mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
142 lines
3.1 KiB
Go
142 lines
3.1 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 js,!wasm
|
|
|
|
package stb
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"syscall/js"
|
|
)
|
|
|
|
var flatten = js.Global().Get("window").Call("eval", `(function(arr) {
|
|
var ch = arr.length;
|
|
var len = arr[0].length;
|
|
var result = new Float32Array(ch * len);
|
|
for (var j = 0; j < len; j++) {
|
|
for (var i = 0; i < ch; i++) {
|
|
result[j*ch+i] = arr[i][j];
|
|
}
|
|
}
|
|
return result;
|
|
})`)
|
|
|
|
func init() {
|
|
// Eval wasm.js first to set the Wasm binary to Module.
|
|
js.Global().Get("window").Call("eval", string(stbvorbis_js))
|
|
}
|
|
|
|
type Samples struct {
|
|
samples [][]float32
|
|
channels int
|
|
lengthInSamples int64
|
|
posInSamples int64
|
|
}
|
|
|
|
func (s *Samples) Read(buf []float32) (int, error) {
|
|
if s.posInSamples == s.lengthInSamples {
|
|
return 0, io.EOF
|
|
}
|
|
if len(buf) == 0 {
|
|
return 0, nil
|
|
}
|
|
|
|
var p int64
|
|
idx := 0
|
|
for idx < len(s.samples) {
|
|
l := int64(len(s.samples[idx])) / int64(s.channels)
|
|
if p+l > s.posInSamples {
|
|
break
|
|
}
|
|
p += l
|
|
idx++
|
|
}
|
|
start := (s.posInSamples - p) * int64(s.channels)
|
|
if start == int64(len(s.samples[idx])) {
|
|
idx++
|
|
start = 0
|
|
}
|
|
if len(s.samples[idx]) == 0 {
|
|
panic(fmt.Sprintf("stb: len(samples[%d]) must be > 0", idx))
|
|
}
|
|
n := copy(buf, s.samples[idx][start:])
|
|
s.posInSamples += int64(n) / int64(s.channels)
|
|
return n, nil
|
|
}
|
|
|
|
func (s *Samples) Length() int64 {
|
|
return s.lengthInSamples
|
|
}
|
|
|
|
func (s *Samples) SetPosition(pos int64) error {
|
|
s.posInSamples = pos
|
|
return nil
|
|
}
|
|
|
|
func DecodeVorbis(buf []byte) (*Samples, int, int, error) {
|
|
ch := make(chan error)
|
|
samples := &Samples{}
|
|
sampleRate := 0
|
|
|
|
f := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
|
|
r := args[0]
|
|
|
|
if e := r.Get("error"); e != js.Null() {
|
|
ch <- fmt.Errorf("audio/vorbis/internal/stb: decode error: %s", e.String())
|
|
close(ch)
|
|
return nil
|
|
}
|
|
|
|
if r.Get("eof").Bool() {
|
|
close(ch)
|
|
return nil
|
|
}
|
|
|
|
if samples.channels == 0 {
|
|
samples.channels = r.Get("data").Length()
|
|
|
|
}
|
|
if sampleRate == 0 {
|
|
sampleRate = r.Get("sampleRate").Int()
|
|
}
|
|
|
|
flattened := flatten.Invoke(r.Get("data"))
|
|
if flattened.Length() == 0 {
|
|
return nil
|
|
}
|
|
|
|
s := make([]float32, flattened.Length())
|
|
arr := js.TypedArrayOf(s)
|
|
arr.Call("set", flattened)
|
|
arr.Release()
|
|
|
|
samples.samples = append(samples.samples, s)
|
|
samples.lengthInSamples += int64(len(s)) / int64(samples.channels)
|
|
return nil
|
|
})
|
|
defer f.Release()
|
|
|
|
arr := js.TypedArrayOf(buf)
|
|
js.Global().Get("stbvorbis").Call("decode", arr, f)
|
|
arr.Release()
|
|
|
|
if err := <-ch; err != nil {
|
|
return nil, 0, 0, err
|
|
}
|
|
|
|
return samples, samples.channels, sampleRate, nil
|
|
}
|