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<pre><a name="line-1"></a><span class='hs-comment'>{-
<a name="line-2"></a>Copyright (c) 2008,2009
<a name="line-3"></a>Russell O'Connor
<a name="line-4"></a>
<a name="line-5"></a>Permission is hereby granted, free of charge, to any person obtaining a copy
<a name="line-6"></a>of this software and associated documentation files (the "Software"), to deal
<a name="line-7"></a>in the Software without restriction, including without limitation the rights
<a name="line-8"></a>to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
<a name="line-9"></a>copies of the Software, and to permit persons to whom the Software is
<a name="line-10"></a>furnished to do so, subject to the following conditions:
<a name="line-11"></a>
<a name="line-12"></a>The above copyright notice and this permission notice shall be included in
<a name="line-13"></a>all copies or substantial portions of the Software.
<a name="line-14"></a>
<a name="line-15"></a>THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
<a name="line-16"></a>IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
<a name="line-17"></a>FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
<a name="line-18"></a>AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
<a name="line-19"></a>LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
<a name="line-20"></a>OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
<a name="line-21"></a>THE SOFTWARE.
<a name="line-22"></a>-}</span>
<a name="line-23"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Colour</span><span class='hs-varop'>.</span><span class='hs-conid'>RGB</span> <span class='hs-keyword'>where</span>
<a name="line-24"></a>
<a name="line-25"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span>
<a name="line-26"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Colour</span><span class='hs-varop'>.</span><span class='hs-conid'>Matrix</span>
<a name="line-27"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Colour</span><span class='hs-varop'>.</span><span class='hs-conid'>CIE</span><span class='hs-varop'>.</span><span class='hs-conid'>Chromaticity</span>
<a name="line-28"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span>
<a name="line-29"></a>
<a name="line-30"></a><a name="RGB"></a><span class='hs-comment'>-- |An RGB triple for an unspecified colour space.</span>
<a name="line-31"></a><a name="RGB"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGB</span> <span class='hs-layout'>{</span><span class='hs-varid'>channelRed</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-varid'>a</span>
<a name="line-32"></a> <span class='hs-layout'>,</span><span class='hs-varid'>channelGreen</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-varid'>a</span>
<a name="line-33"></a> <span class='hs-layout'>,</span><span class='hs-varid'>channelBlue</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-varid'>a</span>
<a name="line-34"></a> <span class='hs-layout'>}</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>,</span> <span class='hs-conid'>Read</span><span class='hs-layout'>)</span>
<a name="line-35"></a>
<a name="line-36"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Functor</span> <span class='hs-conid'>RGB</span> <span class='hs-keyword'>where</span>
<a name="line-37"></a> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGB</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-38"></a>
<a name="line-39"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Applicative</span> <span class='hs-conid'>RGB</span> <span class='hs-keyword'>where</span>
<a name="line-40"></a> <span class='hs-varid'>pure</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>c</span> <span class='hs-varid'>c</span> <span class='hs-varid'>c</span>
<a name="line-41"></a> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>fr</span> <span class='hs-varid'>fg</span> <span class='hs-varid'>fb</span><span class='hs-layout'>)</span> <span class='hs-varop'><*></span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGB</span> <span class='hs-layout'>(</span><span class='hs-varid'>fr</span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fg</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fb</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-42"></a>
<a name="line-43"></a><a name="uncurryRGB"></a><span class='hs-comment'>-- |Uncurries a function expecting three r, g, b parameters.</span>
<a name="line-44"></a><span class='hs-definition'>uncurryRGB</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-45"></a><span class='hs-definition'>uncurryRGB</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span>
<a name="line-46"></a>
<a name="line-47"></a><a name="curryRGB"></a><span class='hs-comment'>-- |Curries a function expecting one RGB parameter.</span>
<a name="line-48"></a><span class='hs-definition'>curryRGB</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>b</span>
<a name="line-49"></a><span class='hs-definition'>curryRGB</span> <span class='hs-varid'>f</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-50"></a>
<a name="line-51"></a><a name="RGBGamut"></a><span class='hs-comment'>-- |An 'RGBGamut' is a 3-D colour &#8220;cube&#8221; that contains all the</span>
<a name="line-52"></a><a name="RGBGamut"></a><span class='hs-comment'>-- colours that can be displayed by a RGB device.</span>
<a name="line-53"></a><a name="RGBGamut"></a><span class='hs-comment'>-- The &#8220;cube&#8221; is normalized so that white has</span>
