From eaac5cc224312daf5aba3cf66fde8baff35d70de Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Tue, 29 Aug 2023 04:09:11 -0500
Subject: [PATCH] C219: fix VGM export

a sample word has two 8-bit samples in reverse order
(need hardware confirmation)
---
 src/engine/platform/c140.cpp          | 9 +++++----
 src/engine/platform/sound/c140_c219.c | 4 ++--
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/engine/platform/c140.cpp b/src/engine/platform/c140.cpp
index 362ece043..61e12c8ae 100644
--- a/src/engine/platform/c140.cpp
+++ b/src/engine/platform/c140.cpp
@@ -573,6 +573,7 @@ void DivPlatformC140::renderSamples(int sysID) {
       if ((memPos&0xfe0000)!=((memPos+length)&0xfe0000)) {
         memPos=((memPos+0x1ffff)&0xfe0000);
       }
+      logV("%d",length);
       if (memPos>=(getSampleMemCapacity())) {
         logW("out of C219 memory for sample %d!",i);
         break;
@@ -584,17 +585,17 @@ void DivPlatformC140::renderSamples(int sysID) {
       if (s->depth==DIV_SAMPLE_DEPTH_C219) {
         for (unsigned int i=0; i<length; i++) {
           if (i>=s->lengthC219) {
-            sampleMem[i+memPos]=0;
+            sampleMem[(memPos+i)^1]=0;
           } else {
-            sampleMem[i+memPos]=s->dataC219[i];
+            sampleMem[(memPos+i)^1]=s->dataC219[i];
           }
         }
       } else {
         for (unsigned int i=0; i<length; i++) {
           if (i>=s->length8) {
-            sampleMem[memPos+i]=0;
+            sampleMem[(memPos+i)^1]=0;
           } else {
-            sampleMem[memPos+i]=s->data8[i];
+            sampleMem[(memPos+i)^1]=s->data8[i];
           }
         }
       }
diff --git a/src/engine/platform/sound/c140_c219.c b/src/engine/platform/sound/c140_c219.c
index 67aa6dc4c..56d96ca19 100644
--- a/src/engine/platform/sound/c140_c219.c
+++ b/src/engine/platform/sound/c140_c219.c
@@ -171,8 +171,8 @@ void c219_voice_tick(struct c219_t *c219, const unsigned char v, const int cycle
 			else
 			{
 				// fetch 8 bit sample
-				signed short s1 = c219->sample_mem[((unsigned int)(c219->bank[(v >> 2) & 3]) << 17) | voice->addr];
-				signed short s2 = c219->sample_mem[((unsigned int)(c219->bank[(v >> 2) & 3]) << 17) | ((voice->addr + 1) & 0x1ffff)];
+				signed short s1 = c219->sample_mem[((unsigned int)(c219->bank[(v >> 2) & 3]) << 17) | (voice->addr^1)];
+				signed short s2 = c219->sample_mem[((unsigned int)(c219->bank[(v >> 2) & 3]) << 17) | (((voice->addr + 1) & 0x1ffff)^1)];
 				if (voice->compressed)
 				{
 					s1 = c219->mulaw[s1&0xff];