add effects for quick legato

doc/3-pattern/effects.md

@@ -34,6 +34,11 @@ however, effects are continuous, which means you only need to type it once and t
 - `E2xy`: **Note slide down.** `x` is the speed, while `y` is how many semitones to slide down.
   - ---
 - `EAxx`: **Toggle legato.** while on, new notes instantly change the pitch of the currently playing sound instead of starting it over.
+- `E6xy`: **Quick legato (compatibility).** transposes note by `y` semitones after `x` ticks.
+  - if `x` is between 0 and 7, it transposes up.
+  - if `x` is between 8 and F, it transposes down.
+- `E8xy`: **Quick legato up**. transposes note up by `y` semitones after `x` ticks.
+- `E9xy`: **Quick legato down**. transposes note down by `y` semitones after `x` ticks.
 - `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.
   - ---

src/engine/engine.cpp

@@ -105,8 +105,14 @@ const char* DivEngine::getEffectDesc(unsigned char effect, int chan, bool notNul
       return "E4xx: Set vibrato range";
     case 0xe5:
       return "E5xx: Set pitch (80: center)";
+    case 0xe6:
+      return "E6xy: Quick legato (x: time (0-7 up; 8-F down); y: semitones)";
     case 0xe7:
       return "E7xx: Macro release";
+    case 0xe8:
+      return "E8xy: Quick legato up (x: time; y: semitones)";
+    case 0xe9:
+      return "E9xy: Quick legato down (x: time; y: semitones)";
     case 0xea:
       return "EAxx: Legato";
     case 0xeb:

src/engine/engine.h

@@ -100,7 +100,7 @@ enum DivMIDIModes {
 struct DivChannelState {
   std::vector<DivDelayedCommand> delayed;
   int note, oldNote, lastIns, pitch, portaSpeed, portaNote;
-  int volume, volSpeed, cut, rowDelay, volMax;
+  int volume, volSpeed, cut, legatoDelay, legatoTarget, rowDelay, volMax;
   int delayOrder, delayRow, retrigSpeed, retrigTick;
   int vibratoDepth, vibratoRate, vibratoPos, vibratoPosGiant, vibratoDir, vibratoFine;
   int tremoloDepth, tremoloRate, tremoloPos;
@@ -123,6 +123,8 @@ struct DivChannelState {
     volume(0x7f00),
     volSpeed(0),
     cut(-1),
+    legatoDelay(-1),
+    legatoTarget(0),
     rowDelay(0),
     volMax(0),
     delayOrder(0),

src/engine/playback.cpp

@@ -956,6 +956,21 @@ void DivEngine::processRow(int i, bool afterDelay) {
         dispatchCmd(DivCommand(DIV_CMD_PITCH,i,chan[i].pitch+(((chan[i].vibratoDepth*vibTable[chan[i].vibratoPos]*chan[i].vibratoFine)>>4)/15)));
         dispatchCmd(DivCommand(DIV_CMD_HINT_PITCH,i,chan[i].pitch));
         break;
+      case 0xe6: // Delayed legato
+        // why does this have to follow FamiTracker verbatim
+        // couldn't you do better?
+        if ((effectVal&15)!=0) {
+          chan[i].legatoDelay=(((effectVal&0xf0)>>4)&7)+1;
+          if (effectVal&128) {
+            chan[i].legatoTarget=-(effectVal&15);
+          } else {
+            chan[i].legatoTarget=(effectVal&15);
+          }
+        } else {
+          chan[i].legatoDelay=-1;
+          chan[i].legatoTarget=0;
+        }
+        break;
       case 0xe7: // delayed macro release
         // "Bruh"
         if (effectVal>0 && (song.delayBehavior==2 || effectVal<nextSpeed)) {
@@ -963,6 +978,25 @@ void DivEngine::processRow(int i, bool afterDelay) {
           chan[i].cutType=2;
         }
         break;
+      case 0xe8: // delayed legato up
+        // see? you COULD do better!
+        if ((effectVal&15)!=0) {
+          chan[i].legatoDelay=((effectVal&0xf0)>>4)+1;
+          chan[i].legatoTarget=(effectVal&15);
+        } else {
+          chan[i].legatoDelay=-1;
+          chan[i].legatoTarget=0;
+        }
+        break;
+      case 0xe9: // delayed legato down
+        if ((effectVal&15)!=0) {
+          chan[i].legatoDelay=((effectVal&0xf0)>>4)+1;
+          chan[i].legatoTarget=-(effectVal&15);
+        } else {
+          chan[i].legatoDelay=-1;
+          chan[i].legatoTarget=0;
+        }
+        break;
       case 0xea: // legato mode
         chan[i].legato=effectVal;
         break;
@@ -1539,6 +1573,15 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
               break;
           }
         }
+        if (chan[i].legatoDelay>0) {
+          if (--chan[i].legatoDelay<1) {
+            chan[i].note+=chan[i].legatoTarget;
+            dispatchCmd(DivCommand(DIV_CMD_LEGATO,i,chan[i].note));
+            dispatchCmd(DivCommand(DIV_CMD_HINT_LEGATO,i,chan[i].note));
+            chan[i].legatoDelay=-1;
+            chan[i].legatoTarget=0;
+          }
+        }
         if (!song.noSlidesOnFirstTick || !firstTick) {
           if ((chan[i].keyOn || chan[i].keyOff) && chan[i].portaSpeed>0) {
             if (dispatchCmd(DivCommand(DIV_CMD_NOTE_PORTA,i,chan[i].portaSpeed*(song.linearPitch==2?song.pitchSlideSpeed:1),chan[i].portaNote))==2 && chan[i].portaStop && song.targetResetsSlides) {

src/gui/guiConst.cpp

@@ -489,10 +489,10 @@ const FurnaceGUIColors fxColors[256]={
   GUI_COLOR_PATTERN_EFFECT_MISC, // E3
   GUI_COLOR_PATTERN_EFFECT_MISC, // E4
   GUI_COLOR_PATTERN_EFFECT_PITCH, // E5
-  GUI_COLOR_PATTERN_EFFECT_INVALID, // E6
+  GUI_COLOR_PATTERN_EFFECT_MISC, // E6
   GUI_COLOR_PATTERN_EFFECT_TIME, // E7
-  GUI_COLOR_PATTERN_EFFECT_INVALID, // E8
-  GUI_COLOR_PATTERN_EFFECT_INVALID, // E9
+  GUI_COLOR_PATTERN_EFFECT_MISC, // E8
+  GUI_COLOR_PATTERN_EFFECT_MISC, // E9
   GUI_COLOR_PATTERN_EFFECT_MISC, // EA
   GUI_COLOR_PATTERN_EFFECT_MISC, // EB
   GUI_COLOR_PATTERN_EFFECT_TIME, // EC