From: Maxious Date: Wed, 29 Feb 2012 13:35:57 +0000 Subject: add php color library csscolor.php X-Git-Url: http://maxious.lambdacomplex.org/git/?p=contractdashboard.git&a=commitdiff&h=9f031a55b5e369448ac7a6ee4be29052817e4965 --- add php color library csscolor.php --- --- /dev/null +++ b/lib/csscolor.php @@ -1,1 +1,423 @@ - +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)); + } + +} + +?> + --- /dev/null +++ b/lib/csscolor.test.php @@ -1,1 +1,37 @@ + + + +.box { + + /* Use the base color, two shades darker */ + background:#bg['-2'] ?>; + + /* Use the corresponding foreground color */ + color:#fg['-2'] ?>; + + /* Use the highlight color as a border */ + border:5px solid #bg['0'] ?> + +} +