init

2019-08-08 17:13:34 +08:00
parent e8e5966a8c
commit f0bf2d5fec
2885 changed files with 1195993 additions and 12 deletions
@@ -0,0 +1,260 @@
+package captcha
+
+import (
+	"github.com/golang/freetype"
+	"github.com/golang/freetype/truetype"
+
+	"image"
+	"image/color"
+	"image/draw"
+	"io/ioutil"
+	"math"
+	"math/rand"
+	"time"
+)
+
+type Captcha struct {
+	frontColors []color.Color
+	bkgColors   []color.Color
+	disturlvl   DisturLevel
+	fonts       []*truetype.Font
+	size        image.Point
+}
+
+type StrType int
+
+const (
+	NUM   StrType = iota // 数字
+	LOWER                // 小写字母
+	UPPER                // 大写字母
+	ALL                  // 全部
+)
+
+type DisturLevel int
+
+const (
+	NORMAL DisturLevel = 4
+	MEDIUM DisturLevel = 8
+	HIGH   DisturLevel = 16
+)
+
+func New() *Captcha {
+	c := &Captcha{
+		disturlvl: NORMAL,
+		size:      image.Point{82, 32},
+	}
+	c.frontColors = []color.Color{color.Black}
+	c.bkgColors = []color.Color{color.White}
+	return c
+}
+
+// AddFont 添加一个字体
+func (c *Captcha) AddFont(path string) error {
+	fontdata, erro := ioutil.ReadFile(path)
+	if erro != nil {
+		return erro
+	}
+	font, erro := freetype.ParseFont(fontdata)
+	if erro != nil {
+		return erro
+	}
+	if c.fonts == nil {
+		c.fonts = []*truetype.Font{}
+	}
+	c.fonts = append(c.fonts, font)
+	return nil
+}
+
+//AddFontFromBytes allows to load font from slice of bytes, for example, load the font packed by https://github.com/jteeuwen/go-bindata
+func (c *Captcha) AddFontFromBytes(contents []byte) error {
+	font, err := freetype.ParseFont(contents)
+	if err != nil {
+		return err
+	}
+	if c.fonts == nil {
+		c.fonts = []*truetype.Font{}
+	}
+	c.fonts = append(c.fonts, font)
+	return nil
+}
+
+// SetFont 设置字体 可以设置多个
+func (c *Captcha) SetFont(paths ...string) error {
+	for _, v := range paths {
+		if erro := c.AddFont(v); erro != nil {
+			return erro
+		}
+	}
+	return nil
+}
+
+func (c *Captcha) SetDisturbance(d DisturLevel) {
+	if d > 0 {
+		c.disturlvl = d
+	}
+}
+
+func (c *Captcha) SetFrontColor(colors ...color.Color) {
+	if len(colors) > 0 {
+		c.frontColors = c.frontColors[:0]
+		for _, v := range colors {
+			c.frontColors = append(c.frontColors, v)
+		}
+	}
+}
+
+func (c *Captcha) SetBkgColor(colors ...color.Color) {
+	if len(colors) > 0 {
+		c.bkgColors = c.bkgColors[:0]
+		for _, v := range colors {
+			c.bkgColors = append(c.bkgColors, v)
+		}
+	}
+}
+
+func (c *Captcha) SetSize(w, h int) {
+	if w < 48 {
+		w = 48
+	}
+	if h < 20 {
+		h = 20
+	}
+	c.size = image.Point{w, h}
+}
+
+func (c *Captcha) randFont() *truetype.Font {
+	return c.fonts[rand.Intn(len(c.fonts))]
+}
+
+// 绘制背景
+func (c *Captcha) drawBkg(img *Image) {
+	ra := rand.New(rand.NewSource(time.Now().UnixNano()))
+	//填充主背景色
+	bgcolorindex := ra.Intn(len(c.bkgColors))
+	bkg := image.NewUniform(c.bkgColors[bgcolorindex])
+	img.FillBkg(bkg)
+}
+
+// 绘制噪点
+func (c *Captcha) drawNoises(img *Image) {
