1 | <?php |
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2 | /** |
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3 | * VizHash_GD |
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4 | * |
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5 | * Visual Hash implementation in php4+GD, |
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6 | * stripped down and modified version for PrivateBin |
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7 | * |
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8 | * @link https://sebsauvage.net/wiki/doku.php?id=php:vizhash_gd |
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9 | * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net) |
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10 | * @license https://www.opensource.org/licenses/zlib-license.php The zlib/libpng License |
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11 | * @version 0.0.5 beta PrivateBin 1.7.3 |
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12 | */ |
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13 | |||
14 | namespace PrivateBin; |
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15 | |||
16 | /** |
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17 | * Vizhash16x16 |
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18 | * |
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19 | * Example: |
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20 | * $vz = new Vizhash16x16(); |
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21 | * $data = $vz->generate(sha512('hello')); |
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22 | * header('Content-type: image/png'); |
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23 | * echo $data; |
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24 | * exit; |
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25 | */ |
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26 | class Vizhash16x16 |
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27 | { |
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28 | /** |
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29 | * hash values |
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30 | * |
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31 | * @access private |
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32 | * @var array |
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33 | */ |
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34 | private $VALUES; |
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35 | |||
36 | /** |
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37 | * index of current value |
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38 | * |
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39 | * @access private |
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40 | * @var int |
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41 | */ |
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42 | private $VALUES_INDEX; |
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43 | |||
44 | /** |
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45 | * image width |
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46 | * |
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47 | * @access private |
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48 | * @var int |
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49 | */ |
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50 | private $width; |
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51 | |||
52 | /** |
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53 | * image height |
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54 | * |
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55 | * @access private |
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56 | * @var int |
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57 | */ |
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58 | private $height; |
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59 | |||
60 | /** |
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61 | * constructor |
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62 | * |
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63 | * @access public |
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64 | */ |
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65 | 2 | public function __construct() |
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66 | { |
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67 | 2 | $this->width = 16; |
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68 | 2 | $this->height = 16; |
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69 | } |
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70 | |||
71 | /** |
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72 | * Generate a 16x16 png corresponding to $text. |
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73 | * |
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74 | * The given text should to be 128 to 150 characters long |
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75 | * |
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76 | * @access public |
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77 | * @param string $text |
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78 | * @return string PNG data. Or empty string if GD is not available. |
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79 | */ |
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80 | 2 | public function generate($text) |
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81 | { |
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82 | 2 | if (!function_exists('gd_info')) { |
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83 | return ''; |
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84 | } |
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85 | |||
86 | 2 | $textlen = strlen($text); |
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87 | |||
88 | // We convert the hash into an array of integers. |
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89 | 2 | $this->VALUES = array(); |
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90 | 2 | for ($i = 0; $i < $textlen; $i = $i + 2) { |
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91 | 2 | array_push($this->VALUES, hexdec(substr($text, $i, 2))); |
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92 | } |
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93 | 2 | $this->VALUES_INDEX = 0; // to walk the array. |
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94 | |||
95 | // Then use these integers to drive the creation of an image. |
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96 | 2 | $image = imagecreatetruecolor($this->width, $this->height); |
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97 | |||
98 | 2 | $r = $r0 = $this->getInt(); |
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99 | 2 | $g = $g0 = $this->getInt(); |
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100 | 2 | $b = $b0 = $this->getInt(); |
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101 | |||
102 | // First, create an image with a specific gradient background. |
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103 | 2 | $op = 'v'; |
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104 | 2 | if (($this->getInt() % 2) == 0) { |
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105 | 2 | $op = 'h'; |
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106 | } |
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107 | 2 | $image = $this->degrade($image, $op, array($r0, $g0, $b0), array(0, 0, 0)); |
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108 | |||
109 | 2 | for ($i = 0; $i < 7; ++$i) { |
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110 | 2 | $action = $this->getInt(); |
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111 | 2 | $color = imagecolorallocate($image, $r, $g, $b); |
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112 | 2 | $r = $r0 = (int) ($r0 + $this->getInt() / 25) % 256; |
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113 | 2 | $g = $g0 = (int) ($g0 + $this->getInt() / 25) % 256; |
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114 | 2 | $b = $b0 = (int) ($b0 + $this->getInt() / 25) % 256; |
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115 | 2 | $this->drawshape($image, $action, $color); |
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116 | } |
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117 | |||
118 | 2 | $color = imagecolorallocate($image, $this->getInt(), $this->getInt(), $this->getInt()); |
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119 | 2 | $this->drawshape($image, $this->getInt(), $color); |
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120 | 2 | ob_start(); |
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121 | 2 | imagepng($image); |
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122 | 2 | $imagedata = ob_get_contents(); |
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123 | 2 | ob_end_clean(); |