<a name="line-54"></a><a name="RGBGamut"></a><span class='hs-comment'>-- 'Data.Colour.CIE.luminance' 1.</span>
<a name="line-55"></a><a name="RGBGamut"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGBGamut</span> <span class='hs-layout'>{</span><span class='hs-varid'>primaries</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chromaticity</span> <span class='hs-conid'>Rational</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-56"></a> <span class='hs-layout'>,</span><span class='hs-varid'>whitePoint</span> <span class='hs-keyglyph'>::</span> <span class='hs-varop'>!</span><span class='hs-layout'>(</span><span class='hs-conid'>Chromaticity</span> <span class='hs-conid'>Rational</span><span class='hs-layout'>)</span>
<a name="line-57"></a> <span class='hs-layout'>}</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>)</span>
<a name="line-58"></a>
<a name="line-59"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Show</span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyword'>where</span>
<a name="line-60"></a> <span class='hs-varid'>showsPrec</span> <span class='hs-varid'>d</span> <span class='hs-varid'>gamut</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>showParen</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span> <span class='hs-varop'>></span> <span class='hs-varid'>app_prec</span><span class='hs-layout'>)</span> <span class='hs-varid'>showStr</span>
<a name="line-61"></a> <span class='hs-keyword'>where</span>
<a name="line-62"></a> <span class='hs-varid'>showStr</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>showString</span> <span class='hs-str'>"mkRGBGamut"</span>
<a name="line-63"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>showString</span> <span class='hs-str'>" "</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varid'>showsPrec</span> <span class='hs-layout'>(</span><span class='hs-varid'>app_prec</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>primaries</span> <span class='hs-varid'>gamut</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-64"></a> <span class='hs-varop'>.</span> <span class='hs-varid'>showString</span> <span class='hs-str'>" "</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varid'>showsPrec</span> <span class='hs-layout'>(</span><span class='hs-varid'>app_prec</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>whitePoint</span> <span class='hs-varid'>gamut</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-65"></a>
<a name="line-66"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Read</span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyword'>where</span>
<a name="line-67"></a> <span class='hs-varid'>readsPrec</span> <span class='hs-varid'>d</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>readParen</span> <span class='hs-layout'>(</span><span class='hs-varid'>d</span> <span class='hs-varop'>></span> <span class='hs-varid'>app_prec</span><span class='hs-layout'>)</span>
<a name="line-68"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>r</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-varid'>mkRGBGamut</span> <span class='hs-varid'>p</span> <span class='hs-varid'>w</span><span class='hs-layout'>,</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span>
<a name="line-69"></a> <span class='hs-keyglyph'>|</span><span class='hs-layout'>(</span><span class='hs-str'>"mkRGBGamut"</span><span class='hs-layout'>,</span><span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>lex</span> <span class='hs-varid'>r</span>
<a name="line-70"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-varid'>p</span><span class='hs-layout'>,</span><span class='hs-varid'>s0</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readsPrec</span> <span class='hs-layout'>(</span><span class='hs-varid'>app_prec</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>s</span>
<a name="line-71"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-varid'>w</span><span class='hs-layout'>,</span><span class='hs-varid'>t</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readsPrec</span> <span class='hs-layout'>(</span><span class='hs-varid'>app_prec</span><span class='hs-varop'>+</span><span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>s0</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>)</span> <span class='hs-varid'>r</span>
<a name="line-72"></a>
<a name="line-73"></a><a name="mkRGBGamut"></a><span class='hs-comment'>-- |An RGB gamut is specified by three primary colours (red, green, and </span>
<a name="line-74"></a><span class='hs-comment'>-- blue) and a white point (often 'Data.Colour.CIE.Illuminant.d65').</span>
<a name="line-75"></a><span class='hs-definition'>mkRGBGamut</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>RGB</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chromaticity</span> <span class='hs-conid'>Rational</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- ^ The three primaries</span>
<a name="line-76"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Chromaticity</span> <span class='hs-conid'>Rational</span> <span class='hs-comment'>-- ^ The white point</span>
<a name="line-77"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>RGBGamut</span>
<a name="line-78"></a><span class='hs-definition'>mkRGBGamut</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGBGamut</span>
<a name="line-79"></a>
<a name="line-80"></a><span class='hs-comment'>{- not for export -}</span>
<a name="line-81"></a>
