PHP Captcha Generator code example

Verification code Generator is a simple, easy-to-use, functional Verification code generation tool, users can use the tool to easily generate verification code.

Captcha Generator Feature Description:
1, Verification code length: the number of characters generated verification code, the default is 4;
2, background point density: that is, in the background to generate n points, the default is 50;
3, the character rotation angle: The character vertical is 0 degrees, namely the normal placement is 0 degrees, rotates left to right, the default is 55;
4, Verification: that is, verify that the characters are correct;
5. If the path is empty, no picture information is generated. If you select a path, you must select a picture format;
6. Can't see Clearly, change one: When the path and picture format is selected, click once to generate a picture;
7. Generated picture information: is to verify that the content is the file name.

This article is mainly for you to introduce the PHP code generator related codes, with a certain reference value, interested in small partners can refer to

This code runs on the WinDOS server platform

<?php$ic = new Idcode (5,60,30), $iC->createpng (), class idcode{Private $words = Array (' A ', ' B ', ' C ', ' d ', ' e ', ' f ', ' G ' , ' h ', ' I ', ' j ', ' K ', ' l ', ' m ', ' n ', ' o ', ' P ', ' Q ', ' R ', ' s ', ' t ', ' u ', ' V ', ' w ', ' x ', ' y ', ' z ', ' A ', ' B ', ' C ', ' D ', ' E ', ' F ', ' G ', ' h ', ' I ', ' J ', ' K ', ' L ', ' M ', ' N ', ' O ', ' P ', ' Q ', ' R ', ' S ', ' T ', ' U ', ' V ', ' W ', ' X ', ' Y ', ' Z ', ' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ', ' 6 ', ' 7 '  );  Private $fonts;  private $count;//The number of authentication code characters private $height;  Private $width; Private $path = '..  \myfolder\fonts ';  Private $keys;    Constructor public function construct ($count, $width, $height) {$this->count = $count;    $this->getfonts ();    $this->height = $height;  $this->width = $width;    } Private Function Getfonts () {$dir = Dir ($this->path); while (false!== ($file = $dir->read ())) {if ($file! = '. ' && $file! = ')        {$this->fonts[count ($this->fonts)] = basename ($file);  }} $dir->close (); } Private Function Createkeys () {for ($i = 0; $i < $this->count; $i + +){$this->keys[$i] [' char '] = $this->words[rand (0,count ($this->words)-1)]; Use the font path to identify $this->keys[$i [' filename '] = $this->path. '    \ \ '. $this->fonts[rand (0,count ($this->fonts)-1)];    }} Public Function Createpng () {$this->createkeys (); Create canvas and color blocks $BG = Imagecreatetruecolor ($this->width + 10*2, $this->height + 3*2);//left 10px blank on both sides, up and down 3px $grey = ima    Gecolorallocate ($BG, 155,155,155);    $blue = Imagecolorallocate ($BG, 0x00,0x00,0xff);    Fill Background Imagefill ($BG, 0,0, $grey);    Add character $pwidth = $this->width/$this->count;    $x; $y;      for ($i = 0; $i < $this->count; $i + +) {$rotation = rand ( -40,40);//deflection angle ±40° $fontsize = 33;      $width _txt;      $height _txt;        do{$fontsize--;        $bbox = Imagettfbbox ($fontsize, $rotation, $this->keys[$i [' filename '], $this->keys[$i] [' char ']);      $width _txt = $bbox [2]-$bbox [0];//x 0 2 4 6,y1 3 5 7; lower left, lower right, upper right, upper left $height _txt = $bbox [7]-$bbox [1]; }while ($fOntsize > 8 && ($height _txt > $this->height | | $width _txt > $pwidth));      $fontcolor = Imagecolorallocate ($BG, Rand (0,255), Rand (0,255), Rand (0,255));      $x = 8 + $pwidth * $i + $pwidth/2-$width _txt/2;//x coordinates basic position $y = $this-&GT;HEIGHT/2-$height _TXT/2; Imagettftext ($BG, $fontsize, $rotation, $x, $y, $fontcolor, $this->keys[$i] [' filename '], $this->keys[$i] [' char '    ]);    }//Draw interference lines//Add interference line Imageline ($BG, 0,15,40,10, $blue) as appropriate;    Image Output header file header (' Content-type:image/png ');    Output PNG image imagepng ($BG);  Clear Cache Resource Imagedestroy ($BG);    The Public Function Checkkeys ($input) {if (count ($input)! = $this->count) {return ' ERROR: incorrect length. '; }else{for ($i =0; $i < $this->count; $i +) {//0 o i l 1 calibration, determine if manual calibration is required based on the selected font ($input [$i]! = $th        is->keys[$i] [' char ']) {return ' SUCCESS. ';        }else{return ' ERROR: Please enter the correct verification code. '; }}}}}?>