mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-25 19:28:57 +01:00
113 lines
2.9 KiB
Go
113 lines
2.9 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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package main
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import (
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"fmt"
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_ "image/jpeg"
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"log"
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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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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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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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// 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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// 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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return g
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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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// 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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return nil
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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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sw, sh := screen.Bounds().Dx(), screen.Bounds().Dy()
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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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// 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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// The image is just too big. Adjust the scale.
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op.GeoM.Scale(0.25, 0.25)
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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.DeviceScaleFactor()
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op.GeoM.Scale(scale, scale)
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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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op.Filter = ebiten.FilterLinear
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screen.DrawImage(g.highDPIImage, op)
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ebitenutil.DebugPrint(screen, fmt.Sprintf("(Init) Device Scale Ratio: %0.2f", scale))
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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.DeviceScaleFactor()
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return int(float64(outsideWidth) * s), int(float64(outsideHeight) * s)
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}
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func main() {
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ebiten.SetWindowSize(640, 480)
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ebiten.SetWindowTitle("High DPI (Ebitengine Demo)")
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if err := ebiten.RunGame(NewGame()); err != nil {
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log.Fatal(err)
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}
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}
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