add more vibrato shapes

doc/3-pattern/effects.md

@@ -42,12 +42,21 @@ however, effects are continuous (unless specified), which means you only need to
 - `00xy`: **Arpeggio.** this effect produces a rapid cycle between the current note, the note plus `x` semitones and the note plus `y` semitones.
 - `E0xx`: **Set arpeggio speed.** this sets the number of ticks between arpeggio values. default is 1.
   - ---
-- `04xy`: **Vibrato.** changes pitch to be "wavy" with a sine LFO. `x` is the speed, while `y` is the depth.
+- `04xy`: **Vibrato.** makes the pitch oscillate. `x` is the speed, while `y` is the depth.
   - maximum vibrato depth is ±1 semitone.
-- `E3xx`: **Set vibrato direction.** `xx` may be one of the following:
+- `E3xx`: **Set vibrato shape.** `xx` may be one of the following:
-  - `00`: up and down. default.
+  - `00`: sine (default)
-  - `01`: up only.
+  - `01`: sine (upper portion only)
-  - `02`: down only.
+  - `02`: sine (lower portion only)
+  - `03`: triangle
+  - `04`: ramp up
+  - `05`: ramp down
+  - `06`: square
+  - `07`: random
+  - `08`: square (up)
+  - `09`: square (down)
+  - `0a`: half sine (up)
+  - `0b`: half sine (down)
 - `E4xx`: **Set vibrato range** in 1/16th of a semitone. 
 
 ## panning

src/engine/engine.cpp

@@ -101,7 +101,7 @@ const char* DivEngine::getEffectDesc(unsigned char effect, int chan, bool notNul
     case 0xe2:
       return _("E2xy: Note slide down (x: speed; y: semitones)");
     case 0xe3:
-      return _("E3xx: Set vibrato shape (0: up/down; 1: up only; 2: down only)");
+      return _("E3xx: Set vibrato shape");
     case 0xe4:
       return _("E4xx: Set vibrato range");
     case 0xe5:

src/engine/engine.h

@@ -135,7 +135,7 @@ struct DivChannelState {
   int note, oldNote, lastIns, pitch, portaSpeed, portaNote;
   int volume, volSpeed, cut, legatoDelay, legatoTarget, rowDelay, volMax;
   int delayOrder, delayRow, retrigSpeed, retrigTick;
-  int vibratoDepth, vibratoRate, vibratoPos, vibratoPosGiant, vibratoDir, vibratoFine;
+  int vibratoDepth, vibratoRate, vibratoPos, vibratoPosGiant, vibratoShape, vibratoFine;
   int tremoloDepth, tremoloRate, tremoloPos;
   int sampleOff;
   unsigned char arp, arpStage, arpTicks, panL, panR, panRL, panRR, lastVibrato, lastPorta, cutType;
@@ -169,7 +169,7 @@ struct DivChannelState {
     vibratoRate(0),
     vibratoPos(0),
     vibratoPosGiant(0),
-    vibratoDir(0),
+    vibratoShape(0),
     vibratoFine(15),
     tremoloDepth(0),
     tremoloRate(0),

src/engine/playback.cpp

@@ -951,9 +951,9 @@ void DivEngine::processRow(int i, bool afterDelay) {
           if (!song.brokenShortcutSlides) dispatchCmd(DivCommand(DIV_CMD_PRE_PORTA,i,false,0));
         }
         break;
-      case 0xe3: // vibrato direction
+      case 0xe3: // vibrato shape
-        chan[i].vibratoDir=effectVal;
+        chan[i].vibratoShape=effectVal;
-        dispatchCmd(DivCommand(DIV_CMD_HINT_VIBRATO_SHAPE,i,chan[i].vibratoDir));
+        dispatchCmd(DivCommand(DIV_CMD_HINT_VIBRATO_SHAPE,i,chan[i].vibratoShape));
         break;
       case 0xe4: // vibrato fine
         chan[i].vibratoFine=effectVal;
@@ -1579,19 +1579,55 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
           while (chan[i].vibratoPos>=64) chan[i].vibratoPos-=64;
 
           chan[i].vibratoPosGiant+=chan[i].vibratoRate;
-          while (chan[i].vibratoPos>=512) chan[i].vibratoPos-=512;
+          while (chan[i].vibratoPosGiant>=512) chan[i].vibratoPosGiant-=512;
 
