From 0518c079ccb6c22b329e7776d3624f4f07613c78 Mon Sep 17 00:00:00 2001
From: Samuel Walker <swalker@piwalker.net>
Date: Mon, 3 Feb 2025 18:51:49 -0700
Subject: [PATCH] working on fixing wave and noise

---
 lib/audio.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/lib/audio.c b/lib/audio.c
index e156f66..1e79b1c 100644
--- a/lib/audio.c
+++ b/lib/audio.c
@@ -96,9 +96,9 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
                 ctx.ch3_period_timer = ctx.ch3_period_reset;
                 ctx.ch3_sample = (ctx.ch3_sample + 1) % 32;
                 if(ctx.ch3_sample & 0b1) {
-                    ctx.ch3_last_sample = ctx.wave_ram[ctx.ch3_sample << 1] & 0xF;
+                    ctx.ch3_last_sample = ctx.wave_ram[ctx.ch3_sample >> 1] & 0xF;
                 } else {
-                    ctx.ch3_last_sample = ctx.wave_ram[ctx.ch3_sample << 1] >> 4;
+                    ctx.ch3_last_sample = ctx.wave_ram[ctx.ch3_sample >> 1] >> 4;
                 }
             }
         }
@@ -106,12 +106,12 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
         for(;lfsr_timer >= lfsr_clock;lfsr_timer -= lfsr_clock) {
             if(lfsr_timer >= lfsr_clock && ctx.ch4_enable) {
                 lfsr_timer = 0;
-                ctx.ch4_lfsr = ctx.ch4_lfsr >> 1;
-                u8 new = (!(ctx.ch4_lfsr & 0b1) ^ ((ctx.ch4_lfsr >> 1)) & 0b1);
+                u8 new = !((ctx.ch4_lfsr & 0b1) ^ ((ctx.ch4_lfsr >> 1) & 0b1)) & 0b1;
                 ctx.ch4_lfsr |= (new << 15);
                 if(ctx.ch4_lfsr_width) {
                     ctx.ch4_lfsr |= (new << 7);
                 }
+                ctx.ch4_lfsr = ctx.ch4_lfsr >> 1;
                 //printf("lfsr: %02X, bit: %d\n", ctx.ch4_lfsr, new);
             }
         }
@@ -134,13 +134,20 @@ static int audio_callback(const void* input_uffer, void *output_buffer,
                 }
             }
 
-            if(ctx.ch3_enable) {
+            if(ctx.ch3_enable && ctx.ch3_volume != 00) {
+                u8 shift = 0;
+                if(ctx.ch3_volume == 0b10) {
+                    shift = 1;
+                }
+                if(ctx.ch3_volume == 0b11) {
+                    shift = 2;
+                }
                 if(ctx.ch3_left) {
-                    left += ((float)ctx.ch3_volume/4.0f) * (((float)(ctx.ch3_last_sample) - 7.5f)/7.5f);
+                    left += (((float)(ctx.ch3_last_sample >> shift) - 7.5f)/7.5f);
                     //printf("left: %d\n", ctx.ch3_volume);
                 }
                 if(ctx.ch3_right) {
-                    right += ((float)ctx.ch3_volume/4.0f) * (((float)(ctx.ch3_last_sample) - 7.5f)/7.5f);
+                    right += (((float)(ctx.ch3_last_sample >> shift) - 7.5f)/7.5f);
                 }
             }