Exploring Interpol: A Lightweight Interpolation Library for Web Animations
Three years ago, I embarked on a journey to create @wbe/interpol, a lightweight interpolation library designed for smooth motion and value tweening on the web. In this blog post, I’ll delve into the origins of Interpol and how it has transformed my animation workflow.
What is Interpol?
@wbe/interpol is primarily an interpolation engine built for projects that don’t require the heavy lifting of comprehensive animation libraries like GSAP or Anime.js. It focuses on providing a lightweight, easy-to-use API that simplifies value interpolation without the unnecessary overhead.
Requirements and Features
To address my animation needs, I established the following requirements for Interpol:
- Lightweight: The library’s bundle size is approximately 3.5 KB.
- Low-level: It avoids unnecessary complexities by focusing solely on value interpolation, ensuring maintainability and predictability.
- Performance-oriented: Multiple Interpol instances can be batched and updated using a single Ticker loop.
- Multiple interpolations: Each instance can handle a set of values, not just one.
- Chaining capabilities: Users can create timelines with instance offsets.
- Familiar API: The syntax is similar to GSAP and Anime.js, allowing ease of adaptation.
- TypeScript support: Strong typing makes it easier to work with the library.
- Optional requestAnimationFrame (RAF): Allows for custom update loops without being locked into the library’s internal RAF.
Understanding Interpolation
Linear Interpolation (lerp) facilitates finding a value between two others. It averages the two values based on a given amount, defined by the formula:
typescript
function lerp(start: number, end: number, amount: number): number {
return start + (end – start) * amount;
}
// Example usage
lerp(0, 100, 0.5); // Output: 50
The power of lerp becomes evident when paired with RAF. Using both, we can achieve smooth transitions between values. Interpol serves as a time-based interpolation engine, where progression is normalized between 0 and 1.
Tweening vs. Damping
It’s crucial to differentiate between tweening and damping in the context of Interpol:
- Tweening refers to time-bound interpolation; for instance, an animation completing at an exact moment.
- Damping lacks a time element; it updates values on each frame without considering elapsed time.
Diving Into the API
The Interpol constructor is straightforward and allows users to define a set of values for interpolation:
typescript
import { Interpol } from “@wbe/interpol”;
new Interpol({
x: [0, 100],
duration: 1300,
onUpdate: ({ x }, time, progress) => {
// Perform actions with interpolated values here
},
});
The constructor supports multiple configuration options, including durations, easing functions, and callback methods, enhancing the developer experience.
Exploring Interpol Methods
The Interpol library includes various methods, such as:
play()pause()resume()stop()
These methods allow seamless control over animations, making integration into projects easy.
Creating Timelines
To build a more complex animation flow, users can manage multiple interpolations using timelines.
typescript
import { Timeline } from “@wbe/interpol”;
const tl = new Timeline();
tl.add({…});
Through the add method, it is possible to sequence interpolations effectively, including support for offsets to reposition tweens.
Performance Optimizations
Interpol emphasizes performance by:
- Batching callbacks: Using a single requestAnimationFrame to update all interpolations enhances efficiency.
- Batching DOM writes: Synchronizing updates minimizes layout thrashing, further boosting performance.
Conclusion
Interpol is not just a tool; it’s a comprehensive research project that allows me to explore fundamental animation concepts and performance issues. While it may not cover every feature, its lightweight nature and simplicity offer significant advantages for specific use cases. I encourage fellow developers to explore such projects, not only to create utility but to deepen their understanding of web development.
Related Keywords
- Interpolation library
- Web animations
- Tweening
- Animation performance
- JavaScript libraries
- TypeScript animations
- Lightweight libraries
