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650e26b6ab
The cos/sin table class now has an at