Files
tactility/Modules/lvgl-module
Adolfo Reyna 75178652e2 feat(lvgl+mdns): complete canvas API + fix GB blank render + mDNS browse API
lvgl-module/symbols.c:
- canvas: full LVGL9 docs API (get_buf, get_image, get_px, get_draw_buf,
  set_palette, copy_buf, init_layer, finish_layer, buf_size) – was only 5 symbols
- draw_buf: create/destroy/init/dup/copy/goto/clear/width_to_stride/align/palette/from_image/to_image
- cache: lv_draw_buf_invalidate_cache, flush_cache, lv_image_cache_drop – critical bugfix for
  GameBoy (and any direct framebuffer) where raw buf mutated but image cache stale -> FPS but no image.
- draw layer helpers, image scale/rotation/pivot/offset, transform scales for GB 2x/3x integer scaling

Reason blank screen: lv_canvas in LVGL9 is lv_image backed by draw_buf. Mutating raw pointer
without lv_image_cache_drop + invalidate_cache leaves stale texture. Timer was calling
lv_obj_invalidate only. Now exports needed symbols and app fixed to drop cache each frame.

mDNS (preserve from local WIP, sits on top of 60764979 'kidsOS-XXXX' mdns init):
- Tactility/network/Mdns.h/cpp: C++ browse + resolveHostname wrappers around esp-idf mdns 1.3.2
  (PTR query, txt records, address extraction, POSIX stub)
- TactilityC/tt_mdns.h/cpp: C copy-based API for ELF apps (TT_MDNS_MAX_RESULTS 32,
  capped addresses/txt, hostname->IP resolve)
- TactilityC/tt_init.cpp: export tt_mdns_is_available / browse / resolve_hostname symbols

Test plan:
- firmware build for es3c28p --dev
- release-sdk-current.py
- GameBoy app build against new SDK (0 missing symbols expected)
- push both branches to personal gitea
2026-07-20 12:32:00 -04:00
..
2026-06-03 23:10:37 +02:00
2026-06-03 23:10:37 +02:00

lvgl-module

This module manages the lifecycle of the LVGL library within the Tactility ecosystem.

What the library does

The lvgl-module provides:

  • Lifecycle Management: Handles initialization and termination of the LVGL library.
  • Task Management: Manages the LVGL main loop task.
  • Thread-Safety: Provides mutex-based locking mechanisms (lvgl_lock, lvgl_unlock) to ensure safe access to LVGL APIs from multiple tasks.
  • Font Access: Provides a unified interface to access pre-configured text and icon fonts.

Different types of fonts

The module supports two main categories of fonts:

Text Fonts

Standard text rendering uses the Montserrat font. Three sizes are pre-configured:

  • FONT_SIZE_SMALL
  • FONT_SIZE_DEFAULT
  • FONT_SIZE_LARGE

Icon Fonts

Icons are provided by the Material Symbols font, divided into three usage-specific sets:

  • Statusbar Icons: Optimized for the system status bar.
  • Launcher Icons: Sized for application launchers.
  • Shared Icons: General purpose icons used across the system.

How to update the fonts

Font sizes and symbols are configurable:

  • On ESP32 (IDF): Sizes can be updated via menuconfig or by editing sdkconfig. Look for CONFIG_TT_LVGL_FONT_SIZE_* and CONFIG_TT_LVGL_*_ICON_SIZE parameters.
  • On Simulator/POSIX: Default sizes are defined in Modules/lvgl-module/CMakeLists.txt.

If you change an icon font size, ensure that a corresponding C file exists in source-fonts/ (e.g., material_symbols_shared_24.c). These files are generated from TTF/OTF fonts using the LVGL font converter.

License

This module is licensed under the Apache v2.0 license.