bezier

README

Bézier interpolation

This module calculates a set of Bézier splines that represent a continuous curve through a set of points. Both integer and floating point versions are provided. I use this to create curves in SVG files.

The algorithm was ported from the Javascript on this page. The page describing what the code does is here. This page also provides a little interactive demo.

If you pass in N + 1 knots (points to be interpolated), you will get N sets of control points back, one set for each part of the curve. Each set has four control points. The first control point (P0) is the starting knot, and the last control point (P3) is the ending knot. P1 and P2 are determined by the module. A sample image is shown below, with the knots in blue and the computed control points in green.

Documentation

Index

• func ControlPointsToSvgI(beziers []Bezier) []string
• func SvgControlPointsI(p []image.Point) []string
• type Bezier
  • func GetControlPointsI(p []image.Point) []Bezier
• type BezierF
  • func GetControlPointsF(p []PointF) []BezierF
• type PointF

Functions

func ControlPointsToSvgI

func ControlPointsToSvgI(beziers []Bezier) []string

func SvgControlPointsI

func SvgControlPointsI(p []image.Point) []string

Types

type Bezier

type Bezier struct {
	P0, P1, P2, P3 image.Point
}

func GetControlPointsI

func GetControlPointsI(p []image.Point) []Bezier

type BezierF

type BezierF struct {
	P0, P1, P2, P3 PointF
}

func GetControlPointsF

func GetControlPointsF(p []PointF) []BezierF

Algorithm ported from https://www.particleincell.com/wp-content/uploads/2012/06/bezier-spline.js

type PointF

type PointF struct {
	X, Y float64
}