From 8e08e1b4eced2ce32b2f8b7896bd60d74950998d Mon Sep 17 00:00:00 2001 From: mzarillo Date: Wed, 4 Jul 2012 07:13:12 -0400 Subject: initial commit --- scripts/ccharter.js | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 scripts/ccharter.js (limited to 'scripts') diff --git a/scripts/ccharter.js b/scripts/ccharter.js new file mode 100644 index 0000000..81c2dd4 --- /dev/null +++ b/scripts/ccharter.js @@ -0,0 +1,99 @@ +var ChordCharter = { + + drawChord: function (canvasId, originX, originY, chordName, chordFrets) { + + var chord = { + name: chordName, + frets: chordFrets + }; + + var c=document.getElementById(canvasId); + var ctx=c.getContext("2d"); + ctx.fillStyle="#000"; + + var origin = { x: originX, y: originY }; + var props = { width: 50, height: 60 }; + + // horizontals + + for (counter in new Array(0, 1, 2, 3, 4)) { + ctx.moveTo(origin.x - 1, origin.y + (counter * props.height / 4)); + ctx.lineTo(origin.x + props.width + 1, origin.y + (counter * props.height / 4)); + ctx.stroke(); + } + + // verts + + for (counter in new Array(0, 1, 2, 3, 4, 5)) { + ctx.moveTo(origin.x + (counter * props.width / 5), origin.y); + ctx.lineTo(origin.x + (counter * props.width / 5), origin.y + props.height); + ctx.stroke(); + } + + ctx.stroke(); + + // label + + ctx.font = "bold 10pt Verdana"; + ctx.textAlign = "center"; + ctx.fillText(chord.name, origin.x + props.width / 2, origin.y - 5); + ctx.font = "7pt Verdana"; + + // If any dots are after 4, adjust the root to be the lowest non-zero fret + // If the root is zero , thicken the top fret + + var baseFret = 0; + var adjBaseFret = false; + var lowestFret = 0; + + for (j=0; j < chord.frets.length; j++) { + if (chord.frets.charAt(j) != 'x' && chord.frets.charAt(j) != 'X' && chord.frets.charAt(j) > 0) { + if (chord.frets.charAt(j) < lowestFret || lowestFret == 0) { + lowestFret = chord.frets.charAt(j); + } + if (chord.frets.charAt(j) > 4) { + adjBaseFret = true; + } + } + } + + if (adjBaseFret) { + baseFret = lowestFret - 1; + } + + // dots + + var dotsize = 3.5; + + var i = 0; + + for (j=0; j < chord.frets.length; j++) { + + ctx.alignText = "left"; + ctx.fillText(chord.frets.charAt(j), origin.x + (i * props.width / 5), origin.y + props.height + 12); + + if (chord.frets.charAt(j) == 0) { + + + } else if (chord.frets.charAt(j) == 'x' || chord.frets.charAt(j) == 'X') { + + } else { + ctx.beginPath(); + ctx.arc(origin.x + (i * props.width / 5), origin.y - 7.5 + (15 * (chord.frets.charAt(j) - baseFret)), dotsize, 0, Math.PI*2,true); + ctx.closePath(); + ctx.fill(); + } + i++; + } + + // base fret indicator + + if (baseFret > 0) { + ctx.alignText = "left"; + ctx.fillText(baseFret + 1, origin.x - 10, origin.y + 11); + } else { + ctx.alignText = "left"; + ctx.fillText("3", origin.x - 10, origin.y + 41); + } + } +}; \ No newline at end of file -- cgit 1.4.1