---
title: "scaleAndAdd | JavaScript maps SDK"
description: "Documentation for MapTiler SDK"
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Function scaleAndAdd

-   scaleAndAdd(out: [vec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.vec4/), a: [ReadonlyVec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyVec4/), b: [ReadonlyVec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyVec4/), scale: number): [vec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.vec4/)[](#scaleandadd)
    
    Adds two vec4's after scaling the second operand by a scalar value
    
    #### Parameters
    
    -   out: [vec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.vec4/)
        
        the receiving vector
        
    -   a: [ReadonlyVec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyVec4/)
        
        the first operand
        
    -   b: [ReadonlyVec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.ReadonlyVec4/)
        
        the second operand
        
    -   scale: number
        
        the amount to scale b by before adding
        
    
    #### Returns [vec4](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.vec4/)
    
    out