[206_18] 字体大小支持0.5的倍数

[Yuki-Nagori]

No description provided.

[Copilot]

Pull request overview

Adds 0.5‑step font size support end‑to‑end through the font stack (core font_rep, TeX/Qt/Freetype/virtual/smart fonts, typesetting environment and UI), with extensive automated and manual test coverage plus some performance/caching tweaks.

Changes:

• Refactor font sizing from int to double across core font types and backends, introducing helper utilities (is_half_multiple, normalize_half_multiple_size, effective_size, set_font_size, to_tex_font_size) to support only 0.5‑step sizes while keeping integer behavior backward compatible.
• Update environment, math script size computation, box layout logic, and virtual/rubber fonts to use floating font sizes and to cache script sizes at half‑step granularity, including TeX font loading and Freetype/TrueType integration.
• Add a new C++ test suite (font_size_test.cpp), a TeXmacs visual test document (206_18.tmu), updated font size presets in the UI, and detailed developer documentation (devel/206_18.md) describing the design and validation.

Reviewed changes

Copilot reviewed 38 out of 38 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/Graphics/Fonts/smart_font_test.cpp	Fixes Chinese punctuation resolution test to iterate correctly over punctuations and uses a platform‑specific CJK font name instead of hard‑coding Noto.
tests/Graphics/Fonts/font_size_test.cpp	New comprehensive unit tests for half‑step sizing helpers, script, TeX size conversion, smart/virtual fonts, cache keys, and performance micro‑benchmarks.
src/Typeset/env.hpp	Changes math size_cache to array<array<double>>, promotes fn_size from int to double, and updates get_script_size’s signature to return double.
src/Typeset/Env/env_semantics.cpp	Reimplements determine_sizes and edit_env_rep::get_script_size to work in double precision with half‑step caching, adds benchmarking hooks, and adjusts update_font to use floating fn_size.
src/Typeset/Env/env_length.cpp	Updates font length computations (exec_fs_length, exec_fbs_length, exec_fn_length, exec_fns_length, exec_bls_length) to use get_double (FONT_BASE_SIZE) consistently with the new floating font size model.
src/Typeset/Concat/concater.cpp	Uses double script sizes from the updated get_script_size when constructing marker/ghost/flag fonts so that math and diagnostic glyphs respect half‑step sizes.
src/Typeset/Concat/concat_animate.cpp	Switches the sound icon font size to use the new script (double, int) function, enabling fractional script sizes.
src/Typeset/Boxes/Modifier/modifier_boxes.cpp	Adjusts superscript baseline computation in macro_box_rep::sup_lo_base to use effective_size() and rounds back to SI, preserving layout while using floating font sizes.
src/Typeset/Boxes/Composite/script_boxes.cpp	Updates several script/limit positioning computations to use fn->effective_size() with explicit rounding back to SI, ensuring math layouts behave correctly under half‑step sizing.
src/Plugins/Qt/qt_gui.cpp	Changes load_system_font to accept a double size, aligning the Qt font loading interface with the new floating font API.
src/Plugins/Qt/qt_font.hpp	Makes qt_font_rep::size a double and updates the constructor signature accordingly.
src/Plugins/Qt/qt_font.cpp	Normalizes Qt font sizes to half‑steps, recomputes QFont/QFontMetricsF when adjusted, and changes design_size to a float‑aware calculation; note: currently does not call set_font_size (this, size), so font_rep::effective_size() remains unset for Qt fonts.
src/Plugins/Metafont/tex_rubber_font.cpp	Converts rubber TeX font size parameters to double, validates/rounds to half‑steps, delegates size setting via set_font_size, and ensures magnification uses effective_size().
src/Plugins/Metafont/tex_font.cpp	Generalizes tex_font_rep and its factory functions to double sizes, normalizes to half‑steps, uses effective_size() in line‑width heuristics, and passes double sizes through magnification and TeX font families.
src/Plugins/Metafont/load_tex.hpp	Changes load_tex’s size parameter to double and exposes the new to_tex_font_size (double) utility.
src/Plugins/Metafont/load_tex.cpp	Introduces to_tex_font_size for mapping point sizes/half‑steps to TeX metric sizes, switches TFM/PK loading and fallback logic to doubles, and adds in‑memory caches (tfm_cache, pk_cache) plus benchmarking for font loading.
src/Plugins/Freetype/unicode_font.hpp	Updates unicode_font_rep and the unicode_font factory declarations to use double sizes.
