doxygen/html/mipmap_8h-source.html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>pbrt: mipmap.h Source File</title>
<link href="doxygen.css" rel="stylesheet" type="text/css">
<link href="tabs.css" rel="stylesheet" type="text/css">
</head><body>
<!-- Generated by Doxygen 1.5.6 -->
<div class="navigation" id="top">
  <div class="tabs">
    <ul>
      <li><a href="index.html"><span>Main&nbsp;Page</span></a></li>
      <li><a href="annotated.html"><span>Classes</span></a></li>
      <li class="current"><a href="files.html"><span>Files</span></a></li>
    </ul>
  </div>
<h1>mipmap.h</h1><a href="mipmap_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 
<a name="l00002"></a>00002 <span class="comment">/*</span>
<a name="l00003"></a>00003 <span class="comment">    pbrt source code Copyright(c) 1998-2007 Matt Pharr and Greg Humphreys.</span>
<a name="l00004"></a>00004 <span class="comment"></span>
<a name="l00005"></a>00005 <span class="comment">    This file is part of pbrt.</span>
<a name="l00006"></a>00006 <span class="comment"></span>
<a name="l00007"></a>00007 <span class="comment">    pbrt is free software; you can redistribute it and/or modify</span>
<a name="l00008"></a>00008 <span class="comment">    it under the terms of the GNU General Public License as published by</span>
<a name="l00009"></a>00009 <span class="comment">    the Free Software Foundation; either version 2 of the License, or</span>
<a name="l00010"></a>00010 <span class="comment">    (at your option) any later version.  Note that the text contents of</span>
<a name="l00011"></a>00011 <span class="comment">    the book "Physically Based Rendering" are *not* licensed under the</span>
<a name="l00012"></a>00012 <span class="comment">    GNU GPL.</span>
<a name="l00013"></a>00013 <span class="comment"></span>
<a name="l00014"></a>00014 <span class="comment">    pbrt is distributed in the hope that it will be useful,</span>
<a name="l00015"></a>00015 <span class="comment">    but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
<a name="l00016"></a>00016 <span class="comment">    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the</span>
<a name="l00017"></a>00017 <span class="comment">    GNU General Public License for more details.</span>
<a name="l00018"></a>00018 <span class="comment"></span>
<a name="l00019"></a>00019 <span class="comment">    You should have received a copy of the GNU General Public License</span>
<a name="l00020"></a>00020 <span class="comment">    along with this program.  If not, see &lt;http://www.gnu.org/licenses/&gt;.</span>
<a name="l00021"></a>00021 <span class="comment"></span>
<a name="l00022"></a>00022 <span class="comment"> */</span>
<a name="l00023"></a>00023 
<a name="l00024"></a>00024 <span class="preprocessor">#ifndef PBRT_MIPMAP_H</span>
<a name="l00025"></a>00025 <span class="preprocessor"></span><span class="preprocessor">#define PBRT_MIPMAP_H</span>
<a name="l00026"></a>00026 <span class="preprocessor"></span><span class="comment">// mipmap.h*</span>
<a name="l00027"></a>00027 <span class="preprocessor">#include "<a class="code" href="pbrt_8h.html">pbrt.h</a>"</span>
<a name="l00028"></a>00028 <span class="preprocessor">#include "<a class="code" href="color_8h.html">color.h</a>"</span>
<a name="l00029"></a>00029 <span class="comment">// MIPMap Declarations</span>
<a name="l00030"></a><a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d">00030</a> <span class="keyword">typedef</span> <span class="keyword">enum</span> {
<a name="l00031"></a><a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d00495d1c135f2864238810ee452996bd">00031</a>         <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d00495d1c135f2864238810ee452996bd">TEXTURE_REPEAT</a>,
<a name="l00032"></a><a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47db1829819a6a0358043fd83035a781158">00032</a>         <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47db1829819a6a0358043fd83035a781158">TEXTURE_BLACK</a>,
<a name="l00033"></a><a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47dc20b5c0b9f8e3421b876c5a8de442365">00033</a>         <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47dc20b5c0b9f8e3421b876c5a8de442365">TEXTURE_CLAMP</a>
<a name="l00034"></a>00034 } <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d">ImageWrap</a>;
<a name="l00035"></a><a class="code" href="classMIPMap.html">00035</a> <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt; <span class="keyword">class </span><a class="code" href="classMIPMap.html">MIPMap</a> {
<a name="l00036"></a>00036 <span class="keyword">public</span>:
<a name="l00037"></a>00037         <span class="comment">// MIPMap Public Methods</span>
<a name="l00038"></a>00038         <a class="code" href="classMIPMap.html#cc335ff937f9880597703900fbc878fb">MIPMap</a>(<span class="keywordtype">int</span> xres, <span class="keywordtype">int</span> yres, <span class="keyword">const</span> T *data, <span class="keywordtype">bool</span> doTri = <span class="keyword">false</span>,
<a name="l00039"></a>00039                    <span class="keywordtype">float</span> maxAniso = 8.f, <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d">ImageWrap</a> <a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a> = <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d00495d1c135f2864238810ee452996bd">TEXTURE_REPEAT</a>);
<a name="l00040"></a>00040         <a class="code" href="classMIPMap.html#00c9d088a7505d6cb6104044338f0c4d">~MIPMap</a>();
<a name="l00041"></a>00041         T <a class="code" href="classMIPMap.html#401e4e6d7bd87aae7df1ed7f87a67ed5">Lookup</a>(<span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t, <span class="keywordtype">float</span> width = 0.f) <span class="keyword">const</span>;
