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0936134 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 | /**
* @module ol/geom/flat/interpolate
*/
import {binarySearch} from '../../array.js';
import {lerp} from '../../math.js';
/**
* @param {Array.<number>} flatCoordinates Flat coordinates.
* @param {number} offset Offset.
* @param {number} end End.
* @param {number} stride Stride.
* @param {number} fraction Fraction.
* @param {Array.<number>=} opt_dest Destination.
* @return {Array.<number>} Destination.
*/
export function interpolatePoint(flatCoordinates, offset, end, stride, fraction, opt_dest) {
let pointX = NaN;
let pointY = NaN;
const n = (end - offset) / stride;
if (n === 1) {
pointX = flatCoordinates[offset];
pointY = flatCoordinates[offset + 1];
} else if (n == 2) {
pointX = (1 - fraction) * flatCoordinates[offset] +
fraction * flatCoordinates[offset + stride];
pointY = (1 - fraction) * flatCoordinates[offset + 1] +
fraction * flatCoordinates[offset + stride + 1];
} else if (n !== 0) {
let x1 = flatCoordinates[offset];
let y1 = flatCoordinates[offset + 1];
let length = 0;
const cumulativeLengths = [0];
for (let i = offset + stride; i < end; i += stride) {
const x2 = flatCoordinates[i];
const y2 = flatCoordinates[i + 1];
length += Math.sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));
cumulativeLengths.push(length);
x1 = x2;
y1 = y2;
}
const target = fraction * length;
const index = binarySearch(cumulativeLengths, target);
if (index < 0) {
const t = (target - cumulativeLengths[-index - 2]) /
(cumulativeLengths[-index - 1] - cumulativeLengths[-index - 2]);
const o = offset + (-index - 2) * stride;
pointX = lerp(
flatCoordinates[o], flatCoordinates[o + stride], t);
pointY = lerp(
flatCoordinates[o + 1], flatCoordinates[o + stride + 1], t);
} else {
pointX = flatCoordinates[offset + index * stride];
pointY = flatCoordinates[offset + index * stride + 1];
}
}
if (opt_dest) {
opt_dest[0] = pointX;
opt_dest[1] = pointY;
return opt_dest;
} else {
return [pointX, pointY];
}
}
/**
* @param {Array.<number>} flatCoordinates Flat coordinates.
* @param {number} offset Offset.
* @param {number} end End.
* @param {number} stride Stride.
* @param {number} m M.
* @param {boolean} extrapolate Extrapolate.
* @return {module:ol/coordinate~Coordinate} Coordinate.
*/
export function lineStringCoordinateAtM(flatCoordinates, offset, end, stride, m, extrapolate) {
if (end == offset) {
return null;
}
let coordinate;
if (m < flatCoordinates[offset + stride - 1]) {
if (extrapolate) {
coordinate = flatCoordinates.slice(offset, offset + stride);
coordinate[stride - 1] = m;
return coordinate;
} else {
return null;
}
} else if (flatCoordinates[end - 1] < m) {
if (extrapolate) {
coordinate = flatCoordinates.slice(end - stride, end);
coordinate[stride - 1] = m;
return coordinate;
} else {
return null;
}
}
// FIXME use O(1) search
if (m == flatCoordinates[offset + stride - 1]) {
return flatCoordinates.slice(offset, offset + stride);
}
let lo = offset / stride;
let hi = end / stride;
while (lo < hi) {
const mid = (lo + hi) >> 1;
if (m < flatCoordinates[(mid + 1) * stride - 1]) {
hi = mid;
} else {
lo = mid + 1;
}
}
const m0 = flatCoordinates[lo * stride - 1];
if (m == m0) {
return flatCoordinates.slice((lo - 1) * stride, (lo - 1) * stride + stride);
}
const m1 = flatCoordinates[(lo + 1) * stride - 1];
const t = (m - m0) / (m1 - m0);
coordinate = [];
for (let i = 0; i < stride - 1; ++i) {
coordinate.push(lerp(flatCoordinates[(lo - 1) * stride + i],
flatCoordinates[lo * stride + i], t));
}
coordinate.push(m);
return coordinate;
}
/**
* @param {Array.<number>} flatCoordinates Flat coordinates.
* @param {number} offset Offset.
* @param {Array.<number>} ends Ends.
* @param {number} stride Stride.
* @param {number} m M.
* @param {boolean} extrapolate Extrapolate.
* @param {boolean} interpolate Interpolate.
* @return {module:ol/coordinate~Coordinate} Coordinate.
*/
export function lineStringsCoordinateAtM(
flatCoordinates, offset, ends, stride, m, extrapolate, interpolate) {
if (interpolate) {
return lineStringCoordinateAtM(
flatCoordinates, offset, ends[ends.length - 1], stride, m, extrapolate);
}
let coordinate;
if (m < flatCoordinates[stride - 1]) {
if (extrapolate) {
coordinate = flatCoordinates.slice(0, stride);
coordinate[stride - 1] = m;
return coordinate;
} else {
return null;
}
}
if (flatCoordinates[flatCoordinates.length - 1] < m) {
if (extrapolate) {
coordinate = flatCoordinates.slice(flatCoordinates.length - stride);
coordinate[stride - 1] = m;
return coordinate;
} else {
return null;
}
}
for (let i = 0, ii = ends.length; i < ii; ++i) {
const end = ends[i];
if (offset == end) {
continue;
}
if (m < flatCoordinates[offset + stride - 1]) {
return null;
} else if (m <= flatCoordinates[end - 1]) {
return lineStringCoordinateAtM(
flatCoordinates, offset, end, stride, m, false);
}
offset = end;
}
return null;
}
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