src/VexFlowPatch/src/tremolo.js
// [VexFlow](http://vexflow.com) - Copyright (c) Mohit Muthanna 2010.
// Author: Mike Corrigan <corrigan@gmail.com>
//
// This class implements tremolo notation.
import { Vex } from './vex';
import { Modifier } from './modifier';
import { Glyph } from './glyph';
import { GraceNote } from './gracenote';
export class Tremolo extends Modifier {
static get CATEGORY() { return 'tremolo'; }
static get YOFFSETSTEMUP() { return -9; }
static get YOFFSETSTEMDOWN() { return -21; }
static get XOFFSETSTEMUP() { return 6; }
static get XOFFSETSTEMDOWN() { return -2; }
constructor(num) {
super();
this.setAttribute('type', 'Tremolo');
this.num = num;
this.note = null;
this.index = null;
this.position = Modifier.Position.CENTER;
this.code = 'v74';
this.y_spacing_scale = 1;
this.extra_stroke_scale = 1;
this.y_offset_for_beam = 5;
}
getCategory() { return Tremolo.CATEGORY; }
draw() {
this.checkContext();
if (!(this.note && this.index != null)) {
throw new Vex.RERR('NoAttachedNote', "Can't draw Tremolo without a note and index.");
}
this.setRendered();
const stemDirection = this.note.getStemDirection();
// VexFlowPatch: add y_spacing_scale
this.y_spacing = 4 * stemDirection * this.y_spacing_scale;
const start = this.note.getModifierStartXY(this.position, this.index);
let x = start.x;
let y = this.note.stem.getExtents().topY;
let scale = this.note.getCategory() === 'gracenotes' ? GraceNote.SCALE : 1;
// VexFlowPatch: add extra stroke scale
scale *= this.extra_stroke_scale;
if (stemDirection < 0) {
y += Tremolo.YOFFSETSTEMDOWN * scale;
} else {
y += Tremolo.YOFFSETSTEMUP * scale;
}
if (this.note.beam) {
y += this.y_offset_for_beam * stemDirection;
}
this.font = {
family: 'Arial',
size: 16 * scale,
weight: '',
};
this.render_options = {
font_scale: 35 * scale,
stroke_px: 3,
stroke_spacing: 10 * scale,
};
x += stemDirection < 0 ? Tremolo.XOFFSETSTEMDOWN : Tremolo.XOFFSETSTEMUP;
for (let i = 0; i < this.num; ++i) {
Glyph.renderGlyph(this.context, x, y, this.render_options.font_scale, this.code);
y += this.y_spacing;
}
}
}