I have implemented the text tool for Graphite, a work in progress vector editor written in the Rust programming language with Web Assembly. Text is stored as a new type of layer that contains a string. When the user is editing the text, the string is rendered as an editable HTML div element for proper OS input handling. This was challenging as the behaviour for these editable DIVs changes in different browsers, with Chromium based browsers inserting extra new lines and not showing an insertion mark when the text input was empty, however Keavon helped me to debug these issues.

​When the text is not editable, it is rendered as a spline so that it can be edited. In order to do this, I used ttf-parser, the standard in Rust for parsing font files, which provides a query for glyphs as well as enabling you to get at their raw curve data,  as bezier curves so no work was needed to convert them to Graphite's svg based paths. I also used used RustyBuzz, a Rust port of HarfBuzz, in order to shape the text. Shaping involves finding the correct glyphs, including any ligatures specified by the font, common examples including 'ff' and 'fi', as well as computing the positions and advances of each glyph, taking into account kerning, which subtly moves glyphs, for example putting a V and A closer together - 'VA'. 

I have recently made several improvements to Graphite, a vector (drawing with shapes instead of pixels) editor written in rust and available at editor.graphite.design/

• Reverse layer panel entries #489 - Keavon requested that the layer panel show the layer on top (rendered last) at the top of the layer panel. This required reversing the order of the layers when submitting them to the layer panel and resolving the issues with the moving of layers due to the indexes being reversed
• Add cursors and hints to global viewport navigation #487 - extends on the work by Asyncth to add the custom cursors to the global navigation (using Ctrl + MMb for rotate / shift + MMB for zoom and MMB for pan in any tool other than navigate). This also cleared the hints list (at the bottom showing possible inputs for the tool) when using the global navigation as the tool cannot be interacted with whilst navigating. Required refactoring to correctly restore the tool cursor and hints after navigation ended.
• Do not transform layers when transforming a parent folder #481 - Fixes a bug where transformations where not applied when the parent folder and the layer were selected at the same time (gif in MR)
• Fix rotation input #472 - mfish had accidentally caused the display for the document rotation to be clamped between 0 and 1 due to TypeScript silently using default values when undefined is passed to a function.
• Migrate to using MoveSelectedLayersTo #469 - Large refactor to change the way layer movements where specified (previously by giving a new neighbour to the place to insert the layers) to allow inserting layers into empty folders via dragging in the layer tree. I also had to fix the insert index code as the old method was corrupted when moving layers down the tree. I also fixed a bug with some of the layers being moved being deselected as well as the dragging in the tree only applying to one layer.
• Refine navigate tool zoom #461 - As requested by Keavon, zoom with navigate tool is relative to the mouse position and snaps to increments whilst holding ctrl.
• Resize panels #443 - allows the boundaries between panels to be dragged. This taught me a lot about flex boxes and event bubbling (the resize event was not triggered causing black areas and a corrupted ruler).
• Fix one item folders #442 - Fix a typo that caused the layer inside folders with one child not to be displayed.
• Add navigate tool #441 - Expand on my previous work adding global navigation to add a specific navigate tool with similar functionality but more accessable key binds
• Add cut, copy, and paste to the Edit menu #440 - bind the buttons in the dropdown to the relevant messages.
• Remove transformations from LayerData #439 - Move the position, rotation and scale attributes from the layerdata and to the movement handler.
• Populate layer entry cache #437 - Fix a bug where the layer tree would not be loaded when loading a previously saved document.
• Update intoiter syntax #436 - Rust 2021 is stable!
• Remove snap rotate from layerdata #435 - Move the snap rotate for the document navigation away from the layerdata.
• Drag to rearrange layers in the layer panel #434 - Major MR allowing the layers to be dragged in the tree
• Snap while dragging with select tool #433 - Builds on previous work on snapping to snap whilst dragging with the select tool
• Fix console error caused by the Pen Tool #432 - Fix error with overlays when switching documents
• Fix line centering #431 - Centring with alt whilst using the line tool caused incorrect behaviour that required careful planning to resolve to make it also work with snapping.
• Fix Ctrl+scroll wheel zoom point relative to the mouse position #429 - I had accidentally multiplied by 2 when adjusting the translation so that the cursor remained over the same document position when zooming.
• Fix new document position #421