@csstools/postcss-trigonometric-functions

What is @csstools/postcss-trigonometric-functions?

@csstools/postcss-trigonometric-functions is a PostCSS plugin that allows you to use trigonometric functions like sine, cosine, and tangent directly in your CSS. This can be particularly useful for creating complex animations, responsive designs, and other dynamic styles that require mathematical calculations.

What are @csstools/postcss-trigonometric-functions's main functionalities?

Sine Function

This feature allows you to use the sine function in your CSS. In this example, the sine of 45 degrees is calculated and used to translate an element along the X-axis.

body {
  --angle: 45deg;
  --sine-value: sin(var(--angle));
  transform: translateX(calc(100px * var(--sine-value)));
}

Cosine Function

This feature allows you to use the cosine function in your CSS. In this example, the cosine of 45 degrees is calculated and used to translate an element along the Y-axis.

body {
  --angle: 45deg;
  --cosine-value: cos(var(--angle));
  transform: translateY(calc(100px * var(--cosine-value)));
}

Tangent Function

This feature allows you to use the tangent function in your CSS. In this example, the tangent of 45 degrees is calculated and used to skew an element along the X-axis.

body {
  --angle: 45deg;
  --tangent-value: tan(var(--angle));
  transform: skewX(calc(10deg * var(--tangent-value)));
}

Other packages similar to @csstools/postcss-trigonometric-functions

postcss-math

postcss-math is a PostCSS plugin that allows you to perform mathematical operations in your CSS. It supports basic arithmetic, trigonometric functions, and more. Compared to @csstools/postcss-trigonometric-functions, postcss-math offers a broader range of mathematical operations but may not be as specialized in trigonometric functions.

postcss-calc

postcss-calc is a PostCSS plugin that reduces calc() references whenever possible. While it doesn't specifically focus on trigonometric functions, it can simplify complex calculations in your CSS. It is more general-purpose compared to @csstools/postcss-trigonometric-functions.

README

PostCSS Trigonometric Functions

npm install @csstools/postcss-trigonometric-functions --save-dev

PostCSS Trigonometric Functions lets you use sin, cos, tan, asin, acos, atan and atan2 to be able to compute trigonometric relationships following the CSS Values 4 specification.

.trigonometry {
	line-height: sin(pi / 4);
	line-height: cos(.125turn);
	line-height: tan(50grad);
	transform: rotate(asin(-1));
	transform: rotate(asin(sin(30deg + 1.0471967rad)));
	transform: rotate(acos(-1));
	transform: rotate(acos(cos(0 / 2 + 1 - 1)));
	transform: rotate(atan(infinity));
	transform: rotate(atan(e - 2.7182818284590452354));
	transform: rotate(atan2(-infinity,-infinity));
	transform: rotate(atan2(-infinity,infinity));
	transform: rotate(atan2(-infinity,infinity));
	transform: rotate(atan2(90, 15));
}

/* becomes */

.trigonometry {
	line-height: 0.70711;
	line-height: 0.70711;
	line-height: 1;
	transform: rotate(-90deg);
	transform: rotate(89.99995deg);
	transform: rotate(180deg);
	transform: rotate(0deg);
	transform: rotate(90deg);
	transform: rotate(0deg);
	transform: rotate(-135deg);
	transform: rotate(-45deg);
	transform: rotate(-45deg);
	transform: rotate(80.53768deg);
}

Usage

Add PostCSS Trigonometric Functions to your project:

npm install postcss @csstools/postcss-trigonometric-functions --save-dev

Use it as a PostCSS plugin:

const postcss = require('postcss');
const postcssTrigonometricFunctions = require('@csstools/postcss-trigonometric-functions');

postcss([
	postcssTrigonometricFunctions(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);

⚠️ About custom properties

Given the dynamic nature of custom properties it's impossible to know what the variable value is, which means the plugin can't compute a final value for the stylesheet.

Because of that, any usage that contains a var is skipped.

Units

PostCSS Trigonometric Functions lets you use different special units that are within the spec and computed at run time to be able to calculate the result of the trigonometric function.

The following units are supported:

• pi: Computes to Math.PI which is 3.141592653589793
• e: Computes to Math.E which is 2.718281828459045
• infinity, -infinity: Compute to Infinity and -Infinity respectively. Note that the usage is case insensitive so InFiNiTy is a valid value.

Some calculations (such as sin(-infinity)) might return NaN as per the spec. Given that NaN can't be replaced with a value that's useful to CSS it is left as is, as the result will be effectively ignored by the browser.

Options

preserve

The preserve option determines whether the original notation is preserved. By default, it is not preserved.

postcssTrigonometricFunctions({ preserve: true })

.trigonometry {
	line-height: sin(pi / 4);
	line-height: cos(.125turn);
	line-height: tan(50grad);
	transform: rotate(asin(-1));
	transform: rotate(asin(sin(30deg + 1.0471967rad)));
	transform: rotate(acos(-1));
	transform: rotate(acos(cos(0 / 2 + 1 - 1)));
	transform: rotate(atan(infinity));
	transform: rotate(atan(e - 2.7182818284590452354));
	transform: rotate(atan2(-infinity,-infinity));
	transform: rotate(atan2(-infinity,infinity));
	transform: rotate(atan2(-infinity,infinity));
	transform: rotate(atan2(90, 15));
}

/* becomes */

.trigonometry {
	line-height: 0.70711;
	line-height: sin(pi / 4);
	line-height: 0.70711;
	line-height: cos(.125turn);
	line-height: 1;
	line-height: tan(50grad);
	transform: rotate(-90deg);
	transform: rotate(asin(-1));
	transform: rotate(89.99995deg);
	transform: rotate(asin(sin(30deg + 1.0471967rad)));
	transform: rotate(180deg);
	transform: rotate(acos(-1));
	transform: rotate(0deg);
	transform: rotate(acos(cos(0 / 2 + 1 - 1)));
	transform: rotate(90deg);
	transform: rotate(atan(infinity));
	transform: rotate(0deg);
	transform: rotate(atan(e - 2.7182818284590452354));
	transform: rotate(-135deg);
	transform: rotate(atan2(-infinity,-infinity));
	transform: rotate(-45deg);
	transform: rotate(atan2(-infinity,infinity));
	transform: rotate(-45deg);
	transform: rotate(atan2(-infinity,infinity));
	transform: rotate(80.53768deg);
	transform: rotate(atan2(90, 15));
}