mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
175 lines
4.4 KiB
HTML
175 lines
4.4 KiB
HTML
<!DOCTYPE html>
|
|
<!--
|
|
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.
|
|
-->
|
|
<link rel="shortcut icon" href="../favicon.png" type="image/png" >
|
|
<link rel="icon" href="../favicon.png" type="image/png" >
|
|
<title>Ebiten example - piano</title>
|
|
<style>
|
|
body {
|
|
font-family: sans-serif;
|
|
}
|
|
iframe {
|
|
border-color: #999;
|
|
border-style: solid;
|
|
border-width: 1px;
|
|
overflow: hidden;
|
|
}
|
|
pre {
|
|
background: #eee;
|
|
padding: 1em;
|
|
}
|
|
</style>
|
|
<nav><a href="..">Ebiten</a></nav>
|
|
|
|
<h1>Ebiten example - piano</h1>
|
|
<iframe src="piano.content.html" width="640" height="480"></iframe>
|
|
<pre><code>package main
|
|
|
|
import (
|
|
"fmt"
|
|
"github.com/hajimehoshi/ebiten"
|
|
"github.com/hajimehoshi/ebiten/ebitenutil"
|
|
"github.com/hajimehoshi/ebiten/example/common"
|
|
"github.com/hajimehoshi/ebiten/exp/audio"
|
|
"image/color"
|
|
"log"
|
|
"math"
|
|
)
|
|
|
|
const (
|
|
screenWidth = 320
|
|
screenHeight = 240
|
|
)
|
|
|
|
var pcm = make([]float64, 4*audio.SampleRate())
|
|
|
|
const baseFreq = 220
|
|
|
|
func init() {
|
|
s := float64(audio.SampleRate())
|
|
amp := []float64{1.0, 0.8, 0.6, 0.4, 0.2}
|
|
x := []float64{4.0, 2.0, 1.0, 0.5, 0.25}
|
|
for i := 0; i < len(pcm); i++ {
|
|
v := 0.0
|
|
twoPiF := 2.0 * math.Pi * baseFreq
|
|
for j := 0; j < len(amp); j++ {
|
|
a := amp[j] * math.Exp(-5*float64(i)/(x[j]*s))
|
|
v += a * math.Sin(float64(i)*twoPiF*float64(j+1)/s)
|
|
}
|
|
pcm[i] = v / 5.0
|
|
}
|
|
}
|
|
|
|
func addNote(freq float64, vol float64) {
|
|
f := int(freq)
|
|
length := len(pcm) * baseFreq / f
|
|
l := make([]int16, length)
|
|
r := make([]int16, length)
|
|
j := 0
|
|
jj := 0
|
|
for i := 0; i < len(l); i++ {
|
|
p := pcm[j]
|
|
l[i] = int16(p * vol * math.MaxInt16)
|
|
r[i] = l[i]
|
|
jj += f
|
|
j = jj / baseFreq
|
|
}
|
|
audio.Play(-1, l, r)
|
|
}
|
|
|
|
var keys = []ebiten.Key{
|
|
ebiten.KeyQ,
|
|
ebiten.KeyA,
|
|
ebiten.KeyW,
|
|
ebiten.KeyS,
|
|
ebiten.KeyD,
|
|
ebiten.KeyR,
|
|
ebiten.KeyF,
|
|
ebiten.KeyT,
|
|
ebiten.KeyG,
|
|
ebiten.KeyH,
|
|
ebiten.KeyU,
|
|
ebiten.KeyJ,
|
|
ebiten.KeyI,
|
|
ebiten.KeyK,
|
|
ebiten.KeyO,
|
|
ebiten.KeyL,
|
|
}
|
|
|
|
var keyStates = map[ebiten.Key]int{}
|
|
|
|
func init() {
|
|
for _, key := range keys {
|
|
keyStates[key] = 0
|
|
}
|
|
}
|
|
|
|
func updateInput() {
|
|
for _, key := range keys {
|
|
if !ebiten.IsKeyPressed(key) {
|
|
keyStates[key] = 0
|
|
continue
|
|
}
|
|
keyStates[key]++
|
|
}
|
|
}
|
|
|
|
func update(screen *ebiten.Image) error {
|
|
updateInput()
|
|
for i, key := range keys {
|
|
if keyStates[key] != 1 {
|
|
continue
|
|
}
|
|
addNote(220*math.Exp2(float64(i-1)/12.0), 1.0)
|
|
}
|
|
|
|
screen.Fill(color.RGBA{0x80, 0x80, 0xc0, 0xff})
|
|
|
|
whiteKeys := []string{"A", "S", "D", "F", "G", "H", "J", "K", "L"}
|
|
width := 24
|
|
y := 48
|
|
for i, k := range whiteKeys {
|
|
x := i*width + 36
|
|
height := 112
|
|
screen.DrawFilledRect(x, y, width-1, height, color.White)
|
|
common.ArcadeFont.DrawText(screen, k, x+8, y+height-16, 1, color.Black)
|
|
}
|
|
|
|
blackKeys := []string{"Q", "W", "", "R", "T", "", "U", "I", "O"}
|
|
for i, k := range blackKeys {
|
|
if k == "" {
|
|
continue
|
|
}
|
|
x := i*width + 24
|
|
height := 64
|
|
screen.DrawFilledRect(x, y, width-1, height, color.Black)
|
|
common.ArcadeFont.DrawText(screen, k, x+8, y+height-16, 1, color.White)
|
|
}
|
|
|
|
ebitenutil.DebugPrint(screen, fmt.Sprintf("FPS: %0.2f", ebiten.CurrentFPS()))
|
|
return nil
|
|
}
|
|
|
|
func main() {
|
|
if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Piano (Ebiten Demo)"); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|
|
</code></pre>
|
|
|
|
|
|
<footer>© 2015 Hajime Hoshi</footer>
|