Curve that touches three points: Difference between revisions
Added Wren
Alpha bravo (talk | contribs) (Added AutoHotkey) |
(Added Wren) |
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}</lang>
See [https://github.com/thundergnat/rc/blob/master/img/Curve-3-points-perl6.png Curve-3-points-perl6.png] (offsite .png image)
=={{header|Wren}}==
{{trans|Go}}
{{libheader|DOME}}
<lang ecmascript>import "graphics" for Canvas, Color, Point
import "dome" for Window
class Game {
static init() {
Window.title = "Quadratic curve"
var width = 210
var height = 210
Window.resize(width, height)
Canvas.resize(width, height)
Canvas.cls(Color.white)
var n = 50
var p = [Point.new(10, 10), Point.new(100, 200), Point.new(200, 10)]
var col = Color.black // black curve
quadratic(n, p, col)
}
static update() {}
static draw(alpha) {}
static lagrange(p, x) {
return (x-p[1].x)*(x-p[2].x)/(p[0].x-p[1].x)/(p[0].x-p[2].x)*p[0].y +
(x-p[0].x)*(x-p[2].x)/(p[1].x-p[0].x)/(p[1].x-p[2].x)*p[1].y +
(x-p[0].x)*(x-p[1].x)/(p[2].x-p[0].x)/(p[2].x-p[1].x)*p[2].y
}
static quadratic(n, p, col) {
var pts = List.filled(2*n+1, null)
var dx = (p[1].x - p[0].x) / n
for (i in 0...n) {
var x = p[0].x + dx*i
pts[i] = Point.new(x, lagrange(p, x))
}
dx = (p[2].x - p[1].x) / n
for (i in n...2*n+1) {
var x = p[1].x + dx*(i-n)
pts[i] = Point.new(x, lagrange(p, x))
}
var prev = pts[0]
for (pt in pts.skip(1)) {
Canvas.line(prev.x, prev.y, pt.x, pt.y, col)
prev = pt
}
}
}</lang>
=={{header|zkl}}==
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