WebGLOptions

Plain JS object passed to CK.GetWebGLContext and CK.MakeWebGLContext. Mirrors the WebGL getContext attribute object, but typed as numbers (CanvasKit converts them at the C++ boundary). All fields are optional; sensible defaults are picked when omitted.

const glHandle = CK.GetWebGLContext(canvasEl, {
  alpha: 1,
  antialias: 1,
  depth: 1,
  majorVersion: 2,
  preserveDrawingBuffer: 0,
});
const grContext = CK.MakeGrContext(glHandle);

You usually only need majorVersion: 2 (force WebGL 2) and preserveDrawingBuffer: 1 (if you need to read back). Everything else is fine at default.

Fields

Field	Type	Notes
`alpha`	`number`	1 to keep canvas alpha; 0 for fully opaque.
`antialias`	`number`	1 to enable hardware MSAA on the default framebuffer.
`depth`	`number`	1 to allocate a depth buffer.
`enableExtensionsByDefault`	`number`	1 to opt into all available WebGL extensions Skia knows about.
`explicitSwapControl`	`number`	Emscripten-specific: 1 to opt out of the auto-swap on rAF.
`failIfMajorPerformanceCaveat`	`number`	1 to refuse a software fallback context.
`majorVersion`	`number`	1 or 2 — pick the WebGL major version. Default 2 if available.
`minorVersion`	`number`	WebGL minor version (rarely set).
`preferLowPowerToHighPerformance`	`number`	1 to bias toward integrated GPU.
`premultipliedAlpha`	`number`	1 if the canvas's backbuffer should be premultiplied.
`preserveDrawingBuffer`	`number`	1 to retain the framebuffer between frames (needed for `readPixels` after rAF).
`renderViaOffscreenBackBuffer`	`number`	1 to render into an offscreen FBO and blit on swap.
`stencil`	`number`	1 to allocate a stencil buffer.

#WebGLOptions

#Fields

#See also

WebGLOptions

Fields

See also