clean up a-pong

diff --git a/scripts/_pong.lua b/scripts/_pong.lua
index 3683209a2b20acb8e4f33e85dfddd5c25c9e0e4c..7ed17648fbeca216ff3003054476821382b02eee 100644 (file)
--- a/scripts/_pong.lua
+++ b/scripts/_pong.lua
@@ -20,29 +20,30 @@ function dsp_params ()
        }
 end
 
-local gametime
-local fps
-local ball_x, ball_y
-local dx, dy
-local pingsound
-local lotsound
-local pingnote
+local fps -- audio samples per game-step
+local game_time -- counts up to fps
+local ball_x, ball_y -- ball position [0..1]
+local dx, dy -- current ball speed
+local lost_sound -- audio-sample counter for game-over [0..3*fps]
+local ping_sound -- audio-sample counter for ping-sound [0..fps]
+local ping_phase -- ping note phase
+local ping_pitch
 
 function dsp_init (rate)
        self:shmem ():allocate (4)
        self:shmem ():clear ()
        fps = rate / 25
-       pingnote = 352 / rate
+       ping_pitch = 752 / rate
        ball_x = 0.5
        ball_y = 0
        dx = 0.011
-       dy = 0.021
+       dy = 0.0237
 end
 
 function dsp_configure (ins, outs)
-       gametime = fps
-       pingsound = fps
-       lostsound = 3 * fps
+       game_time  = fps -- start the ball immediately (notfiy GUI)
+       ping_sound = fps -- set to end of synth cycle
+       lost_sound = 3 * fps
 end
 
 function dsp_run (ins, outs, n_samples)
@@ -50,34 +51,38 @@ function dsp_run (ins, outs, n_samples)
        local shmem = self:shmem ()
        local state = shmem:to_float (0):array () -- "cast" into lua-table
 
-       local changed = false
-       gametime = gametime + n_samples
+       local changed = false -- flag to notify GUI on every game-step
+       game_time = game_time + n_samples
 
        -- simple game engine
-       while gametime > fps do
+       while game_time > fps do
                changed = true
-               gametime = gametime - fps
+               game_time = game_time - fps
 
+               -- move the ball
                ball_x = ball_x + dx
                ball_y = ball_y + dy
 
+               -- reflect left/right
                if ball_x >= 1 or ball_x <= 0 then dx = -dx end
+
+               -- single player (reflect top) -- TODO "stereo" version, 2 ctrls
                if ball_y <= 0 then dy = - dy end
 
                if ball_y > 1 then
-                       local bar = ctrl[1]
+                       local bar = ctrl[1] -- get bar position
                        if math.abs (bar - ball_x) < 0.1 then
                                dy = - dy
                                ball_y = 1.0
                                dx = dx + 0.1 * (bar - ball_x)
                                -- queue sound (unless it's playing)
-                               if (pingsound > fps) then
-                                       pingsound = 0
+                               if (ping_sound >= fps) then
+                                       ping_sound = 0
+                                       ping_phase = 0
                                end
-                               phase = 0
                        else
                                -- game over
-                               lostsound = 0
+                               lost_sound = 0
                                ball_y = 0
                                dx = 0.011
                        end
@@ -85,31 +90,38 @@ function dsp_run (ins, outs, n_samples)
        end
 
        -- simple synth -- TODO Optimize
-       if pingsound <= fps then
+       if ping_sound < fps then
+               local abufs = {}
+               for c = 1,#outs do
+                       abufs[c] = outs[c]:array();
+               end
                for s = 1, n_samples do
-                       pingsound = pingsound + 1
-                       if pingsound > fps then goto note_end end
-                       phase = phase + pingnote
-                       local snd = 0.7 * math.sin(6.283185307 * phase) * math.sin (3.141592 * pingsound / fps)
+                       ping_sound = ping_sound + 1
+                       ping_phase = ping_phase + ping_pitch
+                       local snd = 0.7 * math.sin(6.283185307 * ping_phase) * math.sin (3.141592 * ping_sound / fps)
                        for c = 1,#outs do
-                               -- don't copy this code, it's quick/dirty and not efficient
-                               outs[c]:array()[s] = outs[c]:array()[s] + snd
+                               abufs[c][s] = abufs[c][s] + snd
                        end
-                       ::note_end::
+                       if ping_sound >= fps then goto ping_end end
                end
+               ::ping_end::
        end
 
-       if lostsound <= 3 * fps then
+       if lost_sound < 3 * fps then
+               local abufs = {}
+               for c = 1,#outs do
+                       abufs[c] = outs[c]:array();
+               end
                for s = 1, n_samples do
-                       lostsound = lostsound + 1
-                       if lostsound > 3 * fps then goto noise_end end
+                       lost_sound = lost_sound + 1
+                       -- -12dBFS white noise
                        local snd = 0.5 * (math.random () - 0.5)
                        for c = 1,#outs do
-                               -- don't copy this code, it's quick/dirty and not efficient
-                               outs[c]:array()[s] = outs[c]:array()[s] + snd
+                               abufs[c][s] = abufs[c][s] + snd
                        end
-                       ::noise_end::
+                       if lost_sound >= 3 * fps then goto noise_end end
                end
+               ::noise_end::
        end
 
        if changed then