feat!: display the parameters as knobs in a grid

Also removed the negbandpass & neghighpass parameters
and replaced them with bandpass & highpass set to -1, to
fit the switches better to the GUI.

Closes #51, closes #173

tracker/presets/SY/Guitar.yml

@@ -1,9 +1,9 @@
-name: Guitar
-numvoices: 2
+name: guitar
+numvoices: 1
 units:
-    - type: envelope
-      id: 1
-      parameters: {attack: 27, decay: 80, gain: 112, release: 82, stereo: 0, sustain: 95}
+    - id: 92
+      parameters: {}
+      comment: Karplus-Strong
     - type: envelope
       id: 2
       parameters: {attack: 0, decay: 58, gain: 128, release: 0, stereo: 0, sustain: 0}
@@ -13,19 +13,25 @@ units:
     - type: mulp
       id: 4
       parameters: {stereo: 0}
-    - type: filter
-      id: 5
-      parameters: {bandpass: 1, frequency: 57, highpass: 1, lowpass: 1, negbandpass: 0, neghighpass: 0, resonance: 128, stereo: 0}
     - type: delay
       id: 6
       parameters: {damp: 48, dry: 128, feedback: 126, notetracking: 1, pregain: 128, stereo: 0}
       varargs: [10787]
+    - id: 90
+      parameters: {}
+      comment: Main envelope
+    - type: envelope
+      id: 1
+      parameters: {attack: 27, decay: 80, gain: 112, release: 82, stereo: 0, sustain: 95}
     - type: mulp
       id: 87
       parameters: {stereo: 0}
+    - id: 91
+      parameters: {}
+      comment: Filter & output
     - type: filter
       id: 88
-      parameters: {bandpass: 0, frequency: 72, highpass: 0, lowpass: 1, negbandpass: 0, neghighpass: 0, resonance: 128, stereo: 0}
+      parameters: {bandpass: 0, frequency: 72, highpass: 0, lowpass: 1, resonance: 128, stereo: 0}
     - type: pan
       id: 89
       parameters: {panning: 64, stereo: 0}