A visual and interactive MIDI keyboard component. More...

#include <midi_keyboard.h>

Inheritance diagram for MidiKeyboard:

Public Member Functions
	MidiKeyboard (MidiKeyboardState &state)
	Constructs the MidiKeyboard component.

void	paintBackground (Graphics &g) override
	Paints any background elements of the keyboard, typically key boundaries.

void	parentHierarchyChanged () override
	Called when the parent hierarchy changes.

void	resized () override
	Called when the component is resized.

int	getNoteAtPosition (Point< float > position)
	Determines the MIDI note at a given mouse position.

bool	isBlackKeyHeight (Point< float > position)
	Checks if a given position falls within the vertical range of a black key.

float	getVelocityForNote (int midi, Point< float > position)
	Calculates the note velocity based on vertical mouse click position.

void	init (OpenGlWrapper &open_gl) override
	Initializes OpenGL resources for rendering keys.

void	render (OpenGlWrapper &open_gl, bool animate) override
	Renders the keyboard and its keys using OpenGL.

void	setPressedKeyPositions ()
	Updates which keys are displayed as pressed according to the current MidiKeyboardState.

void	destroy (OpenGlWrapper &open_gl) override
	Destroys OpenGL resources when the component is removed or reinitialized.

void	mouseDown (const MouseEvent &e) override
	Handles mouse down events to trigger note-on messages.

void	mouseUp (const MouseEvent &e) override
	Handles mouse up events to trigger note-off messages.

void	mouseEnter (const MouseEvent &e) override
	Handles mouse enter events to update the hovered note.

void	mouseExit (const MouseEvent &e) override
	Handles mouse exit events to clear the hovered note.

void	mouseDrag (const MouseEvent &e) override
	Handles mouse drag events, allowing note slides across keys.

void	mouseMove (const MouseEvent &e) override
	Handles mouse move events to update which note is hovered.

void	setMidiChannel (int channel)
	Sets the MIDI channel used by note-on and note-off messages.

void	setColors ()
	Updates the color scheme of the keys.

Public Member Functions inherited from OpenGlComponent
	OpenGlComponent (String name="")
	Constructs an OpenGlComponent.

virtual	~OpenGlComponent ()
	Destructor.

void	addRoundedCorners ()
	Adds rounded corners to the component's edges.

void	addBottomRoundedCorners ()
	Adds rounded corners only at the bottom of the component.

void	renderCorners (OpenGlWrapper &open_gl, bool animate, Colour color, float rounding)
	Renders the corner shapes using the given color and rounding amount.

void	renderCorners (OpenGlWrapper &open_gl, bool animate)
	Renders corners with default body color and rounding.

void	repaintBackground ()
	Requests a repaint of the component's background on the OpenGL layer.

Colour	getBodyColor () const
	Retrieves the component's body color.

void	setParent (const SynthSection *parent)
	Sets a pointer to the parent SynthSection for skin value lookups.

float	findValue (Skin::ValueId value_id)
	Finds a float value from the skin associated with this component's parent.

void	setSkinValues (const Skin &skin)
	Applies the skin overrides to this component's colors.

void	setSkinOverride (Skin::SectionOverride skin_override)
	Sets a skin override to control the component's color scheme.

force_inline void	checkGlError ()
	Checks for and asserts that there are no OpenGL errors.

void	setBackgroundColor (const Colour &color)
	Sets the background color of the component for painting operations.

Static Public Member Functions
static force_inline bool	isWhiteKey (int midi)
	Determines if a given MIDI note number corresponds to a white key.

Static Public Member Functions inherited from OpenGlComponent
static bool	setViewPort (Component *component, Rectangle< int > bounds, OpenGlWrapper &open_gl)
	Sets the OpenGL viewport to match a specified rectangle within a component.

static bool	setViewPort (Component *component, OpenGlWrapper &open_gl)
	Convenience overload that sets the viewport for the entire component's local bounds.

static void	setScissor (Component *component, OpenGlWrapper &open_gl)
	Sets the OpenGL scissor region to the entire component's local bounds.

static void	setScissorBounds (Component *component, Rectangle< int > bounds, OpenGlWrapper &open_gl)
	Sets the OpenGL scissor region to a specified rectangle within a component.

static std::unique_ptr< OpenGLShaderProgram::Uniform >	getUniform (const OpenGlWrapper &open_gl, const OpenGLShaderProgram &program, const char *name)
	Retrieves a uniform from the shader program if it exists.

static std::unique_ptr< OpenGLShaderProgram::Attribute >	getAttribute (const OpenGlWrapper &open_gl, const OpenGLShaderProgram &program, const char *name)
	Retrieves an attribute from the shader program if it exists.

static String	translateFragmentShader (const String &code)
	Translates a fragment shader code snippet to be compatible with the current GL version.

static String	translateVertexShader (const String &code)
	Translates a vertex shader code snippet to be compatible with the current GL version.

