Close audio devices, gnuplot audio

* Make sure to close audio devices, else the operating system will
think the device is still busy, and no other apps will play audio
* Removed unused code and comments which are likely to get out of sync
* Added audio-dump-recorded-buffer, which outputs in a format gnuplot
can easily read
* Added configuration for a pretty plot of the audio data

.gitignore

@@ -50,4 +50,5 @@ Dependencies/SDL/
 
 test/100000000PixelShader_ps.glsl
 test/100000000VertexShader_vs.glsl
-test/SDLOgreApp
+test/SDLOgreApp
+test/out.dat

test/AudioPlot.gnuplot

@@ -0,0 +1,44 @@
+# set textcolor '#cccccc'
+# set the color and font of the text of the axis
+text_color = '#c7ae95'
+background_color = '#1c2023'
+grid_color = '#ff0000'
+my_font = "Ubuntu Regular, 12"
+my_axis_width = "1.5"
+
+set terminal qt enhanced size 1920,1080 persist title "Vocal Game Audio" ctrl
+
+set xtics textcolor rgb text_color font my_font
+set ytics textcolor rgb text_color font my_font
+set ztics textcolor rgb text_color font my_font
+
+set title "Vocal Game Audio" textcolor rgb text_color font my_font
+
+set xlabel "Sample index (44.1kHz)" textcolor rgb text_color font my_font
+set ylabel "Sample value" textcolor rgb text_color font my_font
+# set zlabel "Z Label (unit)" textcolor rgb text_color font my_font
+
+set border 31 lw @my_axis_width lc rgb text_color
+
+# set the text color and font for the label
+set label textcolor rgb text_color font my_font
+
+# set the color and width of the axis border
+# set border 31 lw @my_axis_width lc rgb text_color
+
+# set key options
+# set key outside box width 2 height 2 enhanced spacing 2
+set key textcolor rgb text_color
+
+# set grid color
+#set grid lc rgb grid_color
+
+# Hack to make QT have programmable background color
+# from https://stackoverflow.com/questions/27269578/gnuplot-change-background-color
+set object rectangle from screen 0,0 to screen 1,1 behind fillcolor rgb background_color fillstyle solid noborder
+
+set yrange [0:255]
+plot 'out.dat' with lines
+
+# Let the user interact with it, e.g. right click drag to zoom in
+pause mouse close

test/ViewAudioOutput.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+gnuplot AudioPlot.gnuplot

test/src/VocalGame.cake

@@ -9,7 +9,7 @@
 (add-c-search-directory ".")
 
 (c-import "SDL.h" "SDL_syswm.h" "SDL_timer.h"
-          "<math.h>")
+          "<math.h>" "<stdio.h>")
 ;; TODO: Somehow inherit this from SDL.cake?
 (module-use-sdl-build-options)
 
@@ -18,6 +18,18 @@
 (var audio-input-write-head int 0)
 (var audio-input-read-head int 0)
 
+(defun-local audio-dump-recorded-buffer ()
+  (var i int 0)
+  (var dest-file (* FILE) (fopen "out.dat" "w"))
+  (unless dest-file
+    (printf "Could not open file to write data\n")
+    (return))
+
+  (while (< i (array-size audio-input-buffer))
+    (fprintf dest-file "%d %d\n" i (at i audio-input-buffer))
+    (incr i))
+  (fclose dest-file))
+
 (defun-local audio-output-callback (userdata (* void) stream (* Uint8) stream-length int)
   ;; (printf "Audio len %d\n" stream-length)
   (static-var up bool false)
@@ -30,7 +42,7 @@
     (var mono-sample int 127)
     ;; Square
     ;; (set mono-sample (? up 255 0))
-    ;; Triangle
+    ;; Sawtooth
     ;; (set mono-sample (mod (/ i 4) 255))
     ;; Sine
     ;; Map to 0-255
@@ -103,7 +115,7 @@
   (free device-names))
 
