add ability to preview wavetables

issue #16

src/engine/engine.cpp

@@ -2820,9 +2820,32 @@ void DivEngine::previewSample(int sample) {
   samp_prevSample=0;
   sPreview.pos=0;
   sPreview.sample=sample;
+  sPreview.wave=-1;
   isBusy.unlock();
 }
 
+void DivEngine::previewWave(int wave, int note) {
+  isBusy.lock();
+  if (wave<0 || wave>=(int)song.wave.size()) {
+    sPreview.wave=-1;
+    sPreview.pos=0;
+    isBusy.unlock();
+    return;
+  }
+  blip_clear(samp_bb);
+  blip_set_rates(samp_bb,song.wave[wave]->len*(27.5*pow(2.0,(double)(note+3)/12.0)),got.rate);
+  samp_prevSample=0;
+  sPreview.pos=0;
+  sPreview.sample=-1;
+  sPreview.wave=wave;
+  isBusy.unlock();
+}
+
+void DivEngine::stopWavePreview() {
+  sPreview.wave=-1;
+  sPreview.pos=0;
+}
+
 String DivEngine::getConfigPath() {
   return configPath;
 }

src/engine/engine.h

@@ -157,9 +157,11 @@ class DivEngine {
 
   struct SamplePreview {
     int sample;
+    int wave;
     unsigned int pos;
     SamplePreview():
       sample(-1),
+      wave(-1),
       pos(0) {}
   } sPreview;
 
@@ -263,6 +265,10 @@ class DivEngine {
     // trigger sample preview
     void previewSample(int sample);
 
+    // trigger wave preview
+    void previewWave(int wave, int note);
+    void stopWavePreview();
+
     // get config path
     String getConfigPath();
 

src/engine/playback.cpp

@@ -1,4 +1,5 @@
 #include "blip_buf.h"
+#include "wavetable.h"
 #define _USE_MATH_DEFINES
 #include "dispatch.h"
 #include "engine.h"
@@ -938,7 +939,7 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
   }
 
   isBusy.lock();
-  if (out!=NULL && sPreview.sample>=0 && sPreview.sample<(int)song.sample.size()) {
+  if (out!=NULL && ((sPreview.sample>=0 && sPreview.sample<(int)song.sample.size()) || (sPreview.wave>=0 && sPreview.wave<(int)song.wave.size()))) {
     unsigned int samp_bbOff=0;
     unsigned int prevAvail=blip_samples_avail(samp_bb);
     if (prevAvail>size) prevAvail=size;
@@ -946,22 +947,38 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
       blip_read_samples(samp_bb,samp_bbOut,prevAvail,0);
       samp_bbOff=prevAvail;
     }
-
-    DivSample* s=song.sample[sPreview.sample];
     size_t prevtotal=blip_clocks_needed(samp_bb,size-prevAvail);
 
-    for (size_t i=0; i<prevtotal; i++) {
+    if (sPreview.sample>=0 && sPreview.sample<(int)song.sample.size()) {
-      if (sPreview.pos>=s->rendLength) {
+      DivSample* s=song.sample[sPreview.sample];
-        samp_temp=0;
-      } else {
-        samp_temp=s->rendData[sPreview.pos++];
-      }
-      if (s->depth==8) samp_temp<<=8;
-      blip_add_delta(samp_bb,i,samp_temp-samp_prevSample);
-      samp_prevSample=samp_temp;
-    }
 
-    if (sPreview.pos>=s->rendLength) sPreview.sample=-1;
+      for (size_t i=0; i<prevtotal; i++) {
+        if (sPreview.pos>=s->rendLength) {
+          samp_temp=0;
+        } else {
+          samp_temp=s->rendData[sPreview.pos++];
+        }
+        if (s->depth==8) samp_temp<<=8;
+        blip_add_delta(samp_bb,i,samp_temp-samp_prevSample);
+        samp_prevSample=samp_temp;
+      }
+
+      if (sPreview.pos>=s->rendLength) sPreview.sample=-1;
+    } else if (sPreview.wave>=0 && sPreview.wave<(int)song.wave.size()) {
+      DivWavetable* wave=song.wave[sPreview.wave];
+      for (size_t i=0; i<prevtotal; i++) {
+        if (wave->max<=0) {
+          samp_temp=0;
+        } else {
+          samp_temp=((MIN(wave->data[sPreview.pos],wave->max)<<14)/wave->max)-8192;
+        }
+        if (++sPreview.pos>=(unsigned int)wave->len) {
+          sPreview.pos=0;
+        }
+        blip_add_delta(samp_bb,i,samp_temp-samp_prevSample);
+        samp_prevSample=samp_temp;
+      }
+    }
 
     blip_end_frame(samp_bb,prevtotal);
     blip_read_samples(samp_bb,samp_bbOut+samp_bbOff,size-samp_bbOff,0);

src/gui/gui.cpp

@@ -1213,6 +1213,7 @@ void FurnaceGUI::drawWaveEdit() {
         if (wave->len>256) wave->len=256;
         if (wave->len<1) wave->len=1;
         e->notifyWaveChange(curWave);
+        if (wavePreviewOn) e->previewWave(curWave,wavePreviewNote);
         modified=true;
       }
       ImGui::SameLine();
@@ -2907,6 +2908,22 @@ void FurnaceGUI::keyDown(SDL_Event& ev) {
         }
       }
       break;
+    case GUI_WINDOW_WAVE_LIST:
+    case GUI_WINDOW_WAVE_EDIT:
+      if (!ev.key.repeat) {
+        try {
+          int key=noteKeys.at(ev.key.keysym.scancode);
+          int num=12*curOctave+key;
+          if (key!=100) {
+            e->previewWave(curWave,num);
+            wavePreviewOn=true;
+            wavePreviewKey=ev.key.keysym.scancode;
+            wavePreviewNote=num;
+          }
+        } catch (std::out_of_range& e) {
+        }
+      }
+      break;
     default:
       break;
   }
@@ -2919,6 +2936,12 @@ void FurnaceGUI::keyUp(SDL_Event& ev) {
       e->noteOff(noteOffOnReleaseChan);
     }
   }
+  if (wavePreviewOn) {
+    if (ev.key.keysym.scancode==wavePreviewKey) {
+      wavePreviewOn=false;
+      e->stopWavePreview();
+    }
+  }
 }
 
 bool dirExists(String what) {
@@ -3260,6 +3283,12 @@ bool FurnaceGUI::loop() {
                 e->noteOff(noteOffOnReleaseChan);
               }
             }
+            if (wavePreviewOn) {
+              if (ev.key.keysym.scancode==wavePreviewKey) {
+                wavePreviewOn=false;
+                e->stopWavePreview();
+              }
+            }
           }
           break;
         case SDL_QUIT:
@@ -3847,6 +3876,9 @@ FurnaceGUI::FurnaceGUI():
   noteOffOnRelease(false),
   noteOffOnReleaseKey((SDL_Scancode)0),
   noteOffOnReleaseChan(0),
+  wavePreviewOn(false),
+  wavePreviewKey((SDL_Scancode)0),
+  wavePreviewNote(0),
   arpMacroScroll(0),
   macroDragStart(0,0),
   macroDragAreaSize(0,0),

src/gui/gui.h

@@ -223,6 +223,10 @@ class FurnaceGUI {
   SDL_Scancode noteOffOnReleaseKey;
   int noteOffOnReleaseChan;
 
+  bool wavePreviewOn;
+  SDL_Scancode wavePreviewKey;
+  int wavePreviewNote;
+
   std::map<SDL_Scancode,int> noteKeys;
   std::map<SDL_Keycode,int> valueKeys;