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Merge pull request #11719 from ahocevar/less-aggressie-3857-clamping

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Clamp EPSG:3857 y to lowest/highest possible value instead of validity extent
This commit is contained in:
Andreas Hocevar
2020-11-19 13:51:47 +01:00
committed by GitHub
parent 698fca2d56 2526dc738c
commit dd95f56e26
2 changed files with 20 additions and 10 deletions
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18
src/ol/proj/epsg3857.js
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@@ -31,6 +31,13 @@ export const EXTENT = [-HALF_SIZE, -HALF_SIZE, HALF_SIZE, HALF_SIZE];
*/ */
export const WORLD_EXTENT = [-180, -85, 180, 85]; export const WORLD_EXTENT = [-180, -85, 180, 85];
/**
* Maximum safe value in y direction
* @const
* @type {number}
*/
export const MAX_SAFE_Y = RADIUS * Math.log(Math.tan(Math.PI / 2));
/** /**
* @classdesc * @classdesc
* Projection object for web/spherical Mercator (EPSG:3857). * Projection object for web/spherical Mercator (EPSG:3857).
@@ -87,14 +94,13 @@ export function fromEPSG4326(input, opt_output, opt_dimension) {
output = new Array(length); output = new Array(length);
} }
} }
const halfSize = HALF_SIZE;
for (let i = 0; i < length; i += dimension) { for (let i = 0; i < length; i += dimension) {
output[i] = (halfSize * input[i]) / 180; output[i] = (HALF_SIZE * input[i]) / 180;
let y = RADIUS * Math.log(Math.tan((Math.PI * (+input[i + 1] + 90)) / 360)); let y = RADIUS * Math.log(Math.tan((Math.PI * (+input[i + 1] + 90)) / 360));
if (y > halfSize) { if (y > MAX_SAFE_Y) {
y = halfSize; y = MAX_SAFE_Y;
} else if (y < -halfSize) { } else if (y < -MAX_SAFE_Y) {
y = -halfSize; y = -MAX_SAFE_Y;
} }
output[i + 1] = y; output[i + 1] = y;
} }

12
test/spec/ol/proj/epsg3857.test.js
View File

@@ -1,4 +1,8 @@
import {HALF_SIZE, fromEPSG4326} from '../../../../src/ol/proj/epsg3857.js'; import {
HALF_SIZE,
MAX_SAFE_Y,
fromEPSG4326,
} from '../../../../src/ol/proj/epsg3857.js';
import { import {
addCommon, addCommon,
clearAllProjections, clearAllProjections,
@@ -24,11 +28,11 @@ describe('ol/proj/epsg3857', function () {
}, },
{ {
g: [-180, -90], g: [-180, -90],
m: [-HALF_SIZE, -HALF_SIZE], m: [-HALF_SIZE, -MAX_SAFE_Y],
}, },
{ {
g: [180, 90], g: [180, 90],
m: [HALF_SIZE, HALF_SIZE], m: [HALF_SIZE, MAX_SAFE_Y],
}, },
{ {
g: [-111.0429, 45.677], g: [-111.0429, 45.677],
@@ -47,7 +51,7 @@ describe('ol/proj/epsg3857', function () {
it('does not produce unexpected results for string coordinates', function () { it('does not produce unexpected results for string coordinates', function () {
const transformed = fromEPSG4326(['180', '90']); const transformed = fromEPSG4326(['180', '90']);
expect(transformed[0]).to.roughlyEqual(HALF_SIZE, 1e-5); expect(transformed[0]).to.roughlyEqual(HALF_SIZE, 1e-5);
expect(transformed[1]).to.roughlyEqual(HALF_SIZE, 1e-5); expect(transformed[1]).to.roughlyEqual(MAX_SAFE_Y, 1e-5);
}); });
}); });