Productionize PathKit

 - Remove some old API with VerbArgs that we didn't really like.
 - move from experimental/wasm -> experimental/pathkit and rename
wasm_main.cpp to pathkit_wasm_bindings (more descriptive).
 - Make compile.sh nicer to use (with some form of command line args).
 - Use MODULARIZE=1 to make this play nicer with other WASM libraries
and easier to import.
 - Add seperate ToCanvas() API
 - Move Region stuff behind the PATHKIT_TESTING flag (saves 100k on
binary size).
 - Add npm package for wasm version.  asm.js version should also be
supported for older browsers.
 - Remove shell.html, which was largely too complicated. Replace it with
example.html, which is more succinct and demos the more relevant APIs.

See https://www.npmjs.com/package/experimental-pathkit-wasm

Bug: skia:8216
Change-Id: I15f14dd8acd77331729998ae3e30d73e4b006761
Reviewed-on: https://skia-review.googlesource.com/144790
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/experimental/pathkit/.gitignore b/experimental/pathkit/.gitignore
new file mode 100644
index 0000000..6e849a1
--- /dev/null
+++ b/experimental/pathkit/.gitignore
@@ -0,0 +1,3 @@
+**/bin
+node_modules/
+package-lock.json
\ No newline at end of file
diff --git a/experimental/pathkit/Makefile b/experimental/pathkit/Makefile
new file mode 100644
index 0000000..d7dc28a
--- /dev/null
+++ b/experimental/pathkit/Makefile
@@ -0,0 +1,41 @@
+build:
+	./compile.sh
+
+npm:
+	mkdir -p ./npm-wasm/bin
+	mkdir -p ./npm-asmjs/bin
+	./compile.sh
+	cp ../../out/pathkit/pathkit.js ./npm-wasm/bin
+	cp ../../out/pathkit/pathkit.wasm ./npm-wasm/bin
+	#./compile.sh asm.js TODO
+
+publish:
+	cd npm-wasm; npm publish
+
+update-major:
+	cd npm-wasm; npm version major
+	echo "Don't forget to publish."
+
+update-minor:
+	cd npm-wasm; npm version minor
+	echo "Don't forget to publish."
+
+update-patch:
+	cd npm-wasm; npm version patch
+	echo "Don't forget to publish."
+
+dev:
+	./compile.sh dev
+
+dev-npm:
+	mkdir -p ./npm-wasm/bin
+	mkdir -p ./npm-asmjs/bin
+	./compile.sh dev
+	cp ../../out/pathkit/pathkit.js ./npm-wasm/bin
+	cp ../../out/pathkit/pathkit.wasm ./npm-wasm/bin
+	#./compile.sh asm.js TODO
+
+example:
+	npm install experimental-pathkit-wasm
+	echo "Go check out localhost:8000/npm-wasm/example.html"
+	python serve.py
\ No newline at end of file
diff --git a/experimental/pathkit/README.md b/experimental/pathkit/README.md
new file mode 100644
index 0000000..a6b53dd
--- /dev/null
+++ b/experimental/pathkit/README.md
@@ -0,0 +1,15 @@
+PathKit WASM API
+================
+
+This library lets you use Skia's feature-rich PathOps API in the browser.
+
+
+Compiling the source
+--------------------
+
+Download the [Enscriptem SDK](https://kripken.github.io/emscripten-site/docs/getting_started/downloads.html).
+
+Set the EMSDK environment variable to the directory you installed it to.
+
+Run `./experimental/pathkit/compile.sh` to compile a production, WASM build to `$SKIA_HOME/out/pathkit`.
+Add "--help" for more options.
\ No newline at end of file
diff --git a/experimental/pathkit/compile.sh b/experimental/pathkit/compile.sh
new file mode 100755
index 0000000..c905c9b
--- /dev/null
+++ b/experimental/pathkit/compile.sh
@@ -0,0 +1,118 @@
+#!/bin/bash
+# Copyright 2018 Google LLC
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+
+BASE_DIR=`cd $(dirname ${BASH_SOURCE[0]}) && pwd`
+HTML_SHELL=$BASE_DIR/shell.html
+BUILD_DIR="out/pathkit"
+
+# This expects the environment variable EMSDK to be set
+if [[ ! -d $EMSDK ]]; then
+  echo "Be sure to set the EMSDK environment variable."
