ebiten/examples/wheel/main.go
2018-09-30 17:03:40 +09:00

68 lines
1.5 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 (
"image/color"
"log"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
)
var pointerImage *ebiten.Image
func init() {
pointerImage, _ = ebiten.NewImage(4, 4, ebiten.FilterDefault)
pointerImage.Fill(color.RGBA{0xff, 0, 0, 0xff})
}
const (
screenWidth = 320
screenHeight = 240
)
var (
x = 0.0
y = 0.0
)
func update(screen *ebiten.Image) error {
dx, dy := ebiten.Wheel()
x += dx
y += dy
if ebiten.IsDrawingSkipped() {
return nil
}
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(x, y)
op.GeoM.Translate(screenWidth/2, screenHeight/2)
screen.DrawImage(pointerImage, op)
ebitenutil.DebugPrint(screen, "Move the red point by mouse wheeling")
return nil
}
func main() {
if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Wheel (Ebiten Demo)"); err != nil {
log.Fatal(err)
}
}