Add Xray focus blurbs

docs/focus/2018-02-26.md

@@ -5,6 +5,8 @@
 - GitHub Package
 - Teletype
 - Xray
+  - We finished off some up-front planning around Xray's support for real time collaboration.
+  - We're now comfortably scrolling a dev-build of React at 60 frames per second. Frames are rendered in about 1.2ms per frame on our hardware, and rendering is looking identical to Chrome's CPU backend for basic ASCII text, modulo ligatures and kerning. We still have a lot of features to add, but we don't any of them will dramatically impact frame computation time.
 
 ## Focus for week ahead
 
@@ -14,3 +16,5 @@
 - Teletype
 - Tree-sitter
 - Xray
+  - @as-cii will be focused on more sophisticated text-shaping to extend our support beyond basic ASCII. We're working on a [glyph-renderer](https://github.com/atom/xray/tree/glyph-renderer) module that handles text layout and glyph rasterization. To support a standalone web-based component, we're starting with a WebAssembly module based on HarfBuzz and FreeType, but we can always explore using platform-specific frameworks for the Electron use case.
+  - @nathansobo will be focused on implementing selections. We're introducing a new "anchor" abstraction that creates a stable reference to a buffer location, along with methods for converting anchors to offsets or points. Each editor will store selections as a sorted array of anchor ranges. To move a selection, we'll convert its anchors to concrete points, adjust their rows/columns, then convert the points back to anchors. We're curious how long it will take us to do this for thousands of selections. Hopefully it's fast. Then we'll focus on inserting text inside the selections.