Bitmap/Bézier curves/Quadratic: Difference between revisions
Go solution
(Go solution) |
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Line 179:
end subroutine quad_bezier</lang>
=={{header|Go}}==
{{trans|C}}
<lang go>package raster
const b2Seg = 20
func (b *Bitmap) Bézier2(x1, y1, x2, y2, x3, y3 int, p Pixel) {
var px, py [b2Seg + 1]int
fx1, fy1 := float64(x1), float64(y1)
fx2, fy2 := float64(x2), float64(y2)
fx3, fy3 := float64(x3), float64(y3)
for i := range px {
c := float64(i) / b2Seg
a := 1 - c
a, b, c := a*a, 2 * c * a, c*c
px[i] = int(a*fx1 + b*fx2 + c*fx3)
py[i] = int(a*fy1 + b*fy2 + c*fy3)
}
x0, y0 := px[0], py[0]
for i := 1; i <= b2Seg; i++ {
x1, y1 := px[i], py[i]
b.Line(x0, y0, x1, y1, p)
x0, y0 = x1, y1
}
}
func (b *Bitmap) Bézier2Rgb(x1, y1, x2, y2, x3, y3 int, c Rgb) {
b.Bézier2(x1, y1, x2, y2, x3, y3, c.Pixel())
}</lang>
Demonstration program:
[[File:GoBez2.png|thumb|right]]
<lang go>package main
import (
"fmt"
"raster"
)
func main() {
b := raster.NewBitmap(400, 300)
b.FillRgb(0xdfffef)
b.Bézier2Rgb(20, 150, 500, -100, 300, 280, raster.Rgb(0x3f8fef))
if err := b.WritePpmFile("bez2.ppm"); err != nil {
fmt.Println(err)
}
}</lang>
=={{header|Haskell}}==
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