mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
116 lines
3.0 KiB
Go
116 lines
3.0 KiB
Go
// Copyright 2018 The Ebiten Authors
|
|
//
|
|
// 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.
|
|
|
|
// +build example jsgo
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
_ "image/jpeg"
|
|
"log"
|
|
|
|
"github.com/hajimehoshi/ebiten"
|
|
"github.com/hajimehoshi/ebiten/ebitenutil"
|
|
)
|
|
|
|
var (
|
|
count int
|
|
highDPIImage *ebiten.Image
|
|
highDPIImageCh = make(chan *ebiten.Image)
|
|
|
|
// scale represents the device scale when the application starts.
|
|
scale = 1.0
|
|
)
|
|
|
|
func init() {
|
|
// Licensed under Public Domain
|
|
// https://commons.wikimedia.org/wiki/File:As08-16-2593.jpg
|
|
const url = "https://upload.wikimedia.org/wikipedia/commons/1/1f/As08-16-2593.jpg"
|
|
|
|
// Load the image asynchronously.
|
|
go func() {
|
|
img, err := ebitenutil.NewImageFromURL(url)
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
highDPIImageCh <- img
|
|
close(highDPIImageCh)
|
|
}()
|
|
}
|
|
|
|
func update(screen *ebiten.Image) error {
|
|
// TODO: DeviceScaleFactor() might return different values for different monitors.
|
|
// Add a mode to adjust the screen size along with the current device scale (#705).
|
|
// Now this example uses the device scale initialized at the beginning of this application.
|
|
|
|
if highDPIImage == nil {
|
|
// Use select and 'default' clause for non-blocking receiving.
|
|
select {
|
|
case img := <-highDPIImageCh:
|
|
highDPIImage = img
|
|
default:
|
|
}
|
|
}
|
|
|
|
if ebiten.IsDrawingSkipped() {
|
|
return nil
|
|
}
|
|
|
|
if highDPIImage == nil {
|
|
ebitenutil.DebugPrint(screen, "Loading the image...")
|
|
return nil
|
|
}
|
|
|
|
sw, sh := screen.Size()
|
|
|
|
w, h := highDPIImage.Size()
|
|
op := &ebiten.DrawImageOptions{}
|
|
|
|
// Move the images's center to the upper left corner.
|
|
op.GeoM.Translate(float64(-w)/2, float64(-h)/2)
|
|
|
|
// The image is just too big. Adjust the scale.
|
|
op.GeoM.Scale(0.25, 0.25)
|
|
|
|
// Scale the image by the device ratio so that the rendering result can be same
|
|
// on various (different-DPI) environments.
|
|
op.GeoM.Scale(scale, scale)
|
|
|
|
// Move the image's center to the screen's center.
|
|
op.GeoM.Translate(float64(sw)/2, float64(sh)/2)
|
|
|
|
op.Filter = ebiten.FilterLinear
|
|
screen.DrawImage(highDPIImage, op)
|
|
|
|
ebitenutil.DebugPrint(screen, fmt.Sprintf("(Init) Device Scale Ratio: %0.2f", scale))
|
|
return nil
|
|
}
|
|
|
|
func main() {
|
|
const (
|
|
screenWidth = 640
|
|
screenHeight = 480
|
|
)
|
|
|
|
// Pass the invert of scale so that Ebiten's auto scaling by device scale is disabled.
|
|
//
|
|
// Note that DeviceScaleFactor cannot be called from init() functions on some environments.
|
|
scale = ebiten.DeviceScaleFactor()
|
|
s := scale
|
|
if err := ebiten.Run(update, int(screenWidth*s), int(screenHeight*s), 1/s, "High DPI (Ebiten Demo)"); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|