mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-25 03:08:54 +01:00
76 lines
1.8 KiB
Go
76 lines
1.8 KiB
Go
// Copyright 2015 Hajime Hoshi
|
|
//
|
|
// 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
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"image"
|
|
"log"
|
|
|
|
"github.com/hajimehoshi/ebiten"
|
|
"github.com/hajimehoshi/ebiten/ebitenutil"
|
|
)
|
|
|
|
const (
|
|
screenWidth = 320
|
|
screenHeight = 240
|
|
)
|
|
|
|
var (
|
|
noiseImage *image.RGBA
|
|
)
|
|
|
|
type rand struct {
|
|
x, y, z, w uint32
|
|
}
|
|
|
|
func (r *rand) next() uint32 {
|
|
// math/rand is too slow to keep 60 FPS on web browsers.
|
|
// Use Xorshift instead: http://en.wikipedia.org/wiki/Xorshift
|
|
t := r.x ^ (r.x << 11)
|
|
r.x, r.y, r.z = r.y, r.z, r.w
|
|
r.w = (r.w ^ (r.w >> 19)) ^ (t ^ (t >> 8))
|
|
return r.w
|
|
}
|
|
|
|
var randInstance = &rand{12345678, 4185243, 776511, 45411}
|
|
|
|
func update(screen *ebiten.Image) error {
|
|
const l = screenWidth * screenHeight
|
|
for i := 0; i < l; i++ {
|
|
x := randInstance.next()
|
|
noiseImage.Pix[4*i] = uint8(x >> 24)
|
|
noiseImage.Pix[4*i+1] = uint8(x >> 16)
|
|
noiseImage.Pix[4*i+2] = uint8(x >> 8)
|
|
noiseImage.Pix[4*i+3] = 0xff
|
|
}
|
|
if err := screen.ReplacePixels(noiseImage.Pix); err != nil {
|
|
return err
|
|
}
|
|
if err := ebitenutil.DebugPrint(screen, fmt.Sprintf("FPS: %f", ebiten.CurrentFPS())); err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func main() {
|
|
noiseImage = image.NewRGBA(image.Rect(0, 0, screenWidth, screenHeight))
|
|
if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Noise (Ebiten Demo)"); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|