/usr/share/doc/libghc-bmp-doc/html/src/Codec-BMP-BitmapInfoV3.html is in libghc-bmp-doc 1.2.3.4-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 | <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<!-- Generated by HsColour, http://code.haskell.org/~malcolm/hscolour/ -->
<title>Codec/BMP/BitmapInfoV3.hs</title>
<link type='text/css' rel='stylesheet' href='hscolour.css' />
</head>
<body>
<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE PatternGuards #-}</span>
<a name="line-2"></a><span class='hs-comment'>{-# OPTIONS_HADDOCK hide #-}</span>
<a name="line-3"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Codec</span><span class='hs-varop'>.</span><span class='hs-conid'>BMP</span><span class='hs-varop'>.</span><span class='hs-conid'>BitmapInfoV3</span>
<a name="line-4"></a> <span class='hs-layout'>(</span> <span class='hs-conid'>BitmapInfoV3</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-5"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Compression</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-6"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sizeOfBitmapInfoV3</span>
<a name="line-7"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>checkBitmapInfoV3</span>
<a name="line-8"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>imageSizeFromBitmapInfoV3</span><span class='hs-layout'>)</span>
<a name="line-9"></a><span class='hs-keyword'>where</span>
<a name="line-10"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Codec</span><span class='hs-varop'>.</span><span class='hs-conid'>BMP</span><span class='hs-varop'>.</span><span class='hs-conid'>Error</span>
<a name="line-11"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Codec</span><span class='hs-varop'>.</span><span class='hs-conid'>BMP</span><span class='hs-varop'>.</span><span class='hs-conid'>Compression</span>
<a name="line-12"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Binary</span>
<a name="line-13"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Binary</span><span class='hs-varop'>.</span><span class='hs-conid'>Get</span>
<a name="line-14"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Binary</span><span class='hs-varop'>.</span><span class='hs-conid'>Put</span>
<a name="line-15"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Int</span>
<a name="line-16"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Debug</span><span class='hs-varop'>.</span><span class='hs-conid'>Trace</span>
<a name="line-17"></a>
<a name="line-18"></a>
<a name="line-19"></a><a name="BitmapInfoV3"></a><span class='hs-comment'>-- | Device Independent Bitmap (DIB) header for Windows V3.</span>
<a name="line-20"></a><a name="BitmapInfoV3"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>BitmapInfoV3</span>
<a name="line-21"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>BitmapInfoV3</span>
<a name="line-22"></a> <span class='hs-layout'>{</span> <span class='hs-comment'>-- | (+0) Size of the image header, in bytes.</span>
<a name="line-23"></a> <span class='hs-varid'>dib3Size</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-24"></a>
<a name="line-25"></a> <span class='hs-comment'>-- | (+4) Width of the image, in pixels.</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Width</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-27"></a>
<a name="line-28"></a> <span class='hs-comment'>-- | (+8) Height of the image, in pixels.</span>
<a name="line-29"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Height</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-30"></a>
<a name="line-31"></a> <span class='hs-comment'>-- | If the height field in the file is negative then this is interpreted</span>
<a name="line-32"></a> <span class='hs-comment'>-- as an image with the rows flipped.</span>
<a name="line-33"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3HeightFlipped</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Bool</span>
<a name="line-34"></a>
<a name="line-35"></a> <span class='hs-comment'>-- | (+12) Number of color planes.</span>
<a name="line-36"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word16</span>
<a name="line-37"></a>
<a name="line-38"></a> <span class='hs-comment'>-- | (+14) Number of bits per pixel.</span>
<a name="line-39"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word16</span>
<a name="line-40"></a>
<a name="line-41"></a> <span class='hs-comment'>-- | (+16) Image compression mode.</span>
<a name="line-42"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Compression</span>
<a name="line-43"></a>
<a name="line-44"></a> <span class='hs-comment'>-- | (+20) Size of raw image data.</span>
<a name="line-45"></a> <span class='hs-comment'>-- Some encoders set this to zero, so we need to calculate it based</span>
<a name="line-46"></a> <span class='hs-comment'>-- on the overall file size.</span>
<a name="line-47"></a> <span class='hs-comment'>-- </span>
<a name="line-48"></a> <span class='hs-comment'>-- If it is non-zero then we check it matches the file size - header</span>
<a name="line-49"></a> <span class='hs-comment'>-- size.</span>
<a name="line-50"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3ImageSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-51"></a>
<a name="line-52"></a> <span class='hs-comment'>-- | (+24) Prefered resolution in pixels per meter, along the X axis.</span>
<a name="line-53"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3PelsPerMeterX</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-54"></a>
<a name="line-55"></a> <span class='hs-comment'>-- | (+28) Prefered resolution in pixels per meter, along the Y axis.</span>
