ebiten/examples/common/font.go
2016-02-21 01:35:45 +09:00

124 lines
3.0 KiB
Go

// Copyright 2015 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 common
import (
"image/color"
"math"
"path/filepath"
"runtime"
"strings"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
)
var (
ArcadeFont *Font
)
type Font struct {
image *ebiten.Image
offset int
charNumPerLine int
charWidth int
charHeight int
}
func (f *Font) TextWidth(str string) int {
// TODO: Take care about '\n'
return f.charWidth * len(str)
}
func init() {
dir := ""
if runtime.GOARCH != "js" {
// Get the path of this file (font.go).
_, path, _, _ := runtime.Caller(0)
path = filepath.Dir(path)
dir = filepath.Join(path, "..")
}
arcadeFontPath := filepath.Join(dir, "_resources", "images", "arcadefont.png")
arcadeFontImage, _, err := ebitenutil.NewImageFromFile(arcadeFontPath, ebiten.FilterNearest)
if err != nil {
panic(err)
}
ArcadeFont = &Font{arcadeFontImage, 32, 16, 8, 8}
}
type fontImageParts struct {
str string
font *Font
}
func (f *fontImageParts) Len() int {
return len(f.str)
}
func (f *fontImageParts) Dst(i int) (x0, y0, x1, y1 int) {
x := i - strings.LastIndex(f.str[:i], "\n") - 1
y := strings.Count(f.str[:i], "\n")
x *= f.font.charWidth
y *= f.font.charHeight
if x < 0 {
return 0, 0, 0, 0
}
return x, y, x + f.font.charWidth, y + f.font.charHeight
}
func (f *fontImageParts) Src(i int) (x0, y0, x1, y1 int) {
code := int(f.str[i])
if code == '\n' {
return 0, 0, 0, 0
}
x := (code % f.font.charNumPerLine) * f.font.charWidth
y := ((code - f.font.offset) / f.font.charNumPerLine) * f.font.charHeight
return x, y, x + f.font.charWidth, y + f.font.charHeight
}
func (f *Font) DrawText(rt *ebiten.Image, str string, ox, oy, scale int, c color.Color) error {
options := &ebiten.DrawImageOptions{
ImageParts: &fontImageParts{str, f},
}
options.GeoM.Scale(float64(scale), float64(scale))
options.GeoM.Translate(float64(ox), float64(oy))
ur, ug, ub, ua := c.RGBA()
const max = math.MaxUint16
r := float64(ur) / max
g := float64(ug) / max
b := float64(ub) / max
a := float64(ua) / max
if 0 < a {
r /= a
g /= a
b /= a
}
options.ColorM.Scale(r, g, b, a)
return rt.DrawImage(f.image, options)
}
func (f *Font) DrawTextWithShadow(rt *ebiten.Image, str string, x, y, scale int, clr color.Color) error {
if err := f.DrawText(rt, str, x+1, y+1, scale, color.NRGBA{0, 0, 0, 0x80}); err != nil {
return err
}
if err := f.DrawText(rt, str, x, y, scale, clr); err != nil {
return err
}
return nil
}