Module draw 

Draw APIs

Multiple drawing APIs are available. Each has a slightly different purpose:

• High-level “themed widget components” are available through DrawCx. This is the primary drawing interface for widgets.
• Basic drawing components (shapes) are available through DrawIface in this module. This can be accessed via DrawCx::draw_device.
• The graphics backend may support custom pipelines, for example kas-wgpu::draw::CustomPipe (used by the Mandlebrot example).

Text may be drawn by either DrawCx or DrawIface with a slightly different API (using theme properties or directly specifying colors and effects).

Draw order

All draw operations happen within a “draw pass”. The first pass corresponds to the window, while additional passes may be clipped and offset (see DrawIface::new_pass). Draw passes are executed sequentially in the order defined.

Within each pass, draw operations may be batched, thus draw operations may not happen in the order queued. Exact behaviour is defined by the graphics backend. In general, it may be expected that batches are executed in the following order:

1. Square-edged primitives (e.g. Draw::rect)
2. Images
3. Rounded or other partially-transparent primitives (e.g. DrawRounded::circle)
4. Custom draw routines (CustomPipe)
5. Text

Modules

color

Colour types

Structs

AllocError

Allocation failed: too large or zero sized

DrawIface

Draw interface object

ImageHandle

Handle for an image

ImageId

Identifier for an image allocation

PassId

Draw pass identifier

SharedState

Shared draw state

Enums

ImageFormat

Image formats available for upload

PassType

Type of draw pass

Traits

Draw

Basic draw interface for DrawIface

DrawImpl

Implementation target for Draw

DrawRounded

Extended draw interface for DrawIface providing rounded drawing

DrawRoundedImpl

Implementation target for DrawRounded

DrawShared

Interface over SharedState

DrawSharedImpl

Implementation target for DrawShared