Source/core/html/canvas

Contains canvas-related support classes, including:

• the base class for all CanvasRenderingContext
• the base class for all elements that can host a rendering context
  (CanvasRenderingContextHost), namely HTMLCanvasElement and
  OffscreenCanvas
• canvas font cache
• canvas async blob creator
• base class for CanvasImageSource (used as source for drawImage)
• base class for ImageElements (HTMLImageElement and SVGImageElement) that
  can be both a CanvasImageSource and a ImageBitmapSource

For more information on the structure of canvas-related classes, check
Source/modules/canvas/README.md.

Source/modules/canvas

Contains canvas-related subdirectories.

Class structure of Canvas-related objects

The classes on this structure are divided between all subdirectories that are
used by canvas:

1. htmlcanvas

   Contains context creation for HTML canvas element

2. canvas2d

   Contains base class for 2D rendering contexts and CanvasRenderingContext2D related classes.

3. offscreencanvas

   Contains offscreencanvas object.

4. offscreencanvas2d

   Contains offscreencanvas 2D rendering context.

5. imagebitmap

   Contains ImageBitmap rendering context.

Canvas-related classes are also present in these directories in core:
core/html/canvas and core/html.

There are also some other directories in modules that are a bit related to
canvas: modules/webgl, modules/imagebitmap and modules/csspaint.

Virtual classes

CanvasRenderingContextHost : All elements that provides rendering contexts
(HTMLCanvasElement and OffscreenCanvas) This is the main interface that a
CanvasRenderingContext uses.

CanvasRenderingContext - Base class for everything that exposes a rendering
context API. This includes 2d, webgl, webgl2, imagebitmap contexts.

BaseRenderingContext2D - Class for 2D canvas contexts. Implements most 2D
rendering context API. Used by CanvasRenderingContext2D,
OffscreenCanvasRenderingContext2D and PaintRenderingContext2D.

WebGLRenderingContextBase - Base class for webgl contexts.

Final classes

CanvasRenderingContext2D - 2D context for HTML Canvas element. [spec]

OffscreenCanvasRenderingContext2D - 2D context for OffscreenCanvas.
[spec]

WebGLRenderingContext - WebGL context for both HTML and Offscreen canvas.
[spec]

WebGL2RenderingContext - WebGL2 context for both HTML and Offscreen canvas.
[spec]

ImageBitmapRenderingContext - The rendering context provided by ImageBitmap.
[spec]

PaintRenderingContext2D - Rendering context for CSS Painting.
[spec]