--- /dev/null
+++ b/lib/csscolor.php
@@ -1,1 +1,423 @@
-
+<?php
+/*
+ csscolor.php
+ Copyright 2004 Patrick Fitzgerald
+ http://www.barelyfitz.com/projects/csscolor/
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+
+define('CSS_COLOR_ERROR', 100);
+
+class CSS_Color
+{
+ //==================================================
+ //==PARAMETERS======================================
+ //==================================================
+
+ // $this->bg = array of CSS color values
+ // $this->bg[0] is the bg color
+ // $this->bg['+1'..'+5'] are lighter colors
+ // $this->bg['-1'..'-5'] are darker colors
+ var $bg = array();
+
+ // $this->fg = array of foreground colors.
+ // Each color corresponds to a background color.
+ var $fg = array();
+
+ // brightDiff is the minimum brightness difference
+ // between the background and the foreground.
+ // Note: you should not change this directly,
+ // instead use setBrightDiff() and getBrightDiff()
+ var $minBrightDiff = 126;
+
+ // colorDiff is the minimum color difference
+ // between the background and the foreground.
+ // Note: you should not change this directly,
+ // instead use setColorDiff() and getColorDiff()
+ var $minColorDiff = 500;
+
+ //==================================================
+ //==CONSTRUCTOR=====================================
+ //==================================================
+
+ function CSS_Color($bgHex, $fgHex='')
+ {
+ // This is the constructor method for the class,
+ // which is called when a new object is created.
+
+
+ // Initialize the palette
+ $this->setPalette($bgHex, $fgHex);
+ }
+
+ //==================================================
+ //==METHODS=========================================
+ //==================================================
+
+ //--------------------------------------------------
+ function setPalette($bgHex, $fgHex = '')
+ {
+ // Initialize the color palettes
+
+ // If a foreground color was not specified,
+ // just use the background color.
+ if (!$fgHex) {
+ $fgHex = $bgHex;
+ }
+
+ // Clear the existing palette
+ $this->bg = array();
+ $this->fg = array();
+
+ // Make sure we got a valid hex value
+ if (!$this->isHex($bgHex)) {
+ $this->raiseError("background color '$bgHex' is not a hex color value",
+ __FUNCTION__, __LINE__);
+ return false;
+ }
+
+ // Set the bg color
+ $this->bg[0] = $bgHex;
+
+ $this->bg['+1'] = $this->lighten($bgHex, .85);
+ $this->bg['+2'] = $this->lighten($bgHex, .75);
+ $this->bg['+3'] = $this->lighten($bgHex, .5);
+ $this->bg['+4'] = $this->lighten($bgHex, .25);
+ $this->bg['+5'] = $this->lighten($bgHex, .1);
+
+ $this->bg['-1'] = $this->darken($bgHex, .85);
+ $this->bg['-2'] = $this->darken($bgHex, .75);
+ $this->bg['-3'] = $this->darken($bgHex, .5);
+ $this->bg['-4'] = $this->darken($bgHex, .25);
+ $this->bg['-5'] = $this->darken($bgHex, .1);
+
+ // Make sure we got a valid hex value
+ if (!$this->isHex($fgHex)) {
+ $this->raiseError("background color '$bgHex' is not a hex color value",
+ __FUNCTION__, __LINE__);
+ return false;
+ }
+
+ // Set up the foreground colors
+ $this->fg[0] = $this->calcFG( $this->bg[0], $fgHex);
+ $this->fg['+1'] = $this->calcFG( $this->bg['+1'], $fgHex);
+ $this->fg['+2'] = $this->calcFG( $this->bg['+2'], $fgHex);
+ $this->fg['+3'] = $this->calcFG( $this->bg['+3'], $fgHex);
+ $this->fg['+4'] = $this->calcFG( $this->bg['+4'], $fgHex);
+ $this->fg['+5'] = $this->calcFG( $this->bg['+5'], $fgHex);
+ $this->fg['-1'] = $this->calcFG( $this->bg['-1'], $fgHex);
+ $this->fg['-2'] = $this->calcFG( $this->bg['-2'], $fgHex);
