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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
.pragma library
function renderSmoothedLine(ctx, trace, renderPos) {
if (!trace)
return renderPos
if (renderPos >= trace.length)
return renderPos
// Fetch points and draw the initial "dot"
var points, tp
if (renderPos === 0) {
points = trace.points()
tp = points[renderPos++]
ctx.beginPath()
ctx.moveTo(tp.x, tp.y)
ctx.lineTo(tp.x, tp.y + 0.000001)
ctx.stroke()
} else {
points = trace.points(renderPos - 1)
}
// Draw smoothed line using quadratic curve
var i = 1
if (i + 1 < points.length) {
var pt1, pt2
if (renderPos === 1) {
tp = points[i - 1]
} else {
pt1 = points[i - 1]
pt2 = points[i]
tp = Qt.point((pt1.x + pt2.x) / 2, (pt1.y + pt2.y) / 2)
}
ctx.beginPath()
ctx.moveTo(tp.x, tp.y)
while (i + 1 < points.length) {
pt1 = points[i++]
pt2 = points[i]
tp = Qt.point((pt1.x + pt2.x) / 2, (pt1.y + pt2.y) / 2)
ctx.quadraticCurveTo(pt1.x, pt1.y, tp.x, tp.y)
ctx.moveTo(tp.x, tp.y)
}
ctx.stroke()
}
// Draw the remainder of the line
if (trace.final) {
if (i < points.length) {
tp = points[i - 1]
ctx.beginPath()
ctx.moveTo(tp.x, tp.y)
tp = points[i++]
ctx.lineTo(tp.x, tp.y)
ctx.stroke()
}
}
return renderPos + i - 1
}
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