From 2eb2bb82f99ac3c24f2387329971ba548cca3c36 Mon Sep 17 00:00:00 2001
From: Bobbi Webber-Manners <bobbi.manners@gmail.com>
Date: Tue, 18 Oct 2022 00:15:39 -0400
Subject: [PATCH] ADSR refactoring.

---
 applecorn.po    | Bin 819200 -> 819200 bytes
 mainmem.audio.s |  29 ++++++++++++++++++-----------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/applecorn.po b/applecorn.po
index 7bc75f46c7f4d24d95f6da0c73a404e197d7aedb..284abffb4b581e711170e9e89252b9ba6f3322e5 100644
GIT binary patch
delta 414
zcmZo@FluNp+K|p7@YIDNNSBX+q2V!u0*KLE&eC4a!U)7nK+FupAU-P)vjH(X5OV-A
z=k{_IuG9&Pm$%=Y!sTMm=sI2L3RfJEYP`aAnCEDcL~UK%+`70G3X`V?T;&qYQcPID
zzR|{G0ry6mDuro@8)Om|aDezcP(Dw>0?v&#D^@Z9B@_NN#U=C|P3parc!0q`_-<R=
z1tyDx84|T^ac3_jZV+t{Llc_7)WE#<QsUe;pnaRB@43nqQhz3C0mDj#MJx)gNsE>&
z;7|bb8x}DG`SY^kP6>QZ@VFHPw8LY?&Zo&BYxgGs)nov9Nh?+=KzLPAD;*##pji!Y
z)&e-|094(tjD%ZJ$mUe(0=Y;A{Q}Cv%&Lk?kjOonv?_sNt<3?0-w7TH$F}de#%0L7
P><^1X+b6DNpSb$~{Y$Lf

delta 399
zcmZo@FluNp+K|p7aLI)sP}h`^q2V!u0*KLE&eC4a!U)7nK+FupAU-P)vjH(X5OV-A
z=k{_IuG9&P2e#jx!sTMmXf$2v3RfJEYP`aAm}gUxL~UK%+`70G3Juc(u5yWn%Oxye
z-)Q5pfP14&mBNI?4PprkI6!<JAb$gA!UE2XHY-*#B>ZcNOSsz>cY(<wp?81c42jyd
zxD7%F7!26Y?oZsn*}w&)CNMQHuic+Gw+(3c{ORYfa)s3IOj^LOQehE`f>F|<B?~wd
z!2E_q%s~FUthiGG-xEA;MfGh;@>sF+QZmpQg*8b)H5ou&(u$P|5MEW(N(TrFXjTK9
zwE)gK09E%ZBjHvQvN=_{KrWI&zku>Ev#O#JByu+;tx8~6YjeQhcY=q)=I!UNaTzjC
T7GM%y_J>8H?Gx9sPuzU~<glV^

diff --git a/mainmem.audio.s b/mainmem.audio.s
index c23a92b..3a90441 100644
--- a/mainmem.audio.s
+++ b/mainmem.audio.s
@@ -487,7 +487,7 @@ GETENVADDR  LDA   #<ENVBUF0                 ; Copy ENVBUF0 to A1L,A1H
 * Process pitch envelope
 * On entry: X is audio channel #
 * X is preserved
-PITCHENV    LDA   CHANENV,X                 ; Set envelope number
+PITCHENV    LDA   CHANENV,X                 ; Get envelope number
             TAY
             JSR   GETENVADDR                ; Addr of envelope -> A1L,A1H
             LDA   PITCHSECT,X               ; See what section we are in
@@ -551,7 +551,7 @@ UPDPITCH    STX   OSCNUM
 * Process amplitude envelope
 * On entry: X is audio channel #
 * X is preserved
-ADSRENV     LDA   CHANENV,X                 ; Set envelope number
+ADSRENV     LDA   CHANENV,X                 ; Get envelope number
             TAY
             JSR   GETENVADDR                ; Addr of envelope -> A1L,A1H
             LDA   AMPSECT,X                 ; See what section we are in
@@ -577,14 +577,14 @@ ADSRENV     LDA   CHANENV,X                 ; Set envelope number
             LDY   #ENVALD                   ; Parm: level at end of delay
             LDA   (A1L),Y                   ; Get value of parm
             PLY
-*            JSR   ADSRPHASE                 ; Generic ADSR phase handler
+            JSR   ADSRPHASE                 ; Generic ADSR phase handler
             BCS   :NEXTSECT                 ; Phase done -> sustain
             RTS
 :SUSTAIN    LDY   #ENVAS                    ; Parm: delay change/step
             LDA   (A1L),Y                   ; Get value of parm
             TAY
             LDA   #$00                      ; Target level zero
-*            JSR   ADSRPHASE                 ; Generic ADSR phase handler
+            JSR   ADSRPHASE                 ; Generic ADSR phase handler
             RTS
 :NEXTSECT   INC   AMPSECT,X                 ; Next section
             RTS
@@ -593,21 +593,28 @@ ADSRENV     LDA   CHANENV,X                 ; Set envelope number
 * Handle any individual phase of the ADSR envelope. Called by ADSRENV.
 * On entry: A - level at end of phase, X - audio channel, Y - change/step
 * On return: CS if end of phase, CC otherwise.  X preserved.
-ADSRPHASE   CMP   CURRAMP,X                 ; Compare tgt with current level
+ADSRPHASE   STX   OSCNUM
+            STA   :TARGET                   ; Stash target level for later
+            CPY   #$00                      ; Check sign of change/step
+            BMI   :DESCEND                  ; Descending amplitude
+:ASCEND     CMP   CURRAMP,X                 ; Compare tgt with current level
             BNE   :S1                       ; Not equal to target, keep going
             SEC                             ; CS to indicate phase is done
             RTS
-:S1         STA   :TARGET                   ; Target level
-            TYA                             ; Change/step -> A
+:S1         TYA                             ; Change/step -> A
             CLC
             ADC   CURRAMP,X                 ; Add change to current amp
-            BCS   :CLAMP                    ; If wrapped, clamp to target
-            CPY   #$00                      ; Check sign of change/step
-            BMI   :DESCEND                  ; Descending amplitude
             CMP   :TARGET                   ; Compare with target
             BCS   :CLAMP                    ; If target < sum, clamp to target
             BRA   :UPDATE                   
-:DESCEND    CMP   :TARGET                   ; Compare with target
+:DESCEND    CMP   CURRAMP,X                 ; Compare tgt with current level
+            BNE   :S2                       ; Not equal to target, keep going
+            SEC                             ; CS to indicate phase is done
+            RTS
+:S2         TYA                             ; Change/step -> A
+            CLC
+            ADC   CURRAMP,X                 ; Add change to current amp
+            CMP   :TARGET                   ; Compare with target
             BCC   :CLAMP                    ; If target >= sum, clamp to target
             BRA   :UPDATE                   
 :CLAMP      LDA   :TARGET                   ; Recover target level