bit more work on the sound engine

5 files changed, 72 insertions, 16 deletions

diff --git a/jumpmanjr.dasm b/jumpmanjr.dasm
index 77b2963..dde3f36 100644
--- a/jumpmanjr.dasm
+++ b/jumpmanjr.dasm
@@ -1,5 +1,5 @@
 ; da65 V2.15 - Git 104f898
-; Created:    2016-09-05 19:01:23
+; Created:    2016-09-06 14:33:25
 ; Input file: jumpmanjr.rom
 ; Page:       1
 
@@ -71,7 +71,7 @@ sfx_ptr         := $063C
 sfx_slot_tempo  := $063E                        ; tempo of this sfx
 sfx_slot_timer  := $063F
 sfx_slot_duration:= $0646
-sfx_slot_freq   := $0647
+sfx_slot_audc   := $0647
 sfx_slot_curpos := $064E                        ; address we've got to so far, playing this sfx
 sfx_tempo_tmp   := $0661                        ; ??
 num_tmp         := $0665                        ; temp used by print_number
@@ -218,7 +218,7 @@ GRACTL          := $D01D
 HITCLR          := $D01E
 CONSOL          := $D01F
 AUDF1_minus_two := $D1FE
-AUDF1_minus_one := $D1FF
+AUDC1_minus_two := $D1FF
 AUDF1           := $D200
 AUDC1           := $D201
 AUDF2           := $D202
@@ -576,7 +576,7 @@ is_slot_active:
         cmp     sfx_slot_duration,x             ; 8170 DD 46 06                 .F.
         bne     next_sfx_slot                   ; 8173 D0 EA                    ..
         lda     #$00                            ; 8175 A9 00                    ..
-        sta     AUDF1_minus_one,x               ; 8177 9D FF D1                 ...
+        sta     AUDC1_minus_two,x               ; 8177 9D FF D1                 ...
         jmp     next_sfx_slot                   ; 817A 4C 5F 81                 L_.
 
 ; ----------------------------------------------------------------------------
@@ -590,7 +590,7 @@ sfx_next_note:
         cmp     #$04                            ; 818B C9 04                    ..
         bcs     sfx_play_note                   ; 818D B0 77                    .w
         cmp     #$01                            ; 818F C9 01                    ..
-        beq     sfx_change_tempo                ; 8191 F0 1B                    ..
+        beq     sfx_set_audc                    ; 8191 F0 1B                    ..
         cmp     #$02                            ; 8193 C9 02                    ..
         beq     sfx_jump_opcode                 ; 8195 F0 31                    .1
         cmp     #$03                            ; 8197 C9 03                    ..
@@ -601,7 +601,7 @@ sfx_next_note:
 ; y==0 on entry
 sfx_play_rest:
         tya                                     ; 819E 98                       .
-        sta     AUDF1_minus_one,x               ; 819F 9D FF D1                 ...
+        sta     AUDC1_minus_two,x               ; 819F 9D FF D1                 ...
         iny                                     ; 81A2 C8                       .
         lda     (zp_temp1),y                    ; 81A3 B1 CB                    ..
         sta     sfx_slot_timer,x                ; 81A5 9D 3F 06                 .?.
@@ -610,10 +610,10 @@ sfx_play_rest:
 
 ; ----------------------------------------------------------------------------
 ; y==0 on entry
-sfx_change_tempo:
+sfx_set_audc:
         iny                                     ; 81AE C8                       .
         lda     (zp_temp1),y                    ; 81AF B1 CB                    ..
-        sta     sfx_slot_freq,x                 ; 81B1 9D 47 06                 .G.
+        sta     sfx_slot_audc,x                 ; 81B1 9D 47 06                 .G.
         iny                                     ; 81B4 C8                       .
         lda     (zp_temp1),y                    ; 81B5 B1 CB                    ..
         sta     sfx_slot_duration,x             ; 81B7 9D 46 06                 .F.
@@ -663,8 +663,8 @@ sfx_play_note:
         iny                                     ; 8209 C8                       .
         lda     (zp_temp1),y                    ; 820A B1 CB                    ..
         sta     sfx_slot_timer,x                ; 820C 9D 3F 06                 .?.
-        lda     sfx_slot_freq,x                 ; 820F BD 47 06                 .G.
-        sta     AUDF1_minus_one,x               ; 8212 9D FF D1                 ...
+        lda     sfx_slot_audc,x                 ; 820F BD 47 06                 .G.
+        sta     AUDC1_minus_two,x               ; 8212 9D FF D1                 ...
         clc                                     ; 8215 18                       .
         lda     sfx_slot_curpos,x               ; 8216 BD 4E 06                 .N.
         adc     #$02                            ; 8219 69 02                    i.
@@ -679,7 +679,7 @@ cpos_hi_ok:
 sfx_finished:
         lda     #$00                            ; 8226 A9 00                    ..
         sta     sfx_slot_tempo,x                ; 8228 9D 3E 06                 .>.
-        sta     AUDF1_minus_one,x               ; 822B 9D FF D1                 ...
+        sta     AUDC1_minus_two,x               ; 822B 9D FF D1                 ...
         jmp     next_sfx_slot                   ; 822E 4C 5F 81                 L_.
 
