2b:null 2c:["$","title",null,{"children":"Extract Appalachian Trail from PDF | Tanner Hobson | Observable"}] 31:Ta68,PATHS = { const pdf = BAKED; const ops = [ // "transform", "transform", "setStrokeRGBColor", "setLineWidth", "setMiterLimit", "setLineJoin", "constructPath", "stroke", // "transform", ]; const chs = ops.map((op) => PDF.op2ch(op)).join(''); const paths = []; let index = null; for (let breakout=1024; breakout>0; --breakout) { if (index == null) { index = 0; } else { index = index + 1; } index = pdf.chs.indexOf(chs, index); // return index; if (index < 0) break; const { [ops.indexOf('transform')]: [sx, _skewX, _skewY, sy, tx, ty], [ops.indexOf('setStrokeRGBColor')]: [r, g, b], [ops.indexOf('constructPath')]: [fns, args, _minMax], } = pdf.args.slice(index, index + chs.length); if (_skewX != 0 || _skewY != 0) { throw `x: ${_skewX} y: ${_skewY}`; } for (const path of PATHS({ sx, sy, tx, ty, fns, args })) { EMIT({ path, r, g, b}); } function EMIT({ path, r, g, b }) { const { [paths.length-1]: prev } = paths; if (prev && prev.r == r && prev.g == g && prev.b == b) { prev.paths.push(path); } else { paths.push({ paths: [path], r, g, b }); } } } return paths; function PATHS({ sx, sy, tx, ty, fns, args }) { fns = fns.slice(); args = args.slice(); const paths = []; while (args.length > 0) { // break; const fn = fns.shift(); const op = PDF.fn2op(fn); if (false) { // for source code alignment } else if (op === 'rectangle') { const [x, y, width, height] = args.splice(0, 4); continue; // skip } else if (op === 'moveTo') { const [x, y] = args.splice(0, 2); EMITSTART({ x, y }); } else if (op === 'lineTo') { const [x, y] = args.splice(0, 2); EMIT({ x, y }); } else if (op === 'curveTo') { const [cp1x, cp1y, cp2x, cp2y, x, y] = args.splice(0, 6); EMIT({ x, y }); } else if (op === 'curveTo2') { const [cp2x, cp2y, x, y] = args.splice(0, 4); EMIT({ x, y }); } else if (op === 'curveTo3') { const [cp1x, cp1y, x, y] = args.splice(0, 4); EMIT({ x, y }); } else { throw `Unexpected op: ${op}`; } } return paths; function EMITSTART({ x, y }) { paths.push([]); EMIT({ x, y }); } function EMIT({ x, y }) { x = sx * x + tx; y = sy * y + ty; const { [paths.length-1]: path } = paths; path.push({ x, y }); } } }32:T666,{ const $pdf = await RENDER_PDF(); const w = +$pdf.width; const h = +$pdf.height; const s = 1; const ctx = DOM.context2d(w/s, h/s); ctx.resetTransform(); // ctx.translate(0, h); // ctx.scale(1.0, -1.0); ctx.translate(-w+500, 0); ctx.scale(1/s, 1/s); const $index = Inputs.range([0, PATHS.length-1], { value: 0, step: 1 }); yield htl.html`

${$index} ${ctx.canvas} `; for await (const index of Generators.input($index)) { const { [index]: { paths, r, g, b } } = PATHS; // ctx.clearRect(0, 0, w, h); // ctx.save(); // ctx.resetTransform(); // ctx.scale(1/s, 1/s); // ctx.translate(-500, 0); ctx.globalCompositeOperation = 'copy'; ctx.drawImage($pdf, 0, 0, w, h); ctx.globalCompositeOperation = 'source-over'; // ctx.restore(); for (const { lineWidth, strokeStyle } of [ { lineWidth: 4, strokeStyle: 'black' }, { lineWidth: 3, strokeStyle: `rgb(${r}, ${g}, ${b})` }, ]) { for (const path of paths) { ctx.beginPath(); ctx.moveTo(path[0].x, path[0].y); for (let i=1, n=path.length; i { target.addEventListener('mousedown', onmouse); target.addEventListener('mouseup', onmouse); notify({ action: null, x: null, y: null, }); return () => { target.removeEventListener('mousedown', onmouse); target.removeEventListener('mousemove', onmouse); target.removeEventListener('mouseup', onmouse); } function onmouse(e) { e.preventDefault(); const { type } = e; if (type === 'mousedown') { target.addEventListener('mousemove', onmouse); } else if (type === 'mouseup') { target.removeEventListener('mousemove', onmouse); } const { ctrlKey } = e; const [x, y] = d3.pointer(e); notify({ type: ctrlKey ? 