ebiten/ebitenutil/debugprint.go
2018-02-11 01:56:13 +09:00

94 lines
2.4 KiB
Go

// Copyright 2014 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 ebitenutil
import (
"image"
"image/color"
"math"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil/internal/assets"
)
type debugPrintState struct {
textImage *ebiten.Image
debugPrintRenderTarget *ebiten.Image
}
var defaultDebugPrintState = &debugPrintState{}
// DebugPrint draws the string str on the image.
//
// DebugPrint always returns nil as of 1.5.0-alpha.
func DebugPrint(image *ebiten.Image, str string) error {
defaultDebugPrintState.DebugPrint(image, str)
return nil
}
func (d *debugPrintState) drawText(rt *ebiten.Image, str string, ox, oy int, c color.Color) {
op := &ebiten.DrawImageOptions{}
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
}
op.ColorM.Scale(r, g, b, a)
x := 0
y := 0
w, _ := d.textImage.Size()
for _, c := range str {
const (
cw = assets.CharWidth
ch = assets.CharHeight
)
if c == '\n' {
x = 0
y += ch
continue
}
n := w / cw
sx := (int(c) % n) * cw
sy := (int(c) / n) * ch
r := image.Rect(sx, sy, sx+cw, sy+ch)
op.SourceRect = &r
op.GeoM.Reset()
op.GeoM.Translate(float64(x), float64(y))
op.GeoM.Translate(float64(ox+1), float64(oy))
_ = rt.DrawImage(d.textImage, op)
x += cw
}
}
// DebugPrint prints the given text str on the given image r.
func (d *debugPrintState) DebugPrint(r *ebiten.Image, str string) {
if d.textImage == nil {
img := assets.CreateTextImage()
d.textImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterNearest)
}
if d.debugPrintRenderTarget == nil {
width, height := 256, 256
d.debugPrintRenderTarget, _ = ebiten.NewImage(width, height, ebiten.FilterNearest)
}
d.drawText(r, str, 1, 1, color.NRGBA{0x00, 0x00, 0x00, 0x80})
d.drawText(r, str, 0, 0, color.NRGBA{0xff, 0xff, 0xff, 0xff})
}