2nd/10_Wiki/Topics/AI_and_ML/텍스트 렌더링(Text Rendering).md

---
id: wiki-2026-0508-텍스트-렌더링-text-rendering
title: 텍스트 렌더링(Text Rendering)
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [Text Rendering, Typography, Font Rendering]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [rendering, typography, graphics, web]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: TypeScript / GLSL
  framework: HarfBuzz / FreeType
---

# 텍스트 렌더링(Text Rendering)

## 매 한 줄
> **"매 glyph 의 outline → raster — 매 hinting + anti-aliasing + subpixel 의 layered pipeline."**. 매 1980s PostScript 부터 매 2026 의 variable font + COLRv1 emoji + LLM 의 image generation 의 text. 매 web (Skia, FreeType), OS (DirectWrite, Core Text), GPU (signed distance field) 의 cross-stack concern.

## 매 핵심

### 매 pipeline
- **Shaping**: 매 character → glyph index — 매 ligature, kerning, contextual substitution (HarfBuzz).
- **Layout**: 매 line break, justification, bidirectional (Unicode BiDi).
- **Rasterization**: 매 outline → bitmap — 매 hinting (TrueType / PostScript).
- **Anti-aliasing**: 매 grayscale / subpixel (ClearType, LCD striping).
- **Composition**: 매 alpha blend 의 background 위.

### 매 modern challenge
- **Variable font**: 매 single file 의 weight/width/slant axis — `font-variation-settings`.
- **COLRv1**: 매 vector emoji + gradient — 매 modern OS 의 support.
- **High-DPI**: 매 retina display 의 hinting 의 deemphasize.
- **GPU rendering**: 매 SDF (Signed Distance Field) — 매 game / 3D UI 의 sharp text at any scale.
- **AI-generated image text**: 매 FLUX / Imagen 4 / Ideogram 의 legible text — 매 2026 의 breakthrough.

### 매 응용
1. **Web typography**: 매 CSS `font-display`, `font-feature-settings`.
2. **Game UI**: 매 SDF font (Unity TextMeshPro, Three.js).
3. **AI image text**: 매 prompt-to-image 의 readable signage.

## 💻 패턴

### CSS 의 modern typography
```css
@font-face {
  font-family: 'Inter';
  src: url('/fonts/Inter.var.woff2') format('woff2-variations');
  font-weight: 100 900; /* variable axis */
  font-display: swap;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  font-feature-settings: 'ss01', 'cv11', 'kern';
  font-variation-settings: 'wght' 450, 'opsz' 14;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
```

### Canvas text 의 measurement
```ts
const ctx = canvas.getContext('2d')!;
ctx.font = '16px Inter';
const metrics = ctx.measureText('Hello');
console.log({
  width: metrics.width,
  ascent: metrics.actualBoundingBoxAscent,
  descent: metrics.actualBoundingBoxDescent,
});
```

### Three.js 의 SDF text
```ts
import { Text } from 'troika-three-text';

const text = new Text();
text.text = 'Hello 3D';
text.fontSize = 0.5;
text.color = 0x9966FF;
text.font = '/fonts/Inter.woff';
text.anchorX = 'center';
text.sync();
scene.add(text);
```

### HarfBuzz 의 shaping (Python)
```python
import uharfbuzz as hb

with open('Inter.ttf', 'rb') as f:
    face = hb.Face(f.read())
font = hb.Font(face)

buf = hb.Buffer()
buf.add_str('Hello — fi')
buf.guess_segment_properties()
hb.shape(font, buf)

for info, pos in zip(buf.glyph_infos, buf.glyph_positions):
    print(f'glyph={info.codepoint} x_advance={pos.x_advance}')
```

### GPU SDF generation
```glsl
// Fragment shader — SDF text rendering
uniform sampler2D uSdfMap;
varying vec2 vUv;

void main() {
  float dist = texture2D(uSdfMap, vUv).a;
  float alpha = smoothstep(0.5 - fwidth(dist), 0.5 + fwidth(dist), dist);
  gl_FragColor = vec4(1.0, 1.0, 1.0, alpha);
}
```

### React Native 의 custom font
```tsx
import { useFonts } from 'expo-font';

function App() {
  const [loaded] = useFonts({
    'Inter-Regular': require('./assets/Inter-Regular.otf'),
  });
  if (!loaded) return null;
  return <Text style={{ fontFamily: 'Inter-Regular' }}>Hello</Text>;
}
```

### AI image text (FLUX prompt)
```python
# 매 FLUX.1 Pro — 매 readable text 의 prompt pattern
prompt = """
A coffee shop sign with the text "MORNING BREW" in bold serif font,
white letters on black wood, photorealistic, sharp focus on text.
"""
# 매 quote 의 사용 + 매 font style 의 명시 + 매 short phrase (< 10 words)
```

### Skia 의 paragraph layout
```cpp
// Skia ParagraphBuilder
ParagraphStyle style;
style.setMaxLines(3);
auto builder = ParagraphBuilder::make(style, fontCollection);
TextStyle ts;
ts.setFontSize(16);
builder->pushStyle(ts);
builder->addText("Hello world");
auto paragraph = builder->Build();
paragraph->layout(400);
paragraph->paint(canvas, 0, 0);
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| 매 web body text | CSS variable font + font-display: swap |
| 매 web headline | preload + subset (unicode-range) |
| 매 game / 3D | SDF (TextMeshPro, troika-three-text) |
| 매 native iOS | Core Text |
| 매 native Android | Compose Text |
| 매 cross-platform | Skia (Flutter, React Native New Arch) |
| 매 AI image text | FLUX 1.1 Pro / Ideogram 3.0 / Imagen 4 |

**기본값**: 매 web — variable font woff2 + system fallback. 매 game — SDF. 매 AI image — FLUX.

## 🔗 Graph
- 부모: [[Typography]] · [[Rendering Pipeline]]
- 변형: [[Variable Font]] · [[SDF Font]] · [[COLRv1]]
- 응용: [[Web Performance]] · [[Game UI]] · [[AI Image Generation]]
- Adjacent: [[HarfBuzz]] · [[FreeType]] · [[Skia]]

## 🤖 LLM 활용
**언제**: 매 typography spec 의 review, 매 font feature setting 의 explanation, 매 AI image text prompt 의 craft.
**언제 X**: 매 production font rendering 의 implementation — 매 mature library (HarfBuzz, Skia) 의 우선.

## ❌ 안티패턴
- **Font 의 too many**: 매 5+ family 의 load — 매 FOUT + bandwidth 의 cost.
- **No font-display**: 매 default `auto` — 매 invisible text 의 long delay.
- **Pixel font 의 high-DPI**: 매 bitmap font 의 retina 의 blurry.
- **AI image 의 long text**: 매 50+ char 의 prompt — 매 garbled output.
- **No subsetting**: 매 모든 글리프 의 load — 매 KR/JP/CN 의 1MB+ font.

## 🧪 검증 / 중복
- Verified (W3C CSS Fonts Module, HarfBuzz docs, Skia docs, FLUX 1.1 Pro release notes).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — text rendering pipeline + variable font + SDF |