`fma`

Function

Returns a * b + c, componentwise over vectors.

The signature and the sentence under each name are the compiler's own text at commit 26de7be8.

Syntax

declare function fma<V extends vec2 | vec3 | vec4>(a0: V, a1: V, a2: V): V
declare function fma<P0 extends number, P1 extends number, P2 extends number>(a0: P0, a1: P1, a2: P2): ([P0] extends [boolean] ? bool : typeof f32Tag extends keyof P0 ? f32 : typeof i32Tag extends keyof P0 ? i32 : typeof u32Tag extends keyof P0 ? u32 : typeof f64Tag extends keyof P0 ? f64 : ([P1] extends [boolean] ? bool : typeof f32Tag extends keyof P1 ? f32 : typeof i32Tag extends keyof P1 ? i32 : typeof u32Tag extends keyof P1 ? u32 : typeof f64Tag extends keyof P1 ? f64 : ([P2] extends [boolean] ? bool : typeof f32Tag extends keyof P2 ? f32 : typeof i32Tag extends keyof P2 ? i32 : typeof u32Tag extends keyof P2 ? u32 : typeof f64Tag extends keyof P2 ? f64 : number)))
declare function fma<T extends Numeric>(a0: T, a1: T, a2: T): T

A number in a parameter or a return position is the scalar slot. The ambient file declares a GPU scalar as a branded number whose brand is optional, so a literal and any branded scalar both fill it.

type f32 = number & { readonly [f32Tag]?: true }

A declaration you write still needs a width, and a bare number on a field or a parameter is refused; the TypeScript constructs page carries that row with the compiler's own message.

A signature may name a type the ambient file declares for its own use. These are those declarations.

Numeric: type Numeric = number | vec2 | vec3 | vec4 | vec2i | vec3i | vec4i | vec2u | vec3u | vec4u

Parameters

A parameter named by position (a0, a1) carries a name the ambient file generates. A call passes its arguments in order and names none of them.

a0 VP0T
a1 VP1T
a2 VP2T

Return value

V([P0] extends [boolean] ? bool : typeof f32Tag extends keyof P0 ? f32 : typeof i32Tag extends keyof P0 ? i32 : typeof u32Tag extends keyof P0 ? u32 : typeof f64Tag extends keyof P0 ? f64 : ([P1] extends [boolean] ? bool : typeof f32Tag extends keyof P1 ? f32 : typeof i32Tag extends keyof P1 ? i32 : typeof u32Tag extends keyof P1 ? u32 : typeof f64Tag extends keyof P1 ? f64 : ([P2] extends [boolean] ? bool : typeof f32Tag extends keyof P2 ? f32 : typeof i32Tag extends keyof P2 ? i32 : typeof u32Tag extends keyof P2 ? u32 : typeof f64Tag extends keyof P2 ? f64 : number)))T

Description

GLSL ES 3.00 has no fma, so the product and sum are inlined there.

Evaluated in f64 by the CPU oracle.

Targets

WGSL: fma(a, b, c)
GLSL ES 3.00: ((a) * (b) + (c))