Scrawl-canvas VS paper.js

> working with glyphs and iterating them in reverse for RTL is brain-breaking. And line wrapping gets really complicated. It's also the most obscure because nobody has written down everything you need to know in one place

I can confirm this. I've been working on a (much simpler!) text layout engine for my canvas library over the past couple of months and the amount of complexity associated with just stamping some glyphs onto a canvas has left me screaming at my laptop on an almost daily basis. Getting a decent underline was a proud moment!

Question: did you ever find out what algorithm the various browsers are using to calculate how many words can fit on a given line? I'm almost there, except words will occasionally jump between lines when I scale the text. Really annoying!

The PR's still a work in progress, but I've got all the functionality I want in there (shaping lines to fit in non-rectangular containers, styling text, text along a non-straight line, dynamic updates, etc). Just need to test and document it all now ... https://github.com/KaliedaRik/Scrawl-canvas/pull/75

I've got myself organised and prepared a List Of Things To Do[1] to make my 2D Javascript library even better than it already is. Given that I've been working on the library for over 10 years now, and have never before set out such a list, I call this Progress!

[1] https://github.com/KaliedaRik/Scrawl-canvas/discussions/cate...

'Kay, I don't know if this anywhere close to what the OP wants, but this sort of live browser tab manipulation is possible to do using a mix of a a canvas element and the browser's Screen Capture API[1] (plus my JS canvas library, once I merge and publish the changes into its next release[2]).

This solution[3] shows the modified browser tab in a separate browser tab. I've got no idea whether it's possible to do the same sort of trick in the same tab (but probably not). I also have no idea how secure the Screen Capture API is - I'd get very nervous about doing this sort of thing when looking at my bank's online portal!

[1] https://developer.mozilla.org/en-US/docs/Web/API/Screen_Capt...

[2] https://github.com/KaliedaRik/Scrawl-canvas/pull/57

[3] Youtube video of the effect: https://www.youtube.com/watch?v=hCi6LmKMAo0

My canvas library's README[1] has a video embedded in it. FWIW I'm not convinced it adds anything to the library's sales pitch.

[1] https://github.com/KaliedaRik/Scrawl-canvas

> And I’m just mentioning some of the unfixable problems with this approach

I agree that using a canvas instead of leveraging existing accessibility supplied by HTML/CSS/JS and the DOM is an accessibility nightmare.

However, I disagree that canvas accessibility issues are "unfixable". Difficult? Yes. But not unfixable. In my view, the element works best in partnership with its wider environment (HTML/CSS/JS and the DOM), not as a replacement for it. With that in mind, we can start to tackle the accessibility issues you raise - fonts, links, interactions, etc.[1][2]

I have an ambition to one day become intelligent enough to understand/code in Rust, and I'm really glad to see that people are thinking about accessibility as a fundamental part of UIs being developed in Rust.

[1] - Which is what my JS 2d canvas library tries to do: https://scrawl-v8.rikweb.org.uk/

[2] - My thoughts on accessibility, and how I try to fix them using my library: https://scrawl-v8.rikweb.org.uk/learn/eleventh-lesson/

If, however, your company is set on this course, I very strongly suggest you use a canvas library - if only for the MVP. Here's my canvas library (spam alert!) ... even if you don't use it in your product, the library might help give you some ideas on how to overcome some of the responsive, interactive and accessibility issues you'll be facing.

Scrawl-canvas - example and another example (links to code at bottom of each page)

My personal experience as a library developer, who has written my library in JS, not TS ...

TS is an excellent choice for a lib dev starting a new project today. I can see the advantages of using TS for the library code - in particular for a library that gets popular and welcomes contributions from other developers. However TS is a nightmare for someone like me who: 1. started writing the library 9 years ago; 2. has let the library get "quite" big; and 3. has only learned to use TS in the past year (for the day job) and is nowhere near to becoming a types expert.

I've had experience of people suggesting I rewrite the library in TS. Sometimes those suggestions have been quite 'evangelical' in their tone. As an (essentially) solo developer I just don't have the time, capacity or willingness to do that work - however much the end results might please others.

