Struct QuantAffine 

pub struct QuantAffine {
    pub x0: f64,
    pub y0: f64,
    pub sx: f64,
    pub sy: f64,
    pub z0: Option<f64>,
    pub sz: Option<f64>,
}

Per-layer coordinate-quantization affine. Coordinates ship as i32 grid indices; the decoder reconstructs lon = x0 + qx*sx, lat = y0 + qy*sy. sx/sy (degrees per quantum) are sized from a target ground precision in meters at the layer’s mid-latitude, so the worst-case error is ≤ half a quantum (~meters/2). This trades GeoArrow self-describing Float64 for size (coords are the dominant, near-incompressible column) and is opt-in.

Fields

x0: f64

y0: f64

sx: f64

sy: f64

z0: Option<f64>

Z-axis origin/step (metres), present ONLY for 3D point geometry (FixedSizeList<i32,3>). None ⇒ plain 2D coords, byte-identical to the historical affine (the z0/sz keys are simply omitted from the JSON).

sz: Option<f64>

Implementations

impl QuantAffine

pub fn from_json(s: &str) -> Option<QuantAffine>

Parse the affine from its STT_QUANT_META_KEY JSON value. The TS reader applies the identical reconstruction (tile.ts).

pub fn lon(&self, qx: i32) -> f64

Reconstruct longitude from a quantized x grid index.

pub fn lat(&self, qy: i32) -> f64

Reconstruct latitude from a quantized y grid index.

Trait Implementations

impl Clone for QuantAffine

fn clone(&self) -> QuantAffine

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for QuantAffine

impl Debug for QuantAffine

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for QuantAffine

fn eq(&self, other: &QuantAffine) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for QuantAffine