1 /*****************************************************************************/ 2 // Copyright 2006-2019 Adobe Systems Incorporated 3 // All Rights Reserved. 4 // 5 // NOTICE: Adobe permits you to use, modify, and distribute this file in 6 // accordance with the terms of the Adobe license agreement accompanying it. 7 /*****************************************************************************/ 8 9 /** \file 10 * Definition of a lookup table based 1D floating-point to floating-point function abstraction using linear interpolation. 11 */ 12 13 /*****************************************************************************/ 14 15 #ifndef __dng_1d_table__ 16 #define __dng_1d_table__ 17 18 /*****************************************************************************/ 19 20 #include "dng_assertions.h" 21 #include "dng_auto_ptr.h" 22 #include "dng_classes.h" 23 #include "dng_types.h" 24 #include "dng_uncopyable.h" 25 26 /*****************************************************************************/ 27 28 /// \brief A 1D floating-point lookup table using linear interpolation. 29 30 class dng_1d_table: private dng_uncopyable 31 { 32 33 public: 34 35 /// Constant denoting minimum size of table. 36 37 static const uint32 kMinTableSize = 512; 38 39 private: 40 41 /// Constant denoting default size of table. 42 43 static const uint32 kDefaultTableSize = 4096; 44 45 protected: 46 47 AutoPtr<dng_memory_block> fBuffer; 48 49 real32 *fTable; 50 51 const uint32 fTableCount; 52 53 public: 54 55 /// Table constructor. count must be a power of two 56 /// and at least kMinTableSize. 57 58 explicit dng_1d_table (uint32 count = kDefaultTableSize); 59 60 virtual ~dng_1d_table (); 61 62 /// Number of table entries. 63 Count()64 uint32 Count () const 65 { 66 return fTableCount; 67 } 68 69 /// Set up table, initialize entries using functiion. 70 /// This method can throw an exception, e.g. if there is not enough memory. 71 /// \param allocator Memory allocator from which table memory is allocated. 72 /// \param function Table is initialized with values of finction.Evalluate(0.0) to function.Evaluate(1.0). 73 /// \param subSample If true, only sample the function a limited number of times and interpolate. 74 75 void Initialize (dng_memory_allocator &allocator, 76 const dng_1d_function &function, 77 bool subSample = false); 78 79 /// Lookup and interpolate mapping for an input. 80 /// \param x value from 0.0 to 1.0 used as input for mapping 81 /// \retval Approximation of function.Evaluate(x) 82 Interpolate(real32 x)83 real32 Interpolate (real32 x) const 84 { 85 86 real32 y = x * (real32) fTableCount; 87 88 int32 index = (int32) y; 89 90 // Enable vectorization by using DNG_ASSERT instead of DNG_REQUIRE 91 DNG_ASSERT(!(index < 0 || index >(int32) fTableCount), "dng_1d_table::Interpolate parameter out of range"); 92 93 real32 z = (real32) index; 94 95 real32 fract = y - z; 96 97 return fTable [index ] * (1.0f - fract) + 98 fTable [index + 1] * ( fract); 99 100 } 101 102 /// Direct access function for table data. 103 Table()104 const real32 * Table () const 105 { 106 return fTable; 107 } 108 109 /// Expand the table to a 16-bit to 16-bit table. 110 111 void Expand16 (uint16 *table16) const; 112 113 private: 114 115 void SubDivide (const dng_1d_function &function, 116 uint32 lower, 117 uint32 upper, 118 real32 maxDelta); 119 120 }; 121 122 /*****************************************************************************/ 123 124 #endif 125 126 /*****************************************************************************/ 127