<a name="l00042"></a>00042         T <a class="code" href="classMIPMap.html#401e4e6d7bd87aae7df1ed7f87a67ed5">Lookup</a>(<span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t, <span class="keywordtype">float</span> ds0, <span class="keywordtype">float</span> dt0,
<a name="l00043"></a>00043                 <span class="keywordtype">float</span> ds1, <span class="keywordtype">float</span> dt1) <span class="keyword">const</span>;
<a name="l00044"></a>00044 <span class="keyword">private</span>:
<a name="l00045"></a>00045         <span class="comment">// MIPMap Private Methods</span>
<a name="l00046"></a>00046         <span class="keyword">struct </span><a class="code" href="structMIPMap_1_1ResampleWeight.html">ResampleWeight</a>;
<a name="l00047"></a><a class="code" href="classMIPMap.html#3b76496c9c11cd01b335cfe6fccee007">00047</a>         ResampleWeight *<a class="code" href="classMIPMap.html#3b76496c9c11cd01b335cfe6fccee007">resampleWeights</a>(<span class="keywordtype">int</span> oldres, <span class="keywordtype">int</span> newres) {
<a name="l00048"></a>00048                 <a class="code" href="pbrt_8h.html#ab1e54dcc40192f9704e8b252635450f">Assert</a>(newres &gt;= oldres);
<a name="l00049"></a>00049                 ResampleWeight *wt = <span class="keyword">new</span> ResampleWeight[newres];
<a name="l00050"></a>00050                 <span class="keywordtype">float</span> filterwidth = 2.f;
<a name="l00051"></a>00051                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; newres; ++i) {
<a name="l00052"></a>00052                         <span class="comment">// Compute image resampling weights for _i_th texel</span>
<a name="l00053"></a>00053                         <span class="keywordtype">float</span> center = (i + .5f) * oldres / newres;
<a name="l00054"></a>00054                         wt[i].firstTexel = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>((center - filterwidth) + 0.5f);
<a name="l00055"></a>00055                         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> j = 0; j &lt; 4; ++j) {
<a name="l00056"></a>00056                                 <span class="keywordtype">float</span> pos = wt[i].firstTexel + j + .5f;
<a name="l00057"></a>00057                                 wt[i].weight[j] = <a class="code" href="pbrt_8h.html#b1831c563572bacc96729314872ae245">Lanczos</a>((pos - center) / filterwidth);
<a name="l00058"></a>00058                         }
<a name="l00059"></a>00059                         <span class="comment">// Normalize filter weights for texel resampling</span>
<a name="l00060"></a>00060                         <span class="keywordtype">float</span> invSumWts = 1.f / (wt[i].weight[0] + wt[i].weight[1] +
<a name="l00061"></a>00061                                 wt[i].weight[2] + wt[i].weight[3]);
<a name="l00062"></a>00062                         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> j = 0; j &lt; 4; ++j)
<a name="l00063"></a>00063                                 wt[i].weight[j] *= invSumWts;
<a name="l00064"></a>00064                 }
<a name="l00065"></a>00065                 <span class="keywordflow">return</span> wt;
<a name="l00066"></a>00066         }
<a name="l00067"></a><a class="code" href="classMIPMap.html#4b27bc8f33f8c65606c517bc09f67699">00067</a>         <span class="keywordtype">float</span> <a class="code" href="classMIPMap.html#4b27bc8f33f8c65606c517bc09f67699">clamp</a>(<span class="keywordtype">float</span> v) { <span class="keywordflow">return</span> <a class="code" href="pbrt_8h.html#036098e5cec04b73d8720de12e8e5cd1">Clamp</a>(v, 0.f, <a class="code" href="pbrt_8h.html#956e2723d559858d08644ac99146e910">INFINITY</a>); }
<a name="l00068"></a><a class="code" href="classMIPMap.html#7bcad1a278fc8d3dee99fe2ca2447c91">00068</a>         <a class="code" href="classSpectrum.html">Spectrum</a> <a class="code" href="classMIPMap.html#4b27bc8f33f8c65606c517bc09f67699">clamp</a>(<span class="keyword">const</span> <a class="code" href="classSpectrum.html">Spectrum</a> &amp;v) { <span class="keywordflow">return</span> v.<a class="code" href="classSpectrum.html#e1a9c8547a9dd9ffd226bd227432c7ce">Clamp</a>(0.f, <a class="code" href="pbrt_8h.html#956e2723d559858d08644ac99146e910">INFINITY</a>); }
<a name="l00069"></a>00069         <span class="keyword">const</span> T &amp;<a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(<span class="keywordtype">int</span> level, <span class="keywordtype">int</span> s, <span class="keywordtype">int</span> t) <span class="keyword">const</span>;
<a name="l00070"></a>00070         T <a class="code" href="classMIPMap.html#44bb0a47448035276c61097c7f7c743f">triangle</a>(<span class="keywordtype">int</span> level, <span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t) <span class="keyword">const</span>;
<a name="l00071"></a>00071         T <a class="code" href="classMIPMap.html#0713ceee690ef16e6c78b976c36d30d4">EWA</a>(<span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t, <span class="keywordtype">float</span> ds0, <span class="keywordtype">float</span> dt0, <span class="keywordtype">float</span> ds1, <span class="keywordtype">float</span> dt1, <span class="keywordtype">int</span> level) <span class="keyword">const</span>;
<a name="l00072"></a>00072         <span class="comment">// MIPMap Private Data</span>
<a name="l00073"></a><a class="code" href="classMIPMap.html#f03004d9d7c85a3e71008725fd38f70b">00073</a>         <span class="keywordtype">bool</span> <a class="code" href="classMIPMap.html#f03004d9d7c85a3e71008725fd38f70b">doTrilinear</a>;
<a name="l00074"></a><a class="code" href="classMIPMap.html#79b4bfc54e56a204bb196e44ef9e71ce">00074</a>         <span class="keywordtype">float</span> <a class="code" href="classMIPMap.html#79b4bfc54e56a204bb196e44ef9e71ce">maxAnisotropy</a>;