src/Plugins/Freetype/unicode_font.cpp	Normalizes unicode font sizes to half‑steps, uses set_font_size in the constructor, recalculates design_size as a float, and ensures magnification passes effective_size(); factory functions now emit float‑aware resource names.
src/Plugins/Freetype/tt_font.cpp	Migrates TrueType font sizes to double, sets type = FONT_TYPE_TT, normalizes to half‑steps in both metrics and glyphs, uses effective_size() for magnification, and generates float‑aware font keys.
src/Plugins/Freetype/tt_file.hpp	Changes tt_font_glyphs’s size parameter from int to double to align with the rest of the Freetype layer.
src/Plugins/Freetype/tt_file.cpp	Replaces the tt_fonts hashset with a hashmap<string,bool> to cache both existing and non‑existing TT fonts, improving tt_font_exists performance.
src/Plugins/Freetype/tt_face.hpp	Converts tt_font_metric_rep and tt_font_glyphs_rep to store double size and updates their constructors and tt_font_metric declaration accordingly.
src/Plugins/Freetype/tt_face.cpp	Adapts TT metric/glyph loading to double‑precision sizes, fixes FreeType FT_F26Dot6 conversions, and scales bitmap fonts based on computed target pixel sizes.
src/Plugins/Freetype/rubber_unicode_font.cpp	Uses base->effective_size() instead of the old integer field when creating virtual fonts inside rubber unicode fonts.
src/Plugins/Freetype/rubber_stix_font.cpp	Propagates base->effective_size() into various derived STIX unicode fonts to respect half‑step sizing.
src/Plugins/Freetype/rubber_assemble_font.cpp	Uses base->effective_size() when building emu-alt-large virtual fonts for rubber assembly.
src/Graphics/Fonts/virtual_font.cpp	Updates virtual_font_rep and virtual_font to double sizes, enforces half‑step normalization, and encodes sizes as integers or single‑decimal strings in the virtual font cache key.
src/Graphics/Fonts/virtual_enhance.cpp	Uses base->effective_size() when constructing enhancement virtual fonts, ensuring enhanced glyphs match the actual font size.
src/Graphics/Fonts/smart_font.hpp	Changes smart_font_rep::sz to double and updates smart_font_bis’s signature to take a floating size.
src/Graphics/Fonts/smart_font.cpp	Normalizes smart font sizes to half‑steps, generates float‑aware res_name/cache keys, and updates smart_font, math_smart_font, prog_smart_font, and effect calculations to work with effective_size().
src/Graphics/Fonts/poor_rubber.cpp	Switches virtual font construction for poor rubber fonts to use effective_size() rather than the old integer size field.
src/Graphics/Fonts/font_translate.cpp	Changes closest_font’s size parameter to double and formats size components consistently (integer or single decimal) in cache keys.
src/Graphics/Fonts/font.hpp	Introduces half‑step helpers, reworks font_rep to use size_int/size_float with effective_size(), adds set_font_size/get_font_size/font_size_as_int, and migrates all font factory APIs and script to double.
src/Graphics/Fonts/font.cpp	Updates font_rep constructors for the new fields and reimplements script as a double‑precision function with benchmarking and half‑step normalization.
src/Graphics/Fonts/find_font.cpp	Propagates double font sizes through font discovery, adjusts TeX family helpers to work with scaled numeric sizes, and ensures resource names encode float sizes consistently.
devel/206_18.md	Detailed developer note (in Chinese) documenting the motivation, architecture, staged implementation, testing strategy, and performance analysis for half‑step font size support.
TeXmacs/tests/tmu/206_18.tmu	Visual regression document exercising integer, half‑step, and non‑half‑step sizes in text and math to manually verify rendering behavior.
TeXmacs/progs/fonts/font-new-widgets.scm	Updates the default font size presets exposed in the UI to include a curated set of half‑step sizes (e.g., 5.5, 6.5, 7.5, 10.5, 11.5, 12.5).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The qt_font_rep constructor normalizes the local size variable but never updates the base font_rep size fields, so font_rep::effective_size() will remain 0.0 for Qt-backed fonts. To keep the new size_float/size_int fields in sync and ensure generic code that relies on effective_size() (e.g., effects or rubber/virtual fonts) sees the correct size, consider calling set_font_size (this, size) after normalizing size and before computing design_size and other metrics.

Suggested change

	}
	}
	set_font_size (this, size);

[Yuki-Nagori]

Added