Class ZoomLevelLatch

Namespace

LansMap.Core.Tiles.Selection

Holds the integer tile level across zoom jitter near a level boundary.

public sealed class ZoomLevelLatch

Inheritance

object

ZoomLevelLatch

Remarks

Selecting on floor(zoom) alone flips the footprint every frame while zoom oscillates around an integer. Going down, a level is left only once zoom is clear of the boundary by Deadband. Going up, the commit fires as soon as the next level is clearly reached (offset >= 1.0), not 1.0 + Deadband: a zoom animation or a programmatic fly that lands EXACTLY on held-level + 1.0 (offset 1.0) must commit the finer level immediately, or the map rests drawn 2.0x magnified under the coarser one - the asymmetry is deliberate, not a mirror of the down side.

Properties

Deadband

Hysteresis in zoom units, default 0.15 of a level.

public double Deadband { get; set; }

Property Value

double

Level

Currently held integer zoom, or -1 before the first Update(double).

public int Level { get; }

Property Value

int

Methods

Reset()

Clears the latch so the next Update(double) takes floor(zoom).

public void Reset()

Update(double)

Advances the latch for the current zoom.

public int Update(double zoom)

Parameters

zoom double

Fractional zoom, 0 to Max.

Returns

int

The held integer level.