Radial line and area.

Fixes #25. Fixes #26.

index.js

@@ -19,6 +19,7 @@ export {default as line} from "./src/line";
 export {default as monotone} from "./src/curve/monotone";
 export {default as natural} from "./src/curve/natural";
 export {default as pie} from "./src/pie";
+export {default as radialArea} from "./src/radialArea";
 export {default as radialLine} from "./src/radialLine";
 export {default as square} from "./src/symbol/square";
 export {default as stepAfter} from "./src/curve/stepAfter";

src/area.js

@@ -81,8 +81,7 @@ export default function() {
   };
 
   area.curve = function(_) {
-    var n = arguments.length;
-    return n ? (curve = n > 1 ? curveBind(_, arguments) : _, context != null && (output = curve(context)), area) : curve;
+    return arguments.length ? (curve = curveBind(_, arguments), context != null && (output = curve(context)), area) : curve;
   };
 
   area.context = function(_) {

src/curve/basis.js

@@ -9,10 +9,6 @@ export function point(that, x, y) {
   );
 };
 
-function basis(context) {
-  return new Basis(context);
-}
-
 function Basis(context) {
   this._context = context;
 }
@@ -50,4 +46,6 @@ Basis.prototype = {
   }
 };
 
-export default basis;
+export default function(context) {
+  return new Basis(context);
+};

src/curve/basisClosed.js

@@ -1,9 +1,5 @@
 import {point} from "./basis";
 
-function basisClosed(context) {
-  return new BasisClosed(context);
-}
-
 function BasisClosed(context) {
   this._context = context;
 }
@@ -48,4 +44,6 @@ BasisClosed.prototype = {
   }
 };
 
-export default basisClosed;
+export default function(context) {
+  return new BasisClosed(context);
+};

src/curve/basisOpen.js

@@ -1,9 +1,5 @@
 import {point} from "./basis";
 
-function basisOpen(context) {
-  return new BasisOpen(context);
-}
-
 function BasisOpen(context) {
   this._context = context;
 }
@@ -38,4 +34,6 @@ BasisOpen.prototype = {
   }
 };
 
-export default basisOpen;
+export default function(context) {
+  return new BasisOpen(context);
+};

src/curve/bind.js

@@ -1,10 +1,11 @@
 var slice = Array.prototype.slice;
 
-export default function(interpolate, args) {
+export default function(curve, args) {
+  if (args.length < 2) return curve;
   args = slice.call(args);
   args[0] = null;
   return function(context) {
     args[0] = context;
-    return interpolate.apply(null, args);
+    return curve.apply(null, args);
   };
 };

src/curve/bundle.js

@@ -1,11 +1,5 @@
 import basis from "./basis";
 
-function bundle(context, beta) {
-  return beta == null ? new Bundle(context, 0.85)
-      : (beta = +beta) === 1 ? basis(context)
-      : new Bundle(context, beta);
-}
-
 function Bundle(context, beta) {
   this._basis = basis(context);
   this._beta = beta;
@@ -48,4 +42,8 @@ Bundle.prototype = {
   }
 };
 
-export default bundle;
+export default function(context, beta) {
+  return beta == null ? new Bundle(context, 0.85)
+      : (beta = +beta) === 1 ? basis(context)
+      : new Bundle(context, beta);
+};

src/curve/cardinal.js

@@ -9,10 +9,6 @@ export function point(that, x, y) {
   );
 };
 
-function cardinal(context, tension) {
-  return new Cardinal(context, (tension == null ? 1 : 1 - tension) / 6);
-}
-
 function Cardinal(context, k) {
   this._context = context;
   this._k = k;
@@ -51,4 +47,6 @@ Cardinal.prototype = {
   }
 };
 
-export default cardinal;
+export default function(context, tension) {
+  return new Cardinal(context, (tension == null ? 1 : 1 - tension) / 6);
+};

src/curve/cardinalClosed.js

@@ -1,9 +1,5 @@
 import {point} from "./cardinal";
 
-function cardinalClosed(context, tension) {
-  return new CardinalClosed(context, (tension == null ? 1 : 1 - tension) / 6);
-}
-
 function CardinalClosed(context, k) {
   this._context = context;
   this._k = k;
@@ -48,4 +44,6 @@ CardinalClosed.prototype = {
   }
 };
 
-export default cardinalClosed;
+export default function(context, tension) {
+  return new CardinalClosed(context, (tension == null ? 1 : 1 - tension) / 6);
+};

src/curve/cardinalOpen.js

@@ -1,9 +1,5 @@
 import {point} from "./cardinal";
 
-function cardinalOpen(context, tension) {
-  return new CardinalOpen(context, (tension == null ? 1 : 1 - tension) / 6);
-}
-
 function CardinalOpen(context, k) {
   this._context = context;
   this._k = k;
@@ -39,4 +35,6 @@ CardinalOpen.prototype = {
   }
 };
 
-export default cardinalOpen;
+export default function(context, tension) {
+  return new CardinalOpen(context, (tension == null ? 1 : 1 - tension) / 6);
+};

src/curve/catmullRom.js

@@ -25,12 +25,6 @@ export function point(that, x, y) {
   that._context.bezierCurveTo(x1, y1, x2, y2, that._x2, that._y2);
 };
 
-function catmullRom(context, alpha) {
-  return (alpha = alpha == null ? 0.5 : +alpha)
-      ? new CatmullRom(context, alpha)
-      : cardinal(context, 0);
-}
-
 function CatmullRom(context, alpha) {
   this._context = context;
   this._alpha = alpha;
@@ -81,4 +75,8 @@ CatmullRom.prototype = {
   }
 };
 
