PBRT
/home/felix/UBC/projects/AdaptiveLightfieldSampling/pbrt_v2/src/filters/sinc.h
00001 
00002 /*
00003     pbrt source code Copyright(c) 1998-2012 Matt Pharr and Greg Humphreys.
00004 
00005     This file is part of pbrt.
00006 
00007     Redistribution and use in source and binary forms, with or without
00008     modification, are permitted provided that the following conditions are
00009     met:
00010 
00011     - Redistributions of source code must retain the above copyright
00012       notice, this list of conditions and the following disclaimer.
00013 
00014     - Redistributions in binary form must reproduce the above copyright
00015       notice, this list of conditions and the following disclaimer in the
00016       documentation and/or other materials provided with the distribution.
00017 
00018     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
00019     IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
00020     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
00021     PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
00022     HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00023     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00024     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00025     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00026     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00027     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00028     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00029 
00030  */
00031 
00032 #if defined(_MSC_VER)
00033 #pragma once
00034 #endif
00035 
00036 #ifndef PBRT_FILTERS_SINC_H
00037 #define PBRT_FILTERS_SINC_H
00038 
00039 // filters/sinc.h*
00040 #include "filter.h"
00041 
00042 // Sinc Filter Declarations
00043 class LanczosSincFilter : public Filter {
00044 public:
00045     // LanczosSincFilter Public Methods
00046     LanczosSincFilter(float xw, float yw, float t)
00047         : Filter(xw, yw), tau(t) { }
00048     float Evaluate(float x, float y) const;
00049     float Sinc1D(float x) const {
00050         x = fabsf(x);
00051         if (x < 1e-5) return 1.f;
00052         if (x > 1.)   return 0.f;
00053         x *= M_PI;
00054         float sinc = sinf(x) / x;
00055         float lanczos = sinf(x * tau) / (x * tau);
00056         return sinc * lanczos;
00057     }
00058 private:
00059     const float tau;
00060 };
00061 
00062 
00063 LanczosSincFilter *CreateSincFilter(const ParamSet &ps);
00064 
00065 #endif // PBRT_FILTERS_SINC_H