 ; ----------------------------------------------------------------------------
diff --git a/jumpmanjr.inc b/jumpmanjr.inc
index 7341855..ba992fe 100644
--- a/jumpmanjr.inc
+++ b/jumpmanjr.inc
@@ -20,7 +20,7 @@ COLPF2 = $D018
 HSCROL = $D404
 COLBK  = $D01A
 AUDF1_minus_two = $D1FE
-AUDF1_minus_one = $D1FF
+AUDC1_minus_two = $D1FF
 AUDF1  = $D200
 AUDC1  = $D201
 AUDF2  = $D202
diff --git a/jumpmanjr.info b/jumpmanjr.info
index ae933ef..d3f2e51 100644
--- a/jumpmanjr.info
+++ b/jumpmanjr.info
@@ -306,9 +306,9 @@ label { name "sfx_slot_timer"; addr $063F; size 1; };
 label { name "sfx_slot_duration"; addr $0646; size 1; };
 label { name "sfx_play_note"; addr $8206; size 1; comment "y==0, a>=4 on entry"; };
 label { name "sfx_play_rest"; addr $819E; size 1; comment "y==0 on entry"; };
-label { name "sfx_change_tempo"; addr $81AE; size 1; comment "y==0 on entry"; };
+label { name "sfx_set_audc"; addr $81AE; size 1; comment "y==0 on entry"; };
 label { name "sfx_jump_opcode"; addr $81C8; size 1; comment "I *think* this jumps to a different sfx address..."; };
-label { name "sfx_slot_freq"; addr $0647; size 1; };
+label { name "sfx_slot_audc"; addr $0647; size 1; };
 
 range { name "sfx00"; start $BDF2; end $BE24; type bytetable; };
 range { name "sfx01"; start $BE25; end $BE78; type bytetable; };
diff --git a/main.info b/main.info
index 8a49eef..9f987f2 100644
--- a/main.info
+++ b/main.info
@@ -304,9 +304,9 @@ label { name "sfx_slot_timer"; addr $063F; size 1; };
 label { name "sfx_slot_duration"; addr $0646; size 1; };
 label { name "sfx_play_note"; addr $8206; size 1; comment "y==0, a>=4 on entry"; };
 label { name "sfx_play_rest"; addr $819E; size 1; comment "y==0 on entry"; };
-label { name "sfx_change_tempo"; addr $81AE; size 1; comment "y==0 on entry"; };
+label { name "sfx_set_audc"; addr $81AE; size 1; comment "y==0 on entry"; };
 label { name "sfx_jump_opcode"; addr $81C8; size 1; comment "I *think* this jumps to a different sfx address..."; };
-label { name "sfx_slot_freq"; addr $0647; size 1; };
+label { name "sfx_slot_audc"; addr $0647; size 1; };
 
 range { name "sfx00"; start $BDF2; end $BE24; type bytetable; };
 range { name "sfx01"; start $BE25; end $BE78; type bytetable; };
diff --git a/sound.txt b/sound.txt
new file mode 100644
index 0000000..c9754e9
--- /dev/null
+++ b/sound.txt
@@ -0,0 +1,56 @@
+Most of the sounds in the game are played by a sound engine that
+runs 'in the background' (called every vblank). There are some
+exceptions:
+
+- The descending tones played as the letters materialize, on the
+  title screen (but, the music after that uses the engine).
+- The descending tone you hear as Jumpman materializes, at the
+  start of a level.
+- The sound you hear as the screen crumbles, after you lose your
+  last life.
+
+Everything else uses the engine, and is stored as a series of
+engine opcodes. I've labelled these sfx_* in the source.
+
+The engine has 2 entry points: cue_sfx and cue_sfx_lowprior. The
+difference is that the _lowprior entry point will abort, if another call
+to cue_sfx is in progress. Also the arguments are passed differently.
+Also there are _jv (jump vector) versions of both entry points, which
+are the ones most of the rest of the code uses.
+
+Example sound effect:
+
+sfx_jump:
+        .byte   $01,$A5,$00,$79,$04,$60,$04,$51 ; BFBE 01 A5 00 79 04 60 04 51  ...y.`.Q
+        .byte   $04,$3C,$04,$51,$04,$60,$04,$79 ; BFC6 04 3C 04 51 04 60 04 79  .<.Q.`.y
+        .byte   $04,$00                         ; BFCE 04 00                    ..
+
+Sound opcodes:
+
+00          snd_end     end of sound
+01 xx yy    snd_audc    set distortion and volume (AUDCx value) to xx,
+                        play previous freq for yy frames.
+                        yy looks to always be zero in actual use,
+                        except the title screen music where it's $02.
+02 xx yy    snd_jump    jump to address yyxx. this is an unconditional
+                        jump, meaning the sfx plays continuously until
+                        preempted or silenced.
+03 xx       snd_rest    play a rest, xx frames (sets AUDCx to 0)
+[04-FF] xx  snd_note    play [opcode] frequency for xx frames
+
+so sfx_jump might look like this:
+
+sfx_jump:
+  snd_audc $A5,$00
+  snd_note $79,$04
+  snd_note $60,$04
+  snd_note $51,$04
+  snd_note $3C,$04
+  snd_note $51,$04
+  snd_note $60,$04
+  snd_note $79,$04
+  snd_end
+
+or in english: distortion $A (pure tone), volume 5. for 4 frames each,
+play 3 ascending notes, a higher note, then the same 3 notes in reverse
+order. the whole thing takes 28 frames to complete, or about 1/2 sec.