go语言制作一个gif动态图

2020-01-28 11:44:08王旭

如题,关键不是图怎么样,而是说,go可以拿来实现动态图验证码,加上go支持cgi、fcgi,完全可以做个exe拿去增补现有的服务器么。

ball.go


package main
import (
  "github.com/hydra13142/cube"
  "github.com/hydra13142/geom"
  "github.com/hydra13142/paint"
  "image"
  "image/color/palette"
  "image/gif"
  "math"
  "os"
)
var (
  pln *cube.Plain
  unx cube.Vector
  uny cube.Vector
)
const (
  H = 18
  W = 36
)
func init() {
  pln, _ = cube.NewPlain(cube.Point{}, cube.Vector{4, 4, 3})
  uny = cube.FromTo(cube.Point{}, pln.VerticalPoint(cube.Point{0, 0, 10})).Unit()
  unx = cube.OuterProduct(uny, cube.Vector{4, 4, 3}).Unit()
}
func main() {
  var x [H + 1][W]cube.Point
  var y [H + 1][W]geom.Point
  dz := math.Pi / H
  dxy := math.Pi * 2 / W
  for i := 0; i <= H; i++ {
    az := float64(i)*dz - math.Pi/2
    r := 140 * math.Cos(az)
    z := 140 * math.Sin(az)
    for j := 0; j < W; j++ {
      axy := float64(j) * dxy
      x[i][j] = cube.Point{math.Cos(axy) * r, math.Sin(axy) * r, z}
    }
  }
  pics := make([]*image.Paletted, 0, 20)
  img := paint.Image{
    FR: paint.Green,
    BG: paint.White,
  }
  stp := dxy / 20
  delay := make([]int, 0, 20)
  for t := 0; t < 20; t++ {
    img.Image = image.NewPaletted(image.Rect(0, 0, 300, 300), palette.Plan9)
    for i := 0; i <= H; i++ {
      for j := 0; j < W; j++ {
        ox := cube.FromTo(cube.Point{}, x[i][j])
        y[i][j] = geom.Point{cube.InnerProduct(ox, unx), cube.InnerProduct(ox, uny)}
        a, b := x[i][j].X, x[i][j].Y
        x[i][j].X = a*math.Cos(stp) - b*math.Sin(stp)
        x[i][j].Y = b*math.Cos(stp) + a*math.Sin(stp)
      }
    }
    for i := 0; i < H; i++ {
      for j := 0; j < W; j++ {
        img.Line(
          150+int(y[i][j].X),
          150-int(y[i][j].Y),
          150+int(y[i][(j+1)%W].X),
          150-int(y[i][(j+1)%W].Y),
        )
        img.Line(
          150+int(y[i][j].X),
          150-int(y[i][j].Y),
          150+int(y[i+1][j].X),
          150-int(y[i+1][j].Y),
        )
      }
    }
    pics = append(pics, img.Image.(*image.Paletted))
    delay = append(delay, 5)
  }
  file, _ := os.Create("ball.gif")
  defer file.Close()
  gif.EncodeAll(file, &gif.GIF{
    Image:   pics,
    Delay:   delay,
    LoopCount: 5 * len(delay),
  })
}

woniu.go


package main
import (
  "github.com/hydra13142/cube"
  "github.com/hydra13142/geom"
  "github.com/hydra13142/paint"
  "image"
  "image/color/palette"
  "image/gif"
  "math"
  "os"
)
var (
  pln   *cube.Plain
  unx, uny cube.Vector
)
const (
  H = 18
  W = 96
)
func init() {
  pln, _ = cube.NewPlain(cube.Point{}, cube.Vector{2, 2, 1})
  uny = cube.FromTo(cube.Point{}, pln.VerticalPoint(cube.Point{0, 0, 10})).Unit()
  unx = cube.OuterProduct(uny, cube.Vector{2, 2, 1}).Unit()
}
func main() {
  var x [H + 1][W]cube.Point
  var y [H + 1][W]geom.Point
  dz := math.Pi / H
  dxy := math.Pi * 4 / W
  for i := 0; i <= H; i++ {
    az := float64(i)*dz - math.Pi/2
    r := 300 * math.Cos(az)
    z := 100 * math.Sin(az)
    for j := 0; j < W; j++ {
      axy := float64(j) * dxy
      R := float64(j) * r / W
      x[i][j] = cube.Point{math.Cos(axy) * R, math.Sin(axy) * R, z}
    }
  }
  pics := make([]*image.Paletted, 0, 20)
  img := paint.Image{
    FR: paint.Green,
    BG: paint.White,
  }
  stp := math.Pi / W
  delay := make([]int, 0, 2*W)
  for t := 0; t < 2*W; t++ {
    img.Image = image.NewPaletted(image.Rect(0, 0, 600, 300), palette.Plan9)
    for i := 0; i <= H; i++ {
      for j := 0; j < W; j++ {
        ox := cube.FromTo(cube.Point{}, x[i][j])
        y[i][j] = geom.Point{cube.InnerProduct(ox, unx), cube.InnerProduct(ox, uny)}
        a, b := x[i][j].X, x[i][j].Y
        x[i][j].X = a*math.Cos(stp) - b*math.Sin(stp)
        x[i][j].Y = b*math.Cos(stp) + a*math.Sin(stp)
      }
    }
    img.Line(
      300+int(y[0][0].X),
      150-int(y[0][0].Y),
      300+int(y[H][0].X),
      150-int(y[H][0].Y),
    )
    for i := 0; i < H; i++ {
      for j := 1; j < W; j++ {
        img.Line(
          300+int(y[i][j].X),
          150-int(y[i][j].Y),
          300+int(y[i][j-1].X),
          150-int(y[i][j-1].Y),
        )
        img.Line(
          300+int(y[i][j].X),
          150-int(y[i][j].Y),
          300+int(y[i+1][j].X),
          150-int(y[i+1][j].Y),
        )
      }
    }
    pics = append(pics, img.Image.(*image.Paletted))
    delay = append(delay, 5)
  }
  file, _ := os.Create("woniu.gif")
  defer file.Close()
  gif.EncodeAll(file, &gif.GIF{
    Image:   pics,
    Delay:   delay,
    LoopCount: 5 * len(delay),
  })
}