextPt.Y - prevPt.Y;
+        const ctrlPt1: Point = { X: pt.X - alpha * tanX, Y: pt.Y - alpha * tanY };
+        const ctrlPt2: Point = { X: pt.X + alpha * tanX, Y: pt.Y + alpha * tanY };
+        return [ctrlPt1, pt, pt, ctrlPt2];
+    });
+    return [...firstEnd, ...points, ...lastEnd];
+}
+
+export function SVGToBezier(name: SVGType, attributes: any): Point[] {
+    switch (name) {
+        case 'line':
+            const x1 = parseInt(attributes.x1);
+            const x2 = parseInt(attributes.x2);
+            const y1 = parseInt(attributes.y1);
+            const y2 = parseInt(attributes.y2);
+            return [
+                { X: x1, Y: y1 },
+                { X: x1, Y: y1 },
+                { X: x2, Y: y2 },
+                { X: x2, Y: y2 },
+            ];
+        case 'circle':
+        case 'ellipse':
+            const c = 0.551915024494;
+            const centerX = parseInt(attributes.cx);
+            const centerY = parseInt(attributes.cy);
+            const radiusX = parseInt(attributes.rx) || parseInt(attributes.r);
+            const radiusY = parseInt(attributes.ry) || parseInt(attributes.r);
+            return [
+                { X: centerX, Y: centerY + radiusY },
+                { X: centerX + c * radiusX, Y: centerY + radiusY },
+                { X: centerX + radiusX, Y: centerY + c * radiusY },
+                { X: centerX + radiusX, Y: centerY },
+                { X: centerX + radiusX, Y: centerY },
+                { X: centerX + radiusX, Y: centerY - c * radiusY },
+                { X: centerX + c * radiusX, Y: centerY - radiusY },
+                { X: centerX, Y: centerY - radiusY },
+                { X: centerX, Y: centerY - radiusY },
+                { X: centerX - c * radiusX, Y: centerY - radiusY },
+                { X: centerX - radiusX, Y: centerY - c * radiusY },
+                { X: centerX - radiusX, Y: centerY },
+                { X: centerX - radiusX, Y: centerY },
+                { X: centerX - radiusX, Y: centerY + c * radiusY },
+                { X: centerX - c * radiusX, Y: centerY + radiusY },
+                { X: centerX, Y: centerY + radiusY },
+            ];
+        case 'rect':
+            const x = parseInt(attributes.x);
+            const y = parseInt(attributes.y);
+            const width = parseInt(attributes.width);
+            const height = parseInt(attributes.height);
+            return [
+                { X: x, Y: y },
+                { X: x, Y: y },
+                { X: x + width, Y: y },
+                { X: x + width, Y: y },
+                { X: x + width, Y: y },
+                { X: x + width, Y: y },
+                { X: x + width, Y: y + height },
+                { X: x + width, Y: y + height },
+                { X: x + width, Y: y + height },
+                { X: x + width, Y: y + height },
+                { X: x, Y: y + height },
+                { X: x, Y: y + height },
+                { X: x, Y: y + height },
+                { X: x, Y: y + height },
+                { X: x, Y: y },
+                { X: x, Y: y },
+            ];
+        case 'path':
+            const coordList: Point[] = [];
+            const startPt = attributes.d.match(/M(-?\d+\.?\d*),(-?\d+\.?\d*)/);
+            coordList.push({ X: parseInt(startPt[1]), Y: parseInt(startPt[2]) });
+            const matches: RegExpMatchArray[] = Array.from(
+                attributes.d.matchAll(/Q(-?\d+\.?\d*),(-?\d+\.?\d*) (-?\d+\.?\d*),(-?\d+\.?\d*)|C(-?\d+\.?\d*),(-?\d+\.?\d*) (-?\d+\.?\d*),(-?\d+\.?\d*) (-?\d+\.?\d*),(-?\d+\.?\d*)|L(-?\d+\.?\d*),(-?\d+\.?\d*)/g)
+            );
+            let lastPt: Point;
+            matches.forEach(match => {
+                if (match[0].startsWith('Q')) {
+                    coordList.push({ X: parseInt(match[1]), Y: parseInt(match[2]) });
+                    coordList.push({ X: parseInt(match[1]), Y: parseInt(match[2]) });
+                    coordList.push({ X: parseInt(match[3]), Y: parseInt(match[4]) });
+                    coordList.push({ X: parseInt(match[3]), Y: parseInt(match[4]) });
+                    lastPt = { X: parseInt(match[3]), Y: parseInt(match[4]) };
+                } else if (match[0].startsWith('C')) {
+                    coordList.push({ X: parseInt(match[5]), Y: parseInt(match[6]) });
+                    coordList.push({ X: parseInt(match[7]), Y: parseInt(match[8]) });
+                    coordList.push({ X: parseInt(match[9]), Y: parseInt(match[10]) });
+                    coordList.push({ X: parseInt(match[9]), Y: parseInt(match[10]) });
+                    lastPt = { X: parseInt(match[9]), Y: parseInt(match[10]) };
+                } else {
+                    coordList.push(lastPt || { X: parseInt(startPt[1]), Y: parseInt(startPt[2]) });
+                    coordList.push({ X: parseInt(match[11]), Y: parseInt(match[12]) });
+                    coordList.push({ X: parseInt(match[11]), Y: parseInt(match[12]) });
+                    coordList.push({ X: parseInt(match[11]), Y: parseInt(match[12]) });
+                    lastPt = { X: parseInt(match[11]), Y: parseInt(match[12]) };
+                }
+            });
+            const hasZ = attributes.d.match(/Z/);
+            if (hasZ) {
+                coordList.push(lastPt);
+                coordList.push({ X: parseInt(startPt[1]), Y: parseInt(startPt[2]) });
+                coordList.push({ X: parseInt(startPt[1]), Y: parseInt(startPt[2]) });
+            } else {
+                coordList.pop();
+            }
+            return coordList;
+        case 'polygon':
+            const coords: RegExpMatchArray[] = Array.from(attributes.points.matchAll(/(-?\d+\.?\d*),(-?\d+\.?\d*)/g));
+            let list: Point[] = [];
+            coords.forEach(coord => {
+                list.push({ X: parseInt(coord[1]), Y: parseInt(coord[2]) });
+                list.push({ X: parseInt(coord[1]), Y: parseInt(coord[2]) });
+                list.push({ X: parseInt(coord[1]), Y: parseInt(coord[2]) });
+                list.push({ X: parseInt(coord[1]), Y: parseInt(coord[2]) });
+            });
+            const firstPts = list.splice(0, 2);
+            list = list.concat(firstPts);
+            return list;
+        default:
+            return [];
+    }
+}
+
 /*
 static double                GetTValueFromSValue  (const BezierRep &parent, double t, double endT, bool left, double influenceDistance, double &excess) {
 double dist = 0;