UI: Add "Panic" button

Author: AnClark

plugin/MinatonArtwork.cpp

@@ -25,6 +25,16 @@ namespace MinatonArtwork
     const unsigned int newknobWidth    = 42;
     const unsigned int newknobHeight   = 42;
 
+    extern const char* panic_buttonData;
+    const unsigned int panic_buttonDataSize = 11200;
+    const unsigned int panic_buttonWidth    = 70;
+    const unsigned int panic_buttonHeight   = 40;
+
+    extern const char* panic_button_pressedData;
+    const unsigned int panic_button_pressedDataSize = 11200;
+    const unsigned int panic_button_pressedWidth    = 70;
+    const unsigned int panic_button_pressedHeight   = 40;
+
     extern const char* sliderData;
     const unsigned int sliderDataSize = 6084;
     const unsigned int sliderWidth    = 39;

plugin/MinatonArtwork.hpp

@@ -20,7 +20,8 @@ MinatonUI::MinatonUI()
     , fSwitchNoLightImage_OFF(Art::switch_off_nolightData, Art::switch_off_nolightWidth, Art::switch_off_nolightHeight, kImageFormatBGRA)
     , fImgLabelMixMode(Art::mix_mode_labelData, Art::mix_mode_labelWidth, Art::mix_mode_labelHeight, kImageFormatBGRA)
     , fImgLabelMonoStereo(Art::mono_stereo_labelData, Art::mono_stereo_labelWidth, Art::mono_stereo_labelHeight, kImageFormatBGRA)
-
+    , fImgPanicButton(Art::panic_buttonData, Art::panic_buttonWidth, Art::panic_buttonHeight)
+    , fImgPanicButton_Pressed(Art::panic_button_pressedData, Art::panic_button_pressedWidth, Art::panic_button_pressedHeight)
 {
     // Knob initial angles
     constexpr int KNOB_ANGLE = 287;
@@ -100,6 +101,9 @@ MinatonUI::MinatonUI()
     // Equalizer params
     _createKnob(fCutOffFrequency, PARAM_FREQUENCY, 377, 368, KNOB_ANGLE);
     _createKnob(fResonance, PARAM_RESONANCE, 377, 422, KNOB_ANGLE);
+
+    // Panic button
+    _createButton(fPanic, BTN_PANIC, fImgPanicButton, fImgPanicButton_Pressed, 452, 505);
 }
 
 void MinatonUI::parameterChanged(uint32_t index, float value)
@@ -279,6 +283,12 @@ void MinatonUI::parameterChanged(uint32_t index, float value)
 
 void MinatonUI::imageButtonClicked(ImageButton* button, int)
 {
+    switch (button->getId()) {
+    case BTN_PANIC: {
+        panic();
+        break;
+    }
+    }
 }
 
 void MinatonUI::imageSwitchClicked(ImageSwitch* button, bool down)
@@ -365,6 +375,27 @@ void MinatonUI::onDisplay()
 
 void MinatonUI::idleCallback() { }
 
+void MinatonUI::panic()
+{
+    /**
+        There is no API to send MIDI data to DSP side. Instead, DPF provides UI::sendNote().
+        But we can still send any MIDI data via this method, simply doing a hack.
+
+        In method UI::sendNote(uint8_t channel, uint8_t note, uint8_t velocity):
+
+        `channel` will be converted into MIDI data 0 by:
+        `midi_data[0] = (velocity != 0 ? 0x90 : 0x80) | channel;`
+
+        To send MIDI controller data, we need to transform midi_data[0] into MIDI_STATUS_CONTROLLER (0xB0)
+        by simply applying a proper `channel` value. It would be easy to calculate:
+            0x80 | channel = 0xB0
+        => 0b10000000 | channel = 0b10110000
+        => channel = 0b00110000
+        => channel = 0x30
+    */
+    sendNote(0x30, 0x7B, 0); // MIDI_CC_ALL_NOTES_OFF = 0x7B
+}
+
 // -----------------------------------------------------------------------
 
 UI* createUI()

plugin/MinatonUI.cpp

@@ -63,6 +63,7 @@ class MinatonUI : public UI,
     Image fSwitchButtonImage_ON, fSwitchButtonImage_OFF;
     Image fSwitchNoLightImage_ON, fSwitchNoLightImage_OFF;
     Image fImgLabelMixMode, fImgLabelMonoStereo;
+    Image fImgPanicButton, fImgPanicButton_Pressed;
     //  ImageAboutWindow fAboutWindow;
 
     // -------------------------------------------------------------------
@@ -93,6 +94,8 @@ class MinatonUI : public UI,
 
     ScopedPointer<ImageKnob> fMasterVolume;
 
+    ScopedPointer<ImageButton> fPanic;
+
     // -------------------------------------------------------------------
     // Helpers
 
@@ -101,10 +104,21 @@ class MinatonUI : public UI,
     void _createSwitchButton(ScopedPointer<ImageSwitch>& switchButton, MinatonParamId paramId, uint absolutePosX, uint absolutePosY, bool withLight = true);
     void _createButton(ScopedPointer<ImageButton>& button, uint id, Image& imageNormal, Image& imagePressed, uint absolutePosX, uint absolutePosY);
 
+    // -------------------------------------------------------------------
+    // Control plugin from UI side
+
+    void panic();
 
     DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(MinatonUI)
 };
 
 // -----------------------------------------------------------------------
 
+// --------------------------------
+// Button IDs
+
+constexpr uint BTN_PANIC = d_cconst('p', 'n', 'i', 'c');
+
+// -----------------------------------------------------------------------
+
 END_NAMESPACE_DISTRHO