crescendo.js

Table of Contents

  1. accidental.js
  2. annotation.js
  3. articulation.js
  4. barnote.js
  5. beam.js
  6. bend.js
  7. boundingbox.js
  8. canvascontext.js
  9. clef.js
  10. clefnote.js
  11. crescendo.js
  12. curve.js
  13. dot.js
  14. flow.js
  15. vexflow_font.js
  16. formatter.js
  17. fraction.js
  18. frethandfinger.js
  19. ghostnote.js
  20. glyph.js
  21. gracenote.js
  22. gracenotegroup.js
  23. keymanager.js
  24. keysignature.js
  25. modifier.js
  26. modifiercontext.js
  27. music.js
  28. note.js
  29. notehead.js
  30. ornament.js
  31. pedalmarking.js
  32. raphaelcontext.js
  33. renderer.js
  34. stave.js
  35. stavebarline.js
  36. staveconnector.js
  37. stavehairpin.js
  38. staveline.js
  39. stavemodifier.js
  40. stavenote.js
  41. staverepetition.js
  42. stavesection.js
  43. stavetempo.js
  44. stavetext.js
  45. stavetie.js
  46. stavevolta.js
  47. stem.js
  48. stemmablenote.js
  49. stringnumber.js
  50. strokes.js
  51. svgcontext.js
  52. tables.js
  53. tabnote.js
  54. tabslide.js
  55. tabstave.js
  56. tabtie.js
  57. textbracket.js
  58. textdynamics.js
  59. textnote.js
  60. tickable.js
  61. tickcontext.js
  62. timesignature.js
  63. timesignote.js
  64. tremolo.js
  65. tuning.js
  66. tuplet.js
  67. vex.js
  68. vibrato.js
  69. voice.js
  70. voicegroup.js

VexFlow - Copyright (c) Mohit Muthanna 2010.

Description

This file implements the Crescendo object which draws crescendos and decrescendo dynamics markings. A Crescendo is initialized with a duration and formatted as part of a Voice like any other Note type in VexFlow. This object would most likely be formatted in a Voice with TextNotes - which are used to represent other dynamics markings.

Vex.Flow.Crescendo = (function() {
  function Crescendo(note_struct) {
    if (arguments.length > 0) this.init(note_struct);
  }

To enable logging for this class. Set Vex.Flow.Crescendo.DEBUG to true.

  function L() { if (Crescendo.DEBUG) Vex.L("Vex.Flow.Crescendo", arguments); }

Private helper to draw the hairpin

  function renderHairpin(ctx, params) {
    var begin_x = params.begin_x;
    var end_x = params.end_x;
    var y = params.y;
    var half_height =  params.height / 2;

    ctx.beginPath();

    if (params.reverse) {
        ctx.moveTo(begin_x, y - half_height);
        ctx.lineTo(end_x,  y);
        ctx.lineTo(begin_x, y + half_height);
    } else {
        ctx.moveTo(end_x,  y - half_height);
        ctx.lineTo(begin_x, y);
        ctx.lineTo(end_x,  y + half_height);
    }

    ctx.stroke();
    ctx.closePath();
  }

Prototype Methods

  Vex.Inherit(Crescendo, Vex.Flow.Note, {

Initialize the crescendo’s properties

    init: function(note_struct) {
      Crescendo.superclass.init.call(this, note_struct);

Whether the object is a decrescendo

      this.decrescendo = false;

The staff line to be placed on

      this.line = note_struct.line || 0;

The height at the open end of the cresc/decresc

      this.height = 15;

      Vex.Merge(this.render_options, {

Extensions to the length of the crescendo on either side

        extend_left: 0,
        extend_right: 0,

Vertical shift

        y_shift: 0
      });
    },

Set the line to center the element on

    setLine: function(line) { this.line = line; return this; },

Set the full height at the open end

    setHeight: function(height) { this.height = height; return this; },

Set whether the sign should be a descresendo by passing a bool to decresc

    setDecrescendo: function(decresc) {
      this.decrescendo = decresc;
      return this;
    },

Preformat the note

    preFormat: function() { this.preFormatted = true; return this; },

Render the Crescendo object onto the canvas

    draw: function() {
      if (!this.context) throw new Vex.RERR("NoContext",
        "Can't draw Hairpin without a context.");

      var tick_context = this.getTickContext();
      var next_context = Vex.Flow.TickContext.getNextContext(tick_context);

      var begin_x = this.getAbsoluteX();
      var end_x;
      if (next_context) {
        end_x = next_context.getX();
      } else {
        end_x = this.stave.x + this.stave.width;
      }

      var y = this.stave.getYForLine(this.line + (-3)) + 1;

      L("Drawing ",  this.decrescendo ? "decrescendo " : "crescendo ",
        this.height, "x", begin_x - end_x);

      renderHairpin(this.context, {
        begin_x: begin_x - this.render_options.extend_left,
        end_x: end_x + this.render_options.extend_right,
        y: y + this.render_options.y_shift,
        height: this.height,
        reverse: this.decrescendo
      });
    }
  });

  return Crescendo;
})();
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