<a name="line-56"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3PelsPerMeterY</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-57"></a>
<a name="line-58"></a> <span class='hs-comment'>-- | (+32) Number of color entries that are used.</span>
<a name="line-59"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3ColorsUsed</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-60"></a>
<a name="line-61"></a> <span class='hs-comment'>-- | (+36) Number of significant colors.</span>
<a name="line-62"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3ColorsImportant</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Word32</span>
<a name="line-63"></a> <span class='hs-layout'>}</span>
<a name="line-64"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-65"></a>
<a name="line-66"></a>
<a name="line-67"></a><a name="sizeOfBitmapInfoV3"></a><span class='hs-comment'>-- | Size of `BitmapInfoV3` header (in bytes)</span>
<a name="line-68"></a><span class='hs-definition'>sizeOfBitmapInfoV3</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-69"></a><span class='hs-definition'>sizeOfBitmapInfoV3</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>40</span>
<a name="line-70"></a>
<a name="line-71"></a>
<a name="line-72"></a><a name="instance%20Binary%20BitmapInfoV3"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Binary</span> <span class='hs-conid'>BitmapInfoV3</span> <span class='hs-keyword'>where</span>
<a name="line-73"></a> <span class='hs-varid'>get</span>
<a name="line-74"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>size</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-75"></a> <span class='hs-varid'>width</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-76"></a>
<a name="line-77"></a> <span class='hs-comment'>-- We're supposed to treat the height field as a signed integer.</span>
<a name="line-78"></a> <span class='hs-comment'>-- If it's negative it means the image is flipped along the X axis.</span>
<a name="line-79"></a> <span class='hs-comment'>-- (which is crazy, but we just have to eat it)</span>
<a name="line-80"></a> <span class='hs-varid'>heightW32</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-81"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>heightI32</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>heightW32</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int32</span><span class='hs-layout'>)</span>
<a name="line-82"></a> <span class='hs-keyword'>let</span> <span class='hs-layout'>(</span><span class='hs-varid'>height</span><span class='hs-layout'>,</span> <span class='hs-varid'>flipped</span><span class='hs-layout'>)</span>
<a name="line-83"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>heightI32</span> <span class='hs-varop'><</span> <span class='hs-num'>0</span>
<a name="line-84"></a> <span class='hs-keyword'>then</span> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-layout'>(</span><span class='hs-varid'>abs</span> <span class='hs-varid'>heightI32</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-conid'>True</span><span class='hs-layout'>)</span>
<a name="line-85"></a> <span class='hs-keyword'>else</span> <span class='hs-layout'>(</span><span class='hs-varid'>heightW32</span><span class='hs-layout'>,</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span>
<a name="line-86"></a>
<a name="line-87"></a> <span class='hs-varid'>planes</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord16le</span>
<a name="line-88"></a> <span class='hs-varid'>bitc</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord16le</span>
<a name="line-89"></a> <span class='hs-varid'>comp</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>get</span>
<a name="line-90"></a> <span class='hs-varid'>imgsize</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-91"></a> <span class='hs-varid'>pelsX</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-92"></a> <span class='hs-varid'>pelsY</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-93"></a> <span class='hs-varid'>cused</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-94"></a> <span class='hs-varid'>cimp</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getWord32le</span>
<a name="line-95"></a>
<a name="line-96"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>BitmapInfoV3</span>
<a name="line-97"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>dib3Size</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>size</span>
<a name="line-98"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Width</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>width</span>
<a name="line-99"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Height</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>height</span>
<a name="line-100"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3HeightFlipped</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>flipped</span>
<a name="line-101"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>planes</span>
<a name="line-102"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>bitc</span>
<a name="line-103"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>comp</span>
<a name="line-104"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3ImageSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>imgsize</span>
<a name="line-105"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3PelsPerMeterX</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pelsX</span>
<a name="line-106"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3PelsPerMeterY</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>pelsY</span>
