Struct ScrollBlit 

pub struct ScrollBlit {
    pub scroll_clip: Rect,
    pub delta_x: i32,
    pub delta_y: i32,
    pub exposed_band: Rect,
    pub extra_dirty: SmallVec<[Rect; 8]>,
}

When a pure axis-aligned scroll is detected, this describes what changed.

Fields

scroll_clip: Rect

The clipping rect that encloses the scrollable content.

delta_x: i32

Horizontal pixel shift (negative = content moved left = scroll right). Zero for Y-only scrolls.

delta_y: i32

Vertical pixel shift (negative = content moved up = scroll down). Zero for X-only scrolls.

exposed_band: Rect

The strip of newly exposed pixels that must be re-rendered (horizontal band for Y scrolls, vertical band for X scrolls).

extra_dirty: SmallVec<[Rect; 8]>

Regions outside the scrolled content that the blit displaced and must be repainted in place: changed overlays (e.g. the scrollbar) and any static element drawn before/after the scroll block (fixed headers/footers, dev overlays). Each entry already unions the element with the “ghost” position the blit shifted its pixels to.