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<?php
/**
* Copyright 2002-2017 Horde LLC (http://www.horde.org/)
*
* See the enclosed file LICENSE for license information (LGPL). If you
* did not receive this file, see http://www.horde.org/licenses/lgpl21.
*
* @author Chuck Hagenbuch <chuck@horde.org>
* @author Michael J. Rubinsky <mrubinsk@horde.org>
* @author Jan Schneider <jan@horde.org>
* @category Horde
* @license http://www.horde.org/licenses/lgpl21 LGPL-2.1
* @package Image
*/
/**
* This class provides some utility functions, such as generating highlights
* of a color.
*
* @author Chuck Hagenbuch <chuck@horde.org>
* @author Michael J. Rubinsky <mrubinsk@horde.org>
* @author Jan Schneider <jan@horde.org>
* @category Horde
* @copyright 2002-2017 Horde LLC
* @license http://www.horde.org/licenses/lgpl21 LGPL-2.1
* @package Image
*/
class Horde_Image
{
/**
* Calculates a lighter (or darker) version of a color.
*
* @param string $color An HTML color, e.g.: #ffffcc.
* @param integer $factor The brightness difference between -0xff and
* +0xff. Plus values raise the brightness,
* negative values reduce it.
*
* @return string A modified HTML color.
*/
public static function modifyColor($color, $factor = 0x11)
{
list($r, $g, $b) = self::getColor($color);
$r = min(max($r + $factor, 0), 255);
$g = min(max($g + $factor, 0), 255);
$b = min(max($b + $factor, 0), 255);
return '#' . str_pad(dechex($r), 2, '0', STR_PAD_LEFT)
. str_pad(dechex($g), 2, '0', STR_PAD_LEFT)
. str_pad(dechex($b), 2, '0', STR_PAD_LEFT);
}
/**
* Calculates a more intense version of a color.
*
* @param string $color An HTML color, e.g.: #ffffcc.
* @param integer $factor The intensity difference between -0xff and
* +0xff. Plus values raise the intensity,
* negative values reduce it.
*
* @return string A more intense HTML color.
*/
public static function moreIntenseColor($color, $factor = 0x11)
{
list($r, $g, $b) = self::getColor($color);
if ($r >= $g && $r >= $b) {
$g = $g / $r;
$b = $b / $r;
$r += $factor;
$g = floor($g * $r);
$b = floor($b * $r);
} elseif ($g >= $r && $g >= $b) {
$r = $r / $g;
$b = $b / $g;
$g += $factor;
$r = floor($r * $g);
$b = floor($b * $g);
} else {
$r = $r / $b;
$g = $g / $b;
$b += $factor;
$r = floor($r * $b);
$g = floor($g * $b);
}
$r = min(max($r, 0), 255);
$g = min(max($g, 0), 255);
$b = min(max($b, 0), 255);
return '#' . str_pad(dechex($r), 2, '0', STR_PAD_LEFT)
. str_pad(dechex($g), 2, '0', STR_PAD_LEFT)
. str_pad(dechex($b), 2, '0', STR_PAD_LEFT);
}
/**
* Returns the brightness of a color.
*
* @param string $color An HTML color, e.g.: #ffffcc.
*
* @return integer The brightness on a scale of 0 to 255.
*/
public static function brightness($color)
{
list($r, $g, $b) = self::getColor($color);
return round((($r * 299) + ($g * 587) + ($b * 114)) / 1000);
}
/**
* Calculates the grayscale value of a color.
*
* @param integer $r A red value.
* @param integer $g A green value.
* @param integer $b A blue value.
*
* @return integer The grayscale value of the color.
*/
public static function grayscaleValue($r, $g, $b)
{
return round(($r * 0.30) + ($g * 0.59) + ($b * 0.11));
}
/**
* Turns an RGB value into grayscale.
*
* @param integer[] $originalPixel A hash with 'red', 'green', and 'blue'
* values.
*
* @return integer[] A hash with 'red', 'green', and 'blue' values for the
* corresponding gray color.
