jybase/gocaptcha/start.go

package gocaptcha

import (
	"app.yhyue.com/moapp/jybase/go-xweb/httpsession"
	"app.yhyue.com/moapp/jybase/redis"
	"fmt"
	"image/color"
	"log"
	"net/http"

	"math/rand"
)

// 图形验证码大小
const (
	dx = 90
	dy = 30
	Rn = 1
)

// 生成的字符集
var TextCharacters = []rune("ACDEFGHJKLMNPQRSTUVWXY2456789")

// 初始化字体文件
func InitCaptcha() {
	err := SetFontPath("./fonts/")
	if err != nil {
		log.Println(err)
	}
}

// RandText 生成随机字体.
func RandText(num int) string {
	textNum := len(TextCharacters)
	text := make([]rune, num)
	for i := 0; i < num; i++ {
		text[i] = TextCharacters[rand.Intn(textNum)]
	}
	return string(text)
}

// RandLightColor 随机生成浅色底色.
func RandLightColor(n int) color.RGBA {
	// 为每个颜色分量生成一个128到255之间的随机数
	red := rand.Intn(100/n) + 156 + (100 - 100/n)
	green := rand.Intn(100/n) + 156 + (100 - 100/n)
	blue := rand.Intn(100/n) + 156 + (100 - 100/n)
	// Alpha 通道设置为完全不透明
	a := uint8(rand.Intn(8) + 247)

	return color.RGBA{R: uint8(red), G: uint8(green), B: uint8(blue), A: a}
}

func Get(sess *httpsession.Session, checkCode string, w http.ResponseWriter, r *http.Request) (err error) {
	code := RandText(4)
	log.Println(code)
	cacheKey := fmt.Sprintf("captcha_times_%s", sess.Id())
	var (
		// 计次数
		times = redis.GetInt("other", cacheKey)
		ttl   = redis.GetTTL("other", cacheKey)
		rn    = times%6 + 1
		//跳色
		cc = RandLightColor(rn) //
	)
	// cc.A = uint8(rand.Intn(10) + 245)
	captchaImage := New(dx, dy, cc).
		DrawBorder(RandDeepColor())
	if times < 3 {
		captchaImage = captchaImage.DrawNoise(NoiseDensityLower, NewPointNoiseDrawer(), rn).
			DrawNoise(NoiseDensityHigh, NewTextNoiseDrawer(42), rn).
			DrawLine(NewBeeline(), RandDeepColor()).
			DrawText(NewTwistTextDrawer(63, 15, 0.04), code)
	} else if times < 6 {
		captchaImage = captchaImage.DrawNoise(NoiseDensityLower, NewPointNoiseDrawer(), rn).
			DrawNoise(NoiseDensityHigh, NewTextNoiseDrawer(43), rn).
			DrawLine(NewBeeline(), RandDeepColor()).
			DrawText(NewTwistTextDrawer(65, 14, 0.03), code).
			DrawBlur(NewGaussianBlur(), 2, 0.15)
	} else if times < 10 {
		captchaImage = captchaImage.DrawNoise(NoiseDensityLower, NewPointNoiseDrawer(), rn).
			DrawNoise(NoiseDensityHigh, NewTextNoiseDrawer(45), rn).
			DrawLine(NewBeeline(), RandDeepColor()).
			DrawText(NewTwistTextDrawer(66, 18, 0.04), code).
			DrawLine(NewBeeline(), RandDeepColor()).
			DrawBlur(NewGaussianBlur(), 2, 0.41)

	} else {
		captchaImage = captchaImage.DrawNoise(NoiseDensityHigh, NewTextNoiseDrawer(50), rn).
			DrawNoise(NoiseDensityLower, NewPointNoiseDrawer(), rn).
			DrawLine(NewBezier3DLine(), RandLightColor(rn)).
			DrawLine(NewBeeline(), RandDeepColor()).
			DrawText(NewTwistTextDrawer(66, 18, 0.04), code).
			DrawBlur(NewGaussianBlur(), 2, 0.44)
	}
	if times == 0 {
		ttl = 24 * 60 * 60
	}
	//计次
	times++
	redis.Put("other", cacheKey, times, int(ttl))
	if captchaImage.Error != nil {
		log.Println(captchaImage.Error)
		err = captchaImage.Error
		return
	}
	sess.Set(checkCode, code)
	return captchaImage.Encode(w, ImageFormatJpeg)
}