From afbc5440b7a80557d4b772bb369de054b20e8cbf Mon Sep 17 00:00:00 2001
From: "shiwu.wyy" <shiwu.wyy@antfin.com>
Date: Wed, 7 Aug 2019 20:08:06 +0800
Subject: [PATCH] arc edge

---
 demos/test.html   | 30 +++++++++++-----------
 src/shape/edge.js | 63 +++++++++++++++++++++++++++++++++--------------
 2 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/demos/test.html b/demos/test.html
index 51c53677fa..2879447dda 100644
--- a/demos/test.html
+++ b/demos/test.html
@@ -26,13 +26,13 @@ const data = {
   nodes: [{
     id: 'node5',
     x: 100,
-    y: 100,
+    y: 180,
     label: '5',
     size: 80
   },{
     id: 'node6',
     x: 400,
-    y: 50,
+    y: 150,
     label: '6',
     size: 50
   },{
@@ -47,26 +47,28 @@ const data = {
     source: 'node6',
     target: 'node5',
     shape: 'arc',
-    edgeOffset: -50
+    curveOffset: -150
+  },
+  {
+    source: 'node6',
+    target: 'node5',
+    shape: 'arc',
+    curveOffset: 50
   },
   {
     source: 'node5',
     target: 'node6',
     shape: 'arc',
-    edgeOffset: 50
+    curveOffset: 50
   },
   {
-    source: 'node5',
-    target: 'node6',
+    source: 'node7',
+    target: 'node5',
     shape: 'arc',
-    edgeOffset: -50
-  },
-  {
-    source: 'node5',
-    target: 'node7',
-    shape: 'arc',
-    edgeOffset: 50
-  }]
+    controlPoints: [{ x: 200, y: 315 }]
+    // controlPoints: [{ x: 350, y: 315 }]
+  }
+]
 };
 const graph = new G6.Graph({
   container: 'mountNode',
diff --git a/src/shape/edge.js b/src/shape/edge.js
index bb8aca76b0..d4098df9d2 100644
--- a/src/shape/edge.js
+++ b/src/shape/edge.js
@@ -178,34 +178,59 @@ Shape.registerEdge('spline', {
 }, 'single-line');
 
 Shape.registerEdge('arc', {
-  curveOffset: 30,
+  curveOffset: 20,
+  clockwise: 1,
   getControlPoints(cfg) {
-    const startPoint = cfg.sourceNode.getModel().x;
-    const endPoint = cfg.sourceNode.getModel().y;
-    const midPoint = {
-      x: (startPoint.x + endPoint.x) / 2,
-      y: (startPoint.y + endPoint.y) / 2
-    };
-    const vec = {
-      x: endPoint.x - startPoint.x,
-      y: endPoint.y - startPoint.y
-    };
-    const edgeAngle = Math.atan2(vec.y, vec.x);
-    const arcPoint = {
-      x: this.curveOffset * Math.cos((-Math.PI / 2 + edgeAngle)) + midPoint.x,
-      y: this.curveOffset * Math.sin((-Math.PI / 2 + edgeAngle)) + midPoint.y
-    };
+    const startPoint = { x: cfg.sourceNode.getModel().x, y: cfg.sourceNode.getModel().y };
+    const endPoint = { x: cfg.targetNode.getModel().x, y: cfg.targetNode.getModel().y };
+    let arcPoint;
+    // 根据给定点计算圆弧
+    if (cfg.controlPoints !== undefined) {
+      arcPoint = cfg.controlPoints[0];
+      // 根据控制点和直线关系决定 clockwise值
+      // 若给定点和两端点共线，无法生成圆弧，绘制直线
+      if ((arcPoint.x - startPoint.x) / (arcPoint.y - startPoint.y)
+        === (endPoint.x - startPoint.x) / (endPoint.y - startPoint.y)) {
+        return [];
+      }
+    } else { // 根据直线连线中点的的偏移计算圆弧
+      // 若用户给定偏移量则根据其计算，否则按照默认偏移值计算
+      if (cfg.curveOffset !== undefined) {
+        this.curveOffset = cfg.curveOffset;
+      }
+      if (this.curveOffset < 0) this.clockwise = 0;
+      else this.clockwise = 1;
+      const midPoint = {
+        x: (startPoint.x + endPoint.x) / 2,
+        y: (startPoint.y + endPoint.y) / 2
+      };
+      const vec = {
+        x: endPoint.x - startPoint.x,
+        y: endPoint.y - startPoint.y
+      };
+      const edgeAngle = Math.atan2(vec.y, vec.x);
+      arcPoint = {
+        x: this.curveOffset * Math.cos((-Math.PI / 2 + edgeAngle)) + midPoint.x,
+        y: this.curveOffset * Math.sin((-Math.PI / 2 + edgeAngle)) + midPoint.y
+      };
+    }
     const center = Util.getCircleCenterByPoints(startPoint, arcPoint, endPoint);
+    console.log('distance center controlpoint', Util.distance(center, arcPoint));
     const radius = Util.distance(startPoint, center);
-    const controlPoints = [ startPoint, { x: radius, y: radius }, endPoint ];
+    console.log('radius', radius);
+    const controlPoints = [{ x: radius, y: radius }];
 
     return controlPoints;
   },
   getPath(points) {
-    console.log(points);
     const path = [];
     path.push([ 'M', points[0].x, points[0].y ]);
-    path.push([ 'A', points[1].x, points[1].y, 0, 0, 0, points[2].x, points[2].y ]);
+    // 控制点与端点共线
+    if (points.length === 2) {
+      path.push([ 'L', points[1].x, points[1].y ]);
+    } else {
+      path.push([ 'A', points[1].x, points[1].y, 0, 0, this.clockwise, points[2].x, points[2].y ]);
+    }
     return path;
   }
 }, 'single-line');