nessworthy/decasteljau

A stupid way of using De Casteljau's algorithm to calculate control points of a segment in a cubic bezier curve.

Maintainers

Details

github.com/Nessworthy/DeCasteljau

Source

Issues

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1.0.0 2018-07-18 09:25 UTC

Requires (Dev)

WTFPL 8359d1618b807dda5e91c323e5a27843b76ce2bb

  • Sean Nessworthy <sean.woop@nessworthy.me>

This package is auto-updated.

Last update: 2024-12-18 06:56:12 UTC

README

A stupid way of using De Casteljau's algorithm to calculate control points of a segment in a cubic bezier curve in PHP.

I used this a fair amount when trying to work out segments for SVG paths.

Requirements

  • PHP 7

Installation

composer require nessworthy/decasteljau

Usage

The algorithm requires 6 pieces of information - the original 4 control points of your bezier curve, where you want to cut your segment, and how long you want your segment to be.

Example:

<?php

use Nessworthy\DeCasteljau\CubicBezierCurve;
use Nessworthy\DeCasteljau\Point;

$curve = new CubicBezierCurve(
    new Point(0, 0),    // Your start point.
    new Point(75, 0),   // The first curve point.
    new Point(150, 75), // The second curve point.
    new Point(150, 150) // Your finishing point.
);

// Calculate control points for the third quarter of the original curve.
$curveSegment = $curve->getSegment(0.5, 0.75); // Instance of CubicBezierCurve 

// Useful for calculating SVG bezier paths!
echo 'M' . $curveSegment->getControlPoint1()->x() . ' ' . $curveSegment->getControlPoint1()->y();
echo ' C' . $curveSegment->getControlPoint2()->x() . ' ' . $curveSegment->getControlPoint2()->y();
echo ', ' . $curveSegment->getControlPoint3()->x() . ' ' . $curveSegment->getControlPoint3()->y();
echo ', ' . $curveSegment->getControlPoint4()->x() . ' ' . $curveSegment->getControlPoint4()->y();

License

WTFPL - See LICENSE.md