Merge pull request #565 from danvk/gulp

[dygraphs.git] / src / extras / shapes.js

diff --git a/src/extras/shapes.js b/src/extras/shapes.js
new file mode 100644 (file)
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+++ b/src/extras/shapes.js
@@ -0,0 +1,118 @@
+/**
+ * @license
+ * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
+ * MIT-licensed (http://opensource.org/licenses/MIT)
+ */
+
+/**
+ * @fileoverview
+ * Including this file will add several additional shapes to Dygraph.Circles
+ * which can be passed to drawPointCallback.
+ * See tests/custom-circles.html for usage.
+ */
+
+(function() {
+
+/**
+ * @param {!CanvasRenderingContext2D} ctx the canvas context
+ * @param {number} sides the number of sides in the shape.
+ * @param {number} radius the radius of the image.
+ * @param {number} cx center x coordate
+ * @param {number} cy center y coordinate
+ * @param {number=} rotationRadians the shift of the initial angle, in radians.
+ * @param {number=} delta the angle shift for each line. If missing, creates a
+ *     regular polygon.
+ */
+var regularShape = function(
+    ctx, sides, radius, cx, cy, rotationRadians, delta) {
+  rotationRadians = rotationRadians || 0;
+  delta = delta || Math.PI * 2 / sides;
+
+  ctx.beginPath();
+  var initialAngle = rotationRadians;
+  var angle = initialAngle;
+
+  var computeCoordinates = function() {
+    var x = cx + (Math.sin(angle) * radius);
+    var y = cy + (-Math.cos(angle) * radius);
+    return [x, y];
+  };
+
+  var initialCoordinates = computeCoordinates();
+  var x = initialCoordinates[0];
+  var y = initialCoordinates[1];
+  ctx.moveTo(x, y);
+
+  for (var idx = 0; idx < sides; idx++) {
+    angle = (idx == sides - 1) ? initialAngle : (angle + delta);
+    var coords = computeCoordinates();
+    ctx.lineTo(coords[0], coords[1]);
+  }
+  ctx.fill();
+  ctx.stroke();
+};
+
+/**
+ * TODO(danvk): be more specific on the return type.
+ * @param {number} sides
+ * @param {number=} rotationRadians
+ * @param {number=} delta
+ * @return {Function}
+ * @private
+ */
+var shapeFunction = function(sides, rotationRadians, delta) {
+  return function(g, name, ctx, cx, cy, color, radius) {
+    ctx.strokeStyle = color;
+    ctx.fillStyle = "white";
+    regularShape(ctx, sides, radius, cx, cy, rotationRadians, delta);
+  };
+};
+
+Dygraph.update(Dygraph.Circles, {
+  TRIANGLE : shapeFunction(3),
+  SQUARE : shapeFunction(4, Math.PI / 4),
+  DIAMOND : shapeFunction(4),
+  PENTAGON : shapeFunction(5),
+  HEXAGON : shapeFunction(6),
+  CIRCLE : function(g, name, ctx, cx, cy, color, radius) {
+    ctx.beginPath();
+    ctx.strokeStyle = color;
+    ctx.fillStyle = "white";
+    ctx.arc(cx, cy, radius, 0, 2 * Math.PI, false);
+    ctx.fill();
+    ctx.stroke();
+  },
+  STAR : shapeFunction(5, 0, 4 * Math.PI / 5),
+  PLUS : function(g, name, ctx, cx, cy, color, radius) {
+    ctx.strokeStyle = color;
+
+    ctx.beginPath();
+    ctx.moveTo(cx + radius, cy);
+    ctx.lineTo(cx - radius, cy);
+    ctx.closePath();
+    ctx.stroke();
+
+    ctx.beginPath();
+    ctx.moveTo(cx, cy + radius);
+    ctx.lineTo(cx, cy - radius);
+    ctx.closePath();
+    ctx.stroke();
+  },
+  EX : function(g, name, ctx, cx, cy, color, radius) {
+    ctx.strokeStyle = color;
+
+    ctx.beginPath();
+    ctx.moveTo(cx + radius, cy + radius);
+    ctx.lineTo(cx - radius, cy - radius);
+    ctx.closePath();
+    ctx.stroke();
+
+    ctx.beginPath();
+    ctx.moveTo(cx + radius, cy - radius);
+    ctx.lineTo(cx - radius, cy + radius);
+    ctx.closePath();
+    ctx.stroke();
+  }
+});
+
+})();