1 | /*****************************************************************************/ |
2 | // Copyright 2006-2008 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 | /* $Id: //mondo/dng_sdk_1_4/dng_sdk/source/dng_1d_table.h#1 $ */ |
10 | /* $DateTime: 2012/05/30 13:28:51 $ */ |
11 | /* $Change: 832332 $ */ |
12 | /* $Author: tknoll $ */ |
13 | |
14 | /** \file |
15 | * Definition of a lookup table based 1D floating-point to floating-point function abstraction using linear interpolation. |
16 | */ |
17 | |
18 | /*****************************************************************************/ |
19 | |
20 | #ifndef __dng_1d_table__ |
21 | #define __dng_1d_table__ |
22 | |
23 | /*****************************************************************************/ |
24 | |
25 | #include "dng_assertions.h" |
26 | #include "dng_auto_ptr.h" |
27 | #include "dng_classes.h" |
28 | #include "dng_types.h" |
29 | |
30 | /*****************************************************************************/ |
31 | |
32 | /// \brief A 1D floating-point lookup table using linear interpolation. |
33 | |
34 | class dng_1d_table |
35 | { |
36 | |
37 | public: |
38 | |
39 | /// Constants denoting size of table. |
40 | |
41 | enum |
42 | { |
43 | kTableBits = 12, //< Table is always a power of 2 in size. This is log2(kTableSize). |
44 | kTableSize = (1 << kTableBits) //< Number of entries in table. |
45 | }; |
46 | |
47 | protected: |
48 | |
49 | AutoPtr<dng_memory_block> fBuffer; |
50 | |
51 | real32 *fTable; |
52 | |
53 | public: |
54 | |
55 | dng_1d_table (); |
56 | |
57 | virtual ~dng_1d_table (); |
58 | |
59 | /// Set up table, initialize entries using functiion. |
60 | /// This method can throw an exception, e.g. if there is not enough memory. |
61 | /// \param allocator Memory allocator from which table memory is allocated. |
62 | /// \param function Table is initialized with values of finction.Evalluate(0.0) to function.Evaluate(1.0). |
63 | /// \param subSample If true, only sample the function a limited number of times and interpolate. |
64 | |
65 | void Initialize (dng_memory_allocator &allocator, |
66 | const dng_1d_function &function, |
67 | bool subSample = false); |
68 | |
69 | /// Lookup and interpolate mapping for an input. |
70 | /// \param x value from 0.0 to 1.0 used as input for mapping |
71 | /// \retval Approximation of function.Evaluate(x) |
72 | |
73 | real32 Interpolate (real32 x) const |
74 | { |
75 | |
76 | real32 y = x * (real32) kTableSize; |
77 | |
78 | int32 index = (int32) y; |
79 | |
80 | if (index < 0 || index > kTableSize) |
81 | { |
82 | |
83 | ThrowBadFormat("Index out of range." ); |
84 | |
85 | } |
86 | |
87 | DNG_ASSERT (index >= 0 && index <= kTableSize, |
88 | "dng_1d_table::Interpolate parameter out of range" ); |
89 | |
90 | real32 z = (real32) index; |
91 | |
92 | real32 fract = y - z; |
93 | |
94 | return fTable [index ] * (1.0f - fract) + |
95 | fTable [index + 1] * ( fract); |
96 | |
97 | } |
98 | |
99 | /// Direct access function for table data. |
100 | |
101 | const real32 * Table () const |
102 | { |
103 | return fTable; |
104 | } |
105 | |
106 | /// Expand the table to a 16-bit to 16-bit table. |
107 | |
108 | void Expand16 (uint16 *table16) const; |
109 | |
110 | private: |
111 | |
112 | void SubDivide (const dng_1d_function &function, |
113 | uint32 lower, |
114 | uint32 upper, |
115 | real32 maxDelta); |
116 | |
117 | // Hidden copy constructor and assignment operator. |
118 | |
119 | dng_1d_table (const dng_1d_table &table); |
120 | |
121 | dng_1d_table & operator= (const dng_1d_table &table); |
122 | |
123 | }; |
124 | |
125 | /*****************************************************************************/ |
126 | |
127 | #endif |
128 | |
129 | /*****************************************************************************/ |
130 | |