'add' : 'remove', x, y, }); } }); } }34:[] 2f:{"id":"df73e64f6a4d328f","slug":null,"title":"Extract Appalachian Trail from PDF","thumbnail":"7610514ca6feb320940846db9befc7b6651102462dc1e7f1a58a8ef72a3acfa1","access_level":"public","create_time":"$D2023-07-12T22:21:00.080Z","update_time":"$D2023-07-17T19:04:48.752Z","view_time":null,"first_public_time":"$D2023-07-12T22:21:00.080Z","fork":false,"stars":0,"starred":false,"owner":{"type":"team","id":"7343f790779e6735","login":"player1537","name":"Tanner Hobson","avatar_url":"https://avatars-next.observableusercontent.com/16170a1a32e364e1ff6054c6045de6814a032d01331aba01288f82afceeaaec2","tier":"starter_2024"},"version":229,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"e0a627f6b6f3beb0","login":"player1537","name":"Tanner Hobson","avatar_url":"https://avatars-next.observableusercontent.com/16170a1a32e364e1ff6054c6045de6814a032d01331aba01288f82afceeaaec2","tier":null}],"members":[{"type":"individual","id":"e0a627f6b6f3beb0","login":"player1537","name":"Tanner Hobson","avatar_url":"https://avatars-next.observableusercontent.com/16170a1a32e364e1ff6054c6045de6814a032d01331aba01288f82afceeaaec2","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"title":"Extract Appalachian Trail from PDF","cells":[{"id":0,"value":"# Extract Appalachian Trail from PDF","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":4,"value":"import { example as pdf, PDF } from '@player1537/pdf-utilities';","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":28,"value":"pdf","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":147,"value":"{\n\n const $missing = Symbol('missing');\n const $undefined = Symbol('undefined');\n \n const examples = {};\n for (const op of PDF.OPS()) {\n examples[op] = EXAMPLE(op);\n }\n\n return examples;\n\n function EXAMPLE(op) {\n const ch = PDF.op2ch(op);\n const index = pdf.chs.indexOf(ch);\n if (index < 0) return $missing;\n \n for (let index=0;; ++index) {\n index = pdf.chs.indexOf(ch, index);\n if (index < 0) break;\n \n const {\n // fns: { [index]: fn },\n args: { [index]: arg },\n // ops: { [index]: op },\n } = pdf;\n\n if (arg !== undefined) return arg;\n }\n \n return $undefined;\n }\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"PDF.OPS()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":19,"value":"pdf.chs","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":22,"value":"JSON.stringify('km6cfe}ul'.split('').map((ch) => PDF.ch2op(ch)), true, 2)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":153,"value":"BAKED = {\n const ops = pdf.ops.slice();\n const args = pdf.args.slice();\n\n const ctx = DOM.context2d();\n\n ctx.resetTransform();\n for (let i=0, n=ops.length; i PDF.op2fn(op));\n const chs = ops.map((op) => PDF.op2ch(op)).join('');\n\n return {\n ops,\n args,\n fns,\n chs,\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":26,"value":"$31","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":127,"value":"{\n const w = 1000;\n const h = 1000;\n const s = 2;\n const ctx = DOM.context2d(w/s, h/s);\n\n ctx.resetTransform();\n ctx.translate(0, h); // applies \"third\"\n ctx.scale(1.0, -1.0); // applies \"second\"\n ctx.scale(1/s, 1/s); // applies \"first\"\n return transform(ctx, {\n x: 100,\n y: 400,\n }); \n\n function transform(ctx, { x, y }) {\n // Thanks https://stackoverflow.com/a/62841369\n //> const point = {x: 0, y: 0};\n //> const matrix = ctx.getTransform();\n //> const transformedPoint = {\n //> x: matrix.a * point.x + matrix.c * point.y + matrix.e,\n //> y: matrix.b * point.x + matrix.d * point.y + matrix.f,\n //> };\n const { a, b, c, d, e, f } = ctx.getTransform();\n return {\n x: a*x + c*y + e,\n y: b*x + d*y + f,\n };\n }\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":82,"value":"$32","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":179,"value":"$33","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":199,"value":"CALIBRATION_POINTS = ({\n sw: { x: 260.3723995361328, y: 431.95060156249997, lat: 35.473817, lng: -83.920740 },\n ne: { x: 1382.9233995361328, y: 904.5586015625, lat: 35.763457, lng: -83.134908 },\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":197,"value":"{\n const path = PATHS[3].paths[0];\n const { sw, ne } = CALIBRATION_POINTS;\n const x2lng = d3.scaleLinear([sw.x, ne.x], [sw.lng, ne.lng]);\n const y2lat = d3.scaleLinear([sw.y, ne.y], [sw.lat, ne.lat]);\n\n const ret = [];\n for (const { x, y } of path) {\n ret.push({\n lng: x2lng(x),\n lat: y2lat(y),\n });\n }\n\n return htl.html`