README
¶
captcha provides an simple, unopinionated API for captcha generation
Compatibility
This package uses embed package from Go 1.16.
Usage
import "github.com/pchchv/captcha"
func handle(w http.ResponseWriter, r *http.Request) {
// create a captcha of 150x50px
data, _ := captcha.New(150, 50)
// session come from other library such as gorilla/sessions
session.Values["captcha"] = data.Text
session.Save(r, w)
// send image data to client
data.WriteImage(w)
}
Sample image
Documentation
¶
Overview ¶
Package provides an simple, unopinionated API for captcha generation
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func LoadFontFromReader ¶
LoadFontFromReader load an external font from an io.Reader interface.
Types ¶
type Captcha ¶
type Captcha struct {
Text string
// contains filtered or unexported fields
}
Captcha is the result of captcha generation. It has a `Text` field and a private `img` field, which will be used in the `WriteImage` receiver.
func NewCustomGenerator ¶
func NewCustomGenerator(width int, height int, generator func() (anwser string, question string), option ...SetOption) (*Captcha, error)
NewCustomGenerator creates a new captcha based on a custom text generator.
func NewMathExpr ¶
NewMathExpr creates a new captcha. Generates an image with a mathematical expression like `1 + 2`.
func (*Captcha) WriteGIF ¶
WriteGIF encodes the image data into GIF format and writes it to io.Writer. Returns an error possible when encoding GIF.
func (*Captcha) WriteImage ¶
WriteImage encodes image data and writes it to io.Writer. Returns an error possible when encoding PNG.
type Options ¶
type Options struct {
// BackgroundColor is captcha image's background color.
// By default it is color.Transparent.
BackgroundColor color.Color
// CharPreset defines the text on the captcha image.
// By default:
// ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
CharPreset string
// TextLength is the length of the captcha text.
// By default it is 4.
TextLength int
// CurveNumber is the number of curves to draw on captcha image.
// By default it is 2.
CurveNumber int
// FontDPI controls DPI (dots per inch) of font.
// By default it is 72.0.
FontDPI float64
// FontScale controls the scale of font.
// By default it is 1.0.
FontScale float64
// Noise controls the amount of noise to be drawn.
// By default, a noise point is drawn every 28 pixels.
// By default it is 1.0.
Noise float64
// Palette is the set of colors to chose from.
Palette color.Palette
// contains filtered or unexported fields
}
Options manage captcha generation.
Source Files
Directories