使用PHP生成高对比度随机颜色 [英] Generate high contrast random color using PHP

问题描述

我需要为系统中的所有用户生成随机颜色。诀窍是2个用户不能有非常相似的颜色，他们需要是可区分的。我有代码生成随机颜色给定原始的混合颜色，但没有找到一种方法来生成高对比度使用PHP的随机颜色

  public static function generateRandomColor（$ rgb）
 {
 $ red = rand（1，256）; 
 $ green = rand（1，256）; 
 $ blue = rand（1，256）; 
 
 if（！empty（$ rgb））
 {
 $ red =（$ red + $ rgb ['red']）/ 2; 
 $ green =（$ green + $ rgb ['green']）/ 2; 
 $ blue =（$ blue + $ rgb ['blue']）/ 2; 
} 
 
 $ color =rgb（{$ red}，{$ green}，{$ blue}）; 
 
 return $ color; 
} 
  

然后我有一个循环：

  $ colorsArr = array（）; 
 $ mixed = array（'red'=> 255，'green'=> 255，'blue'=> 255）; 
 for（$ i = 0; $ i  {
 $ color = generateRandomColor（$ mixed）; 
 
 $ colorsArr。='< div style =width：25px; height：25px; background-color：'。$ color。'>< / div>'; 
} 
  

现在这会生成颜色，但是一些颜色看起来像。目标是为每个用户都有一个独特的颜色。

注意：我不想为500位用户硬编码颜色

解决方案

我感到无聊，这里有一些代码你可以dink周围：

 <？php 
 define（COL_MIN_AVG，64）; 
 define（COL_MAX_AVG，192）; 
 define（COL_STEP，16）; 
 
 //（192  -  64）/ 16 = 8 
 // 8 ^ 3 = 512颜色
 
 function usercolor（$ username）{
 $ range = COL_MAX_AVG  -  COL_MIN_AVG; 
 $ factor = $ range / 256; 
 $ offset = COL_MIN_AVG; 
 
 $ base_hash = substr（md5（$ username），0，6）; 
 $ b_R = hexdec（substr（$ base_hash，0,2））; 
 $ b_G = hexdec（substr（$ base_hash，2,2））; 
 $ b_B = hexdec（substr（$ base_hash，4,2））; 
 
 $ f_R = floor（（floor（$ b_R * $ factor）+ $ offset）/ COL_STEP）* COL_STEP; 
 $ f_G = floor（（floor（$ b_G * $ factor）+ $ offset）/ COL_STEP）* COL_STEP; 
 $ f_B = floor（（floor（$ b_B * $ factor）+ $ offset）/ COL_STEP）* COL_STEP; 
 
 return sprintf（'＃％02x％02x％02x'，$ f_R，$ f_G，$ f_B）; 
} 
 
 for（$ i = 0; $ i <30; $ i ++）{
 printf（'< div style =height：100px; width：100px; background-color：％s>& nbsp;< / div>'。\\\
，usercolor（rand（）））; 
} 
  

许多颜色看起来很相似，彼此相邻是苗条的。

I need to generate random colors for all the users in the system. The trick is that 2 users cant have very similar colors, they need to be distinguishable. I have the code to generate random colors given the original mix color but cant find a way to generate random colors with high contrast using only PHP

public static function generateRandomColor($rgb)
{
    $red = rand(1, 256);
    $green = rand(1, 256);
    $blue = rand(1, 256);

    if (! empty($rgb))
    {
        $red = ($red + $rgb['red']) / 2;
        $green = ($green + $rgb['green']) / 2;
        $blue = ($blue + $rgb['blue']) / 2;
    }

    $color = "rgb({$red}, {$green}, {$blue})";

    return $color;
}

and then i have a loop:

$colorsArr = array();
$mixed = array('red' => 255, 'green' => 255, 'blue' => 255);
for($i = 0; $i < count($users); $i++)
{
    $color = generateRandomColor($mixed);

    $colorsArr .= '<div style="width:25px; height: 25px; background-color: ' . $color . '"></div>';
}

now this generates colors but some colors look like each other. The goal is to have an unique color for each user. any help appreciated thanks.

NOTE: i do not want to hardcode the colors for 500 users

解决方案

I got bored, here's some code you can dink around with:

<?php
define( COL_MIN_AVG, 64 );
define( COL_MAX_AVG, 192 );
define( COL_STEP, 16 );

// (192 - 64) / 16 = 8
// 8 ^ 3 = 512 colors

function usercolor( $username ) {
        $range = COL_MAX_AVG - COL_MIN_AVG;
        $factor = $range / 256;
        $offset = COL_MIN_AVG;

        $base_hash = substr(md5($username), 0, 6);
        $b_R = hexdec(substr($base_hash,0,2));
        $b_G = hexdec(substr($base_hash,2,2));
        $b_B = hexdec(substr($base_hash,4,2));

        $f_R = floor((floor($b_R * $factor) + $offset) / COL_STEP) * COL_STEP;
        $f_G = floor((floor($b_G * $factor) + $offset) / COL_STEP) * COL_STEP;
        $f_B = floor((floor($b_B * $factor) + $offset) / COL_STEP) * COL_STEP;

        return sprintf('#%02x%02x%02x', $f_R, $f_G, $f_B);
}

for( $i=0; $i<30; $i++ ) {
        printf('<div style="height: 100px; width: 100px; background-color: %s">&nbsp;</div>'."\n", usercolor(rand()));
}

Many colors will look pretty similar, but the chances that they'll be right next to each other are slim.

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