From d951d3c57ea9c8d7b51abaeace5f03370cd15868 Mon Sep 17 00:00:00 2001
From: Tim Stirrat <tim.stirrat@gmail.com>
Date: Fri, 23 Aug 2024 12:34:42 +0800
Subject: [PATCH] Noise channel updates

- Use synth_state struct for consistency
- Fix sustain
---
 Source/io/midi_asm.s | 11 +++++------
 Source/synth/data.c  |  8 ++++----
 Source/synth/noi.c   | 17 ++++++++---------
 Source/synth/noi.h   | 10 ++++------
 4 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/Source/io/midi_asm.s b/Source/io/midi_asm.s
index 0c62e30..3a8e86b 100644
--- a/Source/io/midi_asm.s
+++ b/Source/io/midi_asm.s
@@ -3,8 +3,7 @@
 
   .globl _addressByte
   .globl _dataSet
-  .globl _noiEnv
-  .globl _noiSus
+  .globl _noiState
   .globl _parameterLock
   .globl _pbRange
   .globl _pbWheelIn
@@ -912,7 +911,7 @@ _asmNoiEnv$::
 	RRCA
 	AND #0x0F
 
-	ld	hl,#_noiEnv
+	ld	hl,#_noiState + 0 ; noiState.envelope
 	ld	(hl),A
 
 	ld	de,#_dataSet + 21
@@ -1021,14 +1020,14 @@ _asmNoiSusOn$::
 	ld	A,#0x01
 	ld	de,#_dataSet + 22
     ld	(de),A
-	ld	hl,#_noiSus
+	ld	hl,#_noiState + 1 ; noiState.sus
     ld	(hl),A
 ret
 _asmNoiSusOff$::
 	ld	A,#0x00
 	ld	de,#_dataSet + 22
     ld	(de),A
-	ld	hl,#_noiSus
+	ld	hl,#_noiState + 1 ; noiState.sus
     ld	(hl),A
 
 	ld	hl,#_noteStatus + 15
@@ -1045,7 +1044,7 @@ ret
 _asmNoiNf$::
 	ld	A,#0x00
 	ld (#0xFF21),A
-	ld	hl,#_noiSus
+	ld	hl,#_noiState + 1 ; noiState.sus
     ld	(hl),A
 	ld	de,#_dataSet + 22
     ld	(de),A
diff --git a/Source/synth/data.c b/Source/synth/data.c
index 62fbda2..58a59e2 100644
--- a/Source/synth/data.c
+++ b/Source/synth/data.c
@@ -116,14 +116,14 @@ void updateValueSynth(Parameter p) {
     setOutputPanBySynth(2, dataSet[p]);
     break;
   case NOI_Transpose:
-    noiOct = dataSet[p];
-    noiOct = (noiOct - 2U) * 12U;
+    noiState.octave = dataSet[p];
+    noiState.octave = (noiState.octave - 2U) * 12U;
     break;
   case NOI_Env:
-    noiEnv = dataSet[p];
+    noiState.envelope = dataSet[p];
     break;
   case NOI_Sustain:
-    noiSus = dataSet[p];
+    noiState.sus = dataSet[p];
     if (!dataSet[p] && !noteStatus[NOI].active)
       rAUD4ENV = 0U;
     break;
diff --git a/Source/synth/noi.c b/Source/synth/noi.c
index cc11f2e..830fa4b 100644
--- a/Source/synth/noi.c
+++ b/Source/synth/noi.c
@@ -11,12 +11,7 @@ uint8_t noiFreq[72] = {
     0x6C, 0x5F, 0x5E, 0x5D, 0x5C, 0x4F, 0x4E, 0x4D, 0x4C, 0x3F, 0x3E, 0x3D,
     0x3C, 0x2F, 0x2E, 0x2D, 0x2C, 0x1F, 0x1E, 0x1D, 0x1C, 0x0F, 0x0E, 0x08};
 
-uint8_t noiEnv;
-uint8_t noiMode;
-bool noiSus;
-
-bool noiNoteOffTrigger;
-int8_t noiOct;
+synth_state noiState;
 
 void updateNoi(void) {
   if (pbWheelIn[NOI] != PBWHEEL_CENTER) {
@@ -46,14 +41,18 @@ void updateNoi(void) {
 }
 
 void playNoteNoi(void) {
-  uint8_t noteIndex = addressByte - 24U + noiOct;
+  uint8_t noteIndex = addressByte - 24U + noiState.octave;
+
+  if (noteIndex >= MAX_NOI_FREQ) {
+    return;
+  }
 
   if (valueByte == 0) {
     // Note off
     if (noteStatus[NOI].note == noteIndex) {
       noteStatus[NOI].active = false;
 
-      if (!noiSus) {
+      if (!noiState.sus) {
         rAUD4ENV = 0x00;
       }
     }
@@ -64,7 +63,7 @@ void playNoteNoi(void) {
   noteStatus[NOI].note = noteIndex;
 
   // Set envelope
-  uint8_t envelope = ((valueByte << 1) & 0xF0) | noiEnv;
+  uint8_t envelope = ((valueByte << 1) & 0xF0) | noiState.envelope;
   rAUD4ENV = envelope;
 
   // Set frequency
diff --git a/Source/synth/noi.h b/Source/synth/noi.h
index ce5149e..95e0a88 100644
--- a/Source/synth/noi.h
+++ b/Source/synth/noi.h
@@ -1,15 +1,13 @@
 #pragma once
 
+#include "common.h"
 #include <gbdk/platform.h>
 #include <stdbool.h>
 
-extern uint8_t noiFreq[72];
-extern uint8_t noiEnv;
-extern uint8_t noiMode;
-extern bool noiSus;
+#define MAX_NOI_FREQ 72
 
-extern bool noiNoteOffTrigger;
-extern int8_t noiOct;
+extern uint8_t noiFreq[72];
+extern synth_state noiState;
 
 void updateNoi(void);
 void setPitchBendFrequencyOffsetNoise(void);