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<pre><a name="line-1"></a><span class='hs-comment'>{-
<a name="line-2"></a>Copyright (c) 2008
<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-comment'>-- |An 'RGBSpace' is characterized by 'Chromaticity' for red, green, and</span>
<a name="line-24"></a><span class='hs-comment'>-- blue, the 'Chromaticity' of the white point, and it's</span>
<a name="line-25"></a><span class='hs-comment'>-- 'TransferFunction'.</span>
<a name="line-26"></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'>RGBSpace</span>
<a name="line-27"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Colour</span>
<a name="line-28"></a> <span class='hs-comment'>-- *RGB Tuple</span>
<a name="line-29"></a> <span class='hs-layout'>,</span><span class='hs-conid'>RGB</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-30"></a> <span class='hs-layout'>,</span><span class='hs-varid'>uncurryRGB</span><span class='hs-layout'>,</span> <span class='hs-varid'>curryRGB</span>
<a name="line-31"></a>
<a name="line-32"></a> <span class='hs-comment'>-- *RGB Gamut</span>
<a name="line-33"></a> <span class='hs-layout'>,</span><span class='hs-conid'>RGBGamut</span>
<a name="line-34"></a> <span class='hs-layout'>,</span><span class='hs-varid'>mkRGBGamut</span><span class='hs-layout'>,</span> <span class='hs-varid'>primaries</span><span class='hs-layout'>,</span> <span class='hs-varid'>whitePoint</span>
<a name="line-35"></a> <span class='hs-layout'>,</span><span class='hs-varid'>inGamut</span>
<a name="line-36"></a> <span class='hs-comment'>-- *RGB Space</span>
<a name="line-37"></a> <span class='hs-layout'>,</span><span class='hs-conid'>TransferFunction</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-38"></a> <span class='hs-layout'>,</span><span class='hs-varid'>linearTransferFunction</span><span class='hs-layout'>,</span> <span class='hs-varid'>powerTransferFunction</span>
<a name="line-39"></a> <span class='hs-layout'>,</span><span class='hs-varid'>inverseTransferFunction</span>
<a name="line-40"></a>
<a name="line-41"></a> <span class='hs-layout'>,</span><span class='hs-conid'>RGBSpace</span><span class='hs-conid'>()</span>
<a name="line-42"></a> <span class='hs-layout'>,</span><span class='hs-varid'>mkRGBSpace</span> <span class='hs-layout'>,</span><span class='hs-varid'>gamut</span><span class='hs-layout'>,</span> <span class='hs-varid'>transferFunction</span>
<a name="line-43"></a> <span class='hs-layout'>,</span><span class='hs-varid'>linearRGBSpace</span>
<a name="line-44"></a> <span class='hs-layout'>,</span><span class='hs-varid'>rgbUsingSpace</span>
<a name="line-45"></a> <span class='hs-layout'>,</span><span class='hs-varid'>toRGBUsingSpace</span>
<a name="line-46"></a> <span class='hs-layout'>)</span>
<a name="line-47"></a><span class='hs-keyword'>where</span>
<a name="line-48"></a>
<a name="line-49"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Monoid</span>
<a name="line-50"></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-51"></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-52"></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'>RGB</span>
<a name="line-53"></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'>SRGB</span><span class='hs-varop'>.</span><span class='hs-conid'>Linear</span>
<a name="line-54"></a>
<a name="line-55"></a><a name="inGamut"></a><span class='hs-comment'>-- |Returns 'True' if the given colour lies inside the given gamut.</span>
<a name="line-56"></a><span class='hs-definition'>inGamut</span> <span class='hs-keyglyph'>::</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-conid'>Fractional</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Colour</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-57"></a><span class='hs-definition'>inGamut</span> <span class='hs-varid'>gamut</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>r</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>g</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>b</span>
<a name="line-58"></a> <span class='hs-keyword'>where</span>
<a name="line-59"></a> <span class='hs-varid'>test</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span> <span class='hs-varop'><=</span> <span class='hs-varid'>x</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>x</span> <span class='hs-varop'><=</span> <span class='hs-num'>1</span>
<a name="line-60"></a> <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-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>test</span> <span class='hs-layout'>(</span><span class='hs-varid'>toRGBUsingGamut</span> <span class='hs-varid'>gamut</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span>
<a name="line-61"></a>
<a name="line-62"></a><a name="rtf"></a><span class='hs-definition'>rtf</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Fractional</span> <span class='hs-varid'>b</span><span class='hs-layout'>,</span> <span class='hs-conid'>Real</span> <span class='hs-varid'>a</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> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-keyglyph'>[</span><span class='hs-varid'>b</span><span class='hs-keyglyph'>]</span><span class='hs-keyglyph'>]</span>
