DanS
11de117331
Merge a monochrome Noto Emoji subset into the text fonts so chat messages, the composer, contact names, and memos render emoji (😀 🎉 ❤ 🔥 👍 …) instead of tofu. - Enable IMGUI_USE_WCHAR32 (imconfig.h): emoji live above the BMP (U+1F300+), so 16-bit ImWchar literally can't address them. This widens ImWchar build-wide; the only ImWchar uses in-tree are glyph-range arrays and one BMP private-use codepoint, so nothing else is affected. Tests + full build pass. - Bundle res/fonts/NotoEmoji-Subset.ttf — the OFL monochrome Noto Emoji (color CBDT/COLR fonts can't be rasterized by ImGui's stb_truetype) pinned to wght=400 and subset to the emoji planes (1411 glyphs, 747 KB). Reproducible via scripts/build_emoji_subset.py. Embedded via INCBIN like the CJK subset. - Typography::loadFont merges it (MergeMode) only into the small text fonts (Body/Subtitle/Caption/Button) — not headers, which don't need 1400 emoji. The base font keeps precedence for U+2600–26FF, so text-style symbols stay. Limits: ImGui does no shaping, so single-codepoint emoji render but ZWJ sequences (family/profession) and regional-indicator flags won't compose; emoji are monochrome (the OS emoji picker still inputs them fine, and the composer byte counter already counts their 4-byte UTF-8 cost against the on-chain cap). Verified headless: sizeof(ImWchar)==4 and every probed emoji is in-font and bakes into the atlas. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
88 lines
3.5 KiB
Python
88 lines
3.5 KiB
Python
#!/usr/bin/env python3
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"""
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Build a monochrome Noto Emoji subset for the chat/message UI.
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Dear ImGui rasterizes fonts with stb_truetype, which handles only monochrome
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(outline `glyf`) fonts — NOT color emoji (CBDT/sbix/COLR). So we use Google's
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*monochrome* Noto Emoji (github.com/google/fonts, ofl/notoemoji, OFL-licensed)
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and merge it into the text fonts (see Typography::loadFont, the block after the
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CJK merge). ImGui renders one glyph per codepoint with no shaping, so ZWJ
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sequences / regional-indicator flags won't compose — single-codepoint emoji
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(😀 🎉 ❤ 🔥 👍 …) render fine, which covers the overwhelming majority of use.
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Source is the variable font pinned to wght=400 → static, then subset to the
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emoji planes plus the higher symbol/star ranges the base UI font doesn't cover.
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The base Ubuntu font already owns U+2600–26FF etc.; ImGui's MergeMode gives the
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first-loaded glyph precedence, so those stay text-styled and only the codepoints
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the base lacks fall through to this font.
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Get the source once (OFL, redistributable):
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curl -fsSL -o /tmp/NotoEmoji-VF.ttf \
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'https://github.com/google/fonts/raw/main/ofl/notoemoji/NotoEmoji%5Bwght%5D.ttf'
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Then: python3 scripts/build_emoji_subset.py
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Output: res/fonts/NotoEmoji-Subset.ttf (committed; embedded via INCBIN)
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"""
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import os
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from fontTools import ttLib, subset
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from fontTools.varLib.instancer import instantiateVariableFont
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ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
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SOURCE_VF = '/tmp/NotoEmoji-VF.ttf'
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STATIC = '/tmp/NotoEmoji-Static.ttf'
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OUTPUT = os.path.join(ROOT, 'res', 'fonts', 'NotoEmoji-Subset.ttf')
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# Emoji codepoints to keep. Ranges are inclusive.
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RANGES = [
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(0x1F000, 0x1FAFF), # all the main emoji planes (emoticons, pictographs, transport, supplement, extended)
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(0x2600, 0x27BF), # Miscellaneous Symbols + Dingbats
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(0x2B00, 0x2BFF), # stars (⭐ 2B50) and misc arrows
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(0xFE00, 0xFE0F), # variation selectors (VS16 emoji-style)
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(0x2194, 0x21AA), # arrows used as emoji
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(0x231A, 0x231B), # ⌚ ⌛
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(0x23E9, 0x23FA), # media-control emoji
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(0x25AA, 0x25FE), # small squares
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]
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SINGLES = [0x200D, 0x2934, 0x2935, 0x3030, 0x303D, 0x3297, 0x3299,
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0x00A9, 0x00AE, 0x2122, 0x2139, 0x24C2]
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def main():
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if not os.path.exists(SOURCE_VF):
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raise SystemExit(f"missing source font {SOURCE_VF} — see the header for the curl command")
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# 1. Pin the weight axis so stb_truetype rasterizes a clean static instance.
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f = ttLib.TTFont(SOURCE_VF)
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if 'fvar' in f:
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instantiateVariableFont(f, {'wght': 400}, inplace=True)
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f.save(STATIC)
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unicodes = list(SINGLES)
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for lo, hi in RANGES:
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unicodes.extend(range(lo, hi + 1))
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opts = subset.Options()
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opts.layout_features = [] # ImGui does no shaping — drop GSUB/GPOS
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opts.name_IDs = []
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opts.notdef_outline = True
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opts.glyph_names = False
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opts.drop_tables = ['GSUB', 'GPOS', 'GDEF', 'morx', 'kern']
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font = subset.load_font(STATIC, opts)
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ss = subset.Subsetter(options=opts)
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ss.populate(unicodes=unicodes)
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ss.subset(font)
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subset.save_font(font, OUTPUT, opts)
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out = ttLib.TTFont(OUTPUT)
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cmap = out.getBestCmap()
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color = any(t in out.reader.keys() for t in ('CBDT', 'sbix', 'COLR'))
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print(f"Output: {OUTPUT}")
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print(f"Size: {os.path.getsize(OUTPUT)//1024} KB | glyphs: {len(cmap)} | color tables: {color}")
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if color:
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raise SystemExit("ERROR: subset has color tables — stb_truetype cannot render it")
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if __name__ == '__main__':
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main()
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