mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-09-20 05:12:18 +02:00
107 lines
2.8 KiB
Go
107 lines
2.8 KiB
Go
// Copyright 2022 The Ebitengine 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.
|
|
|
|
package main
|
|
|
|
import (
|
|
"bytes"
|
|
"image"
|
|
_ "image/jpeg"
|
|
"log"
|
|
"math"
|
|
|
|
"github.com/hajimehoshi/ebiten/v2"
|
|
"github.com/hajimehoshi/ebiten/v2/ebitenutil"
|
|
"github.com/hajimehoshi/ebiten/v2/examples/resources/images"
|
|
"github.com/hajimehoshi/ebiten/v2/inpututil"
|
|
)
|
|
|
|
const (
|
|
screenWidth = 640
|
|
screenHeight = 480
|
|
)
|
|
|
|
var (
|
|
gophersImage *ebiten.Image
|
|
)
|
|
|
|
type Game struct {
|
|
count int
|
|
input bool
|
|
introShown bool
|
|
}
|
|
|
|
func (g *Game) Update() error {
|
|
g.count++
|
|
g.input = len(inpututil.AppendPressedKeys(nil)) > 0
|
|
if inpututil.IsKeyJustPressed(ebiten.KeyF) {
|
|
ebiten.SetFullscreen(!ebiten.IsFullscreen())
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (g *Game) Draw(screen *ebiten.Image) {
|
|
// If there is no inpnut, skip draw.
|
|
if !g.input && g.introShown {
|
|
// As SetScreenClearedEveryFrame(false) is called, the screen is not modified.
|
|
// In this case, Ebitengine optimizes and reduces GPU usages.
|
|
return
|
|
}
|
|
|
|
screen.Clear()
|
|
|
|
s := gophersImage.Bounds().Size()
|
|
op := &ebiten.DrawImageOptions{}
|
|
|
|
// Move the image's center to the screen's upper-left corner.
|
|
// This is a preparation for rotating. When geometry matrices are applied,
|
|
// the origin point is the upper-left corner.
|
|
op.GeoM.Translate(-float64(s.X)/2, -float64(s.Y)/2)
|
|
|
|
// Rotate the image. As a result, the anchor point of this rotate is
|
|
// the center of the image.
|
|
op.GeoM.Rotate(float64(g.count%360) * 2 * math.Pi / 360)
|
|
|
|
// Move the image to the screen's center.
|
|
op.GeoM.Translate(screenWidth/2, screenHeight/2)
|
|
|
|
screen.DrawImage(gophersImage, op)
|
|
|
|
ebitenutil.DebugPrint(screen, "Press any keys to keep animations.\nPress F to switch fullscreen.")
|
|
|
|
g.introShown = true
|
|
}
|
|
|
|
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
|
|
return screenWidth, screenHeight
|
|
}
|
|
|
|
func main() {
|
|
ebiten.SetWindowResizingMode(ebiten.WindowResizingModeEnabled)
|
|
ebiten.SetScreenClearedEveryFrame(false)
|
|
|
|
// Decode an image from the image file's byte slice.
|
|
img, _, err := image.Decode(bytes.NewReader(images.Gophers_jpg))
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
gophersImage = ebiten.NewImageFromImage(img)
|
|
|
|
ebiten.SetWindowSize(screenWidth, screenHeight)
|
|
ebiten.SetWindowTitle("Skip Draw (Ebitengine Demo)")
|
|
if err := ebiten.RunGame(&Game{}); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|