Struct ScanlineInterp 

pub struct ScanlineInterp { /* private fields */ }

Per-scanline interpolator for z-buffer depth and (u, v) texture coordinates.

Pre-computes Q16.16 per-pixel step values for z, u, and v so the inner loop only does three wrapping additions instead of floating-point divisions per pixel — useful for MCU scanline rasterization.

Usage

let mut interp = ScanlineInterp::new(
    left_z,  right_z,   // u32 depth values (Q16.16)
    left_u,  right_u,   // u32 U texture coords (Q16.16)
    left_v,  right_v,   // u32 V texture coords (Q16.16)
    span_pixels,         // number of pixels across the scanline
);

for _x in 0..=span_pixels {
    let z = interp.z();
    let u = interp.u();
    let v = interp.v();
    // ... depth test, texture sample, write pixel ...
    interp.step();
}

Implementations

impl ScanlineInterp

pub fn new( z_left: u32, z_right: u32, u_left: u32, u_right: u32, v_left: u32, v_right: u32, span: i32, ) -> Self

Create a new scanline interpolator.

Arguments

• z_left, z_right — depth at the left and right scanline endpoints (Q16.16 u32)
• u_left, u_right — U texture coordinates (Q16.16 u32, range [0, 65536])
• v_left, v_right — V texture coordinates (Q16.16 u32, range [0, 65536])
• span — number of pixels across the scanline (0 is valid — returns left values)

pub fn depth_only(z_left: u32, z_right: u32, span: i32) -> Self

Create an interpolator for depth-only scanlines (no texture mapping).

pub fn z(&self) -> u32

Current depth value (Q16.16 u32).

pub fn u(&self) -> u32

Current U texture coordinate (Q16.16 u32).

pub fn v(&self) -> u32

Current V texture coordinate (Q16.16 u32).

pub fn step(&mut self)

Advance all interpolators by one pixel.

pub fn step_n(&mut self, n: i32)

Advance n pixels at once (useful for skipping clipped scanline segments).

pub fn z_f32(&self) -> f32

Current depth as f32.

Trait Implementations

impl Clone for ScanlineInterp

fn clone(&self) -> ScanlineInterp

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ScanlineInterp

impl Debug for ScanlineInterp

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

Formats the value using the given formatter.