Beta Test: v2.1

[samizdatco]

Hi everybody, I've reached the end of my to-do list for Skia Canvas 2.1 and would really appreciate any time you could put into checking it out and helping me find any bugs or details I've missed. You can install the newest pre-release via:

npm install https://github.com/samizdatco/skia-canvas

Please post general 👍/👎 experiences here or feel free to open an issue if you want to report something specific.

Thanks!

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New Features

GUI

• The App global now has an eventLoop property which can be set to:
  • "native" (the default) in which case the Node event loop is suspended while the OS handles displaying GUI windows
  • "node" where the Node event loop maintains control (allowing setInterval and setTimeout to run) and handles GUI events manually every few milliseconds (though note some of the caveats associated with the Winit feature this uses).
• Window objects now have a read-only closed property and emit a close event when they are closed. Closed windows can later be re-opened by calling the new open() method.
• The new borderless attribute allows Window titlebars and borders to be hidden (thanks to @hydroperx Window#decorations #230)

Imagery

• The loadImage() and loadImageData() helpers now use node-fetch to handle web requests and can accept a fetch options object as the final argument.
• Added support for integrating the Sharp image processor into canvas workflows (if the sharp npm module has been installed):
  • The new Canvas.toSharp() & ImageData.toSharp() convenience methods convert their contents to a Sharp bitmap object
  • loadImage() & loadImageData() can now be called with a Sharp object as their sole argument
  • The src property on a new Image object can be set to a Sharp object and it will begin asynchronously loading

Rendering

• Significant speed-ups for deeply layered drawing in which the canvas isn't cleared or reset (potentially resulting in numerous vector objects being re-drawn despite being hidden by shapes drawn on top):
  • The bitmap generated by getImageData() is now cached. When called repeatedly, only newly added drawing commands will need to be rasterized (and will be layered atop the bitmap saved in the prior call).
  • Window contents are now cached between screen refreshes, improving performance during resizing and in cases where the canvas is drawn to in multiple passes and not cleared with every frame
  • Calling clearRect() or fillRect() with an area that covers the canvas now erases all the vector shapes below
• The saveAs(), toBuffer(), and toDataURL() methods now accept an optional downsample flag (for jpegs only), which enables 4:2:0 chroma-subsampling. By default, no subsampling (a.k.a. 4:4:4) will be performed
• The getImageData() method now accepts additional rendering arguments (density, matte, and msaa) which behave the same as their equivalents in the saveAs() method.

Typography

• Text lightness can now be fine-tuned through a pair of optional arguments that can be passed to the Canvas or Window constructors:
  • textContrast — a number in the range 0.0–1.0 controlling the amount of additional weight to add (defaults to 0.0)
  • textGamma — a number in the range 0.0–4.0 controlling how glyph edges are blended with the background (defaults to 1.4)
• The textAlign attribute can now be set to "justify"

Misc. Improvements

• Added support for Arm-based processors on Windows
• App.launch() now returns a Promise that resolves when the final window is closed, allowing you to schedule code to run before the process would otherwise exit (see also the new idle event which fires under the same circumstances).
• input event objects now contain an inputType property to distinguish between insertion, deletion, and IME composition
• Mouse events are no longer coalesced down to a single instance per frame (most relevant for mousemove events)
• Mouse events now include a standard buttons attribute
• DPI metadata is now included in webp files (reflecting the density option passed to saveAs() or toBuffer())
• Argument validation now emulates browser behavior much more closely—including converting what were previously TypeErrors in certain cases into silent failures. To reënable these errors, set the SKIA_CANVAS_STRICT environment variable to 1 or true.

Bugfixes

• Setting a window's cursor property to "none" now hides the cursor
• Spurious moved window events are no longer emitted during resizes
• roundRect() now reflects context's current transform state and accepts plain {x, y} objects for corner-radii in addition to Numbers and DOMPoints (thanks to @mpaperno Accept any {x:number, y:number} object when parsing corner radii #223)
• Angles passed to createConicGradient() are no longer incorrectly offset by 90°
• Calling lineTo on an empty Path2D no longer adds a line from the origin to the specified coordinates: it now acts as if it were a moveTo
• When exporting to an SVG, text is now converted to paths only if the outline option is set to true