模块

Ink API 已模块化，因此您可以仅使用所需的功能。

笔画

The strokes module serves as the foundation of the Ink API. Key data types within this module are:

• StrokeInputBatch: Represents a series of pointer inputs, including their position, timestamp, and optionally pressure, tilt, and orientation.
• InProgressStroke: Represents a stroke that is actively being drawn. InProgressStroke is used to render partial strokes with low latency and to build the final Stroke once input is complete, after which the object can be reused. InProgressStroke is used by the InProgressStrokes composable.
• Stroke: An immutable representation of a finalized stroke with fixed geometry. Each Stroke has an ImmutableStrokeInputBatch (input points), a Brush (style), and a PartitionedMesh (geometric shape). You can store, manipulate, and render strokes within your application.

几何体

The Geometry module supports geometric operations on primitive shapes (using dedicated classes like Box and Vec), as well as arbitrary shapes (using PartitionedMesh), including intersection detection and transformation. PartitionedMesh can also hold additional data to support rendering.

笔刷

The brush module defines the style of strokes. It consists of two main parts:

• Brush: Specifies the style of a stroke including base color, base size, and BrushFamily. BrushFamily is analogous to a font family, it defines a stroke's style. For example, a BrushFamily can represent a specific style of marker or highlighter, allowing strokes with different sizes and colors to share that style.
• StockBrushes: Provides factory functions for creating ready-to-use BrushFamily instances.

编写

The Compose Authoring module lets you capture user touch input and render it as low-latency strokes on the screen in real time. This is achieved through the InProgressStrokes composable, which processes motion events and displays the strokes as they are drawn.

Once a stroke is completed, the composable notifies the client application using an InProgressStrokesFinishedListener callback. This allows the application to retrieve the finished strokes for rendering or storage.

In Compose, InProgressStrokes takes this callback in the onStrokesFinished parameter. Pass the finished strokes to another composable to commit them to the screen using the rendering module.

渲染

渲染模块可简化在 Android Canvas 上绘制墨水笔画的过程。 它为 Compose 提供 CanvasStrokeRenderer，为基于视图的布局提供 ViewStrokeRenderer。这些渲染器可优化渲染性能，并有助于呈现高质量的视觉效果，包括抗锯齿。

如需渲染笔画，请调用 create() 方法以获取 CanvasStrokeRenderer 实例，然后调用 draw() 方法，以将已完成 (Stroke) 或正在进行 (InProgressStroke) 的笔画渲染到 Canvas 上。

您可以在绘制笔画时转换画布。例如平移、缩放和旋转。为了正确渲染描边，您还必须将 canvas 转换传递给 CanvasStrokeRenderer.draw。

为避免单独跟踪 canvas 转换，请改用 ViewStrokeRenderer。

存储

The storage module provides utilities for efficiently serializing and deserializing stroke data, primarily focusing on StrokeInputBatch.

The module uses protocol buffers and optimized delta compression techniques, resulting in significant storage savings compared to naive methods.

The storage module simplifies saving, loading, and sharing strokes.