Polyspiral: Difference between revisions
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Moved Go entry into correct alphabetical order.
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primaryStage.show();
}
}</lang>
Line 783 ⟶ 664:
2 pages with animation.
</pre>
=={{header|Go}}==
This uses Go's 'image' packages in its standard library to create an animated GIF. The file itself can be created from the terminal as follows:
<pre>
$ go build polyspiral.go
$ ./polyspiral > polyspiral.gif
</pre>
When played this is similar to the Java entry but much quicker. The whole animation completes in 72 seconds and repeats indefinitely.
Although the .gif works fine in Firefox it might not do so in EOG due to optimizations made during its creation. If so, then the following ImageMagick command should fix it:
<pre>
$ convert polyspiral.gif -coalesce polyspiral2.gif
$ eog polyspiral2.gif
</pre>
<lang go>package main
import (
"image"
"image/color"
"image/gif"
"math"
"os"
)
func drawLine(img *image.Paletted, x1, y1, x2, y2 int, ci uint8) {
var first, last int
if x2 != x1 {
m := float64(y2-y1) / float64(x2-x1)
if x1 < x2 {
first, last = x1, x2
} else {
first, last = x2, x1
}
for x := first; x <= last; x++ {
y := int(m*float64(x-x1)+0.5) + y1
img.SetColorIndex(x, y, ci)
}
} else {
if y1 < y2 {
first, last = y1, y2
} else {
first, last = y2, y1
}
for y := first; y <= last; y++ {
img.SetColorIndex(x1, y, ci)
}
}
}
func setBackgroundColor(img *image.Paletted, w, h int, ci uint8) {
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
img.SetColorIndex(x, y, ci)
}
}
}
func hsb2rgb(hue, sat, bri float64) (r, g, b int) {
u := int(bri*255 + 0.5)
if sat == 0 {
r, g, b = u, u, u
} else {
h := (hue - math.Floor(hue)) * 6
f := h - math.Floor(h)
p := int(bri*(1-sat)*255 + 0.5)
q := int(bri*(1-sat*f)*255 + 0.5)
t := int(bri*(1-sat*(1-f))*255 + 0.5)
switch int(h) {
case 0:
r, g, b = u, t, p
case 1:
r, g, b = q, u, p
case 2:
r, g, b = p, u, t
case 3:
r, g, b = p, q, u
case 4:
r, g, b = t, p, u
case 5:
r, g, b = u, p, q
}
}
return
}
func main() {
const degToRad = math.Pi / 180
const nframes = 360
const delay = 20 // 200ms
width, height := 640, 640
anim := gif.GIF{LoopCount: nframes}
rect := image.Rect(0, 0, width, height)
palette := make([]color.Color, 151)
palette[0] = color.White
for i := 1; i <= 150; i++ {
r, g, b := hsb2rgb(float64(i)/150, 1, 1)
palette[i] = color.RGBA{uint8(r), uint8(g), uint8(b), 255}
}
incr := 0
for f := 1; f <= nframes; f++ {
incr = (incr + 1) % 360
x1, y1 := width/2, height/2
length := 5.0
img := image.NewPaletted(rect, palette)
setBackgroundColor(img, width, height, 0) // white background
angle := incr
for ci := uint8(1); ci <= 150; ci++ {
x2 := x1 + int(math.Cos(float64(angle)*degToRad)*length)
y2 := y1 - int(math.Sin(float64(angle)*degToRad)*length)
drawLine(img, x1, y1, x2, y2, ci)
x1, y1 = x2, y2
length += 3
angle = (angle + incr) % 360
}
anim.Delay = append(anim.Delay, delay)
anim.Image = append(anim.Image, img)
}
gif.EncodeAll(os.Stdout, &anim)
}</lang>
=={{header|Haskell}}==
{{Works with|Chrome and Firefox}}
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