<a name="l00075"></a><a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">00075</a>         <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d">ImageWrap</a> <a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a>;
<a name="l00076"></a><a class="code" href="structMIPMap_1_1ResampleWeight.html">00076</a>         <span class="keyword">struct </span><a class="code" href="structMIPMap_1_1ResampleWeight.html">ResampleWeight</a> {
<a name="l00077"></a><a class="code" href="structMIPMap_1_1ResampleWeight.html#fff4aeb86042f727eac238f617952a5f">00077</a>                 <span class="keywordtype">int</span> <a class="code" href="structMIPMap_1_1ResampleWeight.html#fff4aeb86042f727eac238f617952a5f">firstTexel</a>;
<a name="l00078"></a><a class="code" href="structMIPMap_1_1ResampleWeight.html#4927d0b21d0462e7ae0133e011d692e4">00078</a>                 <span class="keywordtype">float</span> <a class="code" href="structMIPMap_1_1ResampleWeight.html#4927d0b21d0462e7ae0133e011d692e4">weight</a>[4];
<a name="l00079"></a>00079         };
<a name="l00080"></a><a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">00080</a>         <a class="code" href="classBlockedArray.html">BlockedArray&lt;T&gt;</a> **<a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>;
<a name="l00081"></a><a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">00081</a>         <span class="keywordtype">int</span> <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>;
<a name="l00082"></a><a class="code" href="mipmap_8h.html#b8aef080a497e9b8cc3f0fe1ef4d8965">00082</a> <span class="preprocessor">        #define WEIGHT_LUT_SIZE 128</span>
<a name="l00083"></a><a class="code" href="classMIPMap.html#4127d975dd0721f8ecc6c23a82d840ba">00083</a> <span class="preprocessor"></span>        <span class="keyword">static</span> <span class="keywordtype">float</span> *<a class="code" href="classMIPMap.html#4127d975dd0721f8ecc6c23a82d840ba">weightLut</a>;
<a name="l00084"></a>00084 };
<a name="l00085"></a>00085 <span class="comment">// MIPMap Method Definitions</span>
<a name="l00086"></a>00086 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00087"></a><a class="code" href="classMIPMap.html#cc335ff937f9880597703900fbc878fb">00087</a> <a class="code" href="classMIPMap.html#cc335ff937f9880597703900fbc878fb">MIPMap&lt;T&gt;::MIPMap</a>(<span class="keywordtype">int</span> sres, <span class="keywordtype">int</span> tres,
<a name="l00088"></a>00088                   <span class="keyword">const</span> T *img, <span class="keywordtype">bool</span> doTri,
<a name="l00089"></a>00089                                   <span class="keywordtype">float</span> maxAniso, <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d">ImageWrap</a> wm) {
<a name="l00090"></a>00090         <a class="code" href="classMIPMap.html#f03004d9d7c85a3e71008725fd38f70b">doTrilinear</a> = doTri;
<a name="l00091"></a>00091         <a class="code" href="classMIPMap.html#79b4bfc54e56a204bb196e44ef9e71ce">maxAnisotropy</a> = maxAniso;
<a name="l00092"></a>00092         <a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a> = wm;
<a name="l00093"></a>00093         T *resampledImage = NULL;
<a name="l00094"></a>00094         <span class="keywordflow">if</span> (!<a class="code" href="pbrt_8h.html#9ed3e1f1916bf19da23d9fb954d2179a">IsPowerOf2</a>(sres) || !<a class="code" href="pbrt_8h.html#9ed3e1f1916bf19da23d9fb954d2179a">IsPowerOf2</a>(tres)) {
<a name="l00095"></a>00095                 <span class="comment">// Resample image to power-of-two resolution</span>
<a name="l00096"></a>00096                 <span class="keywordtype">int</span> sPow2 = <a class="code" href="pbrt_8h.html#8d4117d7c2f2056597da264d3c763ec6">RoundUpPow2</a>(sres), tPow2 = <a class="code" href="pbrt_8h.html#8d4117d7c2f2056597da264d3c763ec6">RoundUpPow2</a>(tres);
<a name="l00097"></a>00097                 <span class="comment">// Resample image in $s$ direction</span>
<a name="l00098"></a>00098                 <a class="code" href="structMIPMap_1_1ResampleWeight.html">ResampleWeight</a> *sWeights = <a class="code" href="classMIPMap.html#3b76496c9c11cd01b335cfe6fccee007">resampleWeights</a>(sres, sPow2);
<a name="l00099"></a>00099                 resampledImage = <span class="keyword">new</span> T[sPow2 * tPow2];
<a name="l00100"></a>00100                 <span class="comment">// Apply _sWeights_ to zoom in $s$ direction</span>
<a name="l00101"></a>00101                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> t = 0; t &lt; tres; ++t) {
<a name="l00102"></a>00102                         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> s = 0; s &lt; sPow2; ++s) {
<a name="l00103"></a>00103                                 <span class="comment">// Compute texel $(s,t)$ in $s$-zoomed image</span>
<a name="l00104"></a>00104                                 resampledImage[t*sPow2+s] = 0.;
<a name="l00105"></a>00105                                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> j = 0; j &lt; 4; ++j) {
<a name="l00106"></a>00106                                         <span class="keywordtype">int</span> origS = sWeights[s].<a class="code" href="structMIPMap_1_1ResampleWeight.html#fff4aeb86042f727eac238f617952a5f">firstTexel</a> + j;
<a name="l00107"></a>00107                                         <span class="keywordflow">if</span> (<a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a> == <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d00495d1c135f2864238810ee452996bd">TEXTURE_REPEAT</a>)
<a name="l00108"></a>00108                                                 origS = <a class="code" href="pbrt_8h.html#32154d1b92d7e28d67e9c4f8619bb6c2">Mod</a>(origS, sres);