*/
public static function grayscalePixel($originalPixel)
{
$gray = Horde_Image::grayscaleValue(
$originalPixel['red'],
$originalPixel['green'],
$originalPixel['blue']
);
return array('red' => $gray, 'green' => $gray, 'blue' => $gray);
}
/**
* Normalizes an HTML color.
*
* @param string $color An HTML color, e.g.: #ffffcc or #ffc.
*
* @return integer[] Array with three elements: red, green, and blue.
*/
public static function getColor($color)
{
if ($color[0] == '#') {
$color = substr($color, 1);
}
if (strlen($color) == 3) {
$color = str_repeat($color[0], 2) .
str_repeat($color[1], 2) .
str_repeat($color[2], 2);
}
return array(
hexdec(substr($color, 0, 2)),
hexdec(substr($color, 2, 2)),
hexdec(substr($color, 4, 2))
);
}
/**
* Returns the RGB values for an HTML color name.
*
* @param string $colorname A color name.
*
* @return array An array of RGB values.
*/
public static function getRGB($colorname)
{
return isset(Horde_Image_Rgb::$colors[$colorname]) ?
Horde_Image_Rgb::$colors[$colorname] :
array(0, 0, 0);
}
/**
* Returns the hexadecimal representation of an HTML color name.
*
* @param string $colorname A color name.
*
* @return string The hex representation of the color.
*/
public static function getHexColor($colorname)
{
list($r, $g, $b) = self::getRGB($colorname);
return '#' . str_pad(dechex(min($r, 255)), 2, '0', STR_PAD_LEFT)
. str_pad(dechex(min($g, 255)), 2, '0', STR_PAD_LEFT)
. str_pad(dechex(min($b, 255)), 2, '0', STR_PAD_LEFT);
}
/**
* Returns an x,y pair on circle, assuming center is 0,0.
*
* @param float $degrees The degrees of arc to get the point for.
* @param integer $diameter The diameter of the circle.
*
* @return array (x coordinate, y coordinate) of the point.
*/
public static function circlePoint($degrees, $diameter)
{
// Avoid problems with floats.
$degrees += 0.0001;
return array(cos(deg2rad($degrees)) * ($diameter / 2),
sin(deg2rad($degrees)) * ($diameter / 2));
}
/**
* Returns point coordinates at the limits of an arc.
*
* @param integer $r The radius of the arc.
* @param integer $start The starting angle.
* @param integer $end The ending angle.
*
* @return array The start point (x1,y1), end point (x2,y2), and anchor
* point (x3,y3).
*/
public static function arcPoints($r, $start, $end)
{
// Start point.
$pts['x1'] = $r * cos(deg2rad($start));
$pts['y1'] = $r * sin(deg2rad($start));
// End point.
$pts['x2'] = $r * cos(deg2rad($end));
$pts['y2'] = $r * sin(deg2rad($end));
// Anchor point.
$pts['x3'] = $pts['y3'] = 0;
// Shift to positive.
if ($pts['x1'] < 0) {
$pts['x2'] += abs($pts['x1']);
$pts['x3'] += abs($pts['x1']);
$pts['x1'] = 0;
}
if ($pts['x2'] < 0) {
$pts['x1'] += abs($pts['x2']);
$pts['x3'] += abs($pts['x2']);
$pts['x2'] = 0;
}
if ($pts['x3'] < 0) {
$pts['x1'] += abs($pts['x3']);
$pts['x2'] += abs($pts['x3']);
$pts['x3'] = 0;
}
if ($pts['y1'] < 0) {
$pts['y2'] += abs($pts['y1']);
$pts['y3'] += abs($pts['y1']);
$pts['y1'] = 0;
}
if ($pts['y2'] < 0) {
$pts['y1'] += abs($pts['y2']);
$pts['y3'] += abs($pts['y2']);
$pts['y2'] = 0;
}
if ($pts['y3'] < 0) {
$pts['y1'] += abs($pts['y3']);
$pts['y2'] += abs($pts['y3']);
$pts['y3'] = 0;
}
return $pts;
}
/**
* Returns the point size for an HTML font size name.
*/
public static function getFontSize($fontsize)
{
switch ($fontsize) {
case 'medium':
return 18;
case 'large':
return 24;
case 'giant':
return 30;
default:
return 12;
}
}
}
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