<a name="line-107"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3ColorsUsed</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cused</span>
<a name="line-108"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3ColorsImportant</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cimp</span> <span class='hs-layout'>}</span>
<a name="line-109"></a>
<a name="line-110"></a> <span class='hs-varid'>put</span> <span class='hs-varid'>header</span>
<a name="line-111"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Size</span> <span class='hs-varid'>header</span>
<a name="line-112"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Width</span> <span class='hs-varid'>header</span>
<a name="line-113"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Height</span> <span class='hs-varid'>header</span>
<a name="line-114"></a> <span class='hs-varid'>putWord16le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-varid'>header</span>
<a name="line-115"></a> <span class='hs-varid'>putWord16le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-varid'>header</span>
<a name="line-116"></a> <span class='hs-varid'>put</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span>
<a name="line-117"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3ImageSize</span> <span class='hs-varid'>header</span>
<a name="line-118"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3PelsPerMeterX</span> <span class='hs-varid'>header</span>
<a name="line-119"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3PelsPerMeterY</span> <span class='hs-varid'>header</span>
<a name="line-120"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3ColorsUsed</span> <span class='hs-varid'>header</span>
<a name="line-121"></a> <span class='hs-varid'>putWord32le</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3ColorsImportant</span> <span class='hs-varid'>header</span>
<a name="line-122"></a>
<a name="line-123"></a>
<a name="line-124"></a><a name="checkBitmapInfoV3"></a><span class='hs-comment'>-- | Check headers for problems and unsupported features. </span>
<a name="line-125"></a><span class='hs-definition'>checkBitmapInfoV3</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>BitmapInfoV3</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Word32</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Error</span>
<a name="line-126"></a><span class='hs-definition'>checkBitmapInfoV3</span> <span class='hs-varid'>header</span> <span class='hs-varid'>physicalBufferSize</span>
<a name="line-127"></a>
<a name="line-128"></a> <span class='hs-comment'>-- We only handle a single color plane.</span>
<a name="line-129"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-varid'>header</span> <span class='hs-varop'>/=</span> <span class='hs-num'>1</span>
<a name="line-130"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ErrorUnhandledPlanesCount</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-varid'>header</span>
<a name="line-131"></a>
<a name="line-132"></a> <span class='hs-comment'>-- We only handle 24 and 32 bit images.</span>
<a name="line-133"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-varid'>header</span> <span class='hs-varop'>/=</span> <span class='hs-num'>24</span>
<a name="line-134"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-varid'>header</span> <span class='hs-varop'>/=</span> <span class='hs-num'>32</span>
<a name="line-135"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ErrorUnhandledColorDepth</span> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-varid'>header</span>
<a name="line-136"></a>
<a name="line-137"></a> <span class='hs-comment'>-- If the image size field in the header is non-zero, </span>
<a name="line-138"></a> <span class='hs-comment'>-- then it must be less than the physical size of the image buffer.</span>
<a name="line-139"></a> <span class='hs-comment'>-- The buffer may be larger than the size of the image stated</span>
<a name="line-140"></a> <span class='hs-comment'>-- in the header, because some encoders add padding to the end.</span>
<a name="line-141"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>headerImageSize</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>dib3ImageSize</span> <span class='hs-varid'>header</span>
<a name="line-142"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>headerImageSize</span> <span class='hs-varop'>/=</span> <span class='hs-num'>0</span>
<a name="line-143"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>physicalBufferSize</span> <span class='hs-varop'><</span> <span class='hs-varid'>headerImageSize</span>
<a name="line-144"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ErrorImagePhysicalSizeMismatch</span>
<a name="line-145"></a> <span class='hs-varid'>headerImageSize</span> <span class='hs-varid'>physicalBufferSize</span>
<a name="line-146"></a>
<a name="line-147"></a> <span class='hs-comment'>-- Check that the physical buffer contains enough image data.</span>
<a name="line-148"></a> <span class='hs-comment'>-- The buffer may be larger than the size of the image stated</span>
<a name="line-149"></a> <span class='hs-comment'>-- in the header, because some encoders add padding to the end.</span>
<a name="line-150"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>calculatedImageSize</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>imageSizeFromBitmapInfoV3</span> <span class='hs-varid'>header</span>
<a name="line-151"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>physicalBufferSize</span> <span class='hs-varop'><</span> <span class='hs-varid'>calculatedImageSize</span>
<a name="line-152"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>trace</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varid'>header</span><span class='hs-layout'>)</span>
