Dan Field 21bb71b627 [Impeller] Improve resolution of text scaling. (flutter/engine#43533) ...

This patch does a few things:

- Changes ownership of the LazyGlyphAtlas to ContentContext from Canvas. This means that drawings with multiple canvases (e.g. calls to DrawPicture) share the same lazy atlas.
- Moves the scale property from Font::Metrics to FontGlyphPair. Font::Metrics contains properties related to the font, whereas scale has to do with the properties of the drawing at render time and is independent of the font.
- Makes the lazy atlas manage FontGlyphPair::Set rather than vectors of TextFrames.
- Makes the determination of font scaling at EntityPass::Render rather than Canvas::DrawTextFrame. The scaling may be altered by calls to Canvas::DrawPicture by render time and otherwise get missed. This is done via a new method: Contents::PopulateGlyphAtlas, which is only implemented by TextContents in this patch.
- Fixes up some miscelleaneous bugs in Font::Metrics hashing and unused/dead code.

This improves over prior attempts: LazyGlyphAtlas ownership is now unambiguous, and glyph scaling happens correctly for all rendered glyphs regardless of the order of canvas operations in Aiks.

Fixes flutter/flutter#130142

2023-07-11 04:57:07 +00:00

..

src/flutter

[Impeller] Improve resolution of text scaling. (flutter/engine#43533)

2023-07-11 04:57:07 +00:00