VexFlow セクション記号

VexFlow 使い方に戻る。

概要

　セクション記号の表示について、説明します。

　staveオブジェクトのメンバ関数.setSectionで、表示したい記号の文字列とオフセットを指定するだけです。以下のとおりの表示になります。

　

セクション記号

　コードは以下のとおりです。

<div id="yonet202403Mid_Output01"></div>
<script>
var VF = Vex.Flow;
(function(){
const {
  Factory,
  Stave,
  StaveNote,
  Formatter,
  Voice,
  StaveTie,
  BarLine,
  Renderer
} = Vex.Flow;

let nscale = 0.68
let nwidth = 1040;
let nheight = 420;

let nHeadMargin = 70;
let nStaveWidth = 350;

const f = new Factory({ 
  renderer: { elementId: 'yonet202403Mid_Output01', width: nwidth, height: nheight * nscale }
  });
const ctx = f.getContext();
ctx.scale(nscale, nscale);

const defaultStyle = {
  lineWidth: ctx.lineWidth,
  strokeStyle: ctx.strokeStyle,
};

for (let i = 0; i <= nwidth * (1 / nscale); i += 10) {
  ctx.beginPath();
  ctx.moveTo(0 + i, 0);
  ctx.lineTo(0 + i, nheight);
  if (i % 100 === 0){
    ctx.setLineWidth(1);
    ctx.setStrokeStyle('rgba(200, 200, 200, 0.8)');
  }
  else{
    ctx.setLineWidth(0.5);
    ctx.setStrokeStyle('rgba(230, 230, 230, 0.8)');
  }
  ctx.stroke();
}

for (let i = 0; i <= nheight; i += 10) {
  ctx.beginPath();
  ctx.moveTo(0, i);
  ctx.lineTo(nwidth * (1 / nscale), i);
  if (i % 100 === 0){
    ctx.setLineWidth(1);
    ctx.setStrokeStyle('rgba(200, 200, 200, 0.8)');
  }
  else{
    ctx.setLineWidth(0.5);
    ctx.setStrokeStyle('rgba(230, 230, 230, 0.8)');
  }
  ctx.stroke();
}

ctx.lineWidth = defaultStyle.lineWidth;
ctx.strokeStyle = defaultStyle.strokeStyle;

const stave1 = new Stave(10, 50, nHeadMargin + nStaveWidth).setContext(ctx);
stave1.setClef("treble").setContext(ctx);
stave1.setTimeSignature('4/4').setContext(ctx);
stave1.setSection("A", 0);
//stave1.setBegBarType(4);//BarLine.type.REPEAT_BEGIN
stave1.setBegBarType(VF.Barline.type.REPEAT_BEGIN);//BarLine.type.REPEAT_BEGIN
stave1.draw();

//SINGLE:1, DOUBLE:2, END:3, REPEAT_BEGIN:4, REPEAT_END:5, REPEAT_BOTH:6, NONE:7

const notes1 = [
  new StaveNote({ keys: ["d/5"], duration: "q" }),
  new StaveNote({ keys: ["e/5"], duration: "q" }),
  new StaveNote({ keys: ["f/5"], duration: "q" }),
  new StaveNote({ keys: ["g/5"], duration: "q" }),
];

Formatter.FormatAndDraw(ctx, stave1, notes1);

const tie1 = new StaveTie({
  first_note: notes1[1],
  last_note: notes1[2],
  first_indices: [0],
  last_indices: [0],
});

const tie2 = new StaveTie({
  first_note: notes1[2],
  last_note: notes1[3],
  first_indices: [0],
  last_indices: [0],
});

tie1.setContext(ctx).draw();
tie2.setContext(ctx).draw();


const stave2 = new Stave(stave1.width + stave1.x, stave1.y, nStaveWidth).setContext(ctx);
stave2.setEndBarType(VF.Barline.type.REPEAT_BOTH);
stave2.draw();


const stave3 = new Stave(stave2.width + stave2.x, stave1.y, nStaveWidth).setContext(ctx);
stave3.setEndBarType(VF.Barline.type.NONE);
stave3.setSection("B", 0);
stave3.draw();


const stave4 = new Stave(stave3.width + stave3.x, stave1.y, nStaveWidth).setContext(ctx);
stave4.setBegBarType(VF.Barline.type.NONE);
stave4.setEndBarType(VF.Barline.type.REPEAT_END);
stave4.draw();


const stave5 = new Stave(stave1.x, stave1.y + 200, nHeadMargin + nStaveWidth).setContext(ctx);
stave5.addClef("treble").setContext(ctx);
stave5.addTimeSignature('4/4').setContext(ctx);
stave5.setSection("C", 0);
stave5.setEndBarType(VF.Barline.type.SINGLE);//規定値(省略可能)

stave5.draw();

const notes5 = [
  new StaveNote({ keys: ["a/4"], duration: "q" }),
  new StaveNote({ keys: ["b/4"], duration: "q" }),
  new StaveNote({ keys: ["c/5"], duration: "q" }),
  new StaveNote({ keys: ["d/5"], duration: "q" }),
];

Formatter.FormatAndDraw(ctx, stave5, notes5);

const tie3 = new StaveTie({
  first_note: notes5[1],
  last_note: notes5[2],
  first_indices: [0],
  last_indices: [0],
});

const tie4 = new StaveTie({
  first_note: notes5[2],
  last_note: notes5[3],
  first_indices: [0],
  last_indices: [0],
});

tie3.setContext(ctx).draw();
tie4.setContext(ctx).draw();

const stave6 = new Stave(stave5.width + stave5.x, stave5.y, nStaveWidth).setContext(ctx);
stave6.setEndBarType(VF.Barline.type.DOUBLE);

stave6.draw();

const notes6 = [
  new StaveNote({ keys: ["e/5"], duration: "q" }),
  new StaveNote({ keys: ["f/5"], duration: "q" }),
  new StaveNote({ keys: ["g/5"], duration: "q" }),
  new StaveNote({ keys: ["a/5"], duration: "q" }),
];

Formatter.FormatAndDraw(ctx, stave6, notes6);

const tie5 = new StaveTie({
  first_note: notes5[3],
  last_note: notes6[0],
  first_indices: [0],
  last_indices: [0],
});

tie5.setContext(ctx).draw();


const stave7 = new Stave(stave6.width + stave6.x, stave5.y, nStaveWidth).setContext(ctx);
stave7.draw();


const stave8 = new Stave(stave7.width + stave7.x, stave5.y, nStaveWidth).setContext(ctx);
stave8.setEndBarType(VF.Barline.type.END);
stave8.draw();
})();

const svgElement = document.querySelector('#Output svg');
svgElement.style.backgroundColor = '#F5F5F5';
</script>

staveオブジェクトのメンバ関数に.setSectionという関数があり

第1引数: 表示させたい文字列リテラルの指定

第2引数: 縦方向のオフセット下がプラス。上にオフセットがマイナス

という感じで指定するだけです。フォントがダサい。ビビる。まぁ使わせてもらっときながら文句ばっかりでるもんですね。ひどいよね。Vexflowの中の人はもうちょっと基本的な機能の部分にこだわりを見せてほしいな。

　

VexFlow 使い方に戻る。