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Diffstat (limited to 'lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php')
| -rw-r--r-- | lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php | 254 |
1 files changed, 0 insertions, 254 deletions
diff --git a/lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php b/lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php deleted file mode 100644 index 545d42622..000000000 --- a/lib/htmlpurifier/library/HTMLPurifier/UnitConverter.php +++ /dev/null @@ -1,254 +0,0 @@ -<?php - -/** - * Class for converting between different unit-lengths as specified by - * CSS. - */ -class HTMLPurifier_UnitConverter -{ - - const ENGLISH = 1; - const METRIC = 2; - const DIGITAL = 3; - - /** - * Units information array. Units are grouped into measuring systems - * (English, Metric), and are assigned an integer representing - * the conversion factor between that unit and the smallest unit in - * the system. Numeric indexes are actually magical constants that - * encode conversion data from one system to the next, with a O(n^2) - * constraint on memory (this is generally not a problem, since - * the number of measuring systems is small.) - */ - protected static $units = array( - self::ENGLISH => array( - 'px' => 3, // This is as per CSS 2.1 and Firefox. Your mileage may vary - 'pt' => 4, - 'pc' => 48, - 'in' => 288, - self::METRIC => array('pt', '0.352777778', 'mm'), - ), - self::METRIC => array( - 'mm' => 1, - 'cm' => 10, - self::ENGLISH => array('mm', '2.83464567', 'pt'), - ), - ); - - /** - * Minimum bcmath precision for output. - */ - protected $outputPrecision; - - /** - * Bcmath precision for internal calculations. - */ - protected $internalPrecision; - - /** - * Whether or not BCMath is available - */ - private $bcmath; - - public function __construct($output_precision = 4, $internal_precision = 10, $force_no_bcmath = false) { - $this->outputPrecision = $output_precision; - $this->internalPrecision = $internal_precision; - $this->bcmath = !$force_no_bcmath && function_exists('bcmul'); - } - - /** - * Converts a length object of one unit into another unit. - * @param HTMLPurifier_Length $length - * Instance of HTMLPurifier_Length to convert. You must validate() - * it before passing it here! - * @param string $to_unit - * Unit to convert to. - * @note - * About precision: This conversion function pays very special - * attention to the incoming precision of values and attempts - * to maintain a number of significant figure. Results are - * fairly accurate up to nine digits. Some caveats: - * - If a number is zero-padded as a result of this significant - * figure tracking, the zeroes will be eliminated. - * - If a number contains less than four sigfigs ($outputPrecision) - * and this causes some decimals to be excluded, those - * decimals will be added on. - */ - public function convert($length, $to_unit) { - - if (!$length->isValid()) return false; - - $n = $length->getN(); - $unit = $length->getUnit(); - - if ($n === '0' || $unit === false) { - return new HTMLPurifier_Length('0', false); - } - - $state = $dest_state = false; - foreach (self::$units as $k => $x) { - if (isset($x[$unit])) $state = $k; - if (isset($x[$to_unit])) $dest_state = $k; - } - if (!$state || !$dest_state) return false; - - // Some calculations about the initial precision of the number; - // this will be useful when we need to do final rounding. - $sigfigs = $this->getSigFigs($n); - if ($sigfigs < $this->outputPrecision) $sigfigs = $this->outputPrecision; - - // BCMath's internal precision deals only with decimals. Use - // our default if the initial number has no decimals, or increase - // it by how ever many decimals, thus, the number of guard digits - // will always be greater than or equal to internalPrecision. - $log = (int) floor(log(abs($n), 10)); - $cp = ($log < 0) ? $this->internalPrecision - $log : $this->internalPrecision; // internal precision - - for ($i = 0; $i < 2; $i++) { - - // Determine what unit IN THIS SYSTEM we need to convert to - if ($dest_state === $state) { - // Simple conversion - $dest_unit = $to_unit; - } else { - // Convert to the smallest unit, pending a system shift - $dest_unit = self::$units[$state][$dest_state][0]; - } - - // Do the conversion if necessary - if ($dest_unit !