Struct SceneTransform 

pub struct SceneTransform {
    pub zoom: f64,
    pub offset: Point,
}

Translation + uniform scale mapping scene space to Scene-local screen space.

Fields

zoom: f64

Screen pixels per scene unit. Always > 0.

offset: Point

Scene→screen translation, applied after scaling (Scene-local Y-up px).

Implementations

impl SceneTransform

pub fn new(zoom: f64, offset: Point) -> Self

pub fn identity() -> Self

Zoom 1, no translation — scene coordinates equal screen coordinates.

pub fn scene_to_screen(&self, p: Point) -> Point

Map a scene-space point to Scene-local screen space.

pub fn to_affine(&self) -> TransAffine

This transform as a crate::TransAffine mapping scene (child) space to Scene-local screen space, i.e. screen = zoom * scene + offset.

This is what Scene returns from Widget::child_transform so the framework’s paint / hit-test / dispatch / inspector traversals all map coordinates through the same pan/zoom the content is drawn under.

pub fn screen_to_scene(&self, p: Point) -> Point

Map a Scene-local screen point back to scene space.

pub fn visible_scene_rect(&self, size: Size) -> Rect

The region of scene space currently visible in a container of size (the Scene widget’s bounds), expressed in scene coordinates.

This is what the caller reads back as the “scene rect”.

pub fn pan(&mut self, delta_screen: Point)

Translate the view by a screen-space delta (drag-to-pan). Content follows the cursor: dragging right moves the scene content right.

pub fn zoom_at( &mut self, cursor_screen: Point, new_zoom: f64, range: (f64, f64), )

Change the zoom to new_zoom (clamped to range) while keeping the scene point currently under cursor_screen fixed on screen.

This is the invariant that makes wheel-zoom feel anchored to the cursor rather than to the origin.

pub fn fit(content: Rect, container: Size, range: (f64, f64)) -> Self

Build a transform that fits content (a rect in scene coords) fully inside a container of the given size, centered, with a uniform scale clamped to range. Used for the initial view and for “reset view”.

Trait Implementations

impl Clone for SceneTransform

fn clone(&self) -> SceneTransform

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SceneTransform

impl Debug for SceneTransform

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

Formats the value using the given formatter.

impl Default for SceneTransform

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for SceneTransform

fn eq(&self, other: &SceneTransform) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SceneTransform