bmfont's Introduction

bmfont

A Go package to load and render bitmap fonts created with AngelCode's bitmap font generator or other tools that generate output in the same format.

This package uses the text format for font descriptor files (.fnt), not the binary format.

Documentation

Package documentation is available on pkg.go.dev.

Example usage

Load a bitmap font and draw text to an image:

package main

import (
	"log"

	"github.com/fzipp/bmfont"
)

func main() {
	font, err := bmfont.Load("ExampleFont.fnt")
	if err != nil {
		log.Fatal(err)
	}
	img := image.NewRGBA(image.Rect(0, 0, 600, 300))
	font.DrawText(img, image.Pt(10, 20), `hello, world
This is an example.
abcdefghijklmnopqrstuvwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ`)
	// ...
}

Measure the text before drawing in order to determine the size of the image:

package main

import (
	"log"

	"github.com/fzipp/bmfont"
)

func main() {
	font, err := bmfont.Load("ExampleFont.fnt")
	if err != nil {
		log.Fatal(err)
	}

    text := `hello, world
This is an example.
abcdefghijklmnopqrstuvwxyz
ABCDEFGHIJKLMNOPQRSTUVWXYZ`

	bounds := font.MeasureText(text)
	img := image.NewRGBA(image.Rect(0, 0, bounds.Dx(), bounds.Dy()))
	font.DrawText(img, image.Point{}.Sub(bounds.Min), text)
	// ...
}

Only load the descriptor of a bitmap font:

package main

import (
	"fmt"
	"log"

	"github.com/fzipp/bmfont"
)

func main() {
	desc, err := bmfont.LoadDescriptor("ExampleFont.fnt")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(desc.Info.Face)
	fmt.Println("line height:", desc.Common.LineHeight)
	fmt.Println("letter A width:", desc.Chars['A'].Width)
}