/
read-index.ts
50 lines (46 loc) · 1.1 KB
/
read-index.ts
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import {
$x,
$xy,
$xyz,
IntTerm,
IVec2Term,
Sampler2DTerm,
texture,
} from "@thi.ng/shader-ast";
import { indexToUV } from "./index-uv";
/**
* Inline function. Returns x component at index `i` in `tex`.
*
* @param tex -
* @param i -
* @param size -
*/
export const readIndex1 = (tex: Sampler2DTerm, i: IntTerm, size: IVec2Term) =>
$x(readIndex4(tex, i, size));
/**
* Inline function. Returns vec2 (x,y components) at index `i` in `tex`.
*
* @param tex -
* @param i -
* @param size -
*/
export const readIndex2 = (tex: Sampler2DTerm, i: IntTerm, size: IVec2Term) =>
$xy(readIndex4(tex, i, size));
/**
* Inline function. Returns vec3 (x,y,z components) at index `i` in `tex`.
*
* @param tex -
* @param i -
* @param size -
*/
export const readIndex3 = (tex: Sampler2DTerm, i: IntTerm, size: IVec2Term) =>
$xyz(readIndex4(tex, i, size));
/**
* Inline function. Returns vec4 at index `i` in `tex`.
*
* @param tex -
* @param i -
* @param size -
*/
export const readIndex4 = (tex: Sampler2DTerm, i: IntTerm, size: IVec2Term) =>
texture(tex, indexToUV(i, size));