+  exit 1
+fi
+
+# Navigate to SKIA_HOME from where this file is located.
+pushd $BASE_DIR/../..
+
+# Run this from $SKIA_HOME, not from the directory this file is in.
+if [[ ! -d ./src ]]; then
+  echo "Cannot locate Skia source. Is the source checkout okay? Exiting."
+  exit 1
+fi
+
+if [[ $@ == *help* ]]; then
+  echo "By default, this script builds a production WASM build of PathKit."
+  echo ""
+  echo "This script takes several optional parameters:"
+  echo "  dev = Make a build suitable for running tests or debugging"
+  echo "  asm.js = Build for asm.js instead of WASM"
+  echo "  serve = starts a webserver allowing a user to navigate to"
+  echo "          localhost:8000/pathkit.html to view the demo page."
+  exit 0
+fi
+
+
+# Use -O0 for larger builds (but generally quicker)
+# Use -Oz for (much slower, but smaller/faster) production builds
+RELEASE_CONF="-Oz"
+if [[ $@ == *dev* ]]; then
+  echo "Building a Debug/Testing build"
+  RELEASE_CONF="-O0 -s ASSERTIONS=1 -s DEMANGLE_SUPPORT=1 -g2 -DPATHKIT_TESTING"
+fi
+
+WASM_CONF="-s WASM=1"
+if [[ $@ == *asm.js* ]]; then
+  echo "Building with asm.js instead of WASM"
+  WASM_CONF="-s WASM=0 -s ALLOW_MEMORY_GROWTH=1 --separate-asm"
+fi
+
+OUTPUT="-o $BUILD_DIR/pathkit.js"
+
+source $EMSDK/emsdk_env.sh
+
+echo "Compiling"
+
+set -e
+
+mkdir -p $BUILD_DIR
+
+em++ $RELEASE_CONF -std=c++14 \
+-Iinclude/config \
+-Iinclude/core \
+-Iinclude/gpu \
+-Iinclude/pathops \
+-Iinclude/private \
+-Iinclude/utils \
+-Isrc/core \
+-Isrc/gpu \
+-Isrc/shaders \
+-Isrc/opts \
+--bind \
+$WASM_CONF \
+-s MODULARIZE=1 \
+-s EXPORT_NAME="PathKitInit" \
+-s NO_EXIT_RUNTIME=1 \
+-s ERROR_ON_UNDEFINED_SYMBOLS=1 \
+-s ERROR_ON_MISSING_LIBRARIES=1 \
+$OUTPUT \
+$BASE_DIR/pathkit_wasm_bindings.cpp \
+src/core/SkAnalyticEdge.cpp \
+src/core/SkArenaAlloc.cpp \
+src/core/SkBlitter.cpp \
+src/core/SkCoverageDelta.cpp \
+src/core/SkEdge.cpp \
+src/core/SkEdgeBuilder.cpp \
+src/core/SkEdgeClipper.cpp \
+src/core/SkFDot6Constants.cpp \
+src/core/SkGeometry.cpp \
+src/core/SkLineClipper.cpp \
+src/core/SkMallocPixelRef.cpp \
+src/core/SkMath.cpp \
+src/core/SkMatrix.cpp \
+src/core/SkOpts.cpp \
+src/core/SkPath.cpp \
+src/core/SkPathRef.cpp \
+src/core/SkPoint.cpp \
+src/core/SkRect.cpp \
+src/core/SkRegion.cpp \
+src/core/SkRegion_path.cpp \
+src/core/SkScan_Path.cpp \
+src/core/SkStream.cpp \
+src/core/SkString.cpp \
+src/core/SkStringUtils.cpp \
+src/core/SkUtils.cpp \
+src/pathops/*.cpp \
+src/ports/SkDebug_stdio.cpp \
+src/ports/SkMemory_malloc.cpp \
+src/utils/SkParse.cpp \
+src/utils/SkParsePath.cpp
+
+if [[ $@ == *serve* ]]; then
+  pushd $BUILD_DIR
+  python serve.py
+fi
+
diff --git a/experimental/pathkit/npm-wasm/LICENSE b/experimental/pathkit/npm-wasm/LICENSE
new file mode 100644
index 0000000..20c685b
--- /dev/null
+++ b/experimental/pathkit/npm-wasm/LICENSE
@@ -0,0 +1,190 @@
+   Copyright 2018 Google LLC
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
diff --git a/experimental/pathkit/npm-wasm/README.md b/experimental/pathkit/npm-wasm/README.md
new file mode 100644
index 0000000..2f02e51
--- /dev/null
+++ b/experimental/pathkit/npm-wasm/README.md
@@ -0,0 +1,54 @@
+A WASM version of Skia's PathOps toolkit.
