From c10079bba4a995a15e34d262fe8e76183494463c Mon Sep 17 00:00:00 2001
From: Shaunak Kishore <kshaunak@gmail.com>
Date: Wed, 30 Sep 2015 01:31:12 -0400
Subject: [PATCH] Get bridges working

---
 client/editor.js        |  2 +-
 client/lib/bridges.js   | 95 +++++++++++++++++++++++++++++++++++++++++
 client/style.less       |  2 +-
 lib/stroke_extractor.js |  3 +-
 4 files changed, 99 insertions(+), 3 deletions(-)
 create mode 100644 client/lib/bridges.js

diff --git a/client/editor.js b/client/editor.js
index 10ea312f..3552ff05 100644
--- a/client/editor.js
+++ b/client/editor.js
@@ -53,7 +53,7 @@ Tracker.autorun(() => {
   const glyph = Session.get('editor.glyph');
   if (!glyph) return;
   if (!last_glyph || glyph.character !== last_glyph.character) {
-    stage = new stages.strokes(glyph);
+    stage = new stages.bridges(glyph);
   }
   stage.refresh(glyph);
   last_glyph = glyph;
diff --git a/client/lib/bridges.js b/client/lib/bridges.js
new file mode 100644
index 00000000..afdbbf30
--- /dev/null
+++ b/client/lib/bridges.js
@@ -0,0 +1,95 @@
+"use strict";
+
+const bridgeKey = (bridge) => bridge.map(Point.key).join('-');
+
+const removeBridge = (bridges, bridge) => {
+  const keys = {};
+  keys[bridgeKey(bridge)] = true;
+  keys[bridgeKey(bridge.reverse())] = true;
+  return bridges.filter((bridge) => !keys[bridgeKey(bridge)]);
+}
+
+stages.bridges = class BridgesStage extends stages.AbstractStage {
+  constructor(glyph) {
+    super();
+    Session.set('stage.type', 'bridges');
+    Session.set('stage.instructions',
+                'Connect each pair of points on the glyph outline such that ' +
+                'the segment connecting those points is part of some stroke ' +
+                'outline. Click on a bridge to drop it.');
+    const bridges = stroke_extractor.getBridges(glyph);
+    this.bridges = bridges.bridges;
+    this.endpoints = [];
+    bridges.endpoints.map(
+        (path) => this.endpoints = this.endpoints.concat(path));
+    this.selected_point = undefined;
+    glyph.stages.strokes = glyph.stages.strokes || this.bridges;
+  }
+  handleClickOnBridge(glyph, bridge) {
+    glyph.stages.bridges = removeBridge(glyph.stages.bridges, bridge);
+    Session.set('editor.glyph', glyph);
+  }
+  handleClickOnPoint(glyph, point) {
+    if (this.selected_point === undefined) {
+      this.selected_point = point;
+      this.refresh(glyph);
+      return;
+    } else if (Point.equal(point, this.selected_point)) {
+      this.selected_point = undefined;
+      this.refresh(glyph);
+      return;
+    }
+    const bridge = [point, this.selected_point];
+    this.selected_point = undefined;
+    const without = removeBridge(glyph.stages.bridges, bridge);
+    if (without.length < glyph.stages.bridges.length) {
+      this.refresh(glyph);
+      return;
+    }
+    glyph.stages.bridges.push(bridge);
+    Session.set('editor.glyph', glyph);
+  }
+  handleEvent(glyph, event, template) {
+    if (template.x1 !== undefined) {
+      this.handleClickOnBridge(
+          glyph, [[template.x1, template.y1], [template.x2, template.y2]]);
+    } else if (template.cx !== undefined) {
+      this.handleClickOnPoint(glyph, [template.cx, template.cy]);
+    }
+  }
+  refresh(glyph) {
+    Session.set('stage.paths',
+                [{d: glyph.stages.path, fill: 'gray', stroke: 'gray'}]);
+    const keys = {};
+    this.bridges.map((bridge) => {
+      keys[bridgeKey(bridge)] = true;
+      keys[bridgeKey(bridge.reverse())] = true;
+    });
+    Session.set('stage.lines', glyph.stages.bridges.map((bridge) => ({
+      cls: 'selectable',
+      stroke: keys[bridgeKey(bridge)] ? 'red' : 'purple',
+      x1: bridge[0][0],
+      y1: bridge[0][1],
+      x2: bridge[1][0],
+      y2: bridge[1][1],
+    })));
+    Session.set('stage.points', this.endpoints.map((endpoint) => {
+      let color = endpoint.corner ? 'red' : 'black';
+      if (this.selected_point &&
+          Point.equal(endpoint.point, this.selected_point)) {
+        color = 'purple';
+      }
+      return {
+        cls: 'selectable',
+        cx: endpoint.point[0],
+        cy: endpoint.point[1],
+        fill: color,
+        stroke: color,
+      }
+    }));
+    const strokes = stroke_extractor.getStrokes(glyph);
+    const n = strokes.strokes.length;
+    const message = `Extracted ${n} stroke${n == 1 ? '' : 's'}.`;
+    Session.set('stage.status', strokes.log.concat([{message: message}]));
+  }
+}
diff --git a/client/style.less b/client/style.less
index e8d53078..4fb31b5b 100644
--- a/client/style.less
+++ b/client/style.less
@@ -86,7 +86,7 @@
     height: 100%;
     margin: 0 auto;
 
-    path.selectable:hover {
+    path.selectable:hover, line.selectable:hover {
       cursor: pointer;
       stroke: blue;
       stroke-width: 8;
diff --git a/lib/stroke_extractor.js b/lib/stroke_extractor.js
index ff19a031..5dee927c 100644
--- a/lib/stroke_extractor.js
+++ b/lib/stroke_extractor.js
@@ -363,7 +363,8 @@ this.stroke_extractor.getBridges = (glyph, classifier) => {
       endpoints.push(new Endpoint(paths, [i, j]));
     }
   }
-  return getBridges(endpoints, classifier || handTunedClassifier);
+  const bridges = getBridges(endpoints, classifier || handTunedClassifier);
+  return {endpoints: endpoints, bridges: bridges};
 }
 
 this.stroke_extractor.getStrokes = (glyph) => {