From ed61bcfee4991ad061d0f6d56ce59170898e248b Mon Sep 17 00:00:00 2001 From: Pavel Krajcevski Date: Mon, 10 Mar 2014 18:30:27 -0400 Subject: [PATCH] Add generatl bit replication function --- Base/include/Bits.h | 23 ++++++++++++++ Base/src/Pixel.cpp | 13 ++------ Base/test/CMakeLists.txt | 2 +- Base/test/TestBits.cpp | 69 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 96 insertions(+), 11 deletions(-) create mode 100644 Base/test/TestBits.cpp diff --git a/Base/include/Bits.h b/Base/include/Bits.h index bb42996..e593b8e 100644 --- a/Base/include/Bits.h +++ b/Base/include/Bits.h @@ -88,5 +88,28 @@ namespace FasTC { } }; + // Replicates low numBits such that [(toBit - 1):(toBit - 1 - fromBit)] + // is the same as [(numBits - 1):0] and repeats all the way down. + template + IntType Replicate(const IntType &val, uint32 numBits, uint32 toBit) { + if(numBits == 0) return 0; + if(toBit == 0) return 0; + IntType v = val & ((1 << numBits) - 1); + IntType res = v; + uint32 reslen = numBits; + while(reslen < toBit) { + uint32 comp = 0; + if(numBits > toBit - reslen) { + uint32 newshift = toBit - reslen; + comp = numBits - newshift; + numBits = newshift; + } + res <<= numBits; + res |= v >> comp; + reslen += numBits; + } + return res; + } + } // namespace FasTC #endif // __BASE_INCLUDE_BITS_H__ diff --git a/Base/src/Pixel.cpp b/Base/src/Pixel.cpp index 7806292..0ee8a87 100644 --- a/Base/src/Pixel.cpp +++ b/Base/src/Pixel.cpp @@ -56,6 +56,8 @@ #include #include +#include "Bits.h" + template static inline T Clamp(const T &v, const T &_min, const T &_max) { return std::max(_min, std::min(v, _max)); @@ -161,16 +163,7 @@ namespace FasTC { } else if(oldDepth == 0 && newDepth != 0) { return (1 << newDepth) - 1; } else if(newDepth > oldDepth) { - uint8 bitsLeft = newDepth; - uint8 ret = 0; - while(bitsLeft > oldDepth) { - ret |= val; - bitsLeft -= oldDepth; - ret <<= std::min(bitsLeft, oldDepth); - } - - return ret | (val >> (oldDepth - bitsLeft)); - + return Replicate(val, oldDepth, newDepth); } else { // oldDepth > newDepth if(newDepth == 0) { diff --git a/Base/test/CMakeLists.txt b/Base/test/CMakeLists.txt index 25deb87..47e5be1 100644 --- a/Base/test/CMakeLists.txt +++ b/Base/test/CMakeLists.txt @@ -55,7 +55,7 @@ INCLUDE_DIRECTORIES(${FasTC_BINARY_DIR}/Base/include ) INCLUDE_DIRECTORIES(${FasTC_SOURCE_DIR}/GTest/include) SET(TESTS - Vector Matrix Pixel Image Color + Vector Matrix Pixel Image Color Bits ) FOREACH(TEST ${TESTS}) diff --git a/Base/test/TestBits.cpp b/Base/test/TestBits.cpp new file mode 100644 index 0000000..3f3b94a --- /dev/null +++ b/Base/test/TestBits.cpp @@ -0,0 +1,69 @@ +/* FasTC + * Copyright (c) 2014 University of North Carolina at Chapel Hill. + * All rights reserved. + * + * Permission to use, copy, modify, and distribute this software and its + * documentation for educational, research, and non-profit purposes, without + * fee, and without a written agreement is hereby granted, provided that the + * above copyright notice, this paragraph, and the following four paragraphs + * appear in all copies. + * + * Permission to incorporate this software into commercial products may be + * obtained by contacting the authors or the Office of Technology Development + * at the University of North Carolina at Chapel Hill . + * + * This software program and documentation are copyrighted by the University of + * North Carolina at Chapel Hill. The software program and documentation are + * supplied "as is," without any accompanying services from the University of + * North Carolina at Chapel Hill or the authors. The University of North + * Carolina at Chapel Hill and the authors do not warrant that the operation of + * the program will be uninterrupted or error-free. The end-user understands + * that the program was developed for research purposes and is advised not to + * rely exclusively on the program for any reason. + * + * IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE + * AUTHORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, + * OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF + * THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF NORTH CAROLINA + * AT CHAPEL HILL OR THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS SPECIFICALLY + * DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ANY + * STATUTORY WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE PROVIDED HEREUNDER IS ON + * AN "AS IS" BASIS, AND THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND + * THE AUTHORS HAVE NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, + * ENHANCEMENTS, OR MODIFICATIONS. + * + * Please send all BUG REPORTS to . + * + * The authors may be contacted via: + * + * Pavel Krajcevski + * Dept of Computer Science + * 201 S Columbia St + * Frederick P. Brooks, Jr. Computer Science Bldg + * Chapel Hill, NC 27599-3175 + * USA + * + * + */ + +#include "gtest/gtest.h" +#include "Bits.h" + +TEST(Bits, Replicate) { + uint32 xv = 3; + EXPECT_EQ(FasTC::Replicate(xv, 2, 8), 0xFF); + EXPECT_EQ(FasTC::Replicate(xv, 0, 7), 0); + EXPECT_EQ(FasTC::Replicate(xv, 3, 4), 0x06); + + xv = 0; + EXPECT_EQ(FasTC::Replicate(xv, 1, 0), 0); + EXPECT_EQ(FasTC::Replicate(xv, 0, 7), 0); + + xv = 5; + EXPECT_EQ(FasTC::Replicate(xv, 2, 0), 0); + EXPECT_EQ(FasTC::Replicate(xv, 3, 6), 0x2D); +}