Struct AdjustedImageSource

pub struct AdjustedImageSource {
    x0: f32,
    y0: f32,
    x1: f32,
    y1: f32,
}

Represents an adjustment to apply to an image primitive. This can be used to compensate for a difference between the bounds of the images expected by the primitive and the bounds that were actually drawn in the texture cache.

This happens when rendering snapshot images: A picture is marked so that a specific reference area in layout space can be rendered as an image. However, the bounds of the rasterized area of the picture typically differ from that reference area.

The adjustment is stored as 4 floats (x0, y0, x1, y1) that represent a transformation of the primitve’s local rect such that:

adjusted_rect.min = prim_rect.min + prim_rect.size() * (x0, y0);
adjusted_rect.max = prim_rect.max + prim_rect.size() * (x1, y1);

Fields

x0: f32

y0: f32

x1: f32

y1: f32

Implementations

impl AdjustedImageSource

pub fn new() -> Self

The “identity” adjustment.

pub fn from_rects(reference: &LayoutRect, actual: &LayoutRect) -> Self

An adjustment to render an image item defined in function of the reference rect whereas the actual rect was cached instead.

pub fn map_local_rect(&self, rect: &LayoutRect) -> LayoutRect

Adjust the primitive’s local rect.

pub fn map_stretch_size(&self, size: LayoutSize) -> LayoutSize

The stretch size has to be adjusted as well because it is defined using the snapshot area as reference but will stretch the rasterized area instead.

It has to be scaled by a factor of (adjusted.size() / prim_rect.size()). We derive the formula in function of the adjustment factors:

factor = (adjusted.max - adjusted.min) / (w, h)
       = (rect.max + (w, h) * (x1, y1) - (rect.min + (w, h) * (x0, y0))) / (w, h)
       = ((w, h) + (w, h) * (x1, y1) - (w, h) * (x0, y0)) / (w, h)
       = (1.0, 1.0) + (x1, y1) - (x0, y0)

Trait Implementations

impl Clone for AdjustedImageSource

fn clone(&self) -> AdjustedImageSource

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for AdjustedImageSource

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

Formats the value using the given formatter.

impl Serialize for AdjustedImageSource

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for AdjustedImageSource