+
+To use the library, run `npm install experimental-pathkit-wasm` and then simply include it:
+
+    <script src="/node_modules/experimental-pathkit-wasm/bin/pathkit.js"></script>
+    PathKitInit({
+        locateFile: (file) => '/node_modules/experimental-pathkit-wasm/bin/'+file,
+    }).then((PathKit) => {
+        // Code goes here using PathKit
+    });
+
+PathKit comes in two parts, a JS loader and the actual WASM code. The JS loader creates
+a global `PathKitInit` that can be called to load the WASM code. The `locateFile` function
+is used to tell the JS loader where to find the .wasm file. By default, it will
+look for /pathkit.wasm, so if this is not the case, use `locateFile` to configure
+this properly.
+The `PathKit` object returned through the .then() callback is fully loaded and ready to use.
+
+See example.html for a fuller example of how to use the library.
+
+Using PathKit and WebPack
+-------------------------
+
+WebPack's support for WASM is still somewhat experimental, but PathKit can be
+used with a few configuration changes.
+
+In the JS code, use require():
+
+    const PathKitInit = require('experimental-pathkit-wasm/bin/pathkit.js')
+    PathKitInit().then((PathKit) => {
+        // Code goes here using PathKit
+    })
+
+Since WebPack does not expose the entire `/node_modules/` directory, but instead
+packages only the needed pieces, we have to copy pathkit.wasm into the build directory.
+One such solution is to use [CopyWebpackPlugin](https://github.com/webpack-contrib/copy-webpack-plugin)
+For example, add the following plugin:
+
+    config.plugins.push(
+        new CopyWebpackPlugin([
+            { from: 'node_modules/experimental-pathkit-wasm/bin/pathkit.wasm' }
+        ])
+    );
+
+If webpack gives an error similar to:
+
+    ERROR in ./node_modules/experimental-pathkit-wasm/bin/pathkit.js
+    Module not found: Error: Can't resolve 'fs' in '...'
+
+Then, add the following configuration change to the node section of the config:
+
+    config.node = {
+        fs: 'empty'
+    };
\ No newline at end of file
diff --git a/experimental/pathkit/npm-wasm/example.html b/experimental/pathkit/npm-wasm/example.html
new file mode 100644
index 0000000..d31e8b4
--- /dev/null
+++ b/experimental/pathkit/npm-wasm/example.html
@@ -0,0 +1,77 @@
+<!DOCTYPE html>
+<title>PathKit (Skia + WASM)</title>
+<meta charset="utf-8" />
+<meta http-equiv="X-UA-Compatible" content="IE=edge">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+
+<style>
+  svg, canvas {
+    border: 1px dashed #AAA;
+  }
+
+  canvas {
+    width: 200px;
+    height: 200px;
+  }
+
+</style>
+
+<svg id=svg xmlns='http://www.w3.org/2000/svg' width=200 height=200></svg>
+
+<canvas id="canvas1"></canvas>
+
+<canvas id="canvas2"></canvas>
+
+<script type="text/javascript" src="/node_modules/experimental-pathkit-wasm/bin/pathkit.js"></script>
+
+<script type="text/javascript" charset="utf-8">
+
+  PathKitInit({
+    locateFile: (file) => '/node_modules/experimental-pathkit-wasm/bin/'+file,
+  }).then((PathKit) => {
+
+    let firstPath = PathKit.FromSVGString('M11.99 2C6.47 2 2 6.48 2 12s4.47 10 9.99 10C17.52 22 22 17.52 22 12S17.52 2 11.99 2zM12 20c-4.42 0-8-3.58-8-8s3.58-8 8-8 8 3.58 8 8-3.58 8-8 8zm.5-13H11v6l5.25 3.15.75-1.23-4.5-2.67z');
+
+    let secondPath = PathKit.NewPath();
+    // Acts somewhat like the Canvas API
+    secondPath.moveTo(1, 1);
+    secondPath.lineTo(20, 1);
+    secondPath.lineTo(10, 30);
+    secondPath.close();
+
+    let combinedPath = PathKit.ApplyPathOp(firstPath, secondPath, PathKit.PathOp.INTERSECT);
+    let simpleStr = PathKit.ToSVGString(combinedPath);
+
