nullsound: vibrato FX for ADPCM-B channel

dciabrin · Dec 14, 2024 · eb67caf · eb67caf
1 parent 0fcea6b
commit eb67caf
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Showing 4 changed files with 62 additions and 1 deletion.
diff --git a/nullsound/nss-adpcm-b.s b/nullsound/nss-adpcm-b.s
@@ -74,6 +74,7 @@ state_b_fx:                     .blkb   1       ; enabled FX for this channel
 state_b_trigger:                .blkb   TRIGGER_SIZE
 state_b_fx_vol_slide:           .blkb   VOL_SLIDE_SIZE
 state_b_fx_slide:               .blkb   SLIDE_SIZE
+state_b_fx_vibrato:             .blkb   VIBRATO_SIZE
 ;;; ADPCM-B-specific state
 ;;; Note
 state_b_note:
@@ -157,6 +158,11 @@ run_adpcm_b_pipeline::
         ld      hl, #state_b_action_funcs
         call    eval_trigger_step
 _b_post_fx_trigger:
+        bit     BIT_FX_VIBRATO, FX(ix)
+        jr      z, _b_post_fx_vibrato
+        call    eval_b_vibrato_step
+        set     BIT_LOAD_NOTE, PIPELINE(ix)
+_b_post_fx_vibrato:
         bit     BIT_FX_SLIDE, FX(ix)
         jr      z, _b_post_fx_slide
         ld      hl, #NOTE_SEMITONE
@@ -410,6 +416,24 @@ adpcm_b_delta_n_half_distance::
         ;;         C,   C#,    D,   D#,    E,    F,   F#,    G,   G#,    A,   A#,    B
         .db     0x60, 0x66, 0x6d, 0x73, 0x7a, 0x81, 0x89, 0x91, 0x99, 0xa3, 0xac, 0xb7
 
+
+;;; Update the vibrato for the ADPCM-B channel
+;;; ------
+;;; ix: mirrored state of the ADPCM-B channel
+eval_b_vibrato_step::
+        push    hl
+        push    de
+        push    bc
+
+        call    vibrato_eval_step
+
+        pop     bc
+        pop     de
+        pop     hl
+
+        ret
+
+
 ;;; Update the slide for the current channel
 ;;; Slide moves up or down by 1/8 of semitone increments * slide depth.
 ;;; ------
@@ -805,3 +829,33 @@ adpcm_b_pan::
 
         ld      a, #1
         ret
+
+
+;;; ADPCM_B_VIBRATO
+;;; Enable vibrato for the channel
+;;; ------
+;;; [ hl ]: speed (4bits) and depth (4bits)
+adpcm_b_vibrato::
+        ;; TODO: move this part to common vibrato_init
+
+        ;; hl == 0 means disable vibrato
+        ld      a, (hl)
+        cp      #0
+        jr      nz, _setup_b_vibrato
+
+        ;; disable vibrato fx
+        res     BIT_FX_VIBRATO, FX(ix)
+
+        ;; reload configured note at the next pipeline run
+        set     BIT_LOAD_NOTE, PIPELINE(ix)
+
+        inc     hl
+        jr      _post_b_vibrato_setup
+
+_setup_b_vibrato:
+        call    vibrato_init
+
+_post_b_vibrato_setup:
+
+        ld      a, #1
+        ret
diff --git a/nullsound/nss-fm.s b/nullsound/nss-fm.s
@@ -956,7 +956,7 @@ fm_f_num_half_distance::
 
 ;;; Update the vibrato for the current FM channel
 ;;; ------
-;;; hl: mirrored state of the current fm channel
+;;; ix: mirrored state of the current fm channel
 eval_fm_vibrato_step::
         push    hl
         push    de

diff --git a/nullsound/stream.s b/nullsound/stream.s
@@ -532,6 +532,7 @@ nss_opcodes:
         .nss_op adpcm_a_retrigger
         .nss_op adpcm_a_pan
         .nss_op adpcm_b_pan
+        .nss_op adpcm_b_vibrato
 
 
 

diff --git a/tools/nsstool.py b/tools/nsstool.py
@@ -291,6 +291,7 @@ def register_nss_ops():
         ("a_retrigger", ["delay"]),
         ("a_pan",    ["pan_mask"]),
         ("b_pan",    ["pan_mask"]),
+        ("b_vibrato", ["speed_depth"]),
         # reserved opcodes
         ("nss_label", ["pat"])
     )
@@ -583,7 +584,12 @@ def convert_b_row(row, channel):
             elif fx in [0x08, 0x80]: # panning
                 pan_mask = convert_pan(fx, fxval)
                 opcodes.append(b_pan(pan_mask))
+            elif fx == 0x04:  # vibrato
+                # fxval == -1 means disable vibrato
+                fxval = max(fxval, 0)
+                opcodes.append(b_vibrato(fxval))
             else:
+                row_warn(row, "VIBRATO")
                 add_unknown_fx('ADPCM-B', fx)
 
         # note