From 3939d47a8d7b1761b05681a582e397addb352fb5 Mon Sep 17 00:00:00 2001
From: Jeff Fessler <JeffFessler@users.noreply.github.com>
Date: Tue, 5 Apr 2022 14:32:13 -0400
Subject: [PATCH] Add tone with buffer example (#117)

---
 examples/tone-buffer.jl | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 examples/tone-buffer.jl

diff --git a/examples/tone-buffer.jl b/examples/tone-buffer.jl
new file mode 100644
index 0000000..fffd1eb
--- /dev/null
+++ b/examples/tone-buffer.jl
@@ -0,0 +1,21 @@
+#=
+This example illustrates synthesizing a long tone in small pieces
+and routing it to the default audio output device using `write()`.
+=#
+
+using PortAudio: PortAudioStream, write
+
+stream = PortAudioStream(0, 1; warn_xruns=false)
+
+function play_tone(stream, freq::Real, duration::Real; buf_size::Int = 1024)
+    S = stream.sample_rate
+    current = 1
+    while current < duration*S
+        x = 0.7 * sin.(2π * (current .+ (1:buf_size)) * freq / S)
+        write(stream, x)
+        current += buf_size
+    end
+    nothing
+end
+
+play_tone(stream, 440, 2)