Add examples/font (#77)

examples/_resources/fonts/license.md

@@ -0,0 +1,22 @@
+# License
+
+## mplus-1p-regular.ttf
+
+```
+M+ FONTS                                Copyright (C) 2002-2015 M+ FONTS PROJECT
+
+-
+
+LICENSE_E
+
+
+
+
+These fonts are free software.
+Unlimited permission is granted to use, copy, and distribute them, with
+or without modification, either commercially or noncommercially.
+THESE FONTS ARE PROVIDED "AS IS" WITHOUT WARRANTY.
+
+
+http://mplus-fonts.sourceforge.jp/mplus-outline-fonts/
+```

examples/font/main.go

@@ -0,0 +1,105 @@
+// Copyright 2016 Hajime Hoshi
+//
+// 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 (
+	"image"
+	"io/ioutil"
+	"log"
+
+	"github.com/golang/freetype/truetype"
+	"github.com/hajimehoshi/ebiten"
+	"github.com/hajimehoshi/ebiten/ebitenutil"
+	"golang.org/x/image/font"
+	"golang.org/x/image/math/fixed"
+)
+
+const (
+	screenWidth  = 640
+	screenHeight = 480
+)
+
+var (
+	textImage *ebiten.Image
+)
+
+// text is a head part of a Japanese novel 山月記 (Sangetsuki)
+// See http://www.aozora.gr.jp/cards/000119/files/624_14544.html.
+var text = []string{
+	"隴西の李徴は博学才穎、天宝の末年、",
+	"若くして名を虎榜に連ね、",
+	"ついで江南尉に補せられたが、",
+	"性、狷介、自ら恃むところ頗厚く、",
+	"賤吏に甘んずるを潔しとしなかった。",
+}
+
+func parseFont() error {
+	f, err := ebitenutil.OpenFile("_resources/fonts/mplus-1p-regular.ttf")
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	b, err := ioutil.ReadAll(f)
+	if err != nil {
+		return err
+	}
+	tt, err := truetype.Parse(b)
+	if err != nil {
+		return err
+	}
+	w, h := textImage.Size()
+	dst := image.NewRGBA(image.Rect(0, 0, w, h))
+	const size = 24
+	const dpi = 72
+	d := &font.Drawer{
+		Dst: dst,
+		Src: image.White,
+		Face: truetype.NewFace(tt, &truetype.Options{
+			Size:    size,
+			DPI:     dpi,
+			Hinting: font.HintingFull,
+		}),
+	}
+	dy := size * dpi / 72
+	y := dy
+	for _, s := range text {
+		d.Dot = fixed.P(0, y)
+		d.DrawString(s)
+		y += dy
+	}
+	textImage.ReplacePixels(dst.Pix)
+	return nil
+}
+
+func update(screen *ebiten.Image) error {
+	if err := screen.DrawImage(textImage, &ebiten.DrawImageOptions{}); err != nil {
+		return err
+	}
+	return nil
+}
+
+func main() {
+	var err error
+	textImage, err = ebiten.NewImage(screenWidth, screenHeight, ebiten.FilterNearest)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err := parseFont(); err != nil {
+		log.Fatal(err)
+	}
+	if err := ebiten.Run(update, screenWidth, screenHeight, 1, "Font (Ebiten Demo)"); err != nil {
+		log.Fatal(err)
+	}
+}