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;;;; verify-code.lisp
;;;; This file is a part of kl-verify.
;;;; License: MIT
;;;; Use image library to generate a simple verify code image.
(in-package :kl-verify)
(defparameter +stringset+
(defun get-rand-char ()
(elt +stringset+ (random (length +stringset+))))
(defun get-rand-str (cnt)
(if (<= cnt 0)
(concatenate 'string (string (get-rand-char)) (get-rand-str (1- cnt)))))
(defun get-rand-op ()
(values (random 100) (random 100)))
(defun get-rand-exp ()
(multiple-value-bind (op1 op2) (get-rand-op)
(let ((m (random 2)))
(case m
(0 (values (format nil "~a+~a=" op1 op2) (+ op1 op2)))
(1 (values (format nil "~a*~a=" op1 op2) (* op1 op2)))))))
(defun make-image (w h r g b)
(let ((image (image:make-image w h)))
(image:rect image 0 0 (1- w) (1- h) t r g b)
(defun get-str-rect (str image)
(image:text image str 0 0 0 0 0 0.0))
(defun get-rand-color ()
(+ (random 200) 56))
(defun draw-char (c image sx ah)
(multiple-value-bind (w h) (get-str-rect (string c) image)
(let ((r (get-rand-color))
(g (get-rand-color))
(b (get-rand-color))
(y (random (- ah h))))
(image:text image (string c) sx y r g b)
(+ sx w))))
(defun get-noise-color ()
(+ (random 80) 176))
(defun draw-rand-line (image w h)
(let ((x0 (random w))
(y0 (random h))
(x1 (random w))
(y1 (random h))
(r (get-noise-color))
(g (get-noise-color))
(b (get-noise-color)))
(image:line image x0 y0 x1 y1 r g b)))
(defun draw-noise (image w h)
(let ((cnt (+ (random 5) 2)))
(loop for x from 1 to cnt
do (draw-rand-line image w h))))
(defgeneric generate-verify-code (name w h str-cnt type))
(defmethod generate-verify-code (stream w h str-cnt (type (eql 'pic)))
(let* ((image (make-image w h 255 255 255))
(str (get-rand-str str-cnt))
(total-w (get-str-rect str image))
(x (random (floor (/ (- w total-w) 2)))))
(map nil #' (lambda (c)
(let ((sx (draw-char c image x h)))
(setf x (+ sx (random 15)))))
(draw-noise image w h)
;(image:export-image image stream)
; to support flexi:with-output-to-sequence
(image::export-to-stream image stream :format :gif)
(defmethod generate-verify-code (stream w h str-cnt (type (eql 'exp)))
(declare (ignore str-cnt))
(multiple-value-bind (str ret) (get-rand-exp)
(let* ((image (make-image w h 255 255 255))
(x 0) (y 0))
(multiple-value-bind (sw sh) (get-str-rect str image)
(setf x (floor (/ (- w sw) 2)))
(setf y (floor (/ (- h sh) 2))))
(image:text image str x y 0 0 0)
(image::export-to-stream image stream :format :gif)
(format nil "~a" ret))))
(defmethod generate-verify-code ((name string) w h str-cnt type)
(with-open-file (stream name :direction :output
:if-exists :supersede
:element-type '(unsigned-byte 8)
:if-does-not-exist :create)
(generate-verify-code stream w h str-cnt type)))
(defun load-font (font)
(image::read-font font)
(image::use-font (net.hexapodia.image.pcf::font-name font)))
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