ebiten/examples/fontvector/main.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.

package main

import (
	"bytes"
	"image/color"
	"log"
	"math"

	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
	"github.com/hajimehoshi/ebiten/v2/text/v2"
	"github.com/hajimehoshi/ebiten/v2/vector"
)

const (
	screenWidth  = 640
	screenHeight = 480
)

type Game struct {
	path vector.Path
	tick int
}

func (g *Game) Update() error {
	if g.tick == 0 {
		s, err := text.NewGoTextFaceSource(bytes.NewReader(fonts.MPlus1pRegular_ttf))
		if err != nil {
			return err
		}
		op := &text.LayoutOptions{}
		op.LineSpacing = 110
		text.AppendVectorPath(&g.path, "ABCEDFG\nabcdefg\nあいうえお\nかきくけこ", &text.GoTextFace{
			Source: s,
			Size:   90,
		}, op)
	}

	g.tick++

	return nil
}

func (g *Game) Draw(screen *ebiten.Image) {
	op := &vector.StrokeOptions{}
	op.Width = 2*(float32(math.Sin(float64(g.tick)*2*math.Pi/180))+1) + 1
	op.LineJoin = vector.LineJoinRound
	op.LineCap = vector.LineCapRound
	var geoM ebiten.GeoM
	geoM.Translate(50, 0)
	vector.StrokePath(screen, g.path.ApplyGeoM(geoM), color.White, true, op)
}

func (*Game) Layout(width, height int) (int, int) {
	return screenWidth, screenHeight
}

func main() {
	ebiten.SetWindowTitle("Font Vector (Ebitengine Demo)")
	if err := ebiten.RunGame(&Game{}); err != nil {
		log.Fatal(err)
	}
}