alphaTab.midi.MidiTickLookup

This class holds all information about when MasterBar s and Beat s are played.

On top level it is organized into MasterBarTickLookup objects indicating the master bar start and end times. This information is used to highlight the currently played bars and it gives access to the played beats in this masterbar and their times.

The BeatTickLookup are then the slices into which the masterbar is separated by the voices and beats of all tracks. An example how things are organized:

Time (eighths): | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |

Track 1: | B1 | B2 | B3 | B4 | B5 | B6 | Track 2: | B7 | B7 | B9 | B10| B11| B12| Track 3: | B13 |

Lookup: | L1 | L2 | L3 | L4 | L5 | L6 | L7 | L8 | Active Beats:

• L1 B1,B7,B13
• L2 B2,B7,B13
• L3 B3,B7,B13
• L4 B4,B7,B13
• L5 B5,B9,B13
• L6 B5,B10,B13
• L7 B6,B11,B13
• L8 B6,B12,B13

Then during playback we build out of this list MidiTickLookupFindBeatResult objects which are sepcific to the visible tracks displayed. This is required because if only Track 2 is displayed we cannot use the the Lookup L1 alone to determine the start and end of the beat cursor. In this case we will derive a MidiTickLookupFindBeatResult which holds for Time 01 the lookup L1 as start and L3 as end. This will be used both for the cursor and beat highlighting.

 class MidiTickLookup

Properties

masterBars

A list of all MasterBarTickLookup sorted by time.

JavaScript

readonly masterBars: MasterBarTickLookup[];

C#

IList<MasterBarTickLookup> MasterBars { get; }

Kotlin

val masterBars: alphaTab.collections.List<MasterBarTickLookup>

multiBarRestInfo

The information about which bars are displayed via multi-bar rests. The key is the start bar, and the value is the additional bars in sequential order. This info allows building the correct "next" beat and duration.

JavaScript

multiBarRestInfo: Map<number, number[]> | null;

C#

Map<double, IList<double>>? MultiBarRestInfo { get; set; }

Kotlin

var multiBarRestInfo: alphaTab.collections.DoubleObjectMap<Double, alphaTab.collections.DoubleList>?

Methods

addBeat

(no description)

JavaScript

addBeat(beat: Beat, start: number, duration: number): void

C#

void AddBeat(Beat beat, double start, double duration)

Kotlin

fun addBeat(beat: Beat, start: Double, duration: Double): Unit

Parameter	Summary
beatAll	(no description)
startAll	(no description)
durationAll	(no description)

addMasterBar

Adds a new MasterBarTickLookup to the lookup table.

JavaScript

addMasterBar(masterBar: MasterBarTickLookup): void

C#

void AddMasterBar(MasterBarTickLookup masterBar)

Kotlin

fun addMasterBar(masterBar: MasterBarTickLookup): Unit

Parameter	Summary
masterBarAll	The item to add.

findBeat

Finds the currently played beat given a list of tracks and the current time.

JavaScript

findBeat(trackLookup: Set<number>, tick: number, currentBeatHint?: MidiTickLookupFindBeatResult | null): MidiTickLookupFindBeatResult | null

C#

MidiTickLookupFindBeatResult? FindBeat(Set<double> trackLookup, double tick, MidiTickLookupFindBeatResult? currentBeatHint)

Kotlin

fun findBeat(trackLookup: Set<Double>, tick: Double, currentBeatHint: MidiTickLookupFindBeatResult?): MidiTickLookupFindBeatResult?

Parameter	Summary
trackLookupAll	The tracks indices in which to search the played beat for.
tickAll	The current time in midi ticks.
currentBeatHintAll	Used for optimized lookup during playback. By passing in a previous result lookup of the next one can be optimized using heuristics. (optional).

Returns

The information about the current beat or null if no beat could be found.

findBeatWithChecker

Finds the currently played beat given a list of tracks and the current time.

JavaScript

findBeatWithChecker(checker: IBeatVisibilityChecker, tick: number, currentBeatHint?: MidiTickLookupFindBeatResult | null): MidiTickLookupFindBeatResult | null

C#

MidiTickLookupFindBeatResult? FindBeatWithChecker(IBeatVisibilityChecker checker, double tick, MidiTickLookupFindBeatResult? currentBeatHint)

Kotlin

fun findBeatWithChecker(checker: IBeatVisibilityChecker, tick: Double, currentBeatHint: MidiTickLookupFindBeatResult?): MidiTickLookupFindBeatResult?

Parameter	Summary
checkerAll	The checker to ask whether a beat is visible and should be considered for result.
tickAll	The current time in midi ticks.
currentBeatHintAll	Used for optimized lookup during playback. By passing in a previous result lookup of the next one can be optimized using heuristics. (optional).

Returns

The information about the current beat or null if no beat could be found.

getBeatStart

Gets the start time in midi ticks for a given beat at which the masterbar is played the first time.

JavaScript

getBeatStart(beat: Beat): number

C#

double GetBeatStart(Beat beat)

Kotlin

fun getBeatStart(beat: Beat): Double

Parameter	Summary
beatAll	The beat to find the time period for.

Returns

The time in midi ticks at which the beat is played the first time or 0 if the beat is not contained

getMasterBar

Gets the MasterBarTickLookup for a given masterbar at which the masterbar is played the first time.

JavaScript

getMasterBar(bar: MasterBar): MasterBarTickLookup

C#

MasterBarTickLookup GetMasterBar(MasterBar bar)

Kotlin

fun getMasterBar(bar: MasterBar): MasterBarTickLookup

Parameter	Summary
barAll	The masterbar to find the time period for.

Returns

A MasterBarTickLookup containing the details about the first time the MasterBar is played.

getMasterBarStart

Gets the start time in midi ticks for a given masterbar at which the masterbar is played the first time.

JavaScript

getMasterBarStart(bar: MasterBar): number

C#

double GetMasterBarStart(MasterBar bar)

Kotlin

fun getMasterBarStart(bar: MasterBar): Double

Parameter	Summary
barAll	The masterbar to find the time period for.

Returns

The time in midi ticks at which the masterbar is played the first time or 0 if the masterbar is not contained