<a name="line-63"></a><span class='hs-definition'>rtf</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>map</span> <span class='hs-layout'>(</span><span class='hs-varid'>map</span> <span class='hs-varid'>realToFrac</span><span class='hs-layout'>)</span>
<a name="line-64"></a>
<a name="line-65"></a><a name="rgbUsingGamut"></a><span class='hs-definition'>rgbUsingGamut</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-conid'>RGBGamut</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-conid'>Colour</span> <span class='hs-varid'>a</span>
<a name="line-66"></a><span class='hs-definition'>rgbUsingGamut</span> <span class='hs-varid'>gamut</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'>rgb</span> <span class='hs-varid'>r0</span> <span class='hs-varid'>g0</span> <span class='hs-varid'>b0</span>
<a name="line-67"></a> <span class='hs-keyword'>where</span>
<a name="line-68"></a> <span class='hs-varid'>matrix</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>rtf</span> <span class='hs-varop'>$</span> <span class='hs-varid'>matrixMult</span> <span class='hs-layout'>(</span><span class='hs-varid'>xyz2rgb</span> <span class='hs-varid'>sRGBGamut</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>rgb2xyz</span> <span class='hs-varid'>gamut</span><span class='hs-layout'>)</span>
<a name="line-69"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r0</span><span class='hs-layout'>,</span><span class='hs-varid'>g0</span><span class='hs-layout'>,</span><span class='hs-varid'>b0</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mult</span> <span class='hs-varid'>matrix</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-70"></a>
<a name="line-71"></a><a name="toRGBUsingGamut"></a><span class='hs-definition'>toRGBUsingGamut</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-conid'>RGBGamut</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Colour</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span>
<a name="line-72"></a><span class='hs-definition'>toRGBUsingGamut</span> <span class='hs-varid'>gamut</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</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>
<a name="line-73"></a> <span class='hs-keyword'>where</span>
<a name="line-74"></a> <span class='hs-conid'>RGB</span> <span class='hs-varid'>r0</span> <span class='hs-varid'>g0</span> <span class='hs-varid'>b0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>toRGB</span> <span class='hs-varid'>c</span>
<a name="line-75"></a> <span class='hs-varid'>matrix</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>rtf</span> <span class='hs-varop'>$</span> <span class='hs-varid'>matrixMult</span> <span class='hs-layout'>(</span><span class='hs-varid'>xyz2rgb</span> <span class='hs-varid'>gamut</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>rgb2xyz</span> <span class='hs-varid'>sRGBGamut</span><span class='hs-layout'>)</span>
<a name="line-76"></a> <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> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mult</span> <span class='hs-varid'>matrix</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>r0</span><span class='hs-layout'>,</span><span class='hs-varid'>g0</span><span class='hs-layout'>,</span><span class='hs-varid'>b0</span><span class='hs-keyglyph'>]</span>
<a name="line-77"></a>
<a name="line-78"></a><a name="TransferFunction"></a><span class='hs-comment'>-- |A 'transfer' function is a function that typically translates linear</span>
<a name="line-79"></a><a name="TransferFunction"></a><span class='hs-comment'>-- colour space coordinates into non-linear coordinates.</span>
<a name="line-80"></a><a name="TransferFunction"></a><span class='hs-comment'>-- The 'transferInverse' function reverses this by translating non-linear</span>
<a name="line-81"></a><a name="TransferFunction"></a><span class='hs-comment'>-- colour space coordinates into linear coordinates.</span>
<a name="line-82"></a><a name="TransferFunction"></a><span class='hs-comment'>-- It is required that</span>
<a name="line-83"></a><a name="TransferFunction"></a><span class='hs-comment'>--</span>
<a name="line-84"></a><a name="TransferFunction"></a><span class='hs-comment'>-- > transfer . transferInverse === id === transferInverse . inverse</span>
<a name="line-85"></a><a name="TransferFunction"></a><span class='hs-comment'>--</span>
<a name="line-86"></a><a name="TransferFunction"></a><span class='hs-comment'>-- (or that this law holds up to floating point rounding errors).</span>
<a name="line-87"></a><a name="TransferFunction"></a><span class='hs-comment'>--</span>
<a name="line-88"></a><a name="TransferFunction"></a><span class='hs-comment'>-- We also require that 'transfer' is approximately @(**transferGamma)@</span>
