31:T874,chart = { const svg = d3.select(DOM.svg(width, height)); let points = {a: [Math.round(width * .1), Math.round(height / 2)], b: [Math.round(width * .9), Math.round(height / 2)]}; let length = geometric.lineLength([points.a, points.b]); const line = svg.append("line") .attr("x1", points.a[0]) .attr("y1", points.a[1]) .attr("x2", points.b[0]) .attr("y2", points.b[1]); const pointACircle = svg.append("circle") .attr("class", "point-a") .attr("data-point", "a") .attr("r", radius) .attr("transform", `translate(${points.a})`) .call(drag); const pointBCircle = svg.append("circle") .attr("class", "point-b") .attr("data-point", "b") .attr("r", radius) .attr("transform", `translate(${points.b})`) .call(drag); const midpointCircle = svg.append("circle") .attr("class", "midpoint") .attr("r", radius) .attr("transform", `translate(${geometric.lineMidpoint([points.a, points.b])})`); function drag(sel){ const selPoint = sel.attr("data-point"); const dragGenerator = d3.drag() .on("start", start) .on("drag", dragging) .on("end", end); function start(){ sel.classed("active", 1); } function dragging(){ event.preventDefault(); let x = Math.round(d3.event.x); x = x < radius ? radius : x > width - radius ? width - radius : x; let y = Math.round(d3.event.y); y = y < radius ? radius : y > height - radius ? height - radius : y; points[selPoint] = [x, y]; line .attr("x1", points.a[0]) .attr("y1", points.a[1]) .attr("x2", points.b[0]) .attr("y2", points.b[1]); pointACircle .attr("transform", `translate(${points.a})`); pointBCircle .attr("transform", `translate(${points.b})`); midpointCircle .attr("transform", `translate(${geometric.lineMidpoint([points.a, points.b])})`); } function end(){ sel.classed("active", 0); } sel.call(dragGenerator); } return svg.node(); }32:[] 2f:{"title":"geometric.lineMidpoint","cells":[{"id":0,"value":"md`# geometric.lineMidpoint\n\n[geometric.lineMidpoint](https://github.com/HarryStevens/geometric#lineMidpoint)(line) returns the midpoint of a line.\n\nDrag either point to see how the midpoint changes with the line.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":10,"value":"$31","pinned":false,"hidden":false,"mode":"ojs"},{"id":36,"value":"{\n while(chart){\n const a = cleanCoords(\"a\"),\n b = cleanCoords(\"b\"),\n midpoint = geometric.lineMidpoint(makeLine(a, b));\n \n yield md`Point A: [${a}]
\n Point B: [${b}]
\n Midpoint:

[${midpoint.join(\", \")}]`;\n  }\n  \n  function clean(x){\n    return x.replace(\"translate(\", \"\").replace(\",\", \", \").replace(\")\", \"\");\n  }\n  function coords(point){\n    return d3.select(`.point-${point}`).attr(\"transform\");\n  }\n  function cleanCoords(cls){\n    return clean(coords(cls));\n  }\n  function makeArray(coords){\n    return coords.split(\", \").map(d => +d);\n  }\n  function makeLine(a, b){\n    return [makeArray(a), makeArray(b)];\n  }\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":21,"value":"md`## Styles`","pinned":false,"hidden":false,"mode":"ojs"},{"id":23,"value":"html`\n\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":12,"value":"md`## Dimensions`","pinned":false,"hidden":false,"mode":"ojs"},{"id":14,"value":"height = 300;","pinned":false,"hidden":false,"mode":"ojs"},{"id":19,"value":"radius = 6;","pinned":false,"hidden":false,"mode":"ojs"},{"id":4,"value":"md`## Imports`","pinned":false,"hidden":false,"mode":"ojs"},{"id":6,"value":"geometric = require(\"geometric@2\");","pinned":false,"hidden":false,"mode":"ojs"},{"id":8,"value":"d3 = require(\"d3@5\");","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W32","stdlib":"1","titling":"auto"}