<?php

namespace addons\captcha\library\gif;

/*
 * GIF 合成类库
 * @Author: Anonymous
 * @Date: 2019-09-28 13:35:44 
 * @Last Modified by: lovefc
 * @Last Modified time: 2019-09-28 13:37:09
 */

class GIFEncoder
{
  public $GIF = "GIF89a";

  public $VER = "GIFEncoder V2.06";

  public $BUF = array();

  public $LOP = 0;

  public $DIS = 2;

  public $COL = -1;

  public $IMG = -1;

  public $ERR = array(
    'ERR00' => "Does not supported public function for only one image!",
    'ERR01' => "Source is not a GIF image!",
    'ERR02' => "Unintelligible flag ",
    'ERR03' => "Could not make animation from animated GIF source",
  );

  public function __construct($GIF_src, $GIF_dly = 100, $GIF_lop = 0, $GIF_dis = 0, $GIF_red = 0, $GIF_grn = 0, $GIF_blu = 0, $GIF_mod = 'bin')
  {
    if (!is_array($GIF_src) && !is_array($GIF_tim)) {
      printf("%s: %s", $this->VER, $this->ERR['ERR00']);
      exit(0);
    }
    $this->LOP = ($GIF_lop > -1) ? $GIF_lop : 0;
    $this->DIS = ($GIF_dis > -1) ? (($GIF_dis < 3) ? $GIF_dis : 3) : 2;
    $this->COL = ($GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : -1;

    for ($i = 0, $src_count = count($GIF_src); $i < $src_count; $i++) {
      if (strToLower($GIF_mod) == "url") {
        $this->BUF[] = fread(fopen($GIF_src[$i], "rb"), filesize($GIF_src[$i]));
      } elseif (strToLower($GIF_mod) == "bin") {
        $this->BUF[] = $GIF_src[$i];
      } else {
        printf("%s: %s(%s)!", $this->VER, $this->ERR['ERR02'], $GIF_mod);
        exit(0);
      }
      if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF[$i], 0, 6) != "GIF89a") {
        printf("%s: %d %s", $this->VER, $i, $this->ERR['ERR01']);
        exit(0);
      }
      for ($j = (13 + 3 * (2 << (ord($this->BUF[$i]{
        10}) & 0x07))), $k = TRUE; $k; $j++) {
        switch ($this->BUF[$i]{
          $j}) {
          case "!":
            if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE") {
              printf("%s: %s(%s source)!", $this->VER, $this->ERR['ERR03'], ($i + 1));
              exit(0);
            }
            break;
          case ";":
            $k = FALSE;
            break;
        }
      }
    }
    GIFEncoder::GIFAddHeader();
    for ($i = 0, $count_buf = count($this->BUF); $i < $count_buf; $i++) {
      GIFEncoder::GIFAddFrames($i, $GIF_dly[$i]);
    }
    GIFEncoder::GIFAddFooter();
  }

  public function GIFAddHeader()
  {
    $cmap = 0;
    if (ord($this->BUF[0]{
      10}) & 0x80) {
      $cmap = 3 * (2 << (ord($this->BUF[0]{
        10}) & 0x07));
      $this->GIF .= substr($this->BUF[0], 6, 7);
      $this->GIF .= substr($this->BUF[0], 13, $cmap);
      $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . GIFEncoder::GIFWord($this->LOP) . "\0";
    }
  }

  public function GIFAddFrames($i, $d)
  {
    $Locals_str = 13 + 3 * (2 << (ord($this->BUF[$i]{
      10}) & 0x07));
    $Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1;
    $Locals_tmp = substr($this->BUF[$i], $Locals_str, $Locals_end);
    $Global_len = 2 << (ord($this->BUF[0]{
      10}) & 0x07);
    $Locals_len = 2 << (ord($this->BUF[$i]{
      10}) & 0x07);
    $Global_rgb = substr($this->BUF[0], 13, 3 * (2 << (ord($this->BUF[0]{
      10}) & 0x07)));
    $Locals_rgb = substr($this->BUF[$i], 13, 3 * (2 << (ord($this->BUF[$i]{
      10}) & 0x07)));
    $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 0) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "\x0\x0";
    if ($this->COL > -1 && ord($this->BUF[$i]{
      10}) & 0x80) {
      for ($j = 0; $j < (2 << (ord($this->BUF[$i]{
        10}) & 0x07)); $j++) {
        if (ord($Locals_rgb{
          3 * $j + 0}) == ($this->COL >> 0) & 0xFF && ord($Locals_rgb{
          3 * $j + 1}) == ($this->COL >> 8) & 0xFF && ord($Locals_rgb{
          3 * $j + 2}) == ($this->COL >> 16) & 0xFF) {
          $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 1) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . chr($j) . "\x0";
          break;
        }
      }
    }
    switch ($Locals_tmp{
      0}) {
      case "!":
        $Locals_img = substr($Locals_tmp, 8, 10);
        $Locals_tmp = substr($Locals_tmp, 18, strlen($Locals_tmp) - 18);
        break;
      case ",":
        $Locals_img = substr($Locals_tmp, 0, 10);
        $Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);
        break;
    }
    if (ord($this->BUF[$i]{
      10}) & 0x80 && $this->IMG > -1) {
      if ($Global_len == $Locals_len) {
        if (GIFEncoder::GIFBlockCompare($Global_rgb, $Locals_rgb, $Global_len)) {
          $this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
        } else {
          $byte = ord($Locals_img{
            9});
          $byte |= 0x80;
          $byte &= 0xF8;
          $byte |= (ord($this->BUF[0]{
            10}) & 0x07);
          $Locals_img{
            9} = chr($byte);
          $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
        }
      } else {
        $byte = ord($Locals_img{
          9});
        $byte |= 0x80;
        $byte &= 0xF8;
        $byte |= (ord($this->BUF[$i]{
          10}) & 0x07);
        $Locals_img{
          9} = chr($byte);
        $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);
      }
    } else {
      $this->GIF .= ($Locals_ext . $Locals_img . $Locals_tmp);
    }
    $this->IMG = 1;
  }

  public function GIFAddFooter()
  {
    $this->GIF .= ";";
  }

  public function GIFBlockCompare($GlobalBlock, $LocalBlock, $Len)
  {
    for ($i = 0; $i < $Len; $i++) {
      if ($GlobalBlock{
        3 * $i + 0} != $LocalBlock{
        3 * $i + 0} || $GlobalBlock{
        3 * $i + 1} != $LocalBlock{
        3 * $i + 1} || $GlobalBlock{
        3 * $i + 2} != $LocalBlock{
        3 * $i + 2}) {
        return (0);
      }
    }
    return (1);
  }

  public function GIFWord($int)
  {
    return (chr($int & 0xFF) . chr(($int >> 8) & 0xFF));
  }

  public function GetAnimation()
  {
    return ($this->GIF);
  }
}