<a name="line-153"></a> <span class='hs-varop'>$</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ErrorImageDataTruncated</span>
<a name="line-154"></a> <span class='hs-varid'>calculatedImageSize</span>
<a name="line-155"></a> <span class='hs-layout'>(</span><span class='hs-varid'>fromIntegral</span> <span class='hs-varid'>physicalBufferSize</span><span class='hs-layout'>)</span>
<a name="line-156"></a>
<a name="line-157"></a> <span class='hs-comment'>-- We only handle uncompresssed images.</span>
<a name="line-158"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span> <span class='hs-varop'>/=</span> <span class='hs-conid'>CompressionRGB</span>
<a name="line-159"></a> <span class='hs-varop'>&&</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span> <span class='hs-varop'>/=</span> <span class='hs-conid'>CompressionBitFields</span>
<a name="line-160"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ErrorUnhandledCompressionMode</span> <span class='hs-layout'>(</span><span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span><span class='hs-layout'>)</span>
<a name="line-161"></a>
<a name="line-162"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-163"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-164"></a>
<a name="line-165"></a>
<a name="line-166"></a><a name="imageSizeFromBitmapInfoV3"></a><span class='hs-comment'>-- | Compute the size of the image data from the header.</span>
<a name="line-167"></a><span class='hs-comment'>--</span>
<a name="line-168"></a><span class='hs-comment'>-- * We can't just use the 'dib3ImageSize' field because some encoders</span>
<a name="line-169"></a><span class='hs-comment'>-- set this to zero.</span>
<a name="line-170"></a><span class='hs-comment'>--</span>
<a name="line-171"></a><span class='hs-comment'>-- * We also can't use the physical size of the data in the file because</span>
<a name="line-172"></a><span class='hs-comment'>-- some encoders add zero padding bytes on the end. </span>
<a name="line-173"></a><span class='hs-comment'>--</span>
<a name="line-174"></a><span class='hs-definition'>imageSizeFromBitmapInfoV3</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>BitmapInfoV3</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Int</span>
<a name="line-175"></a><span class='hs-definition'>imageSizeFromBitmapInfoV3</span> <span class='hs-varid'>header</span>
<a name="line-176"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-num'>32</span>
<a name="line-177"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-num'>1</span>
<a name="line-178"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-conid'>CompressionRGB</span>
<a name="line-179"></a> <span class='hs-varop'>||</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-conid'>CompressionBitFields</span>
<a name="line-180"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fromIntegral</span> <span class='hs-layout'>(</span><span class='hs-varid'>dib3Width</span> <span class='hs-varid'>header</span> <span class='hs-varop'>*</span> <span class='hs-varid'>dib3Height</span> <span class='hs-varid'>header</span> <span class='hs-varop'>*</span> <span class='hs-num'>4</span><span class='hs-layout'>)</span>
<a name="line-181"></a>
<a name="line-182"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>dib3BitCount</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-num'>24</span>
<a name="line-183"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Planes</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-num'>1</span>
<a name="line-184"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-conid'>CompressionRGB</span>
<a name="line-185"></a> <span class='hs-varop'>||</span> <span class='hs-varid'>dib3Compression</span> <span class='hs-varid'>header</span> <span class='hs-varop'>==</span> <span class='hs-conid'>CompressionBitFields</span>
<a name="line-186"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>imageBytesPerLine</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>dib3Width</span> <span class='hs-varid'>header</span> <span class='hs-varop'>*</span> <span class='hs-num'>3</span>
<a name="line-187"></a> <span class='hs-varid'>tailBytesPerLine</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>imageBytesPerLine</span> <span class='hs-varop'>`mod`</span> <span class='hs-num'>4</span>
<a name="line-188"></a> <span class='hs-varid'>padBytesPerLine</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>tailBytesPerLine</span> <span class='hs-varop'>></span> <span class='hs-num'>0</span>
<a name="line-189"></a> <span class='hs-keyword'>then</span> <span class='hs-num'>4</span> <span class='hs-comment'>-</span> <span class='hs-varid'>tailBytesPerLine</span>
<a name="line-190"></a> <span class='hs-keyword'>else</span> <span class='hs-num'>0</span>
<a name="line-191"></a> <span class='hs-keyword'>in</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-varid'>fromIntegral</span>
<a name="line-192"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>dib3Height</span> <span class='hs-varid'>header</span> <span class='hs-varop'>*</span> <span class='hs-varid'>imageBytesPerLine</span> <span class='hs-varop'>+</span> <span class='hs-varid'>padBytesPerLine</span>
<a name="line-193"></a>
<a name="line-194"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-195"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>trace</span> <span class='hs-layout'>(</span><span class='hs-varid'>show</span> <span class='hs-varid'>header</span><span class='hs-layout'>)</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Nothing</span>
<a name="line-196"></a>
</pre></body>
</html>
|