From cf7f170c729bf98945c167de5c02c5a797d5cb88 Mon Sep 17 00:00:00 2001
From: Spencer Russell <spencer.f.russell@gmail.com>
Date: Sun, 20 Mar 2016 04:05:21 -0400
Subject: [PATCH] adds audiometer example

---
 examples/audiometer.jl             | 47 ++++++++++++++++++++++++++++++
 examples/lilyplay.jl               |  8 +++--
 examples/mutable_streaming_node.jl | 40 -------------------------
 examples/ramp.jl                   | 32 --------------------
 4 files changed, 53 insertions(+), 74 deletions(-)
 create mode 100644 examples/audiometer.jl
 delete mode 100644 examples/mutable_streaming_node.jl
 delete mode 100644 examples/ramp.jl

diff --git a/examples/audiometer.jl b/examples/audiometer.jl
new file mode 100644
index 0000000..1b8d261
--- /dev/null
+++ b/examples/audiometer.jl
@@ -0,0 +1,47 @@
+using PortAudio
+
+"""Continuously read from the default audio input and plot an
+ASCII level/peak meter"""
+function micmeter(metersize)
+    mic = PortAudioSource()
+
+    signalmax = zero(eltype(mic))
+    println("Press Ctrl-C to quit")
+    while true
+        block = read(mic, 4096)
+        blockmax = maximum(abs(block)) # find the maximum value in the block
+        signalmax = max(signalmax, blockmax) # keep the maximum value ever
+        print("\r") # reset the cursor to the beginning of the line
+        printmeter(metersize, blockmax, signalmax)
+    end
+end
+
+"""Print an ASCII level meter of the given size. Signal and peak
+levels are assumed to be scaled from 0.0-1.0, with peak >= signal"""
+function printmeter(metersize, signal, peak)
+    # calculate the positions in terms of characters
+    peakpos = clamp(round(Int, peak * metersize), 0, metersize)
+    meterchars = clamp(round(Int, signal * metersize), 0, peakpos-1)
+    blankchars = max(0, peakpos-meterchars-1)
+
+    for position in 1:meterchars
+        print_with_color(barcolor(metersize, position), ">")
+    end
+
+    print(" " ^ blankchars)
+    print_with_color(barcolor(metersize, peakpos), "|")
+    print(" " ^ (metersize - peakpos))
+end
+
+"""Compute the proper color for a given position in the bar graph. The first
+half of the bar should be green, then the remainder is yellow except the final
+character, which is red."""
+function barcolor(metersize, position)
+    if position/metersize <= 0.5
+        :green
+    elseif position == metersize
+        :red
+    else
+        :yellow
+    end
+end
diff --git a/examples/lilyplay.jl b/examples/lilyplay.jl
index 339c50b..6120bb5 100644
--- a/examples/lilyplay.jl
+++ b/examples/lilyplay.jl
@@ -1,5 +1,9 @@
 # Thanks to Jiahao Chen for this great example!
 
+##
+## NOTE: THIS NEEDS TO BE PORTED OVER TO THE NEW ARCHITECTURE
+##
+
 using AudioIO
 import AudioIO.play
 
@@ -129,10 +133,10 @@ soprano = @async parsevoice("""
 f'#.4 f'#. g'. a'. a'. g'. f'#. e'. d'. d'. e'. f'#. e'.~ e' d'8 d'4~ d'2
 """, lyrics="Wir be- tre- ten feu- er- trun- ken, Himm- li- sche, dein Hei- - lig- thum!")
 alto = @async parsevoice("""
-a.4 a. b. c'. c'. b. a. g. f#. f#. g. f#. g.~ g4 f#8 f#~ f#2 
+a.4 a. b. c'. c'. b. a. g. f#. f#. g. f#. g.~ g4 f#8 f#~ f#2
 """)
 tenor = @async parsevoice("""
-d.4 d. d. d. d. d. d. d. d. d. c#. d. c#.~ c# d8 d d2  
+d.4 d. d. d. d. d. d. d. d. d. c#. d. c#.~ c# d8 d d2
 """)
 bass = @async parsevoice("""
 d.4 d. d. d. a,. a,. a,. a., a., a., a., a., a.,~ a, a,8 d, d,2
diff --git a/examples/mutable_streaming_node.jl b/examples/mutable_streaming_node.jl
deleted file mode 100644
index ba6b681..0000000
--- a/examples/mutable_streaming_node.jl
+++ /dev/null
@@ -1,40 +0,0 @@
-# This demos how real-time audio manipulation can be done using AudioNodes. To
-# run it, hook up some input audio to your default recording device and run the
-# script. The demo will run for 10 seconds alternating the node between a muted
-# and unmuted state
-using AudioIO
-
-type MutableNode <: AudioIO.AudioNode
-  active::Bool
-  deactivate_cond::Condition
-  muted::Bool
-
-  function MutableNode(muted::Bool)
-    new(false, Condition(), muted)
-  end
-end
-
-function MutableNode()
-  MutableNode(false)
-end
-
-import AudioIO.render
-function render(node::MutableNode, device_input::AudioIO.AudioBuf, info::AudioIO.DeviceInfo)
-  return device_input .* !node.muted, AudioIO.is_active(node)
-end
-
-function mute(node::MutableNode)
-  node.muted = true
-end
-
-function unmute(node::MutableNode)
-  node.muted = false
-end
-
-mutableNode = MutableNode()
-AudioIO.play(mutableNode)
-muteTransitions = { true => unmute, false => mute }
-for i in 1:10
-  sleep(1)
-  muteTransitions[mutableNode.muted](mutableNode)
-end
diff --git a/examples/ramp.jl b/examples/ramp.jl
deleted file mode 100644
index f1c5b5c..0000000
--- a/examples/ramp.jl
+++ /dev/null
@@ -1,32 +0,0 @@
-using AudioIO
-
-# Give PortAudio time to load
-play([0])
-sleep(2)
-
-println("""
-                    *
-                *   *
-            *   *   *
-        *   *   *   *
-    *   *   *   *   *
-*   *   *   *   *   *
-""")
-wave = SinOsc(440) * LinRamp(0.0, 1.0, 2.0)
-play(wave)
-sleep(2)
-stop(wave)
-
-
-println("""
-                    *
-                *   *   *
-            *   *   *   *   *
-        *   *   *   *   *   *   *
-    *   *   *   *   *   *   *   *   *
-*   *   *   *   *   *   *   *   *   *   *
-""")
-wave = SinOsc(440) * LinRamp([0.0, 1.0, 0.0], [2.0, 2.0])
-play(wave)
-sleep(4)
-stop(wave)
\ No newline at end of file