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Merged
leeoniya merged 2 commits into from
Dec 26, 2019
Merged

draw hooks #76

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82540fb
Added "draw" hooks
Dec 23, 2019
fd8b00d
no message
ldstein Dec 25, 2019
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257 changes: 257 additions & 0 deletions demos/draw-hooks.html
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Original file line number Diff line number Diff line change
@@ -0,0 +1,257 @@
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Draw Hooks</title>
<meta name="viewport" content="width=device-width, initial-scale=1">

<link rel="stylesheet" href="../bench/style.css">
<link rel="stylesheet" href="../src/uPlot.css">
<style>
.uplot {
margin-top: 50px;
}
</style>
</head>
<body>
<script src="../dist/uPlot.iife.js"></script>
<script>

function addCrazyVisualsPlugin() {

// Source: https://stackoverflow.com/questions/21646738/convert-hex-to-rgba
function hexToRgbA(hex, a='1') {
let c;
if(/^#([A-Fa-f0-9]{3}){1,2}$/.test(hex)){
c= hex.substring(1).split('');
if(c.length== 3){
c= [c[0], c[0], c[1], c[1], c[2], c[2]];
}
c= '0x'+c.join('');
return 'rgba('+[(c>>16)&255, (c>>8)&255, c&255].join(',')+',' + a +')';
}
throw new Error('Bad Hex');
}

// Source: https://stackoverflow.com/questions/25837158/how-to-draw-a-star-by-using-canvas-html5
function drawStar(ctx, cx,cy,spikes=6,outerRadius=8,innerRadius=4){

outerRadius = outerRadius * devicePixelRatio;
innerRadius = innerRadius * devicePixelRatio

var rot=Math.PI/2*3;
var x=cx;
var y=cy;
var step=Math.PI/spikes;

ctx.beginPath();
ctx.moveTo(cx,cy-outerRadius)
for(i=0;i<spikes;i++){
x=cx+Math.cos(rot)*outerRadius;
y=cy+Math.sin(rot)*outerRadius;
ctx.lineTo(x,y)
rot+=step

x=cx+Math.cos(rot)*innerRadius;
y=cy+Math.sin(rot)*innerRadius;
ctx.lineTo(x,y)
rot+=step
}
ctx.lineTo(cx,cy-outerRadius);
ctx.closePath();
}

let medians = [];

// https://www.jstips.co/en/javascript/array-average-and-median/
function calculateMedians(u)
{
medians = u.data.map((data) => {
data = [...data];
data.sort((a, b) => a - b);
return (data[(data.length - 1) >> 1] + data[data.length >> 1]) / 2
});
}

function drawBackgroundGradient(u)
{
let {ctx} = u;
let {width, height} = ctx.canvas;

let gradient = u.ctx.createLinearGradient(0, 0, 0, height);
gradient.addColorStop(0, "#666");
gradient.addColorStop(1, "#000");

ctx.save();
ctx.fillStyle = gradient;
ctx.fillRect(0,0,width,height);
ctx.restore();
}

function drawSeriesMedian(u, i)
{
// https://github.com/leeoniya/uPlot/issues/77
i -= 1;

let {ctx} = u;
let {width, height} = ctx.canvas;
let {label, color, min:minVal, max:maxVal, scale} = u.series.y[i];

cy = u.valToPos(medians[i+1], scale) * devicePixelRatio;

ctx.save();
ctx.strokeStyle = hexToRgbA(color, 0.2);
ctx.lineWidth = 50 * devicePixelRatio;
ctx.filter = 'blur(6px)';

ctx.beginPath();
ctx.moveTo(0, cy);
ctx.lineTo(ctx.canvas.width, cy);
ctx.closePath();
ctx.stroke();
ctx.restore();
}

function logDrawGridAxis(u, a)
{
// TODO - Think of something creative to do here
let axis = u.axes[a];
console.log("Draw Grid Axis", a, axis);
}

