81 lines
1.4 KiB
Go
81 lines
1.4 KiB
Go
package captcha
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import (
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"image"
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"justcaptcha/pkg/captcha"
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"math/rand"
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"time"
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"github.com/fogleman/gg"
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)
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const (
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dwImageWidth = 160
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dwImageHeight = 40
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)
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type DwellingCaptcha struct {
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captcha.Captcha
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}
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func NewDwellingCaptcha(expiry time.Duration) *DwellingCaptcha {
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return &DwellingCaptcha{
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Captcha: captcha.Captcha{
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ExpireIn: captcha.ExpiryDate(expiry)}}
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}
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func (c *DwellingCaptcha) generateImage(style string) *image.Image {
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isDark := style == "dark"
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ctx := gg.NewContext(dwImageWidth, dwImageHeight)
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// fill background
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if isDark {
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ctx.SetRGB255(0x0a, 0x0a, 0x0a)
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} else {
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ctx.SetRGB255(0xf5, 0xf5, 0xf5)
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}
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ctx.Clear()
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// draw text
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if isDark {
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ctx.SetRGB255(0xf5, 0xf5, 0xf5)
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} else {
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ctx.SetRGB255(0x0a, 0x0a, 0x0a)
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}
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ctx.Scale(4.0, 2.7)
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ctx.DrawStringAnchored(string(c.GetAnswer()), 20, 5, .5, .5)
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// draw lines and points
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h := float64(ctx.Height())
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for i := 0; i < 24; i++ {
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x0 := rand.Float64() * h
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x1 := rand.Float64() * h
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x2 := rand.Float64() * h
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x3 := rand.Float64() * h
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ctx.DrawLine(x0, 0, h, x1)
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ctx.DrawLine(0, x2, x3, h)
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r := rand.Intn(256)
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g := rand.Intn(256)
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b := rand.Intn(256)
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ctx.SetRGB255(r, g, b)
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lw := float64(rand.Float32() * 4.0)
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if lw == 0 {
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lw = 0.1
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}
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ctx.SetLineWidth(lw)
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ctx.Stroke()
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}
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c.Image = ctx.Image()
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return &c.Image
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}
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func (c *DwellingCaptcha) GetImage(style string) *image.Image {
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if c.Image == nil {
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return c.generateImage(style)
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}
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return &c.Image
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}
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