<a name="l00109"></a>00109                                         <span class="keywordflow">else</span> <span class="keywordflow">if</span> (<a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a> == <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47dc20b5c0b9f8e3421b876c5a8de442365">TEXTURE_CLAMP</a>)
<a name="l00110"></a>00110                                                 origS = <a class="code" href="pbrt_8h.html#036098e5cec04b73d8720de12e8e5cd1">Clamp</a>(origS, 0, sres-1);
<a name="l00111"></a>00111                                         <span class="keywordflow">if</span> (origS &gt;= 0 &amp;&amp; origS &lt; sres)
<a name="l00112"></a>00112                                                 resampledImage[t*sPow2+s] += sWeights[s].<a class="code" href="structMIPMap_1_1ResampleWeight.html#4927d0b21d0462e7ae0133e011d692e4">weight</a>[j] *
<a name="l00113"></a>00113                                                         img[t*sres + origS];
<a name="l00114"></a>00114                                 }
<a name="l00115"></a>00115                         }
<a name="l00116"></a>00116                 }
<a name="l00117"></a>00117                 <span class="keyword">delete</span>[] sWeights;
<a name="l00118"></a>00118                 <span class="comment">// Resample image in $t$ direction</span>
<a name="l00119"></a>00119                 <a class="code" href="structMIPMap_1_1ResampleWeight.html">ResampleWeight</a> *tWeights = <a class="code" href="classMIPMap.html#3b76496c9c11cd01b335cfe6fccee007">resampleWeights</a>(tres, tPow2);
<a name="l00120"></a>00120                 T *workData = <span class="keyword">new</span> T[tPow2];
<a name="l00121"></a>00121                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> s = 0; s &lt; sPow2; ++s) {
<a name="l00122"></a>00122                         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> t = 0; t &lt; tPow2; ++t) {
<a name="l00123"></a>00123                                 workData[t] = 0.;
<a name="l00124"></a>00124                                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> j = 0; j &lt; 4; ++j) {
<a name="l00125"></a>00125                                         <span class="keywordtype">int</span> offset = tWeights[t].<a class="code" href="structMIPMap_1_1ResampleWeight.html#fff4aeb86042f727eac238f617952a5f">firstTexel</a> + j;
<a name="l00126"></a>00126                                         <span class="keywordflow">if</span> (<a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a> == <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d00495d1c135f2864238810ee452996bd">TEXTURE_REPEAT</a>) offset = <a class="code" href="pbrt_8h.html#32154d1b92d7e28d67e9c4f8619bb6c2">Mod</a>(offset, tres);
<a name="l00127"></a>00127                                         <span class="keywordflow">else</span> <span class="keywordflow">if</span> (<a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a> == <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47dc20b5c0b9f8e3421b876c5a8de442365">TEXTURE_CLAMP</a>) offset = <a class="code" href="pbrt_8h.html#036098e5cec04b73d8720de12e8e5cd1">Clamp</a>(offset, 0, tres-1);
<a name="l00128"></a>00128                                         <span class="keywordflow">if</span> (offset &gt;= 0 &amp;&amp; offset &lt; tres)
<a name="l00129"></a>00129                                                 workData[t] += tWeights[t].<a class="code" href="structMIPMap_1_1ResampleWeight.html#4927d0b21d0462e7ae0133e011d692e4">weight</a>[j] *
<a name="l00130"></a>00130                                                         resampledImage[offset*sPow2 + s];
<a name="l00131"></a>00131                                 }
<a name="l00132"></a>00132                         }
<a name="l00133"></a>00133                         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> t = 0; t &lt; tPow2; ++t)
<a name="l00134"></a>00134                                 resampledImage[t*sPow2 + s] = <a class="code" href="classMIPMap.html#4b27bc8f33f8c65606c517bc09f67699">clamp</a>(workData[t]);
<a name="l00135"></a>00135                 }
<a name="l00136"></a>00136                 <span class="keyword">delete</span>[] workData;
<a name="l00137"></a>00137                 <span class="keyword">delete</span>[] tWeights;
<a name="l00138"></a>00138                 img = resampledImage;  <span class="comment">// XXX need to delete resampledImage when done...</span>
<a name="l00139"></a>00139                 sres = sPow2;
<a name="l00140"></a>00140                 tres = tPow2;
<a name="l00141"></a>00141         }
<a name="l00142"></a>00142         <span class="comment">// Initialize levels of MIPMap from image</span>
<a name="l00143"></a>00143         <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a> = 1 + <a class="code" href="pbrt_8h.html#8bc246329312fc639a86e37fa937b483">Log2Int</a>(<span class="keywordtype">float</span>(max(sres, tres)));
<a name="l00144"></a>00144         <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a> = <span class="keyword">new</span> <a class="code" href="classBlockedArray.html">BlockedArray&lt;T&gt;</a> *[<a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>];
<a name="l00145"></a>00145         <span class="comment">// Initialize most detailed level of MIPMap</span>
<a name="l00146"></a>00146         <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[0] = <span class="keyword">new</span> <a class="code" href="classBlockedArray.html">BlockedArray&lt;T&gt;</a>(sres, tres, img);
<a name="l00147"></a>00147         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 1; i &lt; <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>; ++i) {