<a name="line-89"></a><a name="TransferFunction"></a><span class='hs-comment'>-- (and hence 'transferInverse' is approximately</span>
<a name="line-90"></a><a name="TransferFunction"></a><span class='hs-comment'>-- @(**(recip transferGamma))@).</span>
<a name="line-91"></a><a name="TransferFunction"></a><span class='hs-comment'>-- The value 'transferGamma' is for informational purposes only, so there</span>
<a name="line-92"></a><a name="TransferFunction"></a><span class='hs-comment'>-- is no bound on how good this approximation needs to be.</span>
<a name="line-93"></a><a name="TransferFunction"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>TransferFunction</span>
<a name="line-94"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>transfer</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-95"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>transferInverse</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-96"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>transferGamma</span> <span class='hs-keyglyph'>::</span> <span class='hs-varid'>a</span> <span class='hs-layout'>}</span>
<a name="line-97"></a>
<a name="line-98"></a><a name="linearTransferFunction"></a><span class='hs-comment'>-- |This is the identity 'TransferFunction'.</span>
<a name="line-99"></a><span class='hs-definition'>linearTransferFunction</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>a</span>
<a name="line-100"></a><span class='hs-definition'>linearTransferFunction</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>id</span> <span class='hs-varid'>id</span> <span class='hs-num'>1</span>
<a name="line-101"></a>
<a name="line-102"></a><a name="powerTransferFunction"></a><span class='hs-comment'>-- |This is the @(**gamma)@ 'TransferFunction'.</span>
<a name="line-103"></a><span class='hs-definition'>powerTransferFunction</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Floating</span> <span class='hs-varid'>a</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-conid'>TransferFunction</span> <span class='hs-varid'>a</span>
<a name="line-104"></a><span class='hs-definition'>powerTransferFunction</span> <span class='hs-varid'>gamma</span> <span class='hs-keyglyph'>=</span>
<a name="line-105"></a> <span class='hs-conid'>TransferFunction</span> <span class='hs-layout'>(</span><span class='hs-varop'>**</span><span class='hs-varid'>gamma</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varop'>**</span><span class='hs-layout'>(</span><span class='hs-varid'>recip</span> <span class='hs-varid'>gamma</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varid'>gamma</span>
<a name="line-106"></a>
<a name="line-107"></a><a name="inverseTransferFunction"></a><span class='hs-comment'>-- |This reverses a 'TransferFunction'.</span>
<a name="line-108"></a><span class='hs-definition'>inverseTransferFunction</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-conid'>TransferFunction</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>a</span>
<a name="line-109"></a><span class='hs-definition'>inverseTransferFunction</span> <span class='hs-layout'>(</span><span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>for</span> <span class='hs-varid'>rev</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-110"></a> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>rev</span> <span class='hs-varid'>for</span> <span class='hs-layout'>(</span><span class='hs-varid'>recip</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span>
<a name="line-111"></a>
<a name="line-112"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Monoid</span> <span class='hs-layout'>(</span><span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-113"></a> <span class='hs-varid'>mempty</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>linearTransferFunction</span>
<a name="line-114"></a> <span class='hs-layout'>(</span><span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>f0</span> <span class='hs-varid'>f1</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varop'>`mappend`</span> <span class='hs-layout'>(</span><span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>g0</span> <span class='hs-varid'>g1</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-115"></a> <span class='hs-layout'>(</span><span class='hs-conid'>TransferFunction</span> <span class='hs-layout'>(</span><span class='hs-varid'>f0</span> <span class='hs-varop'>.</span> <span class='hs-varid'>g0</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>g1</span> <span class='hs-varop'>.</span> <span class='hs-varid'>f1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span><span class='hs-varop'>*</span><span class='hs-varid'>g</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-116"></a>
<a name="line-117"></a><a name="RGBSpace"></a><span class='hs-comment'>-- |An 'RGBSpace' is a colour coordinate system for colours laying</span>
<a name="line-118"></a><a name="RGBSpace"></a><span class='hs-comment'>-- 'inGamut' of 'gamut'.</span>