+ $this->fg['-3'] = $this->calcFG( $this->bg['-3'], $fgHex);
+ $this->fg['-4'] = $this->calcFG( $this->bg['-4'], $fgHex);
+ $this->fg['-5'] = $this->calcFG( $this->bg['-5'], $fgHex);
+ }
+
+ //--------------------------------------------------
+ function lighten($hex, $percent)
+ {
+ return $this->mix($hex, $percent, 255);
+ }
+
+ //--------------------------------------------------
+ function darken($hex, $percent)
+ {
+ return $this->mix($hex, $percent, 0);
+ }
+
+ //--------------------------------------------------
+ function mix($hex, $percent, $mask)
+ {
+
+ // Make sure inputs are valid
+ if (!is_numeric($percent) || $percent < 0 || $percent > 1) {
+ $this->raiseError("percent=$percent is not valid",
+ __FUNCTION__, __LINE__);
+ return false;
+ }
+
+ if (!is_int($mask) || $mask < 0 || $mask > 255) {
+ $this->raiseError("mask=$mask is not valid",
+ __FUNCTION__, __LINE__);
+ return false;
+ }
+
+ $rgb = $this->hex2RGB($hex);
+ if (!is_array($rgb)) {
+ // hex2RGB will raise an error
+ return false;
+ }
+
+ for ($i=0; $i<3; $i++) {
+ $rgb[$i] = round($rgb[$i] * $percent) + round($mask * (1-$percent));
+
+ // In case rounding up causes us to go to 256
+ if ($rgb[$i] > 255) {
+ $rgb[$i] = 255;
+ }
+
+ }
+ return $this->RGB2Hex($rgb);
+ }
+
+ //--------------------------------------------------
+ function hex2RGB($hex)
+ {
+ //
+ // Given a hex color (rrggbb or rgb),
+ // returns an array (r, g, b) with decimal values
+ // If $hex is not the correct format,
+ // returns false.
+ //
+ // example:
+ // $d = hex2RGB('#abc');
+ // if (!$d) { error }
+
+ // Regexp for a valid hex digit
+ $d = '[a-fA-F0-9]';
+
+ // Make sure $hex is valid
+ if (preg_match("/^($d$d)($d$d)($d$d)\$/", $hex, $rgb)) {
+
+ return array(
+ hexdec($rgb[1]),
+ hexdec($rgb[2]),
+ hexdec($rgb[3])
+ );
+ }
+ if (preg_match("/^($d)($d)($d)$/", $hex, $rgb)) {
+
+ return array(
+ hexdec($rgb[1] . $rgb[1]),
+ hexdec($rgb[2] . $rgb[2]),
+ hexdec($rgb[3] . $rgb[3])
+ );
+ }
+
+ $this->raiseError("cannot convert hex '$hex' to RGB", __FUNCTION__, __LINE__);
+ return false;
+ }
+
+ //--------------------------------------------------
+ function RGB2Hex($rgb)
+ {
+ // Given an array(rval,gval,bval) consisting of
+ // decimal color values (0-255), returns a hex string
+ // suitable for use with CSS.
+ // Returns false if the input is not in the correct format.
+ // Example:
+ // $h = RGB2Hex(array(255,0,255));
+ // if (!$h) { error };
+
+ // Make sure the input is valid
+ if(!$this->isRGB($rgb)) {
+ $this->raiseError("RGB value is not valid", __FUNCTION__, __LINE__);
+ return false;
+ }
+
+ $hex = "";
+ for($i=0; $i < 3; $i++) {
+
+ // Convert the decimal digit to hex
+ $hexDigit = dechex($rgb[$i]);
+
+ // Add a leading zero if necessary
+ if(strlen($hexDigit) == 1) {
+ $hexDigit = "0" . $hexDigit;
+ }
+
+ // Append to the hex string
+ $hex .= $hexDigit;
+ }
+
+ // Return the complete hex string
+ return $hex;
+ }
+
+ //--------------------------------------------------
+ function isHex($hex)
+ {
+ // Returns true if $hex is a valid CSS hex color.
+ // The "#" character at the start is optional.
+
+ // Regexp for a valid hex digit
+ $d = '[a-fA-F0-9]';
+
+ // Make sure $hex is valid
+ if (preg_match("/^#?$d$d$d$d$d$d\$/", $hex) ||
+ preg_match("/^#?$d$d$d\$/", $hex)) {
+ return true;
+ }
+ return false;
+ }
+
+ //--------------------------------------------------
+ function isRGB($rgb)
+ {
+ // Returns true if $rgb is an array with three valid
+ // decimal color digits.
