private/Get-ColorFromGradient.ps1
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#region Helper function NormalizeOver-Range { param ( [double]$Value, [double]$Lo, [double]$Hi ) return ($Value - $Lo) / ($Hi - $Lo) } #endregion function Get-ColorFromGradient { param ( [double]$Value, [double]$Lo, [double]$Mid = $null, [double]$Hi, [hashtable]$Gradient = @{Lo = @(0,98,255); Mid = @(145,255,0); Hi = @(255,40,0)} ) if (!$Mid) {$Mid = ($Hi + $Lo) / 2} #Normalize the value for the specific range #This will be the ratio of each Lo, Mid and Hi colors mixed into the result switch ($Value) { {$_ -le $Lo} {$colorratio = @{Lo = 1; Mid = 0; Hi = 0}; break} {$_ -le $Mid} {$normal = NormalizeOver-Range $Value $Lo $Mid; $colorratio = @{Lo = (1-$normal); Mid = $normal; Hi = 0}; break} {$_ -le $Hi} {$normal = NormalizeOver-Range $Value $Mid $Hi; $colorratio = @{Lo = 0; Mid = (1-$normal); Hi = $normal}; break} {$_ -gt $Hi} {$colorratio = @{Lo = 0; Mid = 0; Hi = 1}} } #Mix the colors from each limit in the appropriate ratios $color = @(0, 0, 0) foreach ($limit in $Gradient.Keys) { for ($i = 0; $i -lt $color.Count; $i++) { $color[$i] += $colorratio[$limit] * $Gradient[$limit][$i] } } #Round the mixed colors to make a valid R,G,B tuple return ($color | % {[math]::Round($_)}) } |