<a name="line-119"></a><a name="RGBSpace"></a><span class='hs-comment'>-- Linear coordinates are passed through a 'transferFunction' to</span>
<a name="line-120"></a><a name="RGBSpace"></a><span class='hs-comment'>-- produce non-linear 'RGB' values.</span>
<a name="line-121"></a><a name="RGBSpace"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>RGBSpace</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGBSpace</span> <span class='hs-layout'>{</span> <span class='hs-varid'>gamut</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>RGBGamut</span><span class='hs-layout'>,</span>
<a name="line-122"></a> <span class='hs-varid'>transferFunction</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>a</span> <span class='hs-layout'>}</span>
<a name="line-123"></a>
<a name="line-124"></a><a name="mkRGBSpace"></a><span class='hs-comment'>-- |An RGBSpace is specified by an 'RGBGamut' and a 'TransferFunction'.</span>
<a name="line-125"></a><span class='hs-definition'>mkRGBSpace</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>RGBGamut</span>
<a name="line-126"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>TransferFunction</span> <span class='hs-varid'>a</span>
<a name="line-127"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>RGBSpace</span> <span class='hs-varid'>a</span>
<a name="line-128"></a><span class='hs-definition'>mkRGBSpace</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGBSpace</span>
<a name="line-129"></a>
<a name="line-130"></a><a name="linearRGBSpace"></a><span class='hs-comment'>-- |Produce a linear colour space from an 'RGBGamut'.</span>
<a name="line-131"></a><span class='hs-definition'>linearRGBSpace</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Num</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>RGBGamut</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>RGBSpace</span> <span class='hs-varid'>a</span>
<a name="line-132"></a><span class='hs-definition'>linearRGBSpace</span> <span class='hs-varid'>gamut</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>RGBSpace</span> <span class='hs-varid'>gamut</span> <span class='hs-varid'>mempty</span>
<a name="line-133"></a>
<a name="line-134"></a><a name="rgbUsingSpace"></a><span class='hs-comment'>-- |Create a 'Colour' from red, green, and blue coordinates given in a</span>
<a name="line-135"></a><span class='hs-comment'>-- general 'RGBSpace'.</span>
<a name="line-136"></a><span class='hs-definition'>rgbUsingSpace</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-conid'>RGBSpace</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'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Colour</span> <span class='hs-varid'>a</span>
<a name="line-137"></a><span class='hs-definition'>rgbUsingSpace</span> <span class='hs-varid'>space</span> <span class='hs-keyglyph'>=</span>
<a name="line-138"></a> <span class='hs-varid'>curryRGB</span> <span class='hs-layout'>(</span><span class='hs-varid'>uncurryRGB</span> <span class='hs-layout'>(</span><span class='hs-varid'>rgbUsingGamut</span> <span class='hs-layout'>(</span><span class='hs-varid'>gamut</span> <span class='hs-varid'>space</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <span class='hs-varop'>.</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>tinv</span><span class='hs-layout'>)</span>
<a name="line-139"></a> <span class='hs-keyword'>where</span>
<a name="line-140"></a> <span class='hs-varid'>tinv</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transferInverse</span> <span class='hs-layout'>(</span><span class='hs-varid'>transferFunction</span> <span class='hs-varid'>space</span><span class='hs-layout'>)</span>
<a name="line-141"></a>
<a name="line-142"></a><a name="toRGBUsingSpace"></a><span class='hs-comment'>-- |Return the coordinates of a given 'Colour' for a general 'RGBSpace'.</span>
<a name="line-143"></a><span class='hs-definition'>toRGBUsingSpace</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-conid'>RGBSpace</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Colour</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>RGB</span> <span class='hs-varid'>a</span>
<a name="line-144"></a><span class='hs-definition'>toRGBUsingSpace</span> <span class='hs-varid'>space</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fmap</span> <span class='hs-varid'>t</span> <span class='hs-layout'>(</span><span class='hs-varid'>toRGBUsingGamut</span> <span class='hs-layout'>(</span><span class='hs-varid'>gamut</span> <span class='hs-varid'>space</span><span class='hs-layout'>)</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span>
<a name="line-145"></a> <span class='hs-keyword'>where</span>
<a name="line-146"></a> <span class='hs-varid'>t</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>transfer</span> <span class='hs-layout'>(</span><span class='hs-varid'>transferFunction</span> <span class='hs-varid'>space</span><span class='hs-layout'>)</span>
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