Struct Edge 

pub struct Edge {
    pub x: F26Dot6,
    pub x_increment: F26Dot6,
    pub direction: i8,
    pub y_max: i32,
    pub y_min: i32,
}

One edge, infinite possibilities

An edge is more than just a line—it’s a promise. It promises that for every scanline it crosses, it knows exactly where to be. We store both its current position and its slope, making rasterization a simple march down the screen.

Fields

x: F26Dot6

Where we are right now (X position at current scanline)

x_increment: F26Dot6

How we move each step down (slope in X per scanline)

direction: i8

Which way we’re going (upward fills vs downward carves)

y_max: i32

The last scanline where we matter (inclusive)

y_min: i32

The first scanline where we appear (inclusive)

Implementations

impl Edge

pub fn new(x1: F26Dot6, y1: F26Dot6, x2: F26Dot6, y2: F26Dot6) -> Option<Self>

Birth of an edge: two points become a rasterization warrior

We transform any two points into a scan-ready edge. Horizontal edges get discarded (they don’t cross scanlines), and everything else gets sorted so we always scan from top to bottom. The result is an edge that knows its purpose from the moment it’s created.

The Point Partnership

• x1, y1 - Where the edge begins its journey
• x2, y2 - Where the edge completes its mission

Returns

A battle-ready edge, or None if the points refuse to cooperate

pub fn step(&mut self)

One step closer to completion

Each scanline brings us one step down the edge. We simply add our slope to our current position—no complex math, just elegant progression.

pub fn is_active(&self, y: i32) -> bool

Are we still relevant at this height?

An edge knows when it’s time to retire. Once we’ve passed our maximum Y coordinate, we’re done contributing to the glyph.

Trait Implementations

impl Clone for Edge

fn clone(&self) -> Edge

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Edge

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

Formats the value using the given formatter.

impl PartialEq for Edge

fn eq(&self, other: &Edge) -> 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 Copy for Edge

impl Eq for Edge

impl StructuralPartialEq for Edge