Struct FlowMap 

pub struct FlowMap {
    pub vectors: Vec<Vec2>,
    pub width: usize,
    pub height: usize,
    pub speed: f32,
    pub strength: f32,
    pub time: f32,
    pub cycle_duration: f32,
}

A flow map for UV distortion.

A flow map stores 2D velocity vectors at each texel. At render time, UVs are offset by the flow direction, creating the illusion of flowing liquid, lava, etc.

Fields

vectors: Vec<Vec2>

Flow vectors stored row-major. Each entry is a 2D direction.

width: usize

Width of the flow map.

height: usize

Height of the flow map.

speed: f32

Flow speed multiplier.

strength: f32

Flow strength multiplier.

time: f32

Current cycle time.

cycle_duration: f32

Duration of one flow cycle (UV offset resets to avoid extreme distortion).

Implementations

impl FlowMap

pub fn new(width: usize, height: usize) -> Self

Create a new flow map with the given dimensions.

pub fn uniform(width: usize, height: usize, direction: Vec2) -> Self

Create a flow map with a uniform direction.

pub fn vortex(width: usize, height: usize, strength: f32) -> Self

Create a circular flow map (vortex).

pub fn divergent(width: usize, height: usize, strength: f32) -> Self

Create a divergent flow map (expanding from center).

pub fn with_speed(self, speed: f32) -> Self

Set flow speed.

pub fn with_strength(self, strength: f32) -> Self

Set flow strength.

pub fn with_cycle(self, duration: f32) -> Self

Set cycle duration.

pub fn tick(&mut self, dt: f32)

Advance time.

pub fn sample(&self, uv: Vec2) -> Vec2

Sample the flow vector at a UV coordinate using bilinear interpolation.

pub fn distort(&self, uv: Vec2) -> Vec2

Apply flow distortion to a UV coordinate.

Uses dual-phase approach to avoid visual discontinuities when the flow cycle resets.

pub fn distort_array(&self, uvs: &mut [[f32; 2]])

Distort an array of UVs.