 (defun-local initialize-audio (output-device-out (* SDL_AudioDeviceID)
-                               input-device-out (* SDL_AudioDeviceID) &return bool)
+                                                 input-device-out (* SDL_AudioDeviceID) &return bool)
   (scope ;; Drivers
    (printf "Available drivers:\n")
    (var num-drivers int (SDL_GetNumAudioDrivers))
@@ -133,7 +145,6 @@
    (set (field desired-spec freq) 44100)
    (set (field desired-spec format) AUDIO_U8)
    (set (field desired-spec channels) 2) ;; 1 = Mono 2 = Stereo
-   ;; 86 times per second. ~11ms delay (I think)
    (set (field desired-spec samples) 512)
    (set (field desired-spec callback) audio-output-callback)
    ;; Use my HDMI output device
@@ -145,13 +156,13 @@
    (var device-name (* (const char)) (at 2 devices))
    (var valid-device-start-num (const int) 2)
    (set output-device-id (SDL_OpenAudioDevice
-                            ;; null = reasonable default (doesn't work in my case)
-                            device-name
-                            false ;; iscapture
-                            (addr desired-spec) (addr obtained-output-spec)
-                            (bit-or SDL_AUDIO_ALLOW_FREQUENCY_CHANGE
-                                    SDL_AUDIO_ALLOW_SAMPLES_CHANGE
-                                    SDL_AUDIO_ALLOW_CHANNELS_CHANGE)))
+                          ;; null = reasonable default (doesn't work in my case)
+                          device-name
+                          false ;; iscapture
+                          (addr desired-spec) (addr obtained-output-spec)
+                          (bit-or SDL_AUDIO_ALLOW_FREQUENCY_CHANGE
+                                  SDL_AUDIO_ALLOW_SAMPLES_CHANGE
+                                  SDL_AUDIO_ALLOW_CHANNELS_CHANGE)))
    (if (>= output-device-id valid-device-start-num)
        (set selected-output-device device-name)
        (sdl-print-error)))
@@ -164,7 +175,6 @@
    (set (field desired-spec freq) 44100)
    (set (field desired-spec format) AUDIO_U8)
    (set (field desired-spec channels) 1) ;; 1 = Mono 2 = Stereo
-   ;; 86 times per second. ~11ms delay (I think)
    (set (field desired-spec samples) 512)
    (set (field desired-spec callback) audio-input-callback)
 
@@ -202,30 +212,7 @@
      (SDL_PauseAudioDevice input-device-id 0))
    (sdl-audio-free-device-list capture-devices num-capture-devices))
 
-  ;; Pick the first working device
-  ;; This doesn't actually make sense for my case, where the first device does open
-  ;; (var i int 0)
-  ;; (while (< i num-devices)
-  ;;   (var device-name (* (const char)) (at i devices))
-  ;;   (var valid-device-start-num (const int) 2)
-  ;;   (set output-device-id (SDL_OpenAudioDevice
-  ;;                            ;; null = reasonable default (doesn't work in my case)
-  ;;                            device-name
-  ;;                            false ;; iscapture
-  ;;                            (addr desired-spec) (addr obtained-spec)
-  ;;                            (bit-or SDL_AUDIO_ALLOW_FREQUENCY_CHANGE
-  ;;                                    SDL_AUDIO_ALLOW_SAMPLES_CHANGE
-  ;;                                    SDL_AUDIO_ALLOW_CHANNELS_CHANGE)))
-  ;;   (if (>= output-device-id
-  ;;           valid-device-start-num)
-  ;;       (block
-  ;;           (set selected-device device-name)
-  ;;         (break))
-  ;;       (block
-  ;;           (sdl-print-error)
-  ;;         (incr i))))
-
-  (when selected-output-device ;; print final settings
+  (when selected-output-device
     (printf "Final output settings:\n")
     (printf "device: %s\n" selected-output-device)
     (sdl-audio-list-specification (addr obtained-output-spec))
@@ -241,6 +228,11 @@
 
   (return (and output-device-id input-device-id)))
 
+(defun-local sdl-audio-close (output-device SDL_AudioDeviceID
+                                            input-device SDL_AudioDeviceID)
+  (SDL_CloseAudioDevice output-device)
+  (SDL_CloseAudioDevice input-device))
+
 (defun main (&return int)
   (var window (* SDL_Window) null)
   (unless (sdl-initialize (addr window))
@@ -254,6 +246,8 @@
   ;; Ogre uses exceptions for error handling, so we can't gracefully close without getting all that
   ;; stuff set up (which I don't really want to do; it belongs in Gamelib)
   (unless (ogre-initialize-sdl)
+    (sdl-audio-close output-device
+                     input-device)
     (return 1))
 
   (var monkey-mesh mesh-handle (ogre-load-mesh "Suzanne.mesh"))
@@ -313,8 +307,13 @@
       (set exit-reason "Failed to render frame")
       (break)))
 
+  (audio-dump-recorded-buffer)
+
   (ogre-shutdown)
+  (sdl-audio-close output-device
+                   input-device)
   (sdl-shutdown window)
+
   (when exit-reason
     (printf "Exit reason: %s\n" exit-reason))
   (return 0))