Struct Viewport 

pub struct Viewport {
    pub zoom: f32,
    pub cx: f64,
    pub cy: f64,
    pub rect: [i32; 4],
    pub dpi: i32,
}

what part of the world the canvas shows: zoom (DIP per world unit, 1 = 100 %), the world point at the centre of rect; rect (absolute px) and dpi are kept by ui.diagram

Fields

zoom: f32

cx: f64

cy: f64

rect: [i32; 4]

dpi: i32

Implementations

impl Viewport

pub const ZOOM_MIN: f32 = 0.1

pub const ZOOM_MAX: f32 = 8.0

pub fn scale(&self) -> f64

px per world unit

pub fn to_screen(&self, p: [f32; 2]) -> [f32; 2]

a world point in absolute px

pub fn to_world(&self, x: f32, y: f32) -> [f32; 2]

an absolute px position in world units

pub fn world_rect(&self) -> [f32; 4]

the world rectangle x0, y0, x1, y1 the canvas shows

pub fn rect_to_screen(&self, r: [f32; 4]) -> [f32; 4]

a world rectangle x, y, w, h in px (x, y, w, h, fractional)

pub fn zoom_at(&mut self, zoom: f32, sx: f32, sy: f32)

zoom (clamped) keeping the world point under the absolute px (sx, sy) in place

pub fn step(&mut self, dir: i32, sx: f32, sy: f32)

the next zoom step above (dir > 0) or below around the absolute px (sx, sy)

pub fn fit(&mut self, b: [f32; 4], margin: i32)

show the world rectangle b (x0, y0, x1, y1) with margin DIP around it, at most 100 %

Trait Implementations

impl Clone for Viewport

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Viewport

impl Debug for Viewport

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

Formats the value using the given formatter.

impl Default for Viewport

fn default() -> Viewport

Returns the “default value” for a type.

impl PartialEq for Viewport

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Viewport