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SoundPatch: design a sound where it can be heard, then convert it

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The bang was guessed at directly in bytes and came out as a low gurgle,
which is what guessing at bytes gets you: a cutoff of 40 looks small and
is 57 Hz, so the filter sweep ended almost shut. Voyager's sound device
is soundThing's voice engine with the editor taken off, so a patch
designed in soundThing - where there is a screen, a keyboard and a pair
of ears - makes the same sound here. What differs is only how it arrives.

SoundPatch converts one into the other. Every parameter the device takes
is a documented function of a natural value and all of them invert: times
are squared into four seconds, cutoff and rate are exponential, depths
and detune are centred on 128. It writes a table of a count and that many
parameter and value pairs, and playPatch hands it to the device - so
every sound after this costs a table and a call rather than forty lines
of its own.

Two things the conversion has to say out loud. soundThing has no field
for the level routing, because there it is always the amplitude envelope,
so the table says so explicitly - a channel keeps its patch between notes
and a leftover from a previous one would otherwise be carried in. And a
field the tool does not recognise STOPS it: a patch format that has moved
on would otherwise produce a table that quietly means something else.

THE BUILD DOES NOT DEPEND ON IT. soundThing lives in its own repository
and is not needed to build anything here; the tables are checked in and
the tool is for when a sound is being changed.

Lander's crash now plays Kick808 as a stand-in until a bang is designed
for it, and the difference is the point: the hand-guessed patch wandered
between 1600 and 8200 for eight tenths of a second, and this decays
3492, 2743, 2037, 1515, 1040, 614, 87, nothing.

