skia2/modules/pathkit/npm-wasm/README.md
Kevin Lubick 275eaff3be [pathkit] Add .ready() to initialize
See https://github.com/kripken/emscripten/issues/5820 and
https://skia-review.googlesource.com/c/skia/+/181177 for more context.

(Problem was discovered in CanvasKit, and this ports the same fix to
PathKit).

Bug: skia:
Change-Id: Ic8b2fb399210631a571595a5b3d11d1736c00def
Reviewed-on: https://skia-review.googlesource.com/c/181178
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
2019-01-04 19:58:22 +00:00

57 lines
2.1 KiB
Markdown

A WASM version of Skia's PathOps toolkit.
To use the library, run `npm install pathkit-wasm` and then simply include it:
<script src="/node_modules/pathkit-wasm/bin/pathkit.js"></script>
PathKitInit({
locateFile: (file) => '/node_modules/pathkit-wasm/bin/'+file,
}).ready().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 upon resolution of the .ready() Promise is fully loaded and ready to use.
See the [API page](https://skia.org/user/modules/pathkit) and
[example.html](https://github.com/google/skia/blob/master/modules/pathkit/npm-wasm/example.html)
for details on 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('pathkit-wasm/bin/pathkit.js')
PathKitInit().ready().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/pathkit-wasm/bin/pathkit.wasm' }
])
);
If webpack gives an error similar to:
ERROR in ./node_modules/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'
};