feat(vm): add frequency modulation for oscillators

Closes #105

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   home directory of the user.
 - Instrument presets. The presets are embedded in the executable and
   there's a button to open a menu to load one of the presets.
+- Frequency modulation target for oscillator, as it was in 4klang
 
 ### Fixed
 - The sointu-vsti-native plugin has different plugin ID and plugin name

tests/CMakeLists.txt

@@ -124,6 +124,8 @@ regression_test(test_oscillat_colormod "VCO_SINE;ENVELOPE;FOP_MULP;FOP_PUSH;SEND
 regression_test(test_oscillat_shapemod "VCO_SINE;ENVELOPE;FOP_MULP;FOP_PUSH;SEND")
 regression_test(test_oscillat_gainmod OSCGAINMOD "VCO_SINE;ENVELOPE;FOP_MULP;FOP_PUSH;SEND")
 regression_test(test_oscillat_gainmod_stereo "" OSCGAINMOD)
+regression_test(test_oscillat_frequencymod "VCO_SINE;ENVELOPE;FOP_MULP;FOP_PUSH;SEND")
+regression_test(test_oscillat_frequencymod_stereo "VCO_SINE;ENVELOPE;FOP_MULP;FOP_PUSH;SEND")
 
 regression_test(test_distort ENVELOPE)
 regression_test(test_distort_mod "VCO_SINE;ENVELOPE;SEND")

tests/test_oscillat_frequencymod.yml

@@ -0,0 +1,27 @@
+bpm: 100
+rowsperbeat: 4
+score:
+    rowsperpattern: 16
+    length: 1
+    tracks:
+        - numvoices: 1
+          order: [0]
+          patterns: [[80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0]]
+patch:
+    - numvoices: 1
+      units:
+        - type: envelope
+          parameters: {attack: 80, decay: 80, gain: 128, release: 80, stereo: 0, sustain: 64}
+        - type: oscillator
+          parameters: {color: 128, detune: 64, gain: 128, lfo: 0, phase: 0, shape: 64, stereo: 0, transpose: 64, type: 0, unison: 0}
+          id: 1
+        - type: mulp
+          parameters: {stereo: 0}
+        - type: push
+          parameters: {stereo: 0}
+        - type: oscillator
+          parameters: {color: 128, detune: 64, gain: 128, lfo: 1, phase: 64, shape: 64, stereo: 0, transpose: 70, type: 0, unison: 0}
+        - type: send
+          parameters: {amount: 68, port: 6, sendpop: 1, stereo: 0, target: 1}
+        - type: out
+          parameters: {gain: 128, stereo: 1}

tests/test_oscillat_frequencymod_stereo.yml

@@ -0,0 +1,27 @@
+bpm: 100
+rowsperbeat: 4
+score:
+    rowsperpattern: 16
+    length: 1
+    tracks:
+        - numvoices: 1
+          order: [0]
+          patterns: [[80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0]]
+patch:
+    - numvoices: 1
+      units:
+        - type: envelope
+          parameters: {attack: 80, decay: 80, gain: 128, release: 80, stereo: 0, sustain: 64}
+        - type: push
+          parameters: {stereo: 0}
+        - type: oscillator
+          parameters: {color: 128, detune: 64, gain: 128, lfo: 0, phase: 0, shape: 64, stereo: 1, transpose: 64, type: 0, unison: 0}
+          id: 1
+        - type: mulp
+          parameters: {stereo: 1}
+        - type: oscillator
+          parameters: {color: 128, detune: 64, gain: 128, lfo: 1, phase: 64, shape: 64, stereo: 0, transpose: 70, type: 0, unison: 0}
+        - type: send
+          parameters: {amount: 68, port: 6, sendpop: 1, stereo: 0, target: 1}
+        - type: out
+          parameters: {gain: 128, stereo: 1}

unittype.go

@@ -105,6 +105,7 @@ var UnitTypes = map[string]([]UnitParameter){
 		{Name: "color", MinValue: 0, MaxValue: 128, CanSet: true, CanModulate: true},
 		{Name: "shape", MinValue: 0, MaxValue: 128, CanSet: true, CanModulate: true},
 		{Name: "gain", MinValue: 0, MaxValue: 128, CanSet: true, CanModulate: true},
+		{Name: "frequency", MinValue: 0, MaxValue: -1, CanSet: false, CanModulate: true},
 		{Name: "type", MinValue: int(Sine), MaxValue: int(Sample), CanSet: true, CanModulate: false},
 		{Name: "lfo", MinValue: 0, MaxValue: 1, CanSet: true, CanModulate: false},
 		{Name: "unison", MinValue: 0, MaxValue: 3, CanSet: true, CanModulate: false},