+    let newSVG = document.createElementNS('http://www.w3.org/2000/svg', 'path');
+    newSVG.setAttribute('stroke', 'rgb(0,0,200)');
+    newSVG.setAttribute('fill', 'white');
+    newSVG.setAttribute('transform', 'scale(5,5)');
+    newSVG.setAttribute('d', simpleStr);
+    document.getElementById('svg').appendChild(newSVG);
+
+    // Draw directly to Canvas
+    let ctx = document.getElementById('canvas1').getContext('2d');
+    ctx.strokeStyle = 'green';
+    ctx.fillStyle = 'white';
+    ctx.scale(8, 4);
+    ctx.beginPath();
+    PathKit.ToCanvas(combinedPath, ctx);
+    ctx.stroke();
+
+    // create Path2D object and use it in a Canvas.
+    let path2D = PathKit.ToPath2D(combinedPath);
+    ctx = document.getElementById('canvas2').getContext('2d');
+    ctx.scale(8, 4);
+    ctx.fillStyle = 'purple';
+    ctx.strokeStyle = 'orange';
+    ctx.fill(path2D);
+    ctx.stroke(path2D);
+
+    // clean up WASM memory
+    // See http://kripken.github.io/emscripten-site/docs/porting/connecting_cpp_and_javascript/embind.html?highlight=memory#memory-management
+    firstPath.delete();
+    secondPath.delete();
+    combinedPath.delete();
+  });
+
+</script>
diff --git a/experimental/pathkit/npm-wasm/package.json b/experimental/pathkit/npm-wasm/package.json
new file mode 100644
index 0000000..cb7fec1
--- /dev/null
+++ b/experimental/pathkit/npm-wasm/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "experimental-pathkit-wasm",
+  "version": "0.0.4",
+  "description": "A WASM version of Skia's PathOps toolkit",
+  "main": "bin/pathkit.js",
+  "homepage": "https://github.com/google/skia/tree/master/experimental/pathkit",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "license": "Apache-2.0"
+}
diff --git a/experimental/pathkit/pathkit_wasm_bindings.cpp b/experimental/pathkit/pathkit_wasm_bindings.cpp
new file mode 100644
index 0000000..dd6245e
--- /dev/null
+++ b/experimental/pathkit/pathkit_wasm_bindings.cpp
@@ -0,0 +1,334 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkFloatBits.h"
+#include "SkFloatingPoint.h"
+#include "SkParsePath.h"
+#include "SkPath.h"
+#include "SkPathOps.h"
+#include "SkRegion.h"
+#include "SkString.h"
+
+#include <emscripten/emscripten.h>
+#include <emscripten/bind.h>
+
+using namespace emscripten;
+
+static const int MOVE = 0;
+static const int LINE = 1;
+static const int QUAD = 2;
+static const int CUBIC = 4;
+static const int CLOSE = 5;
+
+// =================================================================================
+// Creating/Exporting Paths
+// =================================================================================
+
+template <typename VisitFunc>
+void VisitPath(const SkPath& p, VisitFunc&& f) {
+    SkPath::RawIter iter(p);
+    SkPoint pts[4];
+    SkPath::Verb verb;
+    while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
+        f(verb, pts);
+    }
+}
+
+emscripten::val JSArray = emscripten::val::global("Array");
+
+emscripten::val EMSCRIPTEN_KEEPALIVE ToCmds(SkPath path) {
+    val cmds = JSArray.new_();
+
+    VisitPath(path, [&cmds](SkPath::Verb verb, const SkPoint pts[4]) {
+        val cmd = JSArray.new_();
+        switch (verb) {
+        case SkPath::kMove_Verb:
+            cmd.call<void>("push", MOVE, pts[0].x(), pts[0].y());
+            break;
+        case SkPath::kLine_Verb:
+            cmd.call<void>("push", LINE, pts[1].x(), pts[1].y());
+            break;
+        case SkPath::kQuad_Verb:
+            cmd.call<void>("push", QUAD, pts[1].x(), pts[1].y(), pts[2].x(), pts[2].y());
+            break;
+        case SkPath::kConic_Verb:
+            printf("unsupported conic verb\n");
+            // TODO(kjlubick): Port in the logic from SkParsePath::ToSVGString?
