Struct wayland_protocols::wp::viewporter::client::wp_viewport::WpViewport

pub struct WpViewport { /* private fields */ }

Available on crate feature client only.

crop and scale interface to a wl_surface

An additional interface to a wl_surface object, which allows the client to specify the cropping and scaling of the surface contents.

This interface works with two concepts: the source rectangle (src_x, src_y, src_width, src_height), and the destination size (dst_width, dst_height). The contents of the source rectangle are scaled to the destination size, and content outside the source rectangle is ignored. This state is double-buffered, and is applied on the next wl_surface.commit.

The two parts of crop and scale state are independent: the source rectangle, and the destination size. Initially both are unset, that is, no scaling is applied. The whole of the current wl_buffer is used as the source, and the surface size is as defined in wl_surface.attach.

If the destination size is set, it causes the surface size to become dst_width, dst_height. The source (rectangle) is scaled to exactly this size. This overrides whatever the attached wl_buffer size is, unless the wl_buffer is NULL. If the wl_buffer is NULL, the surface has no content and therefore no size. Otherwise, the size is always at least 1x1 in surface local coordinates.

If the source rectangle is set, it defines what area of the wl_buffer is taken as the source. If the source rectangle is set and the destination size is not set, then src_width and src_height must be integers, and the surface size becomes the source rectangle size. This results in cropping without scaling. If src_width or src_height are not integers and destination size is not set, the bad_size protocol error is raised when the surface state is applied.

The coordinate transformations from buffer pixel coordinates up to the surface-local coordinates happen in the following order:

1. buffer_transform (wl_surface.set_buffer_transform)
2. buffer_scale (wl_surface.set_buffer_scale)
3. crop and scale (wp_viewport.set*) This means, that the source rectangle coordinates of crop and scale are given in the coordinates after the buffer transform and scale, i.e. in the coordinates that would be the surface-local coordinates if the crop and scale was not applied.

If src_x or src_y are negative, the bad_value protocol error is raised. Otherwise, if the source rectangle is partially or completely outside of the non-NULL wl_buffer, then the out_of_buffer protocol error is raised when the surface state is applied. A NULL wl_buffer does not raise the out_of_buffer error.

The x, y arguments of wl_surface.attach are applied as normal to the surface. They indicate how many pixels to remove from the surface size from the left and the top. In other words, they are still in the surface-local coordinate system, just like dst_width and dst_height are.

If the wl_surface associated with the wp_viewport is destroyed, all wp_viewport requests except ‘destroy’ raise the protocol error no_surface.

If the wp_viewport object is destroyed, the crop and scale state is removed from the wl_surface. The change will be applied on the next wl_surface.commit.

This interface has no events.

Implementations

impl WpViewport

pub fn destroy(&self)

remove scaling and cropping from the surface

The associated wl_surface’s crop and scale state is removed. The change is applied on the next wl_surface.commit.

pub fn set_source(&self, x: f64, y: f64, width: f64, height: f64)

set the source rectangle for cropping

Set the source rectangle of the associated wl_surface. See wp_viewport for the description, and relation to the wl_buffer size.

If all of x, y, width and height are -1.0, the source rectangle is unset instead. Any other set of values where width or height are zero or negative, or x or y are negative, raise the bad_value protocol error.

The crop and scale state is double-buffered state, and will be applied on the next wl_surface.commit.

pub fn set_destination(&self, width: i32, height: i32)

set the surface size for scaling

Set the destination size of the associated wl_surface. See wp_viewport for the description, and relation to the wl_buffer size.

If width is -1 and height is -1, the destination size is unset instead. Any other pair of values for width and height that contains zero or negative values raises the bad_value protocol error.

The crop and scale state is double-buffered state, and will be applied on the next wl_surface.commit.

Trait Implementations

impl Clone for WpViewport

fn clone(&self) -> WpViewport

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WpViewport

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

Formats the value using the given formatter.

impl PartialEq<WpViewport> for WpViewport

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Proxy for WpViewport

type Request = Request

The request enum for this interface

type Event = Event

The event enum for this interface

fn interface() -> &'static Interface

The interface description

fn id(&self) -> ObjectId

he ID of this object

fn version(&self) -> u32

The version of this object

fn data<U: Send + Sync + 'static>(&self) -> Option<&U>

Access the user-data associated with this object

fn object_data(&self) -> Option<&Arc<dyn ObjectData>>

Access the raw data associated with this object.

fn backend(&self) -> &WeakBackend

Access the backend associated with this object

fn send_request(&self, req: Self::Request) -> Result<(), InvalidId>

Send a request for this object.

fn send_constructor<I: Proxy>(
    &self,
    req: Self::Request,
    data: Arc<dyn ObjectData>
) -> Result<I, InvalidId>

Send a request for this object that creates another object.

fn from_id(conn: &Connection, id: ObjectId) -> Result<Self, InvalidId>

Create an object proxy from its ID

fn parse_event(
    conn: &Connection,
    msg: Message<ObjectId>
) -> Result<(Self, Self::Event), DispatchError>

Parse a event for this object

fn write_request(
    &self,
    conn: &Connection,
    msg: Self::Request
) -> Result<(Message<ObjectId>, Option<(&'static Interface, u32)>), InvalidId>

Serialize a request for this object

impl Eq for WpViewport