add sound

demo/main.fnl

@@ -1,5 +1,6 @@
 (local pxl8 (require :pxl8))
 (local menu (require :mod.menu))
+(local music (require :mod.music))
 (local worldgen (require :mod.worldgen))
 
 (var time 0)
@@ -29,6 +30,8 @@
   (pxl8.load_palette "res/sprites/pxl8_logo.ase")
   (set logo-sprite (pxl8.load_sprite "res/sprites/pxl8_logo.ase"))
   (set particles (pxl8.particles_new 1000))
+  (music.init)
+  (music.start)
   (worldgen.init)))
 
 (global update (fn [dt]
@@ -79,6 +82,8 @@
                 (set logo-dy (- logo-dy))))
       :worldgen (worldgen.update dt))
 
+    (music.update dt)
+
     (when particles
       (pxl8.particles_update particles dt)))
 

demo/mod/music.fnl

@@ -0,0 +1,68 @@
+(local pxl8 (require :pxl8))
+
+(var time 0)
+(var step 0)
+(var ctx nil)
+(var params nil)
+(var bass-params nil)
+(var playing false)
+
+(local melody [60 64 67 72 67 64 60 64 67 72 76 72 67 64 62 66 69 74 69 66 62 66 69 74 78 74 69 66])
+(local bass [36 50 40 36 38 38 50 38])
+(local step-duration 0.15)
+
+(fn init []
+  (set ctx (pxl8.sfx_context_create))
+
+  (local delay (pxl8.sfx_delay_create {:time_l 350 :time_r 500 :feedback 0.4 :mix 0.25}))
+  (local reverb (pxl8.sfx_reverb_create {:room 0.5 :damping 0.5 :mix 0.3}))
+  (local compressor (pxl8.sfx_compressor_create {:threshold -12 :ratio 4 :attack 10 :release 100}))
+
+  (pxl8.sfx_context_append_node ctx delay)
+  (pxl8.sfx_context_append_node ctx reverb)
+  (pxl8.sfx_context_append_node ctx compressor)
+
+  (pxl8.sfx_mixer_attach ctx)
+
+  (set params (pxl8.sfx_voice_params
+    {:waveform pxl8.SFX_WAVE_TRIANGLE
+     :attack 0.005 :decay 0.08 :sustain 0.0 :release 0.05
+     :filter_type pxl8.SFX_FILTER_LOWPASS
+     :filter_cutoff 2500 :filter_resonance 0.15
+     :filter_attack 0.005 :filter_decay 0.1 :filter_sustain 0.1 :filter_release 0.05
+     :filter_env_depth 1500
+     :fx_send 0.3}))
+
+  (set bass-params (pxl8.sfx_voice_params
+    {:waveform pxl8.SFX_WAVE_SQUARE
+     :attack 0.005 :decay 0.1 :sustain 0.0 :release 0.05
+     :filter_type pxl8.SFX_FILTER_LOWPASS
+     :filter_cutoff 600 :filter_resonance 0.2
+     :fx_send 0.2})))
+
+(fn start []
+  (set playing true)
+  (set time 0)
+  (set step 0))
+
+(fn stop []
+  (set playing false)
+  (pxl8.sfx_stop_all ctx))
+
+(fn update [dt]
+  (when playing
+    (set time (+ time dt))
+    (when (>= time step-duration)
+      (set time (- time step-duration))
+      (local note (. melody (+ 1 (% step (length melody)))))
+      (pxl8.sfx_play_note ctx note params 0.4)
+      (when (= (% step 4) 0)
+        (local bass-note (. bass (+ 1 (% (math.floor (/ step 4)) (length bass)))))
+        (pxl8.sfx_play_note ctx bass-note bass-params 0.35))
+      (set step (+ step 1)))))
+
+{:init init
+ :start start
+ :stop stop
+ :update update
+ :is-playing (fn [] playing)}