<a name="line-82"></a><a name="primaryMatrix"></a><span class='hs-definition'>primaryMatrix</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Fractional</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chromaticity</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>a</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-83"></a><span class='hs-definition'>primaryMatrix</span> <span class='hs-varid'>p</span> <span class='hs-keyglyph'>=</span>
<a name="line-84"></a> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>xr</span><span class='hs-layout'>,</span> <span class='hs-varid'>xg</span><span class='hs-layout'>,</span> <span class='hs-varid'>xb</span><span class='hs-keyglyph'>]</span>
<a name="line-85"></a> <span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>yr</span><span class='hs-layout'>,</span> <span class='hs-varid'>yg</span><span class='hs-layout'>,</span> <span class='hs-varid'>yb</span><span class='hs-keyglyph'>]</span>
<a name="line-86"></a> <span class='hs-layout'>,</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>zr</span><span class='hs-layout'>,</span> <span class='hs-varid'>zg</span><span class='hs-layout'>,</span> <span class='hs-varid'>zb</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-87"></a> <span class='hs-keyword'>where</span>
<a name="line-88"></a> <span class='hs-conid'>RGB</span> <span class='hs-layout'>(</span><span class='hs-varid'>xr</span><span class='hs-layout'>,</span> <span class='hs-varid'>yr</span><span class='hs-layout'>,</span> <span class='hs-varid'>zr</span><span class='hs-layout'>)</span>
<a name="line-89"></a> <span class='hs-layout'>(</span><span class='hs-varid'>xg</span><span class='hs-layout'>,</span> <span class='hs-varid'>yg</span><span class='hs-layout'>,</span> <span class='hs-varid'>zg</span><span class='hs-layout'>)</span>
<a name="line-90"></a> <span class='hs-layout'>(</span><span class='hs-varid'>xb</span><span class='hs-layout'>,</span> <span class='hs-varid'>yb</span><span class='hs-layout'>,</span> <span class='hs-varid'>zb</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>chromaCoords</span> <span class='hs-varid'>p</span>
<a name="line-91"></a>
<a name="line-92"></a><a name="rgb2xyz"></a><span class='hs-definition'>rgb2xyz</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-conid'>Rational</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-93"></a><span class='hs-definition'>rgb2xyz</span> <span class='hs-varid'>space</span> <span class='hs-keyglyph'>=</span>
<a name="line-94"></a> <span class='hs-varid'>transpose</span> <span class='hs-layout'>(</span><span class='hs-varid'>zipWith</span> <span class='hs-layout'>(</span><span class='hs-varid'>map</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varop'>*</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-keyword'>as</span> <span class='hs-layout'>(</span><span class='hs-varid'>transpose</span> <span class='hs-varid'>matrix</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-95"></a> <span class='hs-keyword'>where</span>
<a name="line-96"></a> <span class='hs-layout'>(</span><span class='hs-varid'>xn</span><span class='hs-layout'>,</span> <span class='hs-varid'>yn</span><span class='hs-layout'>,</span> <span class='hs-varid'>zn</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>chromaCoords</span> <span class='hs-layout'>(</span><span class='hs-varid'>whitePoint</span> <span class='hs-varid'>space</span><span class='hs-layout'>)</span>
<a name="line-97"></a> <span class='hs-varid'>matrix</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>primaryMatrix</span> <span class='hs-layout'>(</span><span class='hs-varid'>primaries</span> <span class='hs-varid'>space</span><span class='hs-layout'>)</span>
<a name="line-98"></a> <span class='hs-keyword'>as</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mult</span> <span class='hs-layout'>(</span><span class='hs-varid'>inverse</span> <span class='hs-varid'>matrix</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>xn</span><span class='hs-varop'>/</span><span class='hs-varid'>yn</span><span class='hs-layout'>,</span> <span class='hs-num'>1</span><span class='hs-layout'>,</span> <span class='hs-varid'>zn</span><span class='hs-varop'>/</span><span class='hs-varid'>yn</span><span class='hs-keyglyph'>]</span>
<a name="line-99"></a>
<a name="line-100"></a><a name="xyz2rgb"></a><span class='hs-definition'>xyz2rgb</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-conid'>Rational</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-101"></a><span class='hs-definition'>xyz2rgb</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>inverse</span> <span class='hs-varop'>.</span> <span class='hs-varid'>rgb2xyz</span>
<a name="line-102"></a>
<a name="line-103"></a><a name="hslsv"></a><span class='hs-definition'>hslsv</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Fractional</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>,</span><span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-104"></a><span class='hs-definition'>hslsv</span> <span class='hs-layout'>(</span><span class='hs-conid'>RGB</span> <span class='hs-varid'>r</span> <span class='hs-varid'>g</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>mx</span> <span class='hs-varop'>==</span> <span class='hs-varid'>mn</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span><span class='hs-num'>0</span><span class='hs-layout'>,</span><span class='hs-varid'>mx</span><span class='hs-layout'>,</span><span class='hs-num'>0</span> <span class='hs-layout'>,</span><span class='hs-varid'>mx</span><span class='hs-layout'>)</span>
