Ladder filter title animation

src/droplets/droplet.cpp

@@ -21,6 +21,10 @@ int Droplet::GetTitleHeight() {
   return kTitleHeight;
 }
 
+int Droplet::GetScreenWidth() {
+  return screen_max - screen_min;
+}
+
 int Droplet::GetScreenMin() {
   return screen_min;
 }

src/droplets/droplet.h

@@ -99,6 +99,13 @@ public:
    */
   int GetTitleHeight();
 
+  /*
+   * Returns the width of the droplet.
+   *
+   * @return screen width of the droplet
+   */
+  int GetScreenWidth();
+
   /*
    * Returns the minimum screen position based on droplet size.
    *

src/droplets/ladder_filter_droplet.cpp

@@ -26,12 +26,45 @@ void LadderFilterDroplet::Process(AudioHandle::InputBuffer in,
       filter[chn].SetFreq(freq);
       filter[chn].SetRes(res);
       out[chn][i] = filter[chn].Process(in[chn][i]) * (1.0f+res*4);
-      //out[chn][i] = in[chn][i] * res;
     }
   }
 }
 
 void LadderFilterDroplet::Draw() {
+  int filter_cutoff_line = GetScreenMin()+(GetScreenWidth()*(freq/FILTER_MAX));
+  DrawSolidRect(Patch(),
+		GetScreenMin(),
+		3,
+		filter_cutoff_line,
+		GetTitleHeight()-1,
+		true);
+
+  // Draw filter roll off
+  Patch()->display.DrawLine(filter_cutoff_line+1, 5,
+  			    filter_cutoff_line+1, GetTitleHeight()-1, true);
+
+  // Draw Res
+  res_points[0] = filter_cutoff_line-7*(res/RES_MAX);
+  res_points[1] = filter_cutoff_line-3;
+  res_points[2] = filter_cutoff_line-11*(res/RES_MAX);
+  res_points[3] = filter_cutoff_line-2;
+  res_points[4] = filter_cutoff_line-14*(res/RES_MAX);
+  res_points[5] = filter_cutoff_line-1;
+
+  for (int i = 0; i < 6; i++) {
+    res_points[i] = std::max(GetScreenMin(), res_points[i]);
+  }
+  
+  if (res > 0.6*RES_MAX) {
+    Patch()->display.DrawLine(res_points[0], 0, res_points[1], 0, true);
+  }
+  if (res > 0.3*RES_MAX) {
+    Patch()->display.DrawLine(res_points[2], 1, res_points[3], 1, true);
+  }
+  if (res > 0.1*RES_MAX) {
+    Patch()->display.DrawLine(res_points[4], 2, res_points[5], 2, true);
+  }
+  
   DrawName("Ladder");
 }
 
@@ -46,6 +79,6 @@ void LadderFilterDroplet::SetControls() {
     filter_knob = Patch()->controls[Patch()->CTRL_1];
     res_knob = Patch()->controls[Patch()->CTRL_2];
   }
-  freq_ctrl.Init(filter_knob, 5.0f, 10000.0f, Parameter::LOGARITHMIC);
-  res_ctrl.Init(res_knob, 0.0f, 0.95f, Parameter::LINEAR);
+  freq_ctrl.Init(filter_knob, 5.0f, FILTER_MAX, Parameter::LOGARITHMIC);
+  res_ctrl.Init(res_knob, 0.0f, RES_MAX, Parameter::LINEAR);
 }

src/droplets/ladder_filter_droplet.h

@@ -14,6 +14,9 @@ private:
   MoogLadder filter[4];
   Parameter freq_ctrl, res_ctrl;
   float freq, res;
+  float FILTER_MAX = 10000.0f;
+  float RES_MAX = 0.95f;
+  int res_points[6];
 public:
   /*
    * Constructor for a droplet.