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			130 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			130 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright 2018 The Ebiten Authors
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| //
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| //     http://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| 
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| package main
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| 
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| import (
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| 	"flag"
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| 	"fmt"
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| 	_ "image/jpeg"
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| 	"log"
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| 	"runtime"
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| 
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| 	"github.com/hajimehoshi/ebiten/v2"
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| 	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
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| )
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| 
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| type Game struct {
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| 	highDPIImageCh chan *ebiten.Image
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| 	highDPIImage   *ebiten.Image
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| }
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| 
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| func NewGame() *Game {
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| 	g := &Game{
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| 		highDPIImageCh: make(chan *ebiten.Image),
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| 	}
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| 
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| 	// Licensed under Public Domain
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| 	// https://commons.wikimedia.org/wiki/File:As08-16-2593.jpg
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| 	const url = "https://upload.wikimedia.org/wikipedia/commons/1/1f/As08-16-2593.jpg"
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| 
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| 	// Load the image asynchronously.
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| 	go func() {
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| 		img, err := ebitenutil.NewImageFromURL(url)
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| 		if err != nil {
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| 			log.Fatal(err)
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| 		}
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| 		g.highDPIImageCh <- img
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| 		close(g.highDPIImageCh)
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| 	}()
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| 
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| 	return g
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| }
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| 
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| func (g *Game) Update() error {
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| 	if g.highDPIImage != nil {
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| 		return nil
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| 	}
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| 
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| 	// Use select and 'default' clause for non-blocking receiving.
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| 	select {
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| 	case img := <-g.highDPIImageCh:
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| 		g.highDPIImage = img
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| 	default:
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| 	}
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| 
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| 	return nil
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| }
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| 
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| func (g *Game) Draw(screen *ebiten.Image) {
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| 	if g.highDPIImage == nil {
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| 		ebitenutil.DebugPrint(screen, "Loading the image...")
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| 		return
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| 	}
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| 
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| 	sw, sh := screen.Bounds().Dx(), screen.Bounds().Dy()
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| 
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| 	w, h := g.highDPIImage.Bounds().Dx(), g.highDPIImage.Bounds().Dy()
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| 	op := &ebiten.DrawImageOptions{}
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| 
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| 	// Move the images's center to the upper left corner.
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| 	op.GeoM.Translate(float64(-w)/2, float64(-h)/2)
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| 
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| 	// The image is just too big. Adjust the scale.
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| 	op.GeoM.Scale(0.25, 0.25)
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| 
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| 	// Scale the image by the device ratio so that the rendering result can be same
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| 	// on various (different-DPI) environments.
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| 	scale := ebiten.Monitor().DeviceScaleFactor()
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| 	op.GeoM.Scale(scale, scale)
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| 
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| 	// Move the image's center to the screen's center.
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| 	op.GeoM.Translate(float64(sw)/2, float64(sh)/2)
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| 
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| 	op.Filter = ebiten.FilterLinear
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| 	screen.DrawImage(g.highDPIImage, op)
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| 
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| 	msg := fmt.Sprintf("Device Scale Ratio: %0.2f", scale)
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| 	if runtime.GOOS == "js" {
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| 		if !*flagDisable {
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| 			msg += "\nHiDPI rendering is enabled. You can disable HiDPI by -disable flag."
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| 		} else {
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| 			msg += "\nHiDPI rendering is disabled."
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| 		}
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| 	}
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| 	// TODO: The texts might be too small. Improve legibility.
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| 	ebitenutil.DebugPrint(screen, msg)
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| }
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| 
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| func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
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| 	// The unit of outsideWidth/Height is device-independent pixels.
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| 	// By multiplying them by the device scale factor, we can get a hi-DPI screen size.
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| 	s := ebiten.Monitor().DeviceScaleFactor()
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| 	return int(float64(outsideWidth) * s), int(float64(outsideHeight) * s)
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| }
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| 
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| var flagDisable = flag.Bool("disable", false, "disables HiDPI rendering (only on browsers)")
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| 
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| func main() {
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| 	flag.Parse()
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| 
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| 	ebiten.SetWindowSize(640, 480)
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| 	ebiten.SetWindowTitle("High DPI (Ebitengine Demo)")
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| 	op := &ebiten.RunGameOptions{}
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| 	op.DisableHiDPI = *flagDisable
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| 	if err := ebiten.RunGameWithOptions(NewGame(), op); err != nil {
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| 		log.Fatal(err)
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| 	}
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| }
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