<a name="l00148"></a>00148                 <span class="comment">// Initialize $i$th MIPMap level from $i-1$st level</span>
<a name="l00149"></a>00149                 <span class="keywordtype">int</span> sRes = max(1, <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[i-1]-&gt;uSize()/2);
<a name="l00150"></a>00150                 <span class="keywordtype">int</span> tRes = max(1, <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[i-1]-&gt;vSize()/2);
<a name="l00151"></a>00151                 <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[i] = <span class="keyword">new</span> <a class="code" href="classBlockedArray.html">BlockedArray&lt;T&gt;</a>(sRes, tRes);
<a name="l00152"></a>00152                 <span class="comment">// Filter four texels from finer level of pyramid</span>
<a name="l00153"></a>00153                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> t = 0; t &lt; tRes; ++t)
<a name="l00154"></a>00154                         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> s = 0; s &lt; sRes; ++s)
<a name="l00155"></a>00155                                 (*<a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[i])(s, t) = .25f * (
<a name="l00156"></a>00156                                         <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(i-1, 2*s, 2*t) +
<a name="l00157"></a>00157                                         <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(i-1, 2*s+1, 2*t) +
<a name="l00158"></a>00158                                         <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(i-1, 2*s, 2*t+1) +
<a name="l00159"></a>00159                                         <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(i-1, 2*s+1, 2*t+1));
<a name="l00160"></a>00160         }
<a name="l00161"></a>00161         <span class="keywordflow">if</span> (resampledImage) <span class="keyword">delete</span>[] resampledImage;
<a name="l00162"></a>00162         <span class="comment">// Initialize EWA filter weights if needed</span>
<a name="l00163"></a>00163         <span class="keywordflow">if</span> (!<a class="code" href="classMIPMap.html#4127d975dd0721f8ecc6c23a82d840ba">weightLut</a>) {
<a name="l00164"></a>00164                 <a class="code" href="classMIPMap.html#4127d975dd0721f8ecc6c23a82d840ba">weightLut</a> = (<span class="keywordtype">float</span> *)<a class="code" href="pbrt_8h.html#6999b138e9c0d348eee4455b4ba3d624">AllocAligned</a>(<a class="code" href="mipmap_8h.html#b8aef080a497e9b8cc3f0fe1ef4d8965">WEIGHT_LUT_SIZE</a> *
<a name="l00165"></a>00165                         <span class="keyword">sizeof</span>(<span class="keywordtype">float</span>));
<a name="l00166"></a>00166                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; <a class="code" href="mipmap_8h.html#b8aef080a497e9b8cc3f0fe1ef4d8965">WEIGHT_LUT_SIZE</a>; ++i) {
<a name="l00167"></a>00167                         <span class="keywordtype">float</span> alpha = 2;
<a name="l00168"></a>00168                         <span class="keywordtype">float</span> r2 = float(i) / float(WEIGHT_LUT_SIZE - 1);
<a name="l00169"></a>00169                         <a class="code" href="classMIPMap.html#4127d975dd0721f8ecc6c23a82d840ba">weightLut</a>[i] = expf(-alpha * r2) - expf(-alpha);
<a name="l00170"></a>00170                 }
<a name="l00171"></a>00171         }
<a name="l00172"></a>00172 }
<a name="l00173"></a>00173 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00174"></a><a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">00174</a> <span class="keyword">const</span> T &amp;<a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">MIPMap&lt;T&gt;::texel</a>(<span class="keywordtype">int</span> level, <span class="keywordtype">int</span> s, <span class="keywordtype">int</span> t)<span class="keyword"> const </span>{
<a name="l00175"></a>00175         <span class="keyword">const</span> <a class="code" href="classBlockedArray.html">BlockedArray&lt;T&gt;</a> &amp;l = *<a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level];
<a name="l00176"></a>00176         <span class="comment">// Compute texel $(s,t)$ accounting for boundary conditions</span>
<a name="l00177"></a>00177         <span class="keywordflow">switch</span> (<a class="code" href="classMIPMap.html#4c07a42167c80490035e6a81b65148c5">wrapMode</a>) {
<a name="l00178"></a>00178                 <span class="keywordflow">case</span> <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47d00495d1c135f2864238810ee452996bd">TEXTURE_REPEAT</a>:
<a name="l00179"></a>00179                         s = <a class="code" href="pbrt_8h.html#32154d1b92d7e28d67e9c4f8619bb6c2">Mod</a>(s, l.<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>());
<a name="l00180"></a>00180                         t = <a class="code" href="pbrt_8h.html#32154d1b92d7e28d67e9c4f8619bb6c2">Mod</a>(t, l.<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>());
<a name="l00181"></a>00181                         <span class="keywordflow">break</span>;
<a name="l00182"></a>00182                 <span class="keywordflow">case</span> <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47dc20b5c0b9f8e3421b876c5a8de442365">TEXTURE_CLAMP</a>:
<a name="l00183"></a>00183                         s = <a class="code" href="pbrt_8h.html#036098e5cec04b73d8720de12e8e5cd1">Clamp</a>(s, 0, l.<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>() - 1);
<a name="l00184"></a>00184                         t = <a class="code" href="pbrt_8h.html#036098e5cec04b73d8720de12e8e5cd1">Clamp</a>(t, 0, l.<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>() - 1);
<a name="l00185"></a>00185                         <span class="keywordflow">break</span>;