Static Public Attributes
static const float	kBlackKeyOffsets []
	Horizontal offsets for black keys relative to white keys, per octave.

static const bool	kWhiteKeys []
	Array indicating which notes (semitones) in an octave are white keys.

static constexpr int	kNumWhiteKeys = 75
	Total number of white keys across the entire MIDI range.

static constexpr int	kNumWhiteKeysPerOctave = 7
	Number of white keys per octave.

static constexpr int	kNumBlackKeys = vital::kMidiSize - kNumWhiteKeys
	Total number of black keys across the entire MIDI range.

static constexpr int	kNumBlackKeysPerOctave = vital::kNotesPerOctave - kNumWhiteKeysPerOctave
	Number of black keys per octave.

static constexpr float	kBlackKeyHeightRatio = 0.7f
	Ratio of keyboard height covered by black keys.

static constexpr float	kBlackKeyWidthRatio = 0.8f
	Horizontal ratio of the black key width relative to white keys.

Additional Inherited Members
Protected Member Functions inherited from OpenGlComponent
bool	setViewPort (OpenGlWrapper &open_gl)
	Sets the viewport for this component using the current OpenGlWrapper.

Protected Attributes inherited from OpenGlComponent
std::unique_ptr< OpenGlCorners >	corners_
	Optional corners for rounded edges.

bool	only_bottom_corners_
	Flag to round only the bottom corners.

Colour	background_color_
	The background color of the component.

Colour	body_color_
	The body color of the component.

const SynthSection *	parent_
	Pointer to parent SynthSection for skin lookups.

Skin::SectionOverride	skin_override_
	Skin override for custom appearance.

const vital::StatusOutput *	num_voices_readout_
	StatusOutput for voice count lookups.

Detailed Description

A visual and interactive MIDI keyboard component.

The MidiKeyboard component displays a piano keyboard that can be interacted with using the mouse. Users can press keys to produce note-on messages and release them to produce note-off messages. Keys are dynamically colored based on their current state (pressed, hovered, white/black), and velocities are determined by the vertical click position. The component supports real-time rendering using OpenGL for performance.

Constructor & Destructor Documentation

◆ MidiKeyboard()

MidiKeyboard::MidiKeyboard ( MidiKeyboardState & state )

Constructs the MidiKeyboard component.

Parameters

state Reference to a MidiKeyboardState managing current pressed notes.

Member Function Documentation

◆ destroy()

void MidiKeyboard::destroy ( OpenGlWrapper & open_gl )

inlineoverridevirtual

Destroys OpenGL resources when the component is removed or reinitialized.

Parameters

open_gl The OpenGL wrapper.

Reimplemented from OpenGlComponent.

◆ getNoteAtPosition()

int MidiKeyboard::getNoteAtPosition ( Point< float > position )

Determines the MIDI note at a given mouse position.

Parameters

position The mouse position relative to the component.

Returns: The MIDI note number, or -1 if the position doesn't correspond to a note.

◆ getVelocityForNote()

float MidiKeyboard::getVelocityForNote	(	int	midi,
		Point< float >	position )

Calculates the note velocity based on vertical mouse click position.

Parameters

midi	The MIDI note being triggered.
position	The mouse position relative to the component.

Returns: A velocity value in the range [0, 1].

◆ init()

void MidiKeyboard::init ( OpenGlWrapper & open_gl )

inlineoverridevirtual

Initializes OpenGL resources for rendering keys.

Parameters

open_gl The OpenGL wrapper.

Reimplemented from OpenGlComponent.

◆ isBlackKeyHeight()

bool MidiKeyboard::isBlackKeyHeight ( Point< float > position )

inline

Checks if a given position falls within the vertical range of a black key.

Parameters

position The point to check.

Returns: True if the point is within the black key vertical range.

◆ isWhiteKey()

static force_inline bool MidiKeyboard::isWhiteKey ( int midi )

inlinestatic

Determines if a given MIDI note number corresponds to a white key.

Parameters

midi	The MIDI note number.

Returns: True if it's a white key, false if it's black.

◆ mouseDown()

void MidiKeyboard::mouseDown ( const MouseEvent & e )

inlineoverride

Handles mouse down events to trigger note-on messages.

Parameters

e	The mouse event.

◆ mouseDrag()

void MidiKeyboard::mouseDrag ( const MouseEvent & e )

inlineoverride

Handles mouse drag events, allowing note slides across keys.

Parameters

e	The mouse event.

◆ mouseEnter()

void MidiKeyboard::mouseEnter ( const MouseEvent & e )

inlineoverride

Handles mouse enter events to update the hovered note.

Parameters

e	The mouse event.

◆ mouseExit()

void MidiKeyboard::mouseExit ( const MouseEvent & e )

inlineoverride

Handles mouse exit events to clear the hovered note.

Parameters

e	The mouse event.

◆ mouseMove()

void MidiKeyboard::mouseMove ( const MouseEvent & e )

inlineoverride

Handles mouse move events to update which note is hovered.

