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Better smoothing of resolution and center constraints

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Previously the formula for the resolution constraint allowed going way past
the minimum zoom.
Also adjusted the center constraint to avoid a zigzag effect when going out
of resolution bounds.
This commit is contained in:
Olivier Guyot
2019-02-25 23:12:39 +01:00
parent f67baa0dc0
commit 447266cbe8
2 changed files with 24 additions and 9 deletions
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src/ol/centerconstraint.js
+16 -6
View File
@@ -29,12 +29,22 @@ export function createExtent(extent, onlyCenter, smooth) {
if (center) {
const viewWidth = onlyCenter ? 0 : size[0] * resolution;
const viewHeight = onlyCenter ? 0 : size[1] * resolution;
const minX = extent[0] + viewWidth / 2;
const maxX = extent[2] - viewWidth / 2;
const minY = extent[1] + viewHeight / 2;
const maxY = extent[3] - viewHeight / 2;
let x = minX > maxX ? (maxX + minX) / 2 : clamp(center[0], minX, maxX);
let y = minY > maxY ? (maxY + minY) / 2 : clamp(center[1], minY, maxY);
let minX = extent[0] + viewWidth / 2;
let maxX = extent[2] - viewWidth / 2;
let minY = extent[1] + viewHeight / 2;
let maxY = extent[3] - viewHeight / 2;
// note: when zooming out of bounds, min and max values for x and y may
// end up inverted (min > max); this has to be accounted for
if (minX > maxX) {
minX = maxX = (maxX + minX) / 2;
}
if (minY > maxY) {
minY = maxY = (maxY + minY) / 2;
}
let x = clamp(center[0], minX, maxX);
let y = clamp(center[1], minY, maxY);
const ratio = 30 * resolution;
// during an interaction, allow some overscroll