applib/text_layout: pre-load glyph bitmaps in RTL rendering path#1547
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applib/text_layout: pre-load glyph bitmaps in RTL rendering path#1547pebble-aibot wants to merge 1 commit into
pebble-aibot wants to merge 1 commit into
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The BiDi (RTL) rendering path in walk_line() calls render_glyph() without first pre-loading glyph bitmaps into the font cache. Unlike the standard LTR path — which calls text_resources_get_glyph() before the visitor callback so that render_glyph() hits a warm cache — the RTL path lets render_glyph() trigger the full flash I/O call chain (text_resources_get_glyph → prv_load_glyph_bitmap → sys_resource_load_range) from deep in the stack. Combined with the 256 bytes of RTL shaping/reversal buffers already on the stack, this makes the RTL rendering path significantly more stack-hungry than the LTR path and contributes to KernelMain stack overflows during notification text rendering (FIRM-2575 crash family). Add text_resources_get_glyph() pre-load calls before every render_glyph() in the BiDi rendering block — for RTL segments, LTR segments within mixed text, and the trailing suffix glyph — matching the pattern the standard path already uses. Fixes FIRM-2643 Fixes FIRM-2575 Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com> Signed-off-by: Pebble AI Bot <pebbleaibot@repebble.com>
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@pebble-aibot please, open a PR from a branch in your fork |
Collaborator
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I think it only works in linear not in github |
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Summary
walk_line()was missing glyph bitmap pre-loading beforerender_glyph()calls, unlike the standard LTR path which pre-loads viatext_resources_get_glyph()to ensure cache hitstext_resources_get_glyph → prv_load_glyph_bitmap → sys_resource_load_range) from deep in the stack, on top of 256 bytes of RTL shaping/reversal buffers already allocated on the stacktext_resources_get_glyph()pre-load calls before everyrender_glyph()in the BiDi rendering block — for RTL segments, LTR segments within mixed text, and the trailing suffix glyphFixes FIRM-2643
Fixes FIRM-2575
Test plan
🤖 Generated with Claude Code