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Direktori : /var/www/html/news/public/bower_components/chart.js/src/core/ |
Current File : /var/www/html/news/public/bower_components/chart.js/src/core/core.canvasHelpers.js |
'use strict'; module.exports = function(Chart) { // Global Chart canvas helpers object for drawing items to canvas var helpers = Chart.canvasHelpers = {}; helpers.drawPoint = function(ctx, pointStyle, radius, x, y) { var type, edgeLength, xOffset, yOffset, height, size; if (typeof pointStyle === 'object') { type = pointStyle.toString(); if (type === '[object HTMLImageElement]' || type === '[object HTMLCanvasElement]') { ctx.drawImage(pointStyle, x - pointStyle.width / 2, y - pointStyle.height / 2, pointStyle.width, pointStyle.height); return; } } if (isNaN(radius) || radius <= 0) { return; } switch (pointStyle) { // Default includes circle default: ctx.beginPath(); ctx.arc(x, y, radius, 0, Math.PI * 2); ctx.closePath(); ctx.fill(); break; case 'triangle': ctx.beginPath(); edgeLength = 3 * radius / Math.sqrt(3); height = edgeLength * Math.sqrt(3) / 2; ctx.moveTo(x - edgeLength / 2, y + height / 3); ctx.lineTo(x + edgeLength / 2, y + height / 3); ctx.lineTo(x, y - 2 * height / 3); ctx.closePath(); ctx.fill(); break; case 'rect': size = 1 / Math.SQRT2 * radius; ctx.beginPath(); ctx.fillRect(x - size, y - size, 2 * size, 2 * size); ctx.strokeRect(x - size, y - size, 2 * size, 2 * size); break; case 'rectRounded': var offset = radius / Math.SQRT2; var leftX = x - offset; var topY = y - offset; var sideSize = Math.SQRT2 * radius; Chart.helpers.drawRoundedRectangle(ctx, leftX, topY, sideSize, sideSize, radius / 2); ctx.fill(); break; case 'rectRot': size = 1 / Math.SQRT2 * radius; ctx.beginPath(); ctx.moveTo(x - size, y); ctx.lineTo(x, y + size); ctx.lineTo(x + size, y); ctx.lineTo(x, y - size); ctx.closePath(); ctx.fill(); break; case 'cross': ctx.beginPath(); ctx.moveTo(x, y + radius); ctx.lineTo(x, y - radius); ctx.moveTo(x - radius, y); ctx.lineTo(x + radius, y); ctx.closePath(); break; case 'crossRot': ctx.beginPath(); xOffset = Math.cos(Math.PI / 4) * radius; yOffset = Math.sin(Math.PI / 4) * radius; ctx.moveTo(x - xOffset, y - yOffset); ctx.lineTo(x + xOffset, y + yOffset); ctx.moveTo(x - xOffset, y + yOffset); ctx.lineTo(x + xOffset, y - yOffset); ctx.closePath(); break; case 'star': ctx.beginPath(); ctx.moveTo(x, y + radius); ctx.lineTo(x, y - radius); ctx.moveTo(x - radius, y); ctx.lineTo(x + radius, y); xOffset = Math.cos(Math.PI / 4) * radius; yOffset = Math.sin(Math.PI / 4) * radius; ctx.moveTo(x - xOffset, y - yOffset); ctx.lineTo(x + xOffset, y + yOffset); ctx.moveTo(x - xOffset, y + yOffset); ctx.lineTo(x + xOffset, y - yOffset); ctx.closePath(); break; case 'line': ctx.beginPath(); ctx.moveTo(x - radius, y); ctx.lineTo(x + radius, y); ctx.closePath(); break; case 'dash': ctx.beginPath(); ctx.moveTo(x, y); ctx.lineTo(x + radius, y); ctx.closePath(); break; } ctx.stroke(); }; helpers.clipArea = function(ctx, clipArea) { ctx.save(); ctx.beginPath(); ctx.rect(clipArea.left, clipArea.top, clipArea.right - clipArea.left, clipArea.bottom - clipArea.top); ctx.clip(); }; helpers.unclipArea = function(ctx) { ctx.restore(); }; helpers.lineTo = function(ctx, previous, target, flip) { if (target.steppedLine) { if (target.steppedLine === 'after') { ctx.lineTo(previous.x, target.y); } else { ctx.lineTo(target.x, previous.y); } ctx.lineTo(target.x, target.y); return; } if (!target.tension) { ctx.lineTo(target.x, target.y); return; } ctx.bezierCurveTo( flip? previous.controlPointPreviousX : previous.controlPointNextX, flip? previous.controlPointPreviousY : previous.controlPointNextY, flip? target.controlPointNextX : target.controlPointPreviousX, flip? target.controlPointNextY : target.controlPointPreviousY, target.x, target.y); }; Chart.helpers.canvas = helpers; };