-export default catmullRom;
+export default function(context, alpha) {
+  return (alpha = alpha == null ? 0.5 : +alpha)
+      ? new CatmullRom(context, alpha)
+      : cardinal(context, 0);
+};

src/curve/catmullRomClosed.js

@@ -1,12 +1,6 @@
 import cardinalClosed from "./cardinalClosed";
 import {point} from "./catmullRom";
 
-function catmullRomClosed(context, alpha) {
-  return (alpha = alpha == null ? 0.5 : +alpha)
-      ? new CatmullRomClosed(context, alpha)
-      : cardinalClosed(context, 0);
-}
-
 function CatmullRomClosed(context, alpha) {
   this._context = context;
   this._alpha = alpha;
@@ -63,4 +57,8 @@ CatmullRomClosed.prototype = {
   }
 };
 
-export default catmullRomClosed;
+export default function(context, alpha) {
+  return (alpha = alpha == null ? 0.5 : +alpha)
+      ? new CatmullRomClosed(context, alpha)
+      : cardinalClosed(context, 0);
+};

src/curve/catmullRomOpen.js

@@ -1,12 +1,6 @@
 import cardinalOpen from "./cardinalOpen";
 import {point} from "./catmullRom";
 
-function catmullRomOpen(context, alpha) {
-  return (alpha = alpha == null ? 0.5 : +alpha)
-      ? new CatmullRomOpen(context, alpha)
-      : cardinalOpen(context, 0);
-}
-
 function CatmullRomOpen(context, alpha) {
   this._context = context;
   this._alpha = alpha;
@@ -54,4 +48,8 @@ CatmullRomOpen.prototype = {
   }
 };
 
-export default catmullRomOpen;
+export default function(context, alpha) {
+  return (alpha = alpha == null ? 0.5 : +alpha)
+      ? new CatmullRomOpen(context, alpha)
+      : cardinalOpen(context, 0);
+};

src/curve/linear.js

@@ -1,7 +1,3 @@
-function linear(context) {
-  return new Linear(context);
-}
-
 function Linear(context) {
   this._context = context;
 }
@@ -30,4 +26,6 @@ Linear.prototype = {
   }
 };
 
-export default linear;
+export default function(context) {
+  return new Linear(context);
+};

src/curve/linearClosed.js

@@ -1,7 +1,3 @@
-function linearClosed(context) {
-  return new LinearClosed(context);
-}
-
 function LinearClosed(context) {
   this._context = context;
 }
@@ -20,4 +16,6 @@ LinearClosed.prototype = {
   }
 };
 
-export default linearClosed;
+export default function(context) {
+  return new LinearClosed(context);
+};

src/curve/monotone.js

@@ -33,10 +33,6 @@ function point(that, t0, t1) {
   that._context.bezierCurveTo(x0 + dx, y0 + dx * t0, x1 - dx, y1 - dx * t1, x1, y1);
 }
 
-function monotone(context) {
-  return new Monotone(context);
-}
-
 function Monotone(context) {
   this._context = context;
 }
@@ -80,4 +76,6 @@ Monotone.prototype = {
   }
 }
 
-export default monotone;
+export default function(context) {
+  return new Monotone(context);
+};

src/curve/natural.js

@@ -1,7 +1,3 @@
-function natural(context) {
-  return new Natural(context);
-}
-
 function Natural(context) {
   this._context = context;
 }
@@ -64,4 +60,6 @@ function controlPoints(x) {
   return [a, b];
 }
 
-export default natural;
+export default function(context) {
+  return new Natural(context);
+};

src/curve/radial.js

@@ -0,0 +1,36 @@
+import bind from "./bind";
+import {halfPi} from "../math";
+
+function Radial(curve) {
+  this._curve = curve;
+}
+
+Radial.prototype = {
+  areaStart: function() {
+    this._curve.areaStart();
+  },
+  areaEnd: function() {
+    this._curve.areaEnd();
+  },
+  lineStart: function() {
+    this._curve.lineStart();
+  },
+  lineEnd: function() {
+    this._curve.lineEnd();
+  },
+  point: function(r, a) {
+    a -= halfPi, this._curve.point(r * Math.cos(a), r * Math.sin(a));
+  }
+};
+
+export default function(curve, args) {
+  curve = bind(curve, args);
+
+  function radial(context) {
+    return new Radial(curve(context));
+  }
+
+  radial._curve = curve;
+
+  return radial;
+};

src/curve/step.js

@@ -1,7 +1,3 @@
-function step(context) {
-  return new Step(context);
-}
-
 function Step(context) {
   this._context = context;
 }
@@ -38,4 +34,6 @@ Step.prototype = {
   }
 };
 
-export default step;
+export default function(context) {
+  return new Step(context);
+};

src/curve/stepAfter.js

@@ -1,7 +1,3 @@
-function stepAfter(context) {
-  return new StepAfter(context);
-}
-
 function StepAfter(context) {
   this._context = context;
 }
@@ -36,4 +32,6 @@ StepAfter.prototype = {
   }
 };
 
-export default stepAfter;
+export default function(context) {
+  return new StepAfter(context);
+};

src/curve/stepBefore.js

@@ -1,7 +1,3 @@
-function stepBefore(context) {
-  return new StepBefore(context);
-}
-
 function StepBefore(context) {
   this._context = context;
 }
@@ -36,4 +32,6 @@ StepBefore.prototype = {
   }
 };
 
-export default stepBefore;
+export default function(context) {
+  return new StepBefore(context);
+};

src/line.js

@@ -45,8 +45,7 @@ export default function() {
   };
 
   line.curve = function(_) {
-    var n = arguments.length;
-    return n ? (curve = n > 1 ? curveBind(_, arguments) : _, context != null && (output = curve(context)), line) : curve;
+    return arguments.length ? (curve = curveBind(_, arguments), context != null && (output = curve(context)), line) : curve;
   };
 
   line.context = function(_) {