I also understand that having type definitions file for the library's interface is, nowadays, a critical factor if the lib dev wants others to use the library in their projects. But writing a .d.ts file for a large, mature repo to at least help those potential users can quickly turn into a World of Hurt. I know this because I've done that work[1] and I never want to do it again.

As much as I know that TS is a Force for Good in the JS coding world, there are days when I detest it!

[1] - link to the Scrawl-canvas .d.ts file on GitHub - https://github.com/KaliedaRik/Scrawl-canvas/blob/master/sour...

I started with angular and paper.js: http://paperjs.org/

In a thread in the Processing forum, Boolean operations in polygons , user ErraticGenerator suggests using g.js or Paper.js.

It is likely that paper.js provides the functionality needed. I will probably investigate it at some point since it appears to be the more popular library Compare paper.js & bezier.js.

To solve that issue, I searched for some solutions using canvas. I didn’t want to work with pure canvas so after doing some research, I settled with paper.js.

Ooh, the Chebyshev basis is neat. I hadn't seen exactly that before. It reminds me a lot of the "shape control" technique[1] which is also similar to a basis function approach but has a bit of linear solving. Essentially, you get one point (usually at t = 0.5), and also the direction but not magnitudes of the tangents at the endpoints (G1, not C1). This is one of the better-performing existing techniques for offset curve, though does have stability problems (in particular, nasty behavior for a symmetric "S" curve).

Regarding collaboration with Freya, if she is open to it, please get in touch. I do have some ideas.

[1]: A New Shape Control and Classification for Cubic Bézier Curves, Yang and Huang, 1993, PDF cache: https://github.com/paperjs/paper.js/files/752955/A.New.Shape...

Paper.js - example (not interactive, just code)

Just remember you can do some SVG displacement with Paper.JS

> <p>Oh yeah, you reminded me of the template fatigue that was paper.js and it trying to reinvent scripting on the client side with <script type="text/paperscript"> templates that could use templates that could use templates... and so on. [0] I was wondering why people would go to such great lengths just to avoid having to script in the browser.<p>The way I saw it at the time was that I've rediscovered the same mistakes that PHP did back in the days. All the recurs(iv)ed templating problems, all the OOP fatigue that never worked out (magento and zend, anyone?), and all the inheritance based "reinventions" of existing web technologies like OOCSS [1].<p>I mean, at some point every engineer should be wise enough to give up on trying to predict the future. Especially in projects they cannot predict what features are going to be implemented, so I'd naturally assume that modularity and compositional or entity/component aspects will win in later revisions or refactor decisions. But I was wrong with that assumption, I guess :S<p>I also can kinda understand the general bias towards closure among functional folks. I guess that lots of people at the time (or nowadays) had high hopes for it allowing to go more "functional" in its approach, allowing compositional patterns to be useful on the web. But, honestly, JS itself is so flexible and can be used in all kinds of architectural patterns that I think closure's purpose is kind of void by its own concept.<p>When comparing closure with, say, typescript (which I also don't agree with, because "string" and "String" and "any" are pointless from any language design perspective): Typescript at least has the benefit of typed API docs and good IDE integrations (due to LSP) that can be used in large teams to reduce the overhead of getting started with working on foreignly-owned code - whereas closure doesn't have any unique selling point in my opinion. I mean, even scala.js has a unique selling point when being judged like that.<p>[0] <a href="https://github.com/paperjs/paper.js" rel="nofollow">https://github.com/paperjs/paper.js</a><p>[1] <a href="http://oocss.org/" rel="nofollow">http://oocss.org/</a>

Our webapp is written with React and Redux using the official react-redux bindings. Another primary library used in this web app is PaperJS. We recently transitioned this to being a Redux app, though it has used React for a while.

I am currently using http://paperjs.org to create an HTML5 canvas drawing app. I want to let users upload images into the canvas. I know I need to make a login and signup but is there an easier way? I have seen the HTML5 drag and drop upload.