Trait Draw 

pub trait Draw {
    // Required methods
    fn shared(&mut self) -> &mut dyn DrawShared;
    fn animate(&mut self);
    fn animate_at(&mut self, time: Instant);
    fn get_pass(&self) -> PassId;
    fn new_dyn_pass<'b>(
        &'b mut self,
        rect: Rect,
        offset: Offset,
        class: PassType,
    ) -> Box<dyn Draw + 'b>;
    fn get_clip_rect(&self) -> Rect;
    fn rect(&mut self, rect: Quad, col: Rgba);
    fn frame(&mut self, outer: Quad, inner: Quad, col: Rgba);
    fn image(&mut self, id: ImageId, rect: Quad);
    fn text(
        &mut self,
        pos: Vec2,
        bounding_box: Quad,
        text: &TextDisplay,
        col: Rgba,
    );
    fn text_effects(
        &mut self,
        pos: Vec2,
        bounding_box: Quad,
        text: &TextDisplay,
        effects: &[Effect],
        colors: &[Rgba],
    );
}

Basic draw interface for DrawIface

Most methods draw some feature. Exceptions are those starting with get_ and Self::new_dyn_pass.

Additional draw routines are available through extension traits, depending on the graphics backend. Since Rust does not (yet) support trait-object-downcast, accessing these requires reconstruction of the implementing type via DrawIface::downcast_from.

Required Methods

fn shared(&mut self) -> &mut dyn DrawShared

Access shared draw state

fn animate(&mut self)

Request redraw at the next frame time

Animations should call this each frame until complete.

fn animate_at(&mut self, time: Instant)

Request a redraw at a specific time

This may be used for animations with delays, e.g. flashing. Calling this method only ensures that the next draw happens no later than time, thus the method should be called again in each following frame.

fn get_pass(&self) -> PassId

Get the current draw pass

fn new_dyn_pass<'b>( &'b mut self, rect: Rect, offset: Offset, class: PassType, ) -> Box<dyn Draw + 'b>

Add a draw pass

Adds a new draw pass. Passes affect draw order (operations in new passes happen after their parent pass), may clip drawing to a “clip rect” (see Draw::get_clip_rect) and may offset (translate) draw operations.

Case class == PassType::Clip: the new pass is derived from parent_pass; rect and offset are specified relative to this parent and the intersecton of rect and the parent’s “clip rect” is used. be clipped to rect (expressed in the parent’s coordinate system).

Case class == PassType::Overlay: the new pass is derived from the base pass (i.e. the window). Draw operations still happen after those in parent_pass.

fn get_clip_rect(&self) -> Rect

Get drawable rect for a draw pass

The result is in the current target’s coordinate system, thus normally Rect::pos is zero (but this is not guaranteed).

(This is not guaranteed to equal the rect passed to DrawIface::new_pass.)

fn rect(&mut self, rect: Quad, col: Rgba)

Draw a rectangle of uniform colour

Note: where the implementation batches and/or re-orders draw calls, this should be one of the first items drawn such that almost anything else will draw “in front of” a rect.

fn frame(&mut self, outer: Quad, inner: Quad, col: Rgba)

Draw a frame of uniform colour

The frame is defined by the area inside outer and not inside inner.

fn image(&mut self, id: ImageId, rect: Quad)

Draw the image in the given rect

fn text(&mut self, pos: Vec2, bounding_box: Quad, text: &TextDisplay, col: Rgba)

Draw text with a colour

Text is drawn from pos and clipped to bounding_box.

The text object must be configured and prepared prior to calling this method (see crate::theme::Text or crate::text::Text).

fn text_effects( &mut self, pos: Vec2, bounding_box: Quad, text: &TextDisplay, effects: &[Effect], colors: &[Rgba], )

Draw text with effects

Text is drawn from pos and clipped to bounding_box.

The effects list provides underlining/strikethrough information via Effect::flags and an index Effect::e. If effects is empty, this is equivalent to Self::text.

Text colour lookup uses index e and is essentially: colors.get(e).unwrap_or(Rgba::BLACK).

The text object must be configured and prepared prior to calling this method (see crate::theme::Text or crate::text::Text).

Implementors

impl<'a, DS: DrawSharedImpl> Draw for DrawIface<'a, DS>