+            break;
+        case SkPath::kCubic_Verb:
+            cmd.call<void>("push", CUBIC,
+                           pts[1].x(), pts[1].y(),
+                           pts[2].x(), pts[2].y(),
+                           pts[3].x(), pts[3].y());
+            break;
+        case SkPath::kClose_Verb:
+            cmd.call<void>("push", CLOSE);
+            break;
+        case SkPath::kDone_Verb:
+            SkASSERT(false);
+            break;
+        }
+        cmds.call<void>("push", cmd);
+    });
+    return cmds;
+}
+
+// This type signature is a mess, but it's necessary. See, we can't use "bind" (EMSCRIPTEN_BINDINGS)
+// and pointers to primitive types (Only bound types like SkPoint). We could if we used
+// cwrap (see https://becominghuman.ai/passing-and-returning-webassembly-array-parameters-a0f572c65d97)
+// but that requires us to stick to C code and, AFAIK, doesn't allow us to return nice things like
+// SkPath or SkOpBuilder.
+//
+// So, basically, if we are using C++ and EMSCRIPTEN_BINDINGS, we can't have primative pointers
+// in our function type signatures. (this gives an error message like "Cannot call foo due to unbound
+// types Pi, Pf").  But, we can just pretend they are numbers and cast them to be pointers and
+// the compiler is happy.
+SkPath EMSCRIPTEN_KEEPALIVE FromCmds(uintptr_t /* float* */ cptr, int numCmds) {
+    const auto* cmds = reinterpret_cast<const float*>(cptr);
+    SkPath path;
+    float x1, y1, x2, y2, x3, y3;
+
+    // if there are not enough arguments, bail with the path we've constructed so far.
+    #define CHECK_NUM_ARGS(n) \
+        if ((i + n) > numCmds) { \
+            SkDebugf("Not enough args to match the verbs. Saw %d commands\n", numCmds); \
+            return path; \
+        }
+
+    for(int i = 0; i < numCmds;){
+         switch (sk_float_floor2int(cmds[i++])) {
+            case MOVE:
+                CHECK_NUM_ARGS(2);
+                x1 = cmds[i++], y1 = cmds[i++];
+                path.moveTo(x1, y1);
+                break;
+            case LINE:
+                CHECK_NUM_ARGS(2);
+                x1 = cmds[i++], y1 = cmds[i++];
+                path.lineTo(x1, y1);
+                break;
+            case QUAD:
+                CHECK_NUM_ARGS(4);
+                x1 = cmds[i++], y1 = cmds[i++];
+                x2 = cmds[i++], y2 = cmds[i++];
+                path.quadTo(x1, y1, x2, y2);
+                break;
+            case CUBIC:
+                CHECK_NUM_ARGS(6);
+                x1 = cmds[i++], y1 = cmds[i++];
+                x2 = cmds[i++], y2 = cmds[i++];
+                x3 = cmds[i++], y3 = cmds[i++];
+                path.cubicTo(x1, y1, x2, y2, x3, y3);
+                break;
+            case CLOSE:
+                path.close();
+                break;
+            default:
+                SkDebugf("  path: UNKNOWN command %f, aborting dump...\n", cmds[i-1]);
+                return path;
+        }
+    }
+
+    #undef CHECK_NUM_ARGS
+
+    return path;
+}
+
+SkPath EMSCRIPTEN_KEEPALIVE NewPath() {
+    return SkPath();
+}
+
+//========================================================================================
+// SVG THINGS
+//========================================================================================
+
+val EMSCRIPTEN_KEEPALIVE ToSVGString(SkPath path) {
+    SkString s;
+    SkParsePath::ToSVGString(path, &s);
+    // Wrapping it in val automatically turns it into a JS string.