<a name="l00186"></a>00186                 <span class="keywordflow">case</span> <a class="code" href="mipmap_8h.html#37e00616446e8232a39ce3dacc4ed47db1829819a6a0358043fd83035a781158">TEXTURE_BLACK</a>: {
<a name="l00187"></a>00187                         <span class="keyword">static</span> <span class="keyword">const</span> T black = 0.f;
<a name="l00188"></a>00188                         <span class="keywordflow">if</span> (s &lt; 0 || s &gt;= l.<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>() ||
<a name="l00189"></a>00189                                 t &lt; 0 || t &gt;= l.<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>())
<a name="l00190"></a>00190                                 <span class="keywordflow">return</span> black;
<a name="l00191"></a>00191                         <span class="keywordflow">break</span>;
<a name="l00192"></a>00192                 }
<a name="l00193"></a>00193         }
<a name="l00194"></a>00194         <span class="keywordflow">return</span> l(s, t);
<a name="l00195"></a>00195 }
<a name="l00196"></a>00196 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00197"></a><a class="code" href="classMIPMap.html#00c9d088a7505d6cb6104044338f0c4d">00197</a> <a class="code" href="classMIPMap.html#00c9d088a7505d6cb6104044338f0c4d">MIPMap&lt;T&gt;::~MIPMap</a>() {
<a name="l00198"></a>00198         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i &lt; <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>; ++i)
<a name="l00199"></a>00199                 <span class="keyword">delete</span> <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[i];
<a name="l00200"></a>00200         <span class="keyword">delete</span>[] <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>;
<a name="l00201"></a>00201 }
<a name="l00202"></a>00202 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00203"></a><a class="code" href="classMIPMap.html#401e4e6d7bd87aae7df1ed7f87a67ed5">00203</a> T <a class="code" href="classMIPMap.html#401e4e6d7bd87aae7df1ed7f87a67ed5">MIPMap&lt;T&gt;::Lookup</a>(<span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t, <span class="keywordtype">float</span> width)<span class="keyword"> const </span>{
<a name="l00204"></a>00204         <span class="keyword">static</span> <a class="code" href="classStatsCounter.html">StatsCounter</a> mipTrilerps(<span class="stringliteral">"Texture"</span>, <span class="comment">// NOBOOK</span>
<a name="l00205"></a>00205                 <span class="stringliteral">"Trilinear MIPMap lookups"</span>); <span class="comment">// NOBOOK</span>
<a name="l00206"></a>00206         ++mipTrilerps; <span class="comment">// NOBOOK</span>
<a name="l00207"></a>00207         <span class="comment">// Compute MIPMap level for trilinear filtering</span>
<a name="l00208"></a>00208         <span class="keywordtype">float</span> level = <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a> - 1 + <a class="code" href="pbrt_8h.html#30ecb93f0acfedc03c64d08cc7e44f23">Log2</a>(max(width, 1e-8f));
<a name="l00209"></a>00209         <span class="comment">// Perform trilinear interpolation at appropriate MIPMap level</span>
<a name="l00210"></a>00210         <span class="keywordflow">if</span> (level &lt; 0)
<a name="l00211"></a>00211                 <span class="keywordflow">return</span> <a class="code" href="classMIPMap.html#44bb0a47448035276c61097c7f7c743f">triangle</a>(0, s, t);
<a name="l00212"></a>00212         <span class="keywordflow">else</span> <span class="keywordflow">if</span> (level &gt;= <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a> - 1)
<a name="l00213"></a>00213                 <span class="keywordflow">return</span> <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(<a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>-1, 0, 0);
<a name="l00214"></a>00214         <span class="keywordflow">else</span> {
<a name="l00215"></a>00215                 <span class="keywordtype">int</span> iLevel = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>(level);
<a name="l00216"></a>00216                 <span class="keywordtype">float</span> delta = level - iLevel;
<a name="l00217"></a>00217                 <span class="keywordflow">return</span> (1.f-delta) * <a class="code" href="classMIPMap.html#44bb0a47448035276c61097c7f7c743f">triangle</a>(iLevel, s, t) +
<a name="l00218"></a>00218                         delta * <a class="code" href="classMIPMap.html#44bb0a47448035276c61097c7f7c743f">triangle</a>(iLevel+1, s, t);
<a name="l00219"></a>00219         }
<a name="l00220"></a>00220 }
<a name="l00221"></a>00221 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00222"></a><a class="code" href="classMIPMap.html#44bb0a47448035276c61097c7f7c743f">00222</a> T <a class="code" href="classMIPMap.html#44bb0a47448035276c61097c7f7c743f">MIPMap&lt;T&gt;::triangle</a>(<span class="keywordtype">int</span> level, <span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t)<span class="keyword"> const </span>{
<a name="l00223"></a>00223         level = <a class="code" href="pbrt_8h.html#036098e5cec04b73d8720de12e8e5cd1">Clamp</a>(level, 0, <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>-1);
<a name="l00224"></a>00224         s = s * <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>() - 0.5f;
<a name="l00225"></a>00225         t = t * <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>() - 0.5f;
<a name="l00226"></a>00226         <span class="keywordtype">int</span> s0 = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>(s), t0 = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>(t);
<a name="l00227"></a>00227         <span class="keywordtype">float</span> ds = s - s0, dt = t - t0;
