31:T708,# Origami grafting reference translator Say you measure some reference points on the edge of a piece of paper (one half, one quarter, etc.). If you add an extra strip of paper to the end, those references are no longer accurate. The “one quarter” mark is no longer marking one quarter of the new total length. But it still marks _something_ — there's a 1:1 mapping between each mark on the original length, and some new reference point on the new length. Similarly, in origami design there is a technique known as grafting. But instead of physically adding some extra paper onto the end, the original design is shrunk within the boundaries of the paper (and maybe squashed or split into separate parts). This leaves a leftover bit of paper that's the equivalent of the extra piece. This calculator was designed for a specific model where I wanted a 1/16 strip of “extra” paper on the edge for some more fine details. That left the original design being 15/16 of the full square of paper. If I wanted to mark 1/3 on the original design (the **“inner”** length), what would I measure on the full-size paper (the **“outer”** length)? Now it depends on which end I’m measuring from. If the “gap” of extra paper is at one end, and the 1/3 inner mark is measured from the shared edge, it equates to exactly 5/16 of the outer length. But if 1/3 is measured from the other end where the gap is, the length of the gap also needs to be taken into account. In this case, 1/3 of the inner length, _plus_ the gap length, is exactly 3/8 of the outer length. What about other reference marks, or a different gap size? That’s what these inputs are for. **Inner size** says how large the inner length is, as a percentage of the outer length. The initial value is 15/16, which is 0.9375.32:T465,function svgMarker(mark, innerOffset, index) { const xOuter = X(mark.value), xInner = X(mark.value * innerSize + innerOffset), outerOnInner = valueLabel((mark.value - innerOffset) / innerSize), innerOnOuter = valueLabel(mark.value * innerSize + innerOffset), yInv = (index % 2 === 0) ? 0 : 8; return htl.svg` ${mark.label} ${outerOnInner} ${mark.label} ${innerOnOuter} `; }33:[] 2f:{"title":"Origami grafting reference translator","cells":[{"id":0,"value":"$31","pinned":false,"hidden":false,"mode":"md"},{"id":14,"value":"viewof innerSizeRaw = Inputs.text({label: 'Inner size', value: '15/16'})","pinned":false,"hidden":false,"mode":"ojs"},{"id":248,"value":"Marking points are the reference points to find. They can be written as either fractions or decimal numbers (where the outer length is 1, so a 1/5 mark can be written as either “1/5” or “0.2”).","pinned":false,"hidden":false,"mode":"md"},{"id":3,"value":"viewof rawMarks = Inputs.text({label: 'Marking points', value: '1/4, 1/3, 3/8'})","pinned":false,"hidden":false,"mode":"ojs"},{"id":254,"value":"The lines below show the marking points for both inner and outer lengths, measured from both ends. The grey block at the end of each line indicates the “gap” between inner and outer lengths (the grafted strip, in origami terms).","pinned":false,"hidden":false,"mode":"md"},{"id":21,"value":"svg``","pinned":false,"hidden":false,"mode":"ojs"},{"id":24,"value":"height = 300","pinned":false,"hidden":false,"mode":"ojs"},{"id":97,"value":"maxLen = 550","pinned":false,"hidden":false,"mode":"ojs"},{"id":36,"value":"","pinned":false,"hidden":false,"mode":"html"},{"id":282,"value":"function parseMark(mark) {\n let [num, den] = mark.split('/').map(n => parseFloat(n));\n let label = [num, den].join('/');\n if (isNaN(num)) {\n return null;\n }\n if (isNaN(den) || den <= 0) {\n den = 1;\n label = num;\n }\n return { label, value: num / den };\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":280,"value":"innerSize = parseMark(innerSizeRaw).value","pinned":false,"hidden":false,"mode":"ojs"},{"id":72,"value":"marks = rawMarks\n .split(/\\s*,\\s*/)\n .map(parseMark)\n .filter(mark => mark !== null)\n .sort((a, b) => a.value - b.value)","pinned":false,"hidden":false,"mode":"ojs"},{"id":152,"value":"lineY = Math.round(maxLen / 16)","pinned":false,"hidden":false,"mode":"ojs"},{"id":95,"value":"X = (num) => num * maxLen","pinned":false,"hidden":false,"mode":"ojs"},{"id":183,"value":"round = (num, precision) => Math.round(num * 10 ** precision) / 10 ** precision","pinned":false,"hidden":false,"mode":"ojs"},{"id":192,"value":"function valueLabel(value) {\n if (value === 0) {\n return 0;\n }\n for (let i = 2; i <= 64; i++) {\n if (value * i % 1 === 0) {\n return `${value * i}/${i}`;\n }\n }\n return round(value, 4);\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":104,"value":"$32","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W33","stdlib":"1","titling":"auto"}