Currently we're manually computing the width/height of the /Rect-entry in a number of spots throughout the worker-thread Annotation code, which these new getters help avoid.
Currently we're initializing the image-options for every page, which seems unnecessary since it should suffice to do that once per document.
Also, changes the `BasePdfManager` constructor to improve readability/documentation a little bit.
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.
This patch fixes a bug that caused incorrect curve shapes when an endpoint lies beyond the page boundaries. It adds a check for the endpoint's position, and if it is outside the page, the point is excluded from the shape's coordinates.
Steps to reproduce this in `master`:
1. Open https://mozilla.github.io/pdf.js/web/viewer.html
2. Use the "Open"-button (in the secondaryToolbar), or drag-and-drop, to load another PDF document.
3. Enable the highlight-editor.
4. Try to pick a new colour.
Note how it's no longer possible to change the default highlight-colour.
The reason for this is that we're only initializing the viewer-toolbar `ColorPicker` *once*, which doesn't work since every PDF document gets its own `AnnotationEditorUIManager`-instance. To address this we simply need to re-initialize the viewer-toolbar `ColorPicker`, and note that this patch won't affect the Firefox PDF Viewer.
With the changes in PR 18843 the `AnnotationEditorUIManager.prototype.updateMode` method is now asynchronous, which we need to take into account when dispatching the "annotationeditormodechanged" event.
After PR 2317, which landed in 2012, we'd immediately clean-up after rendering for pages with large image resources. This had the effect that re-rendering, e.g. after zooming, would force us to re-parse the entire page which could easily lead to bad performance.
In PR 16108, which landed in 2023, we tried to lessen the impact of that by slightly delaying clean-up however that's obviously not a perfect solution (and it increased the complexity of the relevant code).
Furthermore, the condition for this "immediate" clean-up seems a bit arbitrary to me since a page could easily contain a large number of smaller images whose total size vastly exceeds the threshold.
Hence this patch, which suggests that we remove the conditional and delayed clean-up after rendering. Compared to the situation back in 2012, a number of things have improved since:
- We have *multiple* caches for repeated image-resources on the worker-thread[1], which helps reduce overall memory usage and improves performance.
- We downsize huge images on the worker-thread, which means that the images we're using on the main-thread cannot be arbitrarily large.
- The amount of available RAM on devices should be a lot higher, since more than a decade has passed.
A future improvement here, for more resource constrained environments, could be to instead clean-up when actually needed using e.g. `WeakRef`s (see issue 18148).
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[1] More specifically:
- `LocalImageCache`, which caches image-data by /Name and /Ref on the `PartialEvaluator.prototype.getOperatorList` level.
- `RegionalImageCache`, which caches image-data by /Ref on the `PartialEvaluator`-instance (i.e. at the page) level.
- `GlobalImageCache`, which caches image-data by /Ref globally at the document level.
It fixes#19360.
Each glyph in the test case has a fill and a stroke pattern, so the current transform used
to scale the glyph outline must be the same.
In setting the stroke color to green, I noticed that the last outline contains some non-closed
subpaths, so when generating the glyph outline, every time we 'moveTo', we close the previous
subpath.