<a name="l00228"></a>00228         <span class="keywordflow">return</span> (1.f-ds)*(1.f-dt) * <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(level, s0, t0) +
<a name="l00229"></a>00229                 (1.f-ds)*dt * <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(level, s0, t0+1) +
<a name="l00230"></a>00230                 ds*(1.f-dt) * <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(level, s0+1, t0) +
<a name="l00231"></a>00231                 ds*dt * <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(level, s0+1, t0+1);
<a name="l00232"></a>00232 }
<a name="l00233"></a>00233 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00234"></a><a class="code" href="classMIPMap.html#6b2172ef7a40219558c2464a2f9d57fe">00234</a> T <a class="code" href="classMIPMap.html#401e4e6d7bd87aae7df1ed7f87a67ed5">MIPMap&lt;T&gt;::Lookup</a>(<span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t, <span class="keywordtype">float</span> ds0, <span class="keywordtype">float</span> dt0,
<a name="l00235"></a>00235                 <span class="keywordtype">float</span> ds1, <span class="keywordtype">float</span> dt1)<span class="keyword"> const </span>{
<a name="l00236"></a>00236         <span class="keyword">static</span> <a class="code" href="classStatsCounter.html">StatsCounter</a> ewaLookups(<span class="stringliteral">"Texture"</span>, <span class="stringliteral">"EWA filter lookups"</span>); <span class="comment">// NOBOOK</span>
<a name="l00237"></a>00237         ++ewaLookups; <span class="comment">// NOBOOK</span>
<a name="l00238"></a>00238         <span class="keywordflow">if</span> (<a class="code" href="classMIPMap.html#f03004d9d7c85a3e71008725fd38f70b">doTrilinear</a>)
<a name="l00239"></a>00239                 <span class="keywordflow">return</span> <a class="code" href="classMIPMap.html#401e4e6d7bd87aae7df1ed7f87a67ed5">Lookup</a>(s, t,
<a name="l00240"></a>00240                               2.f * max(max(fabsf(ds0),
<a name="l00241"></a>00241                                                         fabsf(dt0)),
<a name="l00242"></a>00242                                         max(fabsf(ds1),
<a name="l00243"></a>00243                                                                     fabsf(dt1))));
<a name="l00244"></a>00244         <span class="comment">// Compute ellipse minor and major axes</span>
<a name="l00245"></a>00245         <span class="keywordflow">if</span> (ds0*ds0 + dt0*dt0 &lt; ds1*ds1 + dt1*dt1) {
<a name="l00246"></a>00246                 swap(ds0, ds1);
<a name="l00247"></a>00247                 swap(dt0, dt1);
<a name="l00248"></a>00248         }
<a name="l00249"></a>00249         <span class="keywordtype">float</span> majorLength = sqrtf(ds0*ds0 + dt0*dt0);
<a name="l00250"></a>00250         <span class="keywordtype">float</span> minorLength = sqrtf(ds1*ds1 + dt1*dt1);
<a name="l00251"></a>00251         <span class="comment">// Clamp ellipse eccentricity if too large</span>
<a name="l00252"></a>00252         <span class="keywordflow">if</span> (minorLength * <a class="code" href="classMIPMap.html#79b4bfc54e56a204bb196e44ef9e71ce">maxAnisotropy</a> &lt; majorLength) {
<a name="l00253"></a>00253                 <span class="keywordtype">float</span> scale = majorLength /
<a name="l00254"></a>00254                               (minorLength * <a class="code" href="classMIPMap.html#79b4bfc54e56a204bb196e44ef9e71ce">maxAnisotropy</a>);
<a name="l00255"></a>00255                 ds1 *= scale;
<a name="l00256"></a>00256                 dt1 *= scale;
<a name="l00257"></a>00257                 minorLength *= scale;
<a name="l00258"></a>00258         }
<a name="l00259"></a>00259         <span class="comment">// Choose level of detail for EWA lookup and perform EWA filtering</span>
<a name="l00260"></a>00260         <span class="keywordtype">float</span> lod = max(0.f, <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a> - 1.f + <a class="code" href="pbrt_8h.html#30ecb93f0acfedc03c64d08cc7e44f23">Log2</a>(minorLength));
<a name="l00261"></a>00261         <span class="keywordtype">int</span> ilod = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>(lod);
<a name="l00262"></a>00262         <span class="keywordtype">float</span> d = lod - ilod;
<a name="l00263"></a>00263         <span class="keywordflow">return</span> (1.f - d) * <a class="code" href="classMIPMap.html#0713ceee690ef16e6c78b976c36d30d4">EWA</a>(s, t, ds0, dt0, ds1, dt1, ilod) +
<a name="l00264"></a>00264                 d * <a class="code" href="classMIPMap.html#0713ceee690ef16e6c78b976c36d30d4">EWA</a>(s, t, ds0, dt0, ds1, dt1, ilod+1);
<a name="l00265"></a>00265 }
<a name="l00266"></a>00266 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00267"></a><a class="code" href="classMIPMap.html#0713ceee690ef16e6c78b976c36d30d4">00267</a> T <a class="code" href="classMIPMap.html#0713ceee690ef16e6c78b976c36d30d4">MIPMap&lt;T&gt;::EWA</a>(<span class="keywordtype">float</span> s, <span class="keywordtype">float</span> t, <span class="keywordtype">float</span> ds0, <span class="keywordtype">float</span> dt0,
<a name="l00268"></a>00268                 <span class="keywordtype">float</span> ds1, <span class="keywordtype">float</span> dt1, <span class="keywordtype">int</span> level)<span class="keyword"> const </span>{
<a name="l00269"></a>00269         <span class="keywordflow">if</span> (level &gt;= <a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>) <span class="keywordflow">return</span> <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(<a class="code" href="classMIPMap.html#3a1e8158f86d2332aca8323b92e7a7ae">nLevels</a>-1, 0, 0);
<a name="l00270"></a>00270         <span class="comment">// Convert EWA coordinates to appropriate scale for level</span>
