93 lines
1.9 KiB
Markdown
93 lines
1.9 KiB
Markdown
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# js-wmf
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Processor for Windows MetaFile (WMF) files in JS (for the browser and nodejs).
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## Installation
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With [npm](https://www.npmjs.org/package/wmf):
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```bash
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$ npm install wmf
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```
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In the browser:
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```html
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<script src="wmf.js"></script>
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```
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The browser exposes a variable `WMF`.
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## Usage
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The `data` argument is expected to be an `ArrayBuffer`, `Uint8Array` or `Buffer`
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- `WMF.image_size(data)` extracts the image offset and extents, returns an Array
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`[width, height]` where both metrics are measured in pixels.
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- `WMF.draw_canvas(data, canvas)` parses the WMF and draws to a `Canvas`.
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### Notes
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- The library assumes the global `ImageData` is available. For nodejs-powered
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canvas implementations, a shim must be exposed as a global. Using the `canvas`
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npm package:
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```js
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const { createImageData } = require("canvas");
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global.ImageData = createImageData;
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```
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- `OffscreenCanvas` in Chrome and some other Canvas implementations require
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the dimensions in the constructor:
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```js
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const size = WMF.image_size(data);
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const canvas = new OffscreenCanvas(size[0], size[1]);
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```
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## Examples
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<details>
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<summary><b>Browser Fetch into canvas</b> (click to show)</summary>
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```js
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// assume `canvas` is a DOM element
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(async() => {
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const res = await fetch("url/for/image.wmf");
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const ab = await res.arrayBuffer();
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WMF.draw_canvas(ab, document.getElementById("canvas"));
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})();
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```
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</details>
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<details>
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<summary><b>NodeJS (using `canvas` npm module)</b> (click to show)</summary>
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```js
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const { createCanvas, createImageData } = require("canvas");
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global.ImageData = createImageData;
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const size = WMF.image_size(data);
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const canvas = createCanvas(size[0], size[1]);
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WMF.draw_canvas(data, canvas);
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```
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</details>
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## License
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Please consult the attached LICENSE file for details. All rights not explicitly
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granted by the Apache 2.0 License are reserved by the Original Author.
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## References
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- [MS-WMF]: Windows Metafile Format
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