Currently we have a number of spots in the code-base where we need to clamp a value to a [min, max] range. This is either implemented using `Math.min`/`Math.max` or with a local helper function, which leads to some unnecessary duplication.
Hence this patch adds and re-uses a single helper function for this, which we'll hopefully be able to remove in the future once https://github.com/tc39/proposal-math-clamp/ becomes generally available.
This patch fixes an issue when pasting: an exception was thrown when pasting.
And while writing the test and comparing the paths in the svg, I found a difference
which is fixed thanks to call to the right constructor (to take into account the inheritance)
in inkdraw.js
This patch is adding some code in order to extract a drawing as curves from an image.
The algorithm is basically the following:
- reduce the dimensions
- make it gray
- apply a bilateral filter in order to add some blurryness while keeping the edges
- compute the histogram
- guess what's the background color which should contain a large majority of the pixels
- make a binary image
- extract the contours in using the Suzuki algorithm
- apply the Douglas-Peucker algorithm in order to reduce the number of points
The algorithm is improvable but it should work pretty well if there's a clear difference between
the background and the drawing.
In a v2 we could use a ML model in order to improve the extraction.
There's few changes related to the UI in order to make the tool usable, but they're very basic
for the moment.
- it's now possible to start a drawing with a pen and use fingers to zoom
or scroll without interacting with the current drawing;
- it's now possible to draw with a finger and them zoom with two fingers.
This patch makes a clear separation between the way to draw and the editing stuff.
It adds a class DrawEditor which should be extended in order to create new drawing tools.
As an example, the ink tool has been rewritten in order to use it.
and tweak a bit the highlight one (e.g. it's useless to have 64 bits floating point numbers
when 32 bits ones are enough).
It's a required step for the refactoring of the ink tool (in order to use the draw layer).
It avoids to call several functions acting on the same SVG element.
One goal is to make the code for drawing with the Ink tool similar to the one to free highlighting:
it doesn't really make sense to have so different ways to do almost the same thing.
When the zoom level is high, it'll avoid to create a too big canvas covering all the page which consume
more memory, makes the drawing very slow and the overall user xp pretty bad.
A second goal is to be able to easily implement more drawing tools where we would just have to implement
how to draw from the pointer coordinates.
