From ceb27728d38cf065eb7bce90c7372d7b420d1189 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Sat, 17 Dec 2022 22:45:08 -0500
Subject: [PATCH] add option to swap nibbles on raw sample import

issue #791
---
 src/engine/engine.cpp | 10 +++++++++-
 src/engine/engine.h   |  2 +-
 src/gui/gui.cpp       |  7 ++++++-
 src/gui/gui.h         |  2 +-
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 40f9f8cf6..281e7c5d5 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -3293,7 +3293,7 @@ DivSample* DivEngine::sampleFromFile(const char* path) {
 #endif
 }
 
-DivSample* DivEngine::sampleFromFileRaw(const char* path, DivSampleDepth depth, int channels, bool bigEndian, bool unsign) {
+DivSample* DivEngine::sampleFromFileRaw(const char* path, DivSampleDepth depth, int channels, bool bigEndian, bool unsign, bool swapNibbles) {
   if (song.sample.size()>=256) {
     lastError="too many samples!";
     return NULL;
@@ -3459,6 +3459,14 @@ DivSample* DivEngine::sampleFromFileRaw(const char* path, DivSampleDepth depth,
   }
   delete[] buf;
 
+  // swap nibbles if needed
+  if (swapNibbles) {
+    unsigned char* b=(unsigned char*)sample->getCurBuf();
+    for (unsigned int i=0; i<sample->getCurBufLen(); i++) {
+      b[i]=(b[i]<<4)|(b[i]>>4);
+    }
+  }
+
   BUSY_END;
   return sample;
 }
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 612bd4be7..0e10ff66a 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -796,7 +796,7 @@ class DivEngine {
     DivSample* sampleFromFile(const char* path);
 
     // get raw sample
-    DivSample* sampleFromFileRaw(const char* path, DivSampleDepth depth, int channels, bool bigEndian, bool unsign);
+    DivSample* sampleFromFileRaw(const char* path, DivSampleDepth depth, int channels, bool bigEndian, bool unsign, bool swapNibbles);
 
     // delete sample
     void delSample(int index);
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 6753fdfd7..76af88fcb 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -5019,8 +5019,12 @@ bool FurnaceGUI::loop() {
       ImGui::Checkbox("Big endian",&pendingRawSampleBigEndian);
       ImGui::EndDisabled();
 
+      ImGui::BeginDisabled(pendingRawSampleDepth==DIV_SAMPLE_DEPTH_16BIT);
+      ImGui::Checkbox("Swap nibbles",&pendingRawSampleSwapNibbles);
+      ImGui::EndDisabled();
+
       if (ImGui::Button("OK")) {
-        DivSample* s=e->sampleFromFileRaw(pendingRawSample.c_str(),(DivSampleDepth)pendingRawSampleDepth,pendingRawSampleChannels,pendingRawSampleBigEndian,pendingRawSampleUnsigned);
+        DivSample* s=e->sampleFromFileRaw(pendingRawSample.c_str(),(DivSampleDepth)pendingRawSampleDepth,pendingRawSampleChannels,pendingRawSampleBigEndian,pendingRawSampleUnsigned,pendingRawSampleSwapNibbles);
         if (s==NULL) {
           showError(e->getLastError());
         } else {
@@ -5684,6 +5688,7 @@ FurnaceGUI::FurnaceGUI():
   pendingRawSampleChannels(1),
   pendingRawSampleUnsigned(false),
   pendingRawSampleBigEndian(false),
+  pendingRawSampleSwapNibbles(false),
   globalWinFlags(0),
   curFileDialog(GUI_FILE_OPEN),
   warnAction(GUI_WARN_OPEN),
diff --git a/src/gui/gui.h b/src/gui/gui.h
index aa0ff29a9..805ce67ca 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -1116,7 +1116,7 @@ class FurnaceGUI {
 
   String pendingRawSample;
   int pendingRawSampleDepth, pendingRawSampleChannels;
-  bool pendingRawSampleUnsigned, pendingRawSampleBigEndian;
+  bool pendingRawSampleUnsigned, pendingRawSampleBigEndian, pendingRawSampleSwapNibbles;
 
   ImGuiWindowFlags globalWinFlags;