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POA boolean function for finding if a HSL based color is near to another color
 

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    <p>I wanted to write a function which could check if color is close to a background color.</p> <p>For this i make use of the HSL color scheme, let me explain that a bit; HSL colors are defined as Hue Saturation and lightness. In short Hue tells you which color of the rainbow is used and its in the range 0 to 360. And its on the Hue that i would like check.</p> <p>So Saturation how strong the color is, like pure or mixed with grey or Lightness which speaks for itself are not compared. I only want to check for Hue. At first i wrote a Near function like this:</p> <pre><code>Private boolean Near(int background, int mycolor, int difference) { if(math.abs( background - mycolor)&lt;difference){return true;}else{return false} } </code></pre> <p>Later i realized this is wrong. Because HSL is like the image below you see in there the colors are as a circle, so starting at red 0 and it is red again at 360. So a Hue value of 358 and 4 are close together, the above function wouldn't reflect that.</p> <p>(Saturation goes to the center 0..100 lightens 0..100 is like going up or down and Hue is from 0 to 360 degrees around. )</p> <p><img src="https://i.stack.imgur.com/UA7Jx.png" alt="enter image description here"></p> <p>I could rewrite a function with a large if then construction, so that for example if the background where red 5 and the allowed difference is 20 then <code>mycolor</code> would be in range if it is &lt; 5+20 or > (360-(5-20)) .. so making a special construction if the Hue difference would be crossing the 0 or 360 limits.</p> <p>Well that would work, but then i wondered might it be possible to replace such "if then" construction with a modulo calculation in a single line ?, it keeps me wondering still As modulo computations can be used to check within a border and if its over the border of 360 it would be red again close to zero, </p> <p>well i think so, such line might also contain some AND or OR and subtractions or ABS functions..might it be possible to write it in one comparison line ?</p>
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