faster sample format conversion

don't render in all formats when converting

src/engine/engine.h

@@ -52,9 +52,9 @@ class DivWorkPool;
 #define EXTERN_BUSY_BEGIN_SOFT e->softLocked=true; e->isBusy.lock();
 #define EXTERN_BUSY_END e->isBusy.unlock(); e->softLocked=false;
 
-//#define DIV_UNSTABLE
+#define DIV_UNSTABLE
 
-#define DIV_VERSION "0.6.2"
+#define DIV_VERSION "dev197"
 #define DIV_ENGINE_VERSION 197
 // for imports
 #define DIV_VERSION_MOD 0xff01

src/engine/sample.cpp

@@ -807,8 +807,8 @@ bool DivSample::insert(unsigned int pos, unsigned int length) {
   return false;
 }
 
-void DivSample::convert(DivSampleDepth newDepth) {
-  render();
+void DivSample::convert(DivSampleDepth newDepth, unsigned int formatMask) {
+  render(formatMask|(1U<<newDepth));
   depth=newDepth;
   switch (depth) {
     case DIV_SAMPLE_DEPTH_1BIT:
@@ -845,7 +845,7 @@ void DivSample::convert(DivSampleDepth newDepth) {
     default:
       break;
   }
-  render();
+  render(formatMask|(1U<<newDepth));
 }
 
 #define RESAMPLE_BEGIN \
@@ -1309,6 +1309,7 @@ void DivSample::render(unsigned int formatMask) {
     if (!initInternal(DIV_SAMPLE_DEPTH_1BIT_DPCM,samples)) return;
     int accum=63;
     int next=63;
+    
     for (unsigned int i=0; (i<samples && (i>>3)<lengthDPCM); i++) {
       next=((unsigned short)(data16[i]^0x8000))>>9;
       if (next>accum) {

src/engine/sample.h

@@ -288,7 +288,7 @@ struct DivSample {
    * @warning do not attempt to do this outside of a synchronized block!
    * @param newDepth the new depth.
    */
-  void convert(DivSampleDepth newDepth);
+  void convert(DivSampleDepth newDepth, unsigned int formatMask=0xffffffff);
 
   /**
    * initialize the rest of sample formats for this sample.

src/gui/sampleEdit.cpp

@@ -498,7 +498,7 @@ void FurnaceGUI::drawSampleEdit() {
               if (ImGui::Selectable(sampleDepths[i])) {
                 sample->prepareUndo(true);
                 e->lockEngine([this,sample,i]() {
-                  sample->convert((DivSampleDepth)i);
+                  sample->convert((DivSampleDepth)i,e->getSampleFormatMask());
                   e->renderSamples(curSample);
                 });
                 updateSampleTex=true;