ebiten/ebitenutil/gen.go

// Copyright 2022 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build ignore
// +build ignore

package main

import (
	"fmt"
	"image"
	"image/color"
	"image/png"
	"os"

	"github.com/hajimehoshi/bitmapfont/v2"
	"golang.org/x/image/font"
	"golang.org/x/image/math/fixed"
)

func main() {
	if err := run(); err != nil {
		fmt.Fprintf(os.Stderr, "%v\n", err)
	}
}

func run() error {
	// These values are copied from an example in github.com/hajimehoshi/bitmapfont.
	const (
		charWidth  = 6
		lineHeight = 16

		dotX = 4
		dotY = 12
	)

	var lines []string
	for j := 0; j < 8; j++ {
		var line string
		for i := 0; i < 32; i++ {
			line += string(rune(i + j*32))
		}
		lines = append(lines, line)
	}

	d := font.Drawer{
		Dst:  image.NewRGBA(image.Rect(0, 0, charWidth*32, lineHeight*8)),
		Src:  image.NewUniform(color.White),
		Face: bitmapfont.Face,
		Dot:  fixed.P(dotX, dotY),
	}
	for _, line := range lines {
		d.Dot.X = fixed.I(dotX)
		d.DrawString(line)
		d.Dot.Y += fixed.I(lineHeight)
	}

	f, err := os.Create("text.png")
	if err != nil {
		return err
	}
	defer f.Close()

	if err := png.Encode(f, d.Dst); err != nil {
		return err
	}

	return nil
}