30:T460,{ // Unit tests assert(intersectionArea([2, 3, 2, 3, 2, 3, 2, 4, 3, 3, 2, 3, 2, 3], [2, 3, 2, 3, 2, 3, 2, 4, 3, 3, 2, 3, 2, 3]), 0.5); assert(intersectionArea([2, 3, 2, 3, 2, 3, 2, 4, 3, 3, 2, 3, 2, 3], [1, 1, 1, 4, 4, 4, 4, 1, 1, 1]), 0.5); assert(intersectionArea([1, 7, 4, 7, 4, 6, 2, 6, 2, 3, 4, 3, 4, 2, 1, 2], [3, 1, 5, 1, 5, 4, 3, 4, 3, 5, 6, 5, 6, 0, 3, 0]), 0); assert(intersectionArea([1, 1, 1, 2, 2, 1, 2, 2], [0, 0, 0, 4, 4, 4, 4, 0]), 0); assert(intersectionArea([0, 0, 3, 0, 3, 2, 1, 2, 1, 1, 2, 1, 2, 3, 0, 3], [0, 0, 0, 4, 4, 4, 4, 0]), -9); assert(intersectionArea([0, 0, 1, 0, 0, 1], [0, 0, 0, 1, 1, 1, 1, 0]), -0.5); assert(intersectionArea([1, 3, 2, 3, 2, 0, 1, 0], [0, 1, 3, 1, 3, 2, 0, 2]), -1); assert(intersectionArea([0, 0, 0, 2, 2, 2, 2, 0], [1, 1, 3, 1, 3, 3, 1, 3]), -1); assert(intersectionArea([0, 0, 0, 4, 4, 4, 4, 0], [1, 1, 1, 2, 2, 2, 2, 1]), 1); assert(intersectionArea([0, 0, 3, 3], [0, 0, 3, 3]), 0); assert(intersectionArea([0, 0, 3, 3], [1, 1, 1, 2, 2, 2, 2, 1]), 0); assert(intersectionArea([1, 1, 1, 2, 2, 2, 2, 1], [0, 0, 3, 3]), 0); return 'PASS'; }31:[{"id":"86bd56793dc068dc36f33bd7690bf0bdc2a119e0e2df6dc7a11b63f033f1dfd8566f613401f3dc8d7eb1e5ff9f6f06f78a4deb97cbe1ce5b05fcf05dc1c9de5c","href":"https://static.observableusercontent.com/files/86bd56793dc068dc36f33bd7690bf0bdc2a119e0e2df6dc7a11b63f033f1dfd8566f613401f3dc8d7eb1e5ff9f6f06f78a4deb97cbe1ce5b05fcf05dc1c9de5c","name":"pia@4.wasm","type":"application/wasm","lastModified":1591886412835.902,"size":19685}] 2e:{"title":"Intersection Area","cells":[{"id":0,"value":"md`# Intersection Area\n\nA tool to calculate the intersection area of two polygons using a C tool compiled to WebAssembly: https://github.com/smuelpeng/pia\n\nUsage:\n * import {intersectionArea} from '@freedmand/intersection-area'\n * intersectionArea(poly1, poly2), where poly1 and poly2 are arrays of points formatted like [x_0, y_0, x_1, y_1, ..., x_n, y_n]\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":183,"value":"function intersectionArea(poly1, poly2) {\n const f32 = new Float32Array(pia.instance.exports.memory.buffer);\n let i = 0;\n for (let j = 0; j < poly1.length; j++) {\n f32[i++] = poly1[j];\n }\n for (let j = 0; j < poly2.length; j++) {\n f32[i++] = poly2[j];\n }\n\n const startTime = Date.now();\n const result = pia.instance.exports.pia_area(pia.instance.exports.memory.buffer, poly1.length / 2, poly2.length / 2);\n const time = Date.now() - startTime;\n if (time > 25) {\n console.log(poly1, poly2, time);\n }\n console.log(time);\n return result;\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":276,"value":"function assert(a, b) {\n if (a != b) throw new Error(`Expected ${a} to equal ${b}`);\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":263,"value":"$30","pinned":true,"hidden":false,"mode":"ojs"},{"id":63,"value":"pia = {\n const bytes = await FileAttachment('pia@4.wasm').arrayBuffer();\n return await WebAssembly.instantiate(bytes);\n}","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W31","stdlib":"1","titling":"auto"}