File: /home/mmickelson/theflexguys.com/baronconstruct/wp-content/themes/monotone/csscolor.php
<?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 = 128;
// 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 $minColorDiff = 100;
//==================================================
//==CONSTRUCTOR=====================================
//==================================================
function CSS_Color($bgHex, $fgHex='')
{
// This is the constructor method for the class,
// which is called when a new object is created.
// Initialize this PEAR object so I can
// use the PEAR error return mechanism
// 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($bgHex)) {
error_log("background color '$bgHex' is not a hex color value");
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));
}
}
?>