msdf

README

MSDF

Go implementation of Multi-Channel Signed Distance Field generation for font rendering.

What is MSDF?

MSDF encodes vector fonts as textures using RGB channels to preserve sharp corners and fine details.

How it works

1. Parse font outlines into curves
2. Detect sharp corners and assign RGB colors
3. Calculate distances to colored segments for each pixel

Assets

The assets/ folder contains example outputs showcasing MSDF generation capabilities:

Generated Characters

• @, A, U, 8, B, g - Individual character examples
• atlas.png - Combined texture atlas
• atlas.json - Atlas metadata and character mappings

File Types

• *_render.png - Final rendered output showing smooth text rendering
• *_debug.png - Debug visualization showing edge coloring algorithm
• atlas.* - Multi-character texture atlas with JSON metadata

Examples

Atlas Generation

Combined texture atlas containing multiple characters with optimized packing

Rendered Output

@	A	8	B	g

Debug Visualizations (Edge Coloring)

Installation

Build from Source

# Clone the repository
git clone https://github.com/moozd/msdf
cd msdf

# Build the binary
go build -o msdf cmd/msdf/main.go

# Or install globally
go install ./cmd/msdf

Command Line Usage

Generate MSDF atlas for multiple characters:

# Basic atlas generation
./msdf -f /path/to/font.ttf -c "ABCabc123" -o ./assets

# With debug visualization
./msdf -f /path/to/font.ttf -c "Hello" -o ./assets --debug

# Custom settings
./msdf -f /path/to/font.ttf -c "@#$%" -o ./assets --scale 0.5 --seed 42 --size 48 --debug

Command Options

• -f, --font: Path to font file (required)
• -c, --charset: Character set to generate (required)
• -o, --output: Output directory (default: current directory)
• -s, --size: Font size (default: 1.0)
• -d, --debug: Generate debug visualization showing edge coloring
• --scale: Texture scale factor (default: 1.0)
• --seed: Coloring seed for edge assignment (default: 0)
• --distance-field: Distance field range (default: 4.0)

Output Files

The command generates:

• atlas.png - Combined texture atlas containing all characters
• atlas.json - Metadata file with character positions and metrics
• *_debug.png - Individual debug visualizations (when --debug is used)
• *_render.png - Individual rendered outputs (when --debug is used)

Library Usage

package main

import (
    "fmt"
    msdf "github.com/moozd/msdf/pkg"
)

func main() {
    cfg := &msdf.Config{
        Scale: 0.5,
        Debug: true,  // Generate debug visualizations
    }

    generator, _ := msdf.New("/path/to/font.ttf", cfg)

    // Generate MSDF for character
    glyph := generator.Get('R')
    glyph.Save("assets/R.png")
}

Development

Running Tests

# Run all tests
go test ./...

# Run tests with verbose output
go test -v ./...

# Run specific package tests
go test ./pkg

Building

# Build for current platform
go build -o msdf cmd/msdf/main.go

# Build with optimizations for release
go build -ldflags="-s -w" -o msdf cmd/msdf/main.go

# Cross-compile for different platforms
GOOS=windows GOARCH=amd64 go build -o msdf.exe cmd/msdf/main.go
GOOS=darwin GOARCH=amd64 go build -o msdf-mac cmd/msdf/main.go

Dependencies

# Download dependencies
go mod download

# Update dependencies
go mod tidy

# Verify dependencies
go mod verify

Features

• Scale-independent rendering
• Sharp corner preservation
• GPU-friendly texture output
• Atlas generation for multiple characters
• Debug visualization for edge coloring analysis
• Configurable distance field parameters

Credits

This project is based on Viktor Chlumský's original msdfgen repository. The original C++ implementation provided the foundation and inspiration for this Go port of the Multi-Channel Signed Distance Field generation algorithm.