+	ra := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+	// 待绘制图片的尺寸
+	size := img.Bounds().Size()
+	dlen := int(c.disturlvl)
+	// 绘制干扰斑点
+	for i := 0; i < dlen; i++ {
+		x := ra.Intn(size.X)
+		y := ra.Intn(size.Y)
+		r := ra.Intn(size.Y/20) + 1
+		colorindex := ra.Intn(len(c.frontColors))
+		img.DrawCircle(x, y, r, i%4 != 0, c.frontColors[colorindex])
+	}
+
+	// 绘制干扰线
+	for i := 0; i < dlen; i++ {
+		x := ra.Intn(size.X)
+		y := ra.Intn(size.Y)
+		o := int(math.Pow(-1, float64(i)))
+		w := ra.Intn(size.Y) * o
+		h := ra.Intn(size.Y/10) * o
+		colorindex := ra.Intn(len(c.frontColors))
+		img.DrawLine(x, y, x+w, y+h, c.frontColors[colorindex])
+		colorindex++
+	}
+
+}
+
+// 绘制文字
+func (c *Captcha) drawString(img *Image, str string) {
+
+	if c.fonts == nil {
+		panic("没有设置任何字体")
+	}
+	tmp := NewImage(c.size.X, c.size.Y)
+
+	// 文字大小为图片高度的 0.6
+	fsize := int(float64(c.size.Y) * 0.6)
+	// 用于生成随机角度
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+	// 文字之间的距离
+	// 左右各留文字的1/4大小为内部边距
+	padding := fsize / 4
+	gap := (c.size.X - padding*2) / (len(str))
+
+	// 逐个绘制文字到图片上
+	for i, char := range str {
+		// 创建单个文字图片
+		// 以文字为尺寸创建正方形的图形
+		str := NewImage(fsize, fsize)
+		// str.FillBkg(image.NewUniform(color.Black))
+		// 随机取一个前景色
+		colorindex := r.Intn(len(c.frontColors))
+
+		//随机取一个字体
+		font := c.randFont()
+		str.DrawString(font, c.frontColors[colorindex], string(char), float64(fsize))
+
+		// 转换角度后的文字图形
+		rs := str.Rotate(float64(r.Intn(40) - 20))
+		// 计算文字位置
+		s := rs.Bounds().Size()
+		left := i*gap + padding
+		top := (c.size.Y - s.Y) / 2
+		// 绘制到图片上
+		draw.Draw(tmp, image.Rect(left, top, left+s.X, top+s.Y), rs, image.ZP, draw.Over)
+	}
+	if c.size.Y >= 48 {
+		// 高度大于48添加波纹 小于48波纹影响用户识别
+		tmp.distortTo(float64(fsize)/10, 200.0)
+	}
+
+	draw.Draw(img, tmp.Bounds(), tmp, image.ZP, draw.Over)
+}
+
+// Create 生成一个验证码图片
+func (c *Captcha) Create(num int, t StrType) (*Image, string) {
+	if num <= 0 {
+		num = 4
+	}
+	dst := NewImage(c.size.X, c.size.Y)
+	//tmp := NewImage(c.size.X, c.size.Y)
+	c.drawBkg(dst)
+	c.drawNoises(dst)
+
+	str := string(c.randStr(num, int(t)))
+	c.drawString(dst, str)
+	//c.drawString(tmp, str)
+
+	return dst, str
+}
+
+func (c *Captcha) CreateCustom(str string) *Image {
+	if len(str) == 0 {
+		str = "unkown"
+	}
+	dst := NewImage(c.size.X, c.size.Y)
+	c.drawBkg(dst)
+	c.drawNoises(dst)
+	c.drawString(dst, str)
+	return dst
+}
+
+var fontKinds = [][]int{[]int{10, 48}, []int{26, 97}, []int{26, 65}}
+
+// 生成随机字符串
+// size 个数 kind 模式
+func (c *Captcha) randStr(size int, kind int) []byte {
+	ikind, result := kind, make([]byte, size)
+	isAll := kind > 2 || kind < 0
+	rand.Seed(time.Now().UnixNano())
+	for i := 0; i < size; i++ {
+		if isAll {
+			ikind = rand.Intn(3)
+		}
+		scope, base := fontKinds[ikind][0], fontKinds[ikind][1]
+		result[i] = uint8(base + rand.Intn(scope))
+	}
+	return result
+}