From 1d4c717820a24c6459ad0e3f5b2e82e703a7fc35 Mon Sep 17 00:00:00 2001
From: bigfarts <bigfarts@punymail.com>
Date: Wed, 23 Mar 2022 01:32:10 -0700
Subject: [PATCH] Add Context.SetReadBufferSize.

This is useful for cases where you may need to sync visuals with audio.
---
 driver.go         | 17 ++++++++++++++++-
 driver_android.go |  1 +
 driver_darwin.go  |  1 +
 driver_js.go      |  1 +
 driver_unix.go    |  1 +
 driver_windows.go |  1 +
 6 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/driver.go b/driver.go
index 9eec11b..f63c10d 100644
--- a/driver.go
+++ b/driver.go
@@ -26,7 +26,8 @@ import (
 //
 // There can only be one context at any time. Closing a context and opening a new one is allowed.
 type Context struct {
-	context *context
+	context    *context
+	bufferSize int
 }
 
 // NewPlayer creates a new, ready-to-use Player belonging to the Context.
@@ -67,6 +68,17 @@ func (c *Context) Resume() error {
 	return c.context.Resume()
 }
 
+// SetReadBufferSize sets the size of buffer to read from the underlying source.
+//
+// This is useful for cases where you may need to sync visuals with audio.
+//
+// Setting this to 0 will have Oto automatically calculate a buffer size.
+//
+// SetReadBufferSize is not concurrent-safe.
+func (c *Context) SetReadBufferSize(readBufferSize int) {
+	c.context.readBufferSize = readBufferSize
+}
+
 // Err returns the current error.
 //
 // Err is concurrent-safe.
@@ -145,6 +157,9 @@ func (c *context) oneBufferSize() int {
 // 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 {
+	if c.readBufferSize > 0 {
+		return c.readBufferSize
+	}
 	// The number of underlying buffers should be 2.
 	return c.oneBufferSize() * 2
 }
diff --git a/driver_android.go b/driver_android.go
index 42a653c..43f87f0 100644
--- a/driver_android.go
+++ b/driver_android.go
@@ -22,6 +22,7 @@ type context struct {
 	sampleRate      int
 	channelNum      int
 	bitDepthInBytes int
+	readBufferSize  int
 
 	players *players
 }
diff --git a/driver_darwin.go b/driver_darwin.go
index 73e0fcd..9629b8c 100644
--- a/driver_darwin.go
+++ b/driver_darwin.go
@@ -75,6 +75,7 @@ type context struct {
 	sampleRate      int
 	channelNum      int
 	bitDepthInBytes int
+	readBufferSize  int
 
 	audioQueue      C.AudioQueueRef
 	unqueuedBuffers []C.AudioQueueBufferRef
diff --git a/driver_js.go b/driver_js.go
index 88fbe93..f4d6a38 100644
--- a/driver_js.go
+++ b/driver_js.go
@@ -32,6 +32,7 @@ type context struct {
 	sampleRate      int
 	channelNum      int
 	bitDepthInBytes int
+	readBufferSize  int
 }
 
 func newContext(sampleRate int, channelNum int, bitDepthInBytes int) (*context, chan struct{}, error) {
diff --git a/driver_unix.go b/driver_unix.go
index 94c8556..b8bdafb 100644
--- a/driver_unix.go
+++ b/driver_unix.go
@@ -33,6 +33,7 @@ type context struct {
 	sampleRate      int
 	channelNum      int
 	bitDepthInBytes int
+	readBufferSize  int
 
 	suspended bool
 
diff --git a/driver_windows.go b/driver_windows.go
index 4e209c9..de9f848 100644
--- a/driver_windows.go
+++ b/driver_windows.go
@@ -69,6 +69,7 @@ type context struct {
 	sampleRate      int
 	channelNum      int
 	bitDepthInBytes int
+	readBufferSize  int
 
 	waveOut uintptr
 	headers []*header