The docs check caught the tool count in two manuals, which is what it is
for.
This commit is contained in:
Anachronaut
2026-09-04 13:00:18 -04:00
parent 9ae59bfccb
commit a8b6b09a59
18 changed files with 385 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Programs/CosmOS/Apps/Lander.asm
+35 -79
View File
@@ -2661,10 +2661,18 @@ hideSprite:
; ---- The bang, set up once and played in two writes ----
;
; A patch is twenty odd writes and a note is two, which is the whole point of the selector and
; A patch is forty odd writes and a note is two, which is the whole point of the selector and
; value registers - so the instrument is built at startup like the tiles are, and a crash only
; has to say "this channel, this note".
;
; ---- And the numbers came out of soundThing ----
;
; The first version of this was guessed at in bytes, and a byte is not seconds or hertz: a
; cutoff of 40 looked small and is 57 Hz, which made the bang a low gurgle. Voyager's sound
; device is soundThing's voice engine with the editor taken off, so a patch designed there -
; where it can be HEARD - means the same thing here. SoundPatch converts one into the table
; below. Change the sound in soundThing and convert it again; do not edit the numbers.
;
; ---- Channel three, counting down ----
;
; Effects take the top channel and work downwards, so music, if it ever arrives, can take
@@ -2673,87 +2681,31 @@ hideSprite:
putBoom:
INIA 0x03
OUTA 0x41 ; Channel three. Every parameter write below lands on it.
SETD.0 BoomPatch
CALL playPatch
RET
; ---- Noise, which is what an explosion is ----
;
; Every other waveform here has a pitch, and a pitched bang is a note. Writing a port leaves
; A alone, so the three that selected the channel would select parameter three; the wave is
; parameter nought and has to be said.
RSTA
; ---- A whole patch, out of a table ----
;
; DP0 names a count and then that many parameter and value pairs. Every sound after this one
; costs a table and a call rather than forty lines of its own.
playPatch:
LDA.0
SETD.1 PatchLeft
STA.1
INCD.0
playPatchOne:
LDA.0
OUTA 0x42
INIA 0d5 ; Noise.
OUTA 0x43
INIA 0x01 ; Oscillator nought, gain.
OUTA 0x42
INIA 0xFF
OUTA 0x43
; ---- Instant, then a long way down ----
;
; No attack at all, because a bang that fades in is not a bang. A sustain of nothing does NOT
; end the note - a voice holding at nothing is what a held key is - so the gate still has to
; be dropped afterwards, which the explosion does once its pieces have gone.
INIA 0x20 ; Amplitude envelope, attack.
OUTA 0x42
RSTA
OUTA 0x43
INIA 0x21 ; ---- Decay: about half a second ----
OUTA 0x42 ;
; A byte is not seconds. It is squared and scaled to four of them,
; so 200 is two and a half - which over the eight tenths of a
; second the pieces are in the air is not a bang fading, it is the
; first third of one, and it read as a flat wash of noise.
INIA 0d90
OUTA 0x43
INIA 0x22 ; Sustain: nothing.
OUTA 0x42
RSTA
OUTA 0x43
INIA 0x23 ; Release.
OUTA 0x42
INIA 0d40
OUTA 0x43
; ---- And a filter closing, which is what makes it a boom and not a hiss ----
;
; Noise on its own is a cymbal. The modulation envelope shuts the low pass over the same
; moment the level falls, so the bright part is only at the front of it.
INIA 0x40 ; Filter, on.
OUTA 0x42
INIA 0x01
OUTA 0x43
INIA 0x41 ; Type: low pass.
OUTA 0x42
RSTA
OUTA 0x43
INIA 0x42 ; Cutoff, low, which is where it ends up.
OUTA 0x42
INIA 0d40
OUTA 0x43
INIA 0x43 ; A little resonance, so the sweep can be heard.
OUTA 0x42
INIA 0d120
OUTA 0x43
INIA 0x44 ; What opens it: the modulation envelope.
OUTA 0x42
INIA 0d2
OUTA 0x43
INIA 0x45 ; And how far above where it sits.
OUTA 0x42
INIA 0d200
OUTA 0x43
INIA 0x30 ; That envelope: open at once,
OUTA 0x42
RSTA
OUTA 0x43
INIA 0x31 ; shut over about a third of a second,
OUTA 0x42
INIA 0d90
OUTA 0x43
INIA 0x32 ; and stay shut.
OUTA 0x42
RSTA
INCD.0
LDA.0
OUTA 0x43
INCD.0
SETD.1 PatchLeft
LDA.1
DECA
STA.1
BNA playPatchOne
RET
; Two writes, which is what a note is meant to cost.
@@ -3948,6 +3900,8 @@ CopyLeft:
0x00
HideSlot:
0x00
PatchLeft:
0x00
; What a flame is being asked to be, before it is written out.
FlameSlot:
@@ -4132,3 +4086,5 @@ LanderArtAt:
#Reserve 0d2
#Include math.asm
#Include boom.asm
Programs/Sounds/boom.asm
+55
View File
@@ -0,0 +1,55 @@
; BoomPatch, converted from External/soundThing/patches/Drums/Kick808.json by SoundPatch.
; Designed in soundThing, where it can be heard. Do not edit the numbers
; here: change the patch and convert it again.
#Data
BoomPatch:
0d47 ; how many pairs follow
0x50 0x01 ; the level is the amplitude envelope
0x00 0d0 ; oscillator 0, waveform
0x01 0d255 ; gain
0x02 0d128 ; duty
0x03 0d128 ; detune, in cents
0x04 0d127 ; octave
0x05 0d1 ; on
0x06 0d0 ; what moves its width
0x07 0d128 ; and how far
0x08 0d2 ; what moves its pitch
0x09 0d197 ; and how far
0x0A 0d0 ; what moves its gain
0x0B 0d128 ; and how far
0x10 0d5 ; oscillator 1, waveform
0x11 0d146 ; gain
0x12 0d128 ; duty
0x13 0d128 ; detune, in cents
0x14 0d128 ; octave
0x15 0d1 ; on
0x16 0d0 ; what moves its width
0x17 0d128 ; and how far
0x18 0d0 ; what moves its pitch
0x19 0d128 ; and how far
0x1A 0d0 ; what moves its gain
0x1B 0d128 ; and how far
0x20 0d4 ; amplitude envelope, attack
0x21 0d79 ; decay
0x22 0d0 ; sustain
0x23 0d31 ; release
0x30 0d4 ; modulation envelope, attack
0x31 0d35 ; decay
0x32 0d0 ; sustain
0x33 0d13 ; release
0x40 0d1 ; filter, on
0x41 0d0 ; type: 0 low, 1 high, 2 band
0x42 0d92 ; cutoff, in hertz
0x43 0d10 ; resonance
0x44 0d0 ; what moves the cutoff
0x45 0d128 ; and how far, in hertz
0x46 0d0 ; what moves the resonance
0x47 0d128 ; and how far
0x60 0d0 ; LFO 0, on
0x61 0d0 ; waveform
0x62 0d127 ; rate, in hertz
0x70 0d0 ; LFO 1, on
0x71 0d0 ; waveform
0x72 0d127 ; rate, in hertz