+    // Not too sure on performance implications, but is is simpler than
+    // returning a raw pointer to const char * and then using
+    // Pointer_stringify() on the calling side.
+    return val(s.c_str());
+}
+
+
+SkPath EMSCRIPTEN_KEEPALIVE FromSVGString(std::string str) {
+    SkPath path;
+    SkParsePath::FromSVGString(str.c_str(), &path);
+    return path;
+}
+
+//========================================================================================
+// PATHOP THINGS
+//========================================================================================
+
+SkPath EMSCRIPTEN_KEEPALIVE SimplifyPath(SkPath path) {
+    SkPath simple;
+    Simplify(path, &simple);
+    return simple;
+}
+
+SkPath EMSCRIPTEN_KEEPALIVE ApplyPathOp(SkPath pathOne, SkPath pathTwo, SkPathOp op) {
+    SkPath path;
+    Op(pathOne, pathTwo, op, &path);
+    return path;
+}
+
+SkPath EMSCRIPTEN_KEEPALIVE ResolveBuilder(SkOpBuilder builder) {
+    SkPath path;
+    builder.resolve(&path);
+    return path;
+}
+
+//========================================================================================
+// Canvas THINGS
+//========================================================================================
+
+void EMSCRIPTEN_KEEPALIVE ToCanvas(SkPath path, val/* Path2D or Canvas*/ ctx) {
+    SkPath::Iter iter(path, false);
+    SkPoint pts[4];
+    SkPath::Verb verb;
+    while ((verb = iter.next(pts, false)) != SkPath::kDone_Verb) {
+        switch (verb) {
+            case SkPath::kMove_Verb:
+                ctx.call<void>("moveTo", pts[0].x(), pts[0].y());
+                break;
+            case SkPath::kLine_Verb:
+                ctx.call<void>("lineTo", pts[1].x(), pts[1].y());
+                break;
+            case SkPath::kQuad_Verb:
+                ctx.call<void>("quadraticCurveTo", pts[1].x(), pts[1].y(), pts[2].x(), pts[2].y());
+                break;
+            case SkPath::kConic_Verb:
+                printf("unsupported conic verb\n");
+                // TODO(kjlubick): Port in the logic from SkParsePath::ToSVGString?
+                break;
+            case SkPath::kCubic_Verb:
+                ctx.call<void>("bezierCurveTo", pts[1].x(), pts[1].y(), pts[2].x(), pts[2].y(),
+                                                   pts[3].x(), pts[3].y());
+                break;
+            case SkPath::kClose_Verb:
+                ctx.call<void>("closePath");
+                break;
+            case SkPath::kDone_Verb:
+                break;
+        }
+    }
+}
+
+emscripten::val JSPath2D = emscripten::val::global("Path2D");
+
+emscripten::val EMSCRIPTEN_KEEPALIVE ToPath2D(SkPath path) {
+    val retVal = JSPath2D.new_();
+    ToCanvas(path, retVal);
+    return retVal;
+}
+
+//========================================================================================
+// Region things
+//========================================================================================
+
+#ifdef PATHKIT_TESTING
+SkPath GetBoundaryPathFromRegion(SkRegion region) {
+    SkPath p;
+    region.getBoundaryPath(&p);
+    return p;
+}
+#endif
+
+// Binds the classes to the JS
+EMSCRIPTEN_BINDINGS(skia) {
+    class_<SkPath>("SkPath")
+        .constructor<>()
+
+        .function("moveTo",
+            select_overload<void(SkScalar, SkScalar)>(&SkPath::moveTo))
+        .function("lineTo",
+            select_overload<void(SkScalar, SkScalar)>(&SkPath::lineTo))
+        .function("quadTo",
+            select_overload<void(SkScalar, SkScalar, SkScalar, SkScalar)>(&SkPath::quadTo))
+        .function("cubicTo",
+            select_overload<void(SkScalar, SkScalar, SkScalar, SkScalar, SkScalar, SkScalar)>(&SkPath::cubicTo))
+        .function("close", &SkPath::close)
+#ifdef PATHKIT_TESTING
+        .function("dump", select_overload<void() const>(&SkPath::dump))
+#endif
+        ;
+
+    class_<SkOpBuilder>("SkOpBuilder")
+        .constructor<>()
+
+        .function("add", &SkOpBuilder::add);
+
+
+    // Without these function() bindings, the function would be exposed but oblivious to
+    // our types (e.g. SkPath)
+
+    // Import
+    function("FromSVGString", &FromSVGString);
+    function("FromCmds", &FromCmds);
+    function("NewPath", &NewPath);
+    // Path2D is opaque, so we can't read in from it.