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124 | 2 | imagedestroy($image); |
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125 | |||
126 | 2 | return $imagedata; |
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127 | } |
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128 | |||
129 | /** |
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130 | * Returns a single integer from the $VALUES array (0...255) |
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131 | * |
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132 | * @access private |
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133 | * @return int |
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134 | */ |
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135 | 2 | private function getInt() |
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136 | { |
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137 | 2 | $v = $this->VALUES[$this->VALUES_INDEX]; |
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138 | 2 | ++$this->VALUES_INDEX; |
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139 | 2 | $this->VALUES_INDEX %= count($this->VALUES); // Wrap around the array |
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140 | 2 | return $v; |
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141 | } |
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142 | |||
143 | /** |
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144 | * Returns a single integer from the array (roughly mapped to image width) |
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145 | * |
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146 | * @access private |
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147 | * @return int |
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148 | */ |
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149 | 2 | private function getX() |
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150 | { |
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151 | 2 | return (int) ($this->width * $this->getInt() / 256); |
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152 | } |
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153 | |||
154 | /** |
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155 | * Returns a single integer from the array (roughly mapped to image height) |
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156 | * |
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157 | * @access private |
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158 | * @return int |
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159 | */ |
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160 | 2 | private function getY() |
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161 | { |
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162 | 2 | return (int) ($this->height * $this->getInt() / 256); |
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163 | } |
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164 | |||
165 | /** |
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166 | * Gradient function |
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167 | * |
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168 | * taken from: |
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169 | * @link https://www.supportduweb.com/scripts_tutoriaux-code-source-41-gd-faire-un-degrade-en-php-gd-fonction-degrade-imagerie.html |
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170 | * |
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171 | * @access private |
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172 | * @param resource $img |
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173 | * @param string $direction |
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174 | * @param array $color1 |
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175 | * @param array $color2 |
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176 | * @return resource |
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177 | */ |
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178 | 2 | private function degrade($img, $direction, $color1, $color2) |
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179 | { |
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180 | 2 | if ($direction == 'h') { |
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181 | 2 | $size = imagesx($img); |
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182 | 2 | $sizeinv = imagesy($img); |
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183 | } else { |
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184 | 1 | $size = imagesy($img); |
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185 | 1 | $sizeinv = imagesx($img); |
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186 | } |
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187 | 2 | $diffs = array( |
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188 | 2 | ($color2[0] - $color1[0]) / $size, |
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189 | 2 | ($color2[1] - $color1[1]) / $size, |
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190 | 2 | ($color2[2] - $color1[2]) / $size, |
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191 | 2 | ); |
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192 | 2 | for ($i = 0; $i < $size; ++$i) { |
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193 | 2 | $r = $color1[0] + ((int) $diffs[0] * $i); |
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194 | 2 | $g = $color1[1] + ((int) $diffs[1] * $i); |
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195 | 2 | $b = $color1[2] + ((int) $diffs[2] * $i); |
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196 | 2 | if ($direction == 'h') { |
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197 | 2 | imageline($img, $i, 0, $i, $sizeinv, imagecolorallocate($img, $r, $g, $b)); |
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198 | } else { |
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199 | 1 | imageline($img, 0, $i, $sizeinv, $i, imagecolorallocate($img, $r, $g, $b)); |
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200 | } |
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201 | } |
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202 | 2 | return $img; |
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203 | } |
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204 | |||
205 | /** |
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206 | * Draw a shape |
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207 | * |
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208 | * @access private |
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209 | * @param resource $image |
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210 | * @param int $action |
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211 | * @param int $color |
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212 | */ |
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213 | 2 | private function drawshape($image, $action, $color) |
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214 | { |
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215 | 2 | switch ($action % 7) { |
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216 | 2 | case 0: |
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217 | 1 | imagefilledrectangle($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $color); |
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218 | 1 | break; |
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219 | 2 | case 1: |
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220 | 2 | case 2: |
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221 | 2 | imagefilledellipse($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $color); |
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222 | 2 | break; |
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223 | 2 | case 3: |
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224 | 2 | $points = array($this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY()); |
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225 | 2 | version_compare(PHP_VERSION, '8.1', '<') ? imagefilledpolygon($image, $points, 4, $color) : imagefilledpolygon($image, $points, $color); |
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226 | 2 | break; |
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227 | default: |
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228 | 2 | $start = (int) ($this->getInt() * 360 / 256); |
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229 | 2 | $end = (int) ($start + $this->getInt() * 180 / 256); |
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230 | 2 | imagefilledarc($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $start, $end, $color, IMG_ARC_PIE); |
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231 | } |
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232 | } |
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233 | } |
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234 |