-          switch (chan[i].vibratoDir) {
+          int vibratoOut=0;
-            case 1: // up
+          switch (chan[i].vibratoShape) {
-              dispatchCmd(DivCommand(DIV_CMD_PITCH,i,chan[i].pitch+(MAX(0,(chan[i].vibratoDepth*vibTable[chan[i].vibratoPos]*chan[i].vibratoFine)>>4)/15)));
+            case 1: // sine, up only
+              vibratoOut=MAX(0,vibTable[chan[i].vibratoPos]);
               break;
-            case 2: // down
+            case 2: // sine, down only
-              dispatchCmd(DivCommand(DIV_CMD_PITCH,i,chan[i].pitch+(MIN(0,(chan[i].vibratoDepth*vibTable[chan[i].vibratoPos]*chan[i].vibratoFine)>>4)/15)));
+              vibratoOut=MIN(0,vibTable[chan[i].vibratoPos]);
               break;
-            default: // both
+            case 3: // triangle
-              dispatchCmd(DivCommand(DIV_CMD_PITCH,i,chan[i].pitch+(((chan[i].vibratoDepth*vibTable[chan[i].vibratoPos]*chan[i].vibratoFine)>>4)/15)));
+              vibratoOut=(chan[i].vibratoPos&31);
+              if (chan[i].vibratoPos&16) {
+                vibratoOut=32-(chan[i].vibratoPos&31);
+              }
+              if (chan[i].vibratoPos&32) {
+                vibratoOut=-vibratoOut;
+              }
+              vibratoOut<<=3;
+              break;
+            case 4: // ramp up
+              vibratoOut=chan[i].vibratoPos<<1;
+              break;
+            case 5: // ramp down
+              vibratoOut=-chan[i].vibratoPos<<1;
+              break;
+            case 6: // square
+              vibratoOut=(chan[i].vibratoPos>=32)?-127:127;
+              break;
+            case 7: // random (TODO: use LFSR)
+              vibratoOut=(rand()&255)-128;
+              break;
+            case 8: // square up
+              vibratoOut=(chan[i].vibratoPos>=32)?0:127;
+              break;
+            case 9: // square down
+              vibratoOut=(chan[i].vibratoPos>=32)?0:-127;
+              break;
+            case 10: // half sine up
+              vibratoOut=vibTable[chan[i].vibratoPos>>1];
+              break;
+            case 11: // half sine down
+              vibratoOut=vibTable[32|(chan[i].vibratoPos>>1)];
+              break;
+            default: // sine
+              vibratoOut=vibTable[chan[i].vibratoPos];
               break;
           }
+          dispatchCmd(DivCommand(DIV_CMD_PITCH,i,chan[i].pitch+(((chan[i].vibratoDepth*vibratoOut*chan[i].vibratoFine)>>4)/15)));
         }
         if (chan[i].legatoDelay>0) {
           if (--chan[i].legatoDelay<1) {

src/gui/debugWindow.cpp

@@ -155,7 +155,7 @@ void FurnaceGUI::drawDebug() {
           ImGui::Text("- depth = %d",ch->vibratoDepth);
           ImGui::Text("- rate = %d",ch->vibratoRate);
           ImGui::Text("- pos = %d",ch->vibratoPos);
-          ImGui::Text("- dir = %d",ch->vibratoDir);
+          ImGui::Text("- shape = %d",ch->vibratoShape);
           ImGui::Text("- fine = %d",ch->vibratoFine);
           ImGui::PopStyleColor();
           ImGui::PushStyleColor(ImGuiCol_Text,(ch->tremoloDepth>0)?uiColors[GUI_COLOR_MACRO_VOLUME]:uiColors[GUI_COLOR_TEXT]);