<a name="line-105"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-layout'>,</span><span class='hs-varid'>s</span><span class='hs-layout'>,</span><span class='hs-varid'>l</span> <span class='hs-layout'>,</span><span class='hs-varid'>s0</span><span class='hs-layout'>,</span><span class='hs-varid'>mx</span><span class='hs-layout'>)</span>
<a name="line-106"></a> <span class='hs-keyword'>where</span>
<a name="line-107"></a> <span class='hs-varid'>mx</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>maximum</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span>
<a name="line-108"></a> <span class='hs-varid'>mn</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>minimum</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span>
<a name="line-109"></a> <span class='hs-varid'>l</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-varop'>+</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-num'>2</span>
<a name="line-110"></a> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>l</span> <span class='hs-varop'><=</span> <span class='hs-num'>0.5</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-comment'>-</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-varop'>+</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span>
<a name="line-111"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-comment'>-</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-layout'>(</span><span class='hs-num'>2</span><span class='hs-comment'>-</span><span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-varop'>+</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-112"></a> <span class='hs-varid'>s0</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-comment'>-</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-varid'>mx</span>
<a name="line-113"></a> <span class='hs-comment'>-- hue calcuation</span>
<a name="line-114"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>x</span><span class='hs-layout'>,</span><span class='hs-varid'>y</span><span class='hs-layout'>,</span><span class='hs-varid'>z</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>take</span> <span class='hs-num'>3</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dropWhile</span> <span class='hs-layout'>(</span><span class='hs-varop'>/=</span><span class='hs-varid'>mx</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-layout'>,</span><span class='hs-varid'>r</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-keyglyph'>]</span>
<a name="line-115"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>o</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>elemIndex</span> <span class='hs-varid'>mx</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r</span><span class='hs-layout'>,</span><span class='hs-varid'>g</span><span class='hs-layout'>,</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span>
<a name="line-116"></a> <span class='hs-varid'>h0</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>60</span><span class='hs-varop'>*</span><span class='hs-layout'>(</span><span class='hs-varid'>y</span><span class='hs-comment'>-</span><span class='hs-varid'>z</span><span class='hs-layout'>)</span><span class='hs-varop'>/</span><span class='hs-layout'>(</span><span class='hs-varid'>mx</span><span class='hs-comment'>-</span><span class='hs-varid'>mn</span><span class='hs-layout'>)</span> <span class='hs-varop'>+</span> <span class='hs-num'>120</span><span class='hs-varop'>*</span><span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>o</span><span class='hs-layout'>)</span>
<a name="line-117"></a> <span class='hs-varid'>h</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>h0</span> <span class='hs-varop'><</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>h0</span> <span class='hs-varop'>+</span> <span class='hs-num'>360</span>
<a name="line-118"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>h0</span>
<a name="line-119"></a>
<a name="line-120"></a><a name="hue"></a><span class='hs-comment'>-- |The 'hue' coordinate of an 'RGB' value is in degrees. Its value is</span>
<a name="line-121"></a><span class='hs-comment'>-- always in the range 0-360.</span>
<a name="line-122"></a><span class='hs-definition'>hue</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Fractional</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Ord</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-123"></a><span class='hs-definition'>hue</span> <span class='hs-varid'>rgb</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>h</span>
<a name="line-124"></a> <span class='hs-keyword'>where</span>
<a name="line-125"></a> <span class='hs-layout'>(</span><span class='hs-varid'>h</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>hslsv</span> <span class='hs-varid'>rgb</span>
<a name="line-126"></a>
<a name="line-127"></a><a name="mod1"></a><span class='hs-definition'>mod1</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>pf</span> <span class='hs-varop'><</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pf</span><span class='hs-varop'>+</span><span class='hs-num'>1</span>
<a name="line-128"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pf</span>
<a name="line-129"></a> <span class='hs-keyword'>where</span>
<a name="line-130"></a> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span><span class='hs-varid'>pf</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>properFraction</span> <span class='hs-varid'>x</span>
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