+
+ if (!is_array($rgb) || count($rgb) != 3) {
+ return false;
+ }
+
+ for($i=0; $i < 3; $i++) {
+
+ // Get the decimal digit
+ $dec = intval($rgb[$i]);
+
+ // Make sure the decimal digit is between 0 and 255
+ if (!is_int($dec) || $dec < 0 || $dec > 255) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ //--------------------------------------------------
+ function calcFG($bgHex, $fgHex)
+ {
+ // Given a background color $bgHex and a foreground color $fgHex,
+ // modifies the foreground color so it will have enough contrast
+ // to be seen against the background color.
+ //
+ // The following parameters are used:
+ // $this->minBrightDiff
+ // $this->minColorDiff
+
+ // Loop through brighter and darker versions
+ // of the foreground color.
+ // The numbers here represent the amount of
+ // foreground color to mix with black and white.
+ foreach (array(1, 0.75, 0.5, 0.25, 0) as $percent) {
+
+ $darker = $this->darken($fgHex, $percent);
+ $lighter = $this->lighten($fgHex, $percent);
+
+ $darkerBrightDiff = $this->brightnessDiff($bgHex, $darker);
+ $lighterBrightDiff = $this->brightnessDiff($bgHex, $lighter);
+
+ if ($lighterBrightDiff > $darkerBrightDiff) {
+ $newFG = $lighter;
+ $newFGBrightDiff = $lighterBrightDiff;
+ } else {
+ $newFG = $darker;
+ $newFGBrightDiff = $darkerBrightDiff;
+ }
+ $newFGColorDiff = $this->colorDiff($bgHex, $newFG);
+
+ if ($newFGBrightDiff >= $this->minBrightDiff &&
+ $newFGColorDiff >= $this->minColorDiff) {
+ break;
+ }
+ }
+
+ return $newFG;
+ }
+
+ //--------------------------------------------------
+ function getMinBrightDiff()
+ {
+ return $this->minBrightDiff;
+ }
+ function setMinBrightDiff($b, $resetPalette = true)
+ {
+ $this->minBrightDiff = $b;
+ if ($resetPalette) {
+ $this->setPalette($this->bg[0],$this->fg[0]);
+ }
+ }
+
+ //--------------------------------------------------
+ function getMinColorDiff()
+ {
+ return $this->minColorDiff;
+ }
+ function setMinColorDiff($d, $resetPalette = true)
+ {
+ $this->minColorDiff = $d;
+ if ($resetPalette) {
+ $this->setPalette($this->bg[0],$this->fg[0]);
+ }
+ }
+
+ //--------------------------------------------------
+ function brightness($hex)
+ {
+ // Returns the brightness value for a color,
+ // a number between zero and 178.
+ // To allow for maximum readability, the difference between
+ // the background brightness and the foreground brightness
+ // should be greater than 125.
+
+ $rgb = $this->hex2RGB($hex);
+ if (!is_array($rgb)) {
+ // hex2RGB will raise an error
+ return false;
+ }
+
+ return( (($rgb[0] * 299) + ($rgb[1] * 587) + ($rgb[2] * 114)) / 1000 );
+ }
+
+ //--------------------------------------------------
+ function brightnessDiff($hex1, $hex2)
+ {
+ // Returns the brightness value for a color,
+ // a number between zero and 178.
+ // To allow for maximum readability, the difference between
+ // the background brightness and the foreground brightness
+ // should be greater than 125.
+
+ $b1 = $this->brightness($hex1);
+ $b2 = $this->brightness($hex2);
+ if (is_bool($b1) || is_bool($b2)) {
+ return false;
+ }
+ return abs($b1 - $b2);
+ }
+
+ //--------------------------------------------------
+ function colorDiff($hex1, $hex2)
+ {
+ // Returns the contrast between two colors,
+ // an integer between 0 and 675.
+ // To allow for maximum readability, the difference between
+ // the background and the foreground color should be > 500.
+
+ $rgb1 = $this->hex2RGB($hex1);
+ $rgb2 = $this->hex2RGB($hex2);
+
+ if (!is_array($rgb1) || !is_array($rgb2)) {
+ // hex2RGB will raise an error
+ return -1;
+ }
+
+ $r1 = $rgb1[0];
+ $g1 = $rgb1[1];
+ $b1 = $rgb1[2];
+
+ $r2 = $rgb2[0];
+ $g2 = $rgb2[1];
+ $b2 = $rgb2[2];
+
+ return(abs($r1-$r2) + abs($g1-$g2) + abs($b1-$b2));
+ }
+
+}
+
+?>
+