Struct Weights 

pub struct Weights { /* private fields */ }

Precomputed weights for one resize pass along one axis.

Built once per pass and shared by every row (or column) it is applied to, which is what turns a resize into a multiply-accumulate loop.

Implementations

impl Weights

pub fn build(filter: Filter, input_len: u32, output_len: u32) -> Result<Self>

Build the weight table mapping input_len samples onto output_len.

Errors

Returns PixelsError::InvalidArgument if either length is zero, or if the filter support at this scale would exceed what u32 can index.

pub fn window(self, offset: u32, len: u32) -> Self

The table restricted to output positions offset..offset + len, renumbered from zero: the window a cropping resize keeps. The weights are shared, so nothing is recomputed and the kept positions resample exactly as they would in the full table.

pub fn runs(&self) -> &[Run]

The runs, one per output position.

pub fn quantized(&self, run: &Run) -> &[i32]

The fixed-point weights of run.

pub fn exact(&self, run: &Run) -> &[f32]

The exact weights of run.

pub const fn max_len(&self) -> u32

The longest run in the table.

pub fn for_tile( &self, out_start: u32, out_len: u32, in_start: u32, ) -> Result<Self>

The sub-table covering out_len output positions from out_start, rebased so run starts are relative to input index in_start.

This is how a tile uses the image’s weights rather than its own. Building a fresh table from the tile’s dimensions would resample at the tile’s scale instead of the image’s, so an output pixel would depend on where the tile boundaries fell — which SPEC §Guarantees 2 forbids.

Errors

Returns PixelsError::graph if the requested outputs fall outside this table, or if a run would start before in_start — either means the tile is not the footprint input_regions asked for.

pub fn footprint(&self, from: u32, len: u32) -> (u32, u32)

The first and last input index any output position reads.

This is what input_regions needs: the footprint of a whole pass.

Trait Implementations

impl Clone for Weights

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Weights

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

Formats the value using the given formatter.