debugprint.go (2241B)
1 // Copyright 2014 Hajime Hoshi 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package ebitenutil 16 17 import ( 18 "image" 19 20 "github.com/hajimehoshi/ebiten/v2" 21 "github.com/hajimehoshi/ebiten/v2/ebitenutil/internal/assets" 22 ) 23 24 var ( 25 debugPrintTextImage = ebiten.NewImageFromImage(assets.CreateTextImage()) 26 debugPrintTextSubImages = map[rune]*ebiten.Image{} 27 ) 28 29 // DebugPrint draws the string str on the image on left top corner. 30 // 31 // The available runes are in U+0000 to U+00FF, which is C0 Controls and Basic Latin and C1 Controls and Latin-1 Supplement. 32 func DebugPrint(image *ebiten.Image, str string) { 33 DebugPrintAt(image, str, 0, 0) 34 } 35 36 // DebugPrintAt draws the string str on the image at (x, y) position. 37 // 38 // The available runes are in U+0000 to U+00FF, which is C0 Controls and Basic Latin and C1 Controls and Latin-1 Supplement. 39 func DebugPrintAt(image *ebiten.Image, str string, x, y int) { 40 drawDebugText(image, str, x+1, y+1, true) 41 drawDebugText(image, str, x, y, false) 42 } 43 44 func drawDebugText(rt *ebiten.Image, str string, ox, oy int, shadow bool) { 45 op := &ebiten.DrawImageOptions{} 46 if shadow { 47 op.ColorM.Scale(0, 0, 0, 0.5) 48 } 49 x := 0 50 y := 0 51 w, _ := debugPrintTextImage.Size() 52 for _, c := range str { 53 const ( 54 cw = assets.CharWidth 55 ch = assets.CharHeight 56 ) 57 if c == '\n' { 58 x = 0 59 y += ch 60 continue 61 } 62 s, ok := debugPrintTextSubImages[c] 63 if !ok { 64 n := w / cw 65 sx := (int(c) % n) * cw 66 sy := (int(c) / n) * ch 67 s = debugPrintTextImage.SubImage(image.Rect(sx, sy, sx+cw, sy+ch)).(*ebiten.Image) 68 debugPrintTextSubImages[c] = s 69 } 70 op.GeoM.Reset() 71 op.GeoM.Translate(float64(x), float64(y)) 72 op.GeoM.Translate(float64(ox+1), float64(oy)) 73 rt.DrawImage(s, op) 74 x += cw 75 } 76 }