Struct Levels 

pub struct Levels {
    pub width: u32,
    pub height: u32,
    pub levels: Vec<Vec<u8>>,
}

An RGBA8 texture’s mip levels, each stored row by row, four bytes a texel. Level n is the base size halved n times (at least 1); Levels::size gives it.

Fields

width: u32

The base level’s width in texels.

height: u32

The base level’s height in texels.

levels: Vec<Vec<u8>>

The RGBA8 bytes of each level, base level first. The fields are public, so the sampling methods check the level they read: one that is missing, or does not hold exactly its Levels::size in texels, is refused.

Implementations

impl Levels

pub fn one(width: u32, height: u32, rgba: Vec<u8>) -> Result<Levels>

One level of RGBA8 texels.

pub fn rows_reversed(self) -> Result<Levels>

Each level’s rows in reverse order, for a texture stored bottom row first when row 0 is wanted at v = 0: addressing then applies about that texture’s own origin. A level that isn’t its size’s whole rows is refused.

pub fn size(&self, level: usize) -> (u32, u32)

Level level’s size: the base halved per level, at least 1.

pub fn texel( &self, level: usize, x: i64, y: i64, address: [Address; 2], ) -> Result<[u8; 4]>

The texel at (x, y) of level level, addressed by address. A level that is not stored, or does not hold its size’s bytes, is refused, as is a coordinate outside a Address::Border axis (it reads no stored texel).

pub fn bilinear( &self, level: usize, uv: [f64; 2], address: impl Into<Addressing<2>>, transfer: Transfer, ) -> Result<[f64; 4]>

Bilinear at uv of level level, in f64: weights (1 - tx)(1 - ty), tx (1 - ty), (1 - tx) ty, tx ty summed in that order, a texel outside a border axis the border colour. A coordinate that isn’t finite or past an i32’s range is refused, as is a border axis with no colour (Addressing::border).

pub fn point( &self, level: usize, uv: [f64; 2], address: impl Into<Addressing<2>>, transfer: Transfer, ) -> Result<[f64; 4]>

The texel of level level that uv falls in (texel i covering [i, i + 1) after scaling by the level’s size), in f64: point filtering; outside a border axis, the border colour. A coordinate that isn’t finite or past an i32’s range is refused, as is a border axis with no colour.

pub fn decoded(&self, level: usize, transfer: Transfer) -> Result<Decoded>

Level level decoded once to f32 by transfer, for Decoded::bilinear. A level that is not stored, or does not hold its size’s bytes, is refused.

impl Levels

pub fn trilinear( &self, uv: [f64; 2], lod: f64, address: impl Into<Addressing<2>>, transfer: Transfer, ) -> Result<[f64; 4]>

Trilinear at uv: the level of detail lod clamped to the stored levels, the bilinear values (Levels::bilinear) of the level below it and the next mixed by its fraction (a + (b - a) f); a level of detail that isn’t a number, or a coordinate or addressing Levels::bilinear refuses, is refused.

pub fn nearest_level(&self, lod: f64) -> Result<usize>

The stored level nearest the level of detail lod, as a point mip filter picks it: floor(lod + 0.5) (a half rounds up), clamped to the stored levels. A level of detail that isn’t a number is refused.

Trait Implementations

impl Clone for Levels

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 Levels

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

Formats the value using the given formatter.