ebiten/audio/internal/readerdriver/driver.go

66 lines
1.7 KiB
Go

// Copyright 2021 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.
package readerdriver
import (
"io"
)
type Context interface {
NewPlayer(io.Reader) Player
MaxBufferSize() int
Suspend() error
Resume() error
io.Closer
}
type Player interface {
Pause()
Play()
IsPlaying() bool
Reset()
Volume() float64
SetVolume(volume float64)
UnplayedBufferSize() int64
Err() error
io.Closer
}
type playerState int
const (
playerPaused playerState = iota
playerPlay
playerClosed
)
// TODO: The term 'buffer' is confusing. Name each buffer with good terms.
// oneBufferSize returns the size of one buffer in the player implementation.
func (c *context) oneBufferSize() int {
bytesPerSample := c.channelNum * c.bitDepthInBytes
s := c.sampleRate * bytesPerSample / 4
// Align s in multiples of bytes per sample, or a buffer could have extra bytes.
return s / bytesPerSample * bytesPerSample
}
// maxBufferSize returns the maximum size of the buffer for the audio source.
// This buffer is used when unreading on pausing the player.
func (c *context) MaxBufferSize() int {
// The number of underlying buffers should be 2.
return c.oneBufferSize() * 2
}