<a name="l00271"></a>00271         s = s * <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>() - 0.5f;
<a name="l00272"></a>00272         t = t * <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>() - 0.5f;
<a name="l00273"></a>00273         ds0 *= <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>();
<a name="l00274"></a>00274         dt0 *= <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>();
<a name="l00275"></a>00275         ds1 *= <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#84ae63abb4fad0865935237c381ed6c3">uSize</a>();
<a name="l00276"></a>00276         dt1 *= <a class="code" href="classMIPMap.html#6b79075bc9a4424901559693a2625019">pyramid</a>[level]-&gt;<a class="code" href="classBlockedArray.html#75ebac9da54aee7b4f4765e245f2fed6">vSize</a>();
<a name="l00277"></a>00277         <span class="comment">// Compute ellipse coefficients to bound EWA filter region</span>
<a name="l00278"></a>00278         <span class="keywordtype">float</span> A = dt0*dt0 + dt1*dt1 + 1;
<a name="l00279"></a>00279         <span class="keywordtype">float</span> B = -2.f * (ds0*dt0 + ds1*dt1);
<a name="l00280"></a>00280         <span class="keywordtype">float</span> C = ds0*ds0 + ds1*ds1 + 1;
<a name="l00281"></a>00281         <span class="keywordtype">float</span> invF = 1.f / (A*C - B*B*0.25f);
<a name="l00282"></a>00282         A *= invF;
<a name="l00283"></a>00283         B *= invF;
<a name="l00284"></a>00284         C *= invF;
<a name="l00285"></a>00285         <span class="comment">// Compute the ellipse's $(s,t)$ bounding box in texture space</span>
<a name="l00286"></a>00286         <span class="keywordtype">float</span> det = -B*B + 4.f*A*C;
<a name="l00287"></a>00287         <span class="keywordtype">float</span> invDet = 1.f / det;
<a name="l00288"></a>00288         <span class="keywordtype">float</span> uSqrt = sqrtf(det * C), vSqrt = sqrtf(A * det);
<a name="l00289"></a>00289         <span class="keywordtype">int</span> s0 = <a class="code" href="pbrt_8h.html#1a941973fe233e9e8179a48dff4115c8">Ceil2Int</a> (s - 2.f * invDet * uSqrt);
<a name="l00290"></a>00290         <span class="keywordtype">int</span> s1 = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>(s + 2.f * invDet * uSqrt);
<a name="l00291"></a>00291         <span class="keywordtype">int</span> t0 = <a class="code" href="pbrt_8h.html#1a941973fe233e9e8179a48dff4115c8">Ceil2Int</a> (t - 2.f * invDet * vSqrt);
<a name="l00292"></a>00292         <span class="keywordtype">int</span> t1 = <a class="code" href="pbrt_8h.html#02648670ea7bf29f5782902cd9aa87c1">Floor2Int</a>(t + 2.f * invDet * vSqrt);
<a name="l00293"></a>00293         <span class="keyword">static</span> <a class="code" href="classStatsRatio.html">StatsRatio</a> ewaTexels(<span class="stringliteral">"Texture"</span>, <span class="stringliteral">"Texels per EWA lookup"</span>); <span class="comment">// NOBOOK</span>
<a name="l00294"></a>00294         ewaTexels.<a class="code" href="classStatsRatio.html#c0530f7ffbb92fa6f736767f0217ed51">Add</a>((1+s1-s0) * (1+t1-t0), 1); <span class="comment">// NOBOOK</span>
<a name="l00295"></a>00295         <span class="comment">// Scan over ellipse bound and compute quadratic equation</span>
<a name="l00296"></a>00296         T num(0.);
<a name="l00297"></a>00297         <span class="keywordtype">float</span> den = 0;
<a name="l00298"></a>00298         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> it = t0; it &lt;= t1; ++it) {
<a name="l00299"></a>00299                 <span class="keywordtype">float</span> tt = it - t;
<a name="l00300"></a>00300                 <span class="keywordflow">for</span> (<span class="keywordtype">int</span> is = s0; is &lt;= s1; ++is) {
<a name="l00301"></a>00301                         <span class="keywordtype">float</span> ss = is - s;
<a name="l00302"></a>00302                         <span class="comment">// Compute squared radius and filter texel if inside ellipse</span>
<a name="l00303"></a>00303                         <span class="keywordtype">float</span> r2 = A*ss*ss + B*ss*tt + C*tt*tt;
<a name="l00304"></a>00304                         <span class="keywordflow">if</span> (r2 &lt; 1.) {
<a name="l00305"></a>00305                                 <span class="keywordtype">float</span> weight =
<a name="l00306"></a>00306                                         <a class="code" href="classMIPMap.html#4127d975dd0721f8ecc6c23a82d840ba">weightLut</a>[min(<a class="code" href="pbrt_8h.html#83f20d5f659d8dcbbb5623d1f39cf244">Float2Int</a>(r2 * <a class="code" href="mipmap_8h.html#b8aef080a497e9b8cc3f0fe1ef4d8965">WEIGHT_LUT_SIZE</a>),
<a name="l00307"></a>00307                                         WEIGHT_LUT_SIZE-1)];
<a name="l00308"></a>00308                                 num += <a class="code" href="classMIPMap.html#c39a74b22a6413c1eb7ca15227954282">texel</a>(level, is, it) * weight;
<a name="l00309"></a>00309                                 den += weight;
<a name="l00310"></a>00310                         }
<a name="l00311"></a>00311                 }
<a name="l00312"></a>00312         }
<a name="l00313"></a>00313         <span class="keywordflow">return</span> num / den;
<a name="l00314"></a>00314 }
<a name="l00315"></a>00315 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt; <span class="keywordtype">float</span> *<a class="code" href="classMIPMap.html">MIPMap&lt;T&gt;::weightLut</a> = NULL;
<a name="l00316"></a>00316 <span class="preprocessor">#endif // PBRT_MIPMAP_H</span>
</pre></div></div>
<hr size="1"><address style="text-align: right;"><small>Generated on Mon Jul 20 17:31:53 2009 for pbrt by&nbsp;
<a href="http://www.doxygen.org/index.html">
<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.6 </small></address>
</body>
</html>