function enableBlurBeforeGridRender(u)
{
let {ctx} = u;
ctx.save();
ctx.filter = 'blur(2px)';
}

function disableBlurAfterGridRender(u, axis)
{
let {ctx} = u;
// This is a bit buggy. There are some cases where the y axis will not be rendered
// Resulting in the the canvas to be rendered with the previously applied blur
if (axis == 'y')
ctx.restore();
}

function drawPointsAsStars(u, i)
{
// https://github.com/leeoniya/uPlot/issues/77
i -= 1;

let {ctx} = u;
let {label, color, scale} = u.series.y[i];
let yVals = u.data[i+1];

ctx.save();
ctx.fillStyle = color;
yVals.forEach((val, i) => {
// Can add additional check if visible on Canvas before drawing
let cx = u.valToPos(u.data[0][i], 'x') * devicePixelRatio;
let cy = u.valToPos(val, scale) * devicePixelRatio;
drawStar(ctx, cx, cy);
ctx.fill();
});

ctx.restore();
}

let startRenderTime = null;

function setStartRenderTime()
{
startRenderTime = Date.now();
}

function drawRenderStats(u)
{
let {ctx} = u;
let {width:canWidth} = ctx.canvas;
let text = "Time to Draw: " + (Date.now() - startRenderTime) + "ms";

ctx.save();
ctx.font = '12px Arial';
ctx.fillStyle = 'white';
ctx.fillText(text, 6, 18);
ctx.restore();
}

return {
setData: [
calculateMedians
],
drawClear: [
setStartRenderTime,
drawBackgroundGradient,
enableBlurBeforeGridRender
],
drawGrid: [
disableBlurAfterGridRender
],
drawSeries: [
drawSeriesMedian,
drawPointsAsStars
],
draw: [
drawRenderStats
]
}
}

function makeChart() {

const data = [
[ 1, 2, 3, 4, 5, 6, 7, 9,10],
[40,43,60,65,71,73,40,22,20],
[30,23,35,27,11,13,30,32,30],
[15,13,39,17,21,53,10,11,13],
];

let opts =
{
width: 600,
height: 400,
axes: {
y: [
{grid:{show:true, color:'#000', width:1}},
],
x: [
{grid:{show:true, color:'#000', width:1}}
]
},
scales: {
x: {
time: false,
},
},
plugins: [
addCrazyVisualsPlugin(),
],
series: {
y: [
{
label: "blah",
color: "#ff3333",
},
{
label: "yerp",
color: "#33ccff",
},
{
label: "zort",
color: "#ffcc33",
}
]
}
};

let u = new uPlot.Line(opts, data);
document.body.appendChild(u.root);
}

makeChart();
</script>

</body>
</html>
11 changes: 9 additions & 2 deletions src/Line.js
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Original file line number Diff line number Diff line change
Expand Up @@ -411,6 +411,8 @@ export function Line(opts, data) {

const { can, ctx } = makeCanvas(canCssWidth, canCssHeight);

self.ctx = ctx;

plot.appendChild(can);

const pendScales = {};
Expand Down Expand Up @@ -536,8 +538,10 @@ export function Line(opts, data) {
});

series.forEach((s, i) => {
if (i > 0 && s.show)
if (i > 0 && s.show) {
drawPath(i);
fire("drawSeries", i);
}
});
}

Expand Down Expand Up @@ -716,6 +720,7 @@ export function Line(opts, data) {
ctx.stroke();

ctx.translate(-offset, -offset);
fire("drawGrid", axis.scale);
}
});
}
Expand Down Expand Up @@ -743,9 +748,11 @@ export function Line(opts, data) {
// log("paint()", arguments);

ctx.clearRect(0, 0, can[WIDTH], can[HEIGHT]);
drawAxesGrid();
fire("drawClear");
drawAxesGrid();
drawSeries();
didPaint = true;
fire("draw");
}

// redraw() => setScale('x', scales.x.min, scales.x.max);
Expand Down