Parameters

e	The mouse event.

◆ mouseUp()

void MidiKeyboard::mouseUp ( const MouseEvent & e )

inlineoverride

Handles mouse up events to trigger note-off messages.

Parameters

e	The mouse event.

◆ paintBackground()

void MidiKeyboard::paintBackground ( Graphics & g )

overridevirtual

Paints any background elements of the keyboard, typically key boundaries.

Parameters

g	The graphics context.

Reimplemented from OpenGlComponent.

◆ parentHierarchyChanged()

void MidiKeyboard::parentHierarchyChanged ( )

overridevirtual

Called when the parent hierarchy changes.

Used to apply color schemes from the parent SynthGuiInterface if available.

Reimplemented from OpenGlComponent.

◆ render()

void MidiKeyboard::render	(	OpenGlWrapper &	open_gl,
		bool	animate )

overridevirtual

Renders the keyboard and its keys using OpenGL.

Parameters

open_gl	The OpenGL wrapper.
animate	If true, animate transitions or changes in state.

Implements OpenGlComponent.

◆ resized()

void MidiKeyboard::resized ( )

overridevirtual

Called when the component is resized.

Recalculates key positions and updates OpenGL quads for keys.

Reimplemented from OpenGlComponent.

◆ setColors()

void MidiKeyboard::setColors ( )

Updates the color scheme of the keys.

◆ setMidiChannel()

void MidiKeyboard::setMidiChannel ( int channel )

inline

Sets the MIDI channel used by note-on and note-off messages.

Parameters

channel The MIDI channel number (1-based).

◆ setPressedKeyPositions()

void MidiKeyboard::setPressedKeyPositions ( )

Updates which keys are displayed as pressed according to the current MidiKeyboardState.

Member Data Documentation

◆ kBlackKeyHeightRatio

float MidiKeyboard::kBlackKeyHeightRatio = 0.7f

staticconstexpr

Ratio of keyboard height covered by black keys.

◆ kBlackKeyOffsets

const float MidiKeyboard::kBlackKeyOffsets

static

Initial value:

= {
0f - 0.6f * kBlackKeyWidthRatio,
0f - 0.4f * kBlackKeyWidthRatio,
0f - 0.7f * kBlackKeyWidthRatio,
0f - 0.5f * kBlackKeyWidthRatio,
0f - 0.3f * kBlackKeyWidthRatio,
}

Horizontal offsets for black keys relative to white keys, per octave.

These offsets define the placement of black keys within each octave, ensuring a visually accurate piano layout.

◆ kBlackKeyWidthRatio

float MidiKeyboard::kBlackKeyWidthRatio = 0.8f

staticconstexpr

Horizontal ratio of the black key width relative to white keys.

◆ kNumBlackKeys

int MidiKeyboard::kNumBlackKeys = vital::kMidiSize - kNumWhiteKeys

staticconstexpr

Total number of black keys across the entire MIDI range.

◆ kNumBlackKeysPerOctave

int MidiKeyboard::kNumBlackKeysPerOctave = vital::kNotesPerOctave - kNumWhiteKeysPerOctave

staticconstexpr

Number of black keys per octave.

◆ kNumWhiteKeys

int MidiKeyboard::kNumWhiteKeys = 75

staticconstexpr

Total number of white keys across the entire MIDI range.

◆ kNumWhiteKeysPerOctave

int MidiKeyboard::kNumWhiteKeysPerOctave = 7

staticconstexpr

Number of white keys per octave.

◆ kWhiteKeys

const bool MidiKeyboard::kWhiteKeys

static

Initial value:

= {
  true, false, true, false, true, true, false, true, false, true, false, true
}

Array indicating which notes (semitones) in an octave are white keys.

True values represent white keys, false values represent black keys.

The documentation for this class was generated from the following files:

/Users/davidvogel/repos/VitalHelp/src/interface/editor_components/midi_keyboard.h
/Users/davidvogel/repos/VitalHelp/src/interface/editor_components/midi_keyboard.cpp

Public Member Functions

Static Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MidiKeyboard()

Member Function Documentation

◆ destroy()

◆ getNoteAtPosition()

◆ getVelocityForNote()

◆ init()

◆ isBlackKeyHeight()

◆ isWhiteKey()

◆ mouseDown()

◆ mouseDrag()

◆ mouseEnter()

◆ mouseExit()

◆ mouseMove()

◆ mouseUp()

◆ paintBackground()

◆ parentHierarchyChanged()

◆ render()

◆ resized()

◆ setColors()

◆ setMidiChannel()

◆ setPressedKeyPositions()

Member Data Documentation

◆ kBlackKeyHeightRatio

◆ kBlackKeyOffsets

◆ kBlackKeyWidthRatio

◆ kNumBlackKeys

◆ kNumBlackKeysPerOctave

◆ kNumWhiteKeys

◆ kNumWhiteKeysPerOctave

◆ kWhiteKeys