== $unit) { - $factor = $this->div(self::$units[$state][$unit], self::$units[$state][$dest_unit], $cp); - $n = $this->mul($n, $factor, $cp); - $unit = $dest_unit; - } - - // Output was zero, so bail out early. Shouldn't ever happen. - if ($n === '') { - $n = '0'; - $unit = $to_unit; - break; - } - - // It was a simple conversion, so bail out - if ($dest_state === $state) { - break; - } - - if ($i !== 0) { - // Conversion failed! Apparently, the system we forwarded - // to didn't have this unit. This should never happen! - return false; - } - - // Pre-condition: $i == 0 - - // Perform conversion to next system of units - $n = $this->mul($n, self::$units[$state][$dest_state][1], $cp); - $unit = self::$units[$state][$dest_state][2]; - $state = $dest_state; - - // One more loop around to convert the unit in the new system. - - } - - // Post-condition: $unit == $to_unit - if ($unit !== $to_unit) return false; - - // Useful for debugging: - //echo "<pre>n"; - //echo "$n\nsigfigs = $sigfigs\nnew_log = $new_log\nlog = $log\nrp = $rp\n</pre>\n"; - - $n = $this->round($n, $sigfigs); - if (strpos($n, '.') !== false) $n = rtrim($n, '0'); - $n = rtrim($n, '.'); - - return new HTMLPurifier_Length($n, $unit); - } - - /** - * Returns the number of significant figures in a string number. - * @param string $n Decimal number - * @return int number of sigfigs - */ - public function getSigFigs($n) { - $n = ltrim($n, '0+-'); - $dp = strpos($n, '.'); // decimal position - if ($dp === false) { - $sigfigs = strlen(rtrim($n, '0')); - } else { - $sigfigs = strlen(ltrim($n, '0.')); // eliminate extra decimal character - if ($dp !== 0) $sigfigs--; - } - return $sigfigs; - } - - /** - * Adds two numbers, using arbitrary precision when available. - */ - private function add($s1, $s2, $scale) { - if ($this->bcmath) return bcadd($s1, $s2, $scale); - else return $this->scale($s1 + $s2, $scale); - } - - /** - * Multiples two numbers, using arbitrary precision when available. - */ - private function mul($s1, $s2, $scale) { - if ($this->bcmath) return bcmul($s1, $s2, $scale); - else return $this->scale($s1 * $s2, $scale); - } - - /** - * Divides two numbers, using arbitrary precision when available. - */ - private function div($s1, $s2, $scale) { - if ($this->bcmath) return bcdiv($s1, $s2, $scale); - else return $this->scale($s1 / $s2, $scale); - } - - /** - * Rounds a number according to the number of sigfigs it should have, - * using arbitrary precision when available. - */ - private function round($n, $sigfigs) { - $new_log = (int) floor(log(abs($n), 10)); // Number of digits left of decimal - 1 - $rp = $sigfigs - $new_log - 1; // Number of decimal places needed - $neg = $n < 0 ? '-' : ''; // Negative sign - if ($this->bcmath) { - if ($rp >= 0) { - $n = bcadd($n, $neg . '0.' . str_repeat('0', $rp) . '5', $rp + 1); - $n = bcdiv($n, '1', $rp); - } else { - // This algorithm partially depends on the standardized - // form of numbers that comes out of bcmath. - $n = bcadd($n, $neg . '5' . str_repeat('0', $new_log - $sigfigs), 0); - $n = substr($n, 0, $sigfigs + strlen($neg)) . str_repeat('0', $new_log - $sigfigs + 1); - } - return $n; - } else { - return $this->scale(round($n, $sigfigs - $new_log - 1), $rp + 1); - } - } - - /** - * Scales a float to $scale digits right of decimal point, like BCMath. - */ - private function scale($r, $scale) { - if ($scale < 0) { - // The f sprintf type doesn't support negative numbers, so we - // need to cludge things manually. First get the string. - $r = sprintf('%.0f', (float) $r); - // Due to floating point precision loss, $r will more than likely - // look something like 4652999999999.9234. We grab one more digit - // than we need to precise from $r and then use that to round - // appropriately. - $precise = (string) round(substr($r, 0, strlen($r) + $scale), -1); - // Now we return it, truncating the zero that was rounded off. - return substr($precise, 0, -1) . str_repeat('0', -$scale + 1); - } - return sprintf('%.' . $scale . 'f', (float) $r); - } - -} - -// vim: et sw=4 sts=4 |