PHP Graident Script

[Kaboom]

These two PHP functions will allow you to create a gradient of text, without having to calculate all the colours yourself (similar to my user title)

PHP Code:

function gradientComposite( $text, $minr, $ming, $minb, $maxr, $maxg, $maxb) {
 // check given values are correct
 if( $minr < 0 || $minr > 255) trigger_error( "Given minimal Red value is out of range" E_USER_WARNING);
 if( $ming < 0 || $ming > 255) trigger_error( "Given minimal Green value is out of range" E_USER_WARNING);
 if( $minb < 0 || $minb > 255) trigger_error( "Given minimal Blue value is out of range" E_USER_WARNING);
 if( $maxr < 0 || $maxr > 255) trigger_error( "Given maximal Red value is out of range" E_USER_WARNING);
 if( $maxg < 0 || $maxg > 255) trigger_error( "Given maximal Green value is out of range" E_USER_WARNING);
 if( $maxb < 0 || $maxb > 255) trigger_error( "Given maximal Blue value is out of range" E_USER_WARNING);
 
 // get length of $text
 $length = strlen( $text);
 
 // calculate range of each component
 $difr = $maxr-$minr;
 $difg = $maxg-$ming;
 $difb = $maxb-$minb;
 
 // calculate step for each component
 $stepr = $difr/($length-1);
 $stepg = $difg/($length-1);
 $stepb = $difb/($length-1);
 
 // process each character
 $return = "";
 for( $i=0; $i<$length; $i++) {
  // calculate components for this character
  $thisr = sprintf( "%02s", dechex( floor( $minr+$stepr*$i)));
  $thisg = sprintf( "%02s", dechex( floor( $ming+$stepg*$i)));
  $thisb = sprintf( "%02s", dechex( floor( $minb+$stepb*$i)));
  $thiscol = $thisr.$thisg.$thisb;
 
  // append new SPAN to $return
  $return .= "<span style=\"color: #{$thiscol}\">".$text[$i]."</span>";
 }
 
 // return gradiented string
 return $return;
} 


This function takes seven arguments:
string $text: The string to be parsed
int $minr: The red component of the left side (0-255)
int $ming: The green component of the left side (0-255)
int $minb: The blue component of the left side (0-255)
int $maxr: The red component of the right side (0-255)
int $maxg: The green component of the right side (0-255)
int $maxb: The blue component of the right side (0-255)
A string is returned containing the HTML code required for the gradient. The code is HTML5, compatible HTML4.01 Strict and Transitional.

PHP Code:

function gradientHue( $text, $minh, $maxh) {
 // check given values are correct
 if( $minh < 0 || $minh > 360) trigger_error( "Given minimal Hue value is out of range", E_USER_WARNING);
 if( $maxh < 0 || $maxh > 360) trigger_error( "Given maximal Hue value is out of range", E_USER_WARNING);
 
 // get length of text
 $length = strlen( $text);
 
 // calculate hue range
 $dif = $maxh-$minh;
 
 // calculate step
 $step = $dif/($length-1);
 
 // process each character
 $return = "";
 for( $i=0; $i<$length; $i++) {
  // calculate hue for this character
  $thish = floor( $minh+$step*$i);
 
  // calculate rgb from hue
  if( $thish <= 60) {
   $thisr = 255;
   $thisg = 255*$thish/60;
   $thisb = 0;
  }
  if( $thish > 60 && $thish <= 120) {
   $thisr = 255*(120-$thish)/60;
   $thisg = 255;
   $thisb = 0;
  }
  if( $thish > 120 && $thish <= 180) {
   $thisr = 0;
   $thisg = 255;
   $thisb = 255*($thish-120)/60;
  }
  if( $thish > 180 && $thish <= 240) {
   $thisr = 0;
   $thisg = 255*(240-$thish)/60;
   $thisb = 255;
  }
  if( $thish > 240 && $thish <= 300) {
   $thisr = 255*($thish-240)/60;
   $thisg = 0;
   $thisb = 255;
  }
  if( $thish > 300) {
   $thisr = 255;
   $thisg = 0;
   $thisb = 255*(360-$thish)/60;
  }
 
  // to hex
  $thisr = sprintf( "%02s", dechex( $thisr));
  $thisg = sprintf( "%02s", dechex( $thisg));
  $thisb = sprintf( "%02s", dechex( $thisb));
  $thiscol = $thisr.$thisg.$thisb;
 
  // append new SPAN to $return
  $return .= "<span style=\"color: #{$thiscol}\">".$text[$i]."</span>";
 }
 return $return;
} 


This function takes five arguments:
string $text: The string to be parsed
int $minh: The hue of the left side (0-360)
int $maxh: The hue of the right side (0-360)
float $sat: The saturation of the text (0-1)
float $val: The value of the text (0-1)
A string is returned containing the HTML code required for the gradient. The code is HTML5, compatible HTML4.01 Strict and Transitional.


ERRATA:

• I accidentally typed $thish instead of $thisr in the second script.
• The gradient started in the wrong place.
• gradientHue() did not take the saturation and value into account. For now they are removed.

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Last Edited by FreezeWarp with Title Change on May 1st