Finish PR 58 - Support counter-clockwise arcs (#83)

* Support counter-clockwise arcs

* Update changelog

Author: JordanMartinez

CHANGELOG.md

@@ -6,6 +6,7 @@ Notable changes to this project are documented in this file. The format is based
 
 Breaking changes:
 - Migrate FFI to ES modules (#85 by @JordanMartinez)
+- Support arcs that are drawn counter-clockwise (#58, #83 by @karljs and @JordanMartinez)
 
 New features:
 - Added `createImageDataWith` (#81)

src/Graphics/Canvas.js

@@ -227,7 +227,7 @@ export function closePath(ctx) {
 export function arc(ctx) {
   return function(a) {
     return function() {
-      ctx.arc(a.x, a.y, a.radius, a.start, a.end);
+      ctx.arc(a.x, a.y, a.radius, a.start, a.end, a.useCounterClockwise);
     };
   };
 }

src/Graphics/Canvas.purs

@@ -415,12 +415,15 @@ fillPath ctx path = do
 -- | - The center coordinates `x` and `y`,
 -- | - The radius `r`,
 -- | - The starting and ending angles, `start` and `end`.
+-- | - Whether to draw the arc counter-clockwise (true) or clockwise (false) direction.
+-- |   Normally, this value is `false`.
 type Arc =
   { x :: Number
   , y :: Number
   , radius :: Number
   , start :: Number
   , end   :: Number
+  , useCounterClockwise :: Boolean
   }
 
 -- | Render an arc object.