+
+    // Export
+    function("ToPath2D", &ToPath2D);
+    function("ToCanvas", &ToCanvas);
+    function("ToSVGString", &ToSVGString);
+    function("ToCmds", &ToCmds);
+
+    // PathOps
+    function("SimplifyPath", &SimplifyPath);
+    function("ApplyPathOp", &ApplyPathOp);
+    function("ResolveBuilder", &ResolveBuilder);
+
+    enum_<SkPathOp>("PathOp")
+        .value("DIFFERENCE",         SkPathOp::kDifference_SkPathOp)
+        .value("INTERSECT",          SkPathOp::kIntersect_SkPathOp)
+        .value("UNION",              SkPathOp::kUnion_SkPathOp)
+        .value("XOR",                SkPathOp::kXOR_SkPathOp)
+        .value("REVERSE_DIFFERENCE", SkPathOp::kReverseDifference_SkPathOp);
+
+    constant("MOVE_VERB",  MOVE);
+    constant("LINE_VERB",  LINE);
+    constant("QUAD_VERB",  QUAD);
+    constant("CUBIC_VERB", CUBIC);
+    constant("CLOSE_VERB", CLOSE);
+
+    // coming soon - Stroke
+
+    // coming soon - Matrix
+
+    // coming soon - Bounds/Trim
+
+#ifdef PATHKIT_TESTING
+    function("SkBits2Float", &SkBits2Float);
+
+    function("GetBoundaryPathFromRegion", &GetBoundaryPathFromRegion);
+
+    enum_<SkRegion::Op>("RegionOp")
+        .value("DIFFERENCE",         SkRegion::Op::kDifference_Op)
+        .value("INTERSECT",          SkRegion::Op::kIntersect_Op)
+        .value("UNION",              SkRegion::Op::kUnion_Op)
+        .value("XOR",                SkRegion::Op::kXOR_Op)
+        .value("REVERSE_DIFFERENCE", SkRegion::Op::kReverseDifference_Op)
+        .value("REPLACE",            SkRegion::Op::kReplace_Op);
+
+    class_<SkRegion>("SkRegion")
+        .constructor<>()
+
+        .function("setRect",
+            select_overload<bool(int32_t, int32_t, int32_t, int32_t)>(&SkRegion::setRect))
+        .function("setPath", &SkRegion::setPath)
+        .function("opLTRB",
+            select_overload<bool(int32_t, int32_t, int32_t, int32_t, SkRegion::Op)>(&SkRegion::op))
+        .function("opRegion",
+            select_overload<bool(const SkRegion&, SkRegion::Op)>(&SkRegion::op))
+        .function("opRegionAB",
+            select_overload<bool(const SkRegion&, const SkRegion&, SkRegion::Op)>(&SkRegion::op));
+#endif
+}
diff --git a/experimental/pathkit/serve.py b/experimental/pathkit/serve.py
new file mode 100644
index 0000000..8c6541f
--- /dev/null
+++ b/experimental/pathkit/serve.py
@@ -0,0 +1,20 @@
+# Copyright 2018 Google LLC
+
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import SimpleHTTPServer
+import SocketServer
+
+PORT = 8000
+
+class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+    pass
+
+Handler.extensions_map['.js'] = 'application/javascript'
+# Without the correct MIME type, async compilation doesn't work
+Handler.extensions_map['.wasm'] = 'application/wasm'
+
+httpd = SocketServer.TCPServer(("", PORT), Handler)
+
+httpd.serve_forever()