vm/compiler/templates/amd64-386/sources.asm

@@ -99,6 +99,11 @@ su_op_noise_mono:
 ;   Stereo: push l r on stack, where l has opposite detune compared to r
 ;-------------------------------------------------------------------------------
 {{.Func "su_op_oscillator" "Opcode"}}
+{{- if .SupportsModulation "oscillator" "frequency"}}
+    push    0
+    pop     {{.CX}}     ; clear cx without affecting flags
+    xchg    ecx, dword [{{.Modulation "oscillator" "frequency"}}]
+{{- end}}
     lodsb                                   ; load the flags
 {{- if .Library}}
     mov     {{.DI}}, [{{.Stack "SampleTable"}}]; we need to put this in a register, as the stereo & unisons screw the stack positions
@@ -175,6 +180,11 @@ su_op_oscillat_normalize_note:
     fmul    dword [{{.Float 0.000092696138 | .Use}}]   ; // st0 is now frequency
 su_op_oscillat_normalized:
     fadd    dword [{{.WRK}}]
+{{- if .SupportsModulation "oscillator" "frequency"}}
+    push    {{.CX}}
+    fadd    dword [{{.SP}}]
+    pop     {{.CX}}
+{{- end}}
 {{- if .SupportsParamValue "oscillator" "type" .Sample}}
     test    al, byte 0x80
     jz      short su_op_oscillat_not_sample

vm/compiler/templates/wasm/sources.wat

@@ -107,9 +107,16 @@
 {{- if .SupportsParamValueOtherThan "oscillator" "unison" 0}}
     (local $unison i32) (local $WRK_stash i32) (local $detune_stash f32)
 {{- end}}
+{{- if .SupportsModulation "oscillator" "frequency"}}
+    (local $freqMod f32)
+{{- end}}
 {{- if .Stereo "oscillator"}}
     (local $WRK_stereostash i32)
     (local.set $WRK_stereostash (global.get $WRK))
+{{- end}}
+{{- if .SupportsModulation "oscillator" "frequency"}}
+    (local.set $freqMod (f32.load offset={{.InputNumber "oscillator" "frequency" | mul 4 | add 32}} (global.get $WRK)))
+    (f32.store offset={{.InputNumber "oscillator" "frequency" | mul 4 | add 32}} (global.get $WRK) (f32.const 0))
 {{- end}}
     (local.set $flags (call $scanValueByte))
     (local.set $detune (call $inputSigned (i32.const {{.InputNumber "oscillator" "detune"}})))
@@ -146,6 +153,9 @@
                         (f32.const 0.000092696138) ;; scaling constant to get middle-C to where it should be
                         (i32.and (local.get $flags) (i32.const 0x8))
                     ))
+{{- if .SupportsModulation "oscillator" "frequency"}}
+                    (f32.add (local.get $freqMod))
+{{- end}}
                     (f32.add (f32.load (global.get $WRK))) ;; add the current phase of the oscillator
                 )
                 (f32.floor (local.get $phase))

vm/interpreter.go

@@ -454,6 +454,7 @@ func (s *Interpreter) Render(buffer []float32, maxtime int) (samples int, time i
 						} else {
 							omega *= 0.000038 //  pretty random scaling constant to get LFOs into reasonable range. Historical reasons, goes all the way back to 4klang
 						}
+						omega += float64(unit.ports[6]) // add frequency modulation
 						var amplitude float32
 						*statevar += float32(omega)
 						if flags&0x80 == 0x80 { // if this is a sample oscillator
@@ -515,6 +516,7 @@ func (s *Interpreter) Render(buffer []float32, maxtime int) (samples int, time i
 					stack = append(stack, output)
 					detuneStereo = -detuneStereo
 				}
+				unit.ports[6] = 0
 			case opDelay:
 				pregain2 := params[0] * params[0]
 				damp := params[3]