RuntimeEffect

Compile your own SkSL shader source at runtime, get back a RuntimeEffect, instantiate Shader instances from it. SkSL is Skia's GLSL-like shading language — same syntax for vertex / fragment math, same uniforms model.


const sksl = `
uniform float u_time;
uniform float2 u_resolution;

half4 main(float2 xy) {
  float2 uv = xy / u_resolution;
  float r = 0.5 + 0.5 * sin(u_time + uv.x * 6.28);
  float g = 0.5 + 0.5 * sin(u_time + uv.y * 6.28 + 2.0);
  float b = 0.5 + 0.5 * sin(u_time + (uv.x + uv.y) * 6.28 + 4.0);
  return half4(r, g, b, 1.0);
}
`;

const effect = CK.RuntimeEffect.Make(sksl);
const paint = new CK.Paint();

let t = 0;
loop(() => {
  t += 0.02;
  const shader = effect.makeShader([t, w, h]);
  paint.setShader(shader);
  canvas.drawRect(CK.LTRBRect(0, 0, w, h), paint);
  shader.delete();
  surface.flush();
});

effect.makeShader(uniforms) allocates a new Shader per call — delete inside the loop or you'll leak one shader per frame. Uniforms are passed as a flat number[]; their order matches the uniform declarations in the SkSL source.

Members

Member	Args	Returns	Notes
`delete`	—	`void`	Free the WASM memory. Required.
`getUniformCount`	—	`number`	Number of uniforms in the program.
`getUniformFloatCount`	—	`number`	Total float slots across all uniforms (the array length you pass to `makeShader`).
`getUniform`	`i: number`	`SkSLUniform`	Metadata for the i-th uniform.
`getUniformName`	`i: number`	`string`	Name of the i-th uniform.
`makeShader`	`uniforms: number[] \| Float32Array, localMatrix?: Matrix`	`Shader`	Instantiate a shader with these uniform values.
`makeShaderWithChildren`	`uniforms, children: Shader[], localMatrix?: Matrix`	`Shader`	Instantiate with child shaders that the SkSL program samples (declared as `uniform shader` in source).

Static factories

Factory	Args	Returns	Notes
`CK.RuntimeEffect.Make`	`sksl: string, errorCallback?: (msg: string) => void`	`RuntimeEffect \| null`	Compile SkSL source. Returns null on compile error; errorCallback receives the diagnostic.
`CK.RuntimeEffect.MakeForBlender`	`sksl: string, errorCallback?`	`RuntimeEffect \| null`	Compile a SkSL blender (operates on src+dst rather than just src).

#RuntimeEffect

#Members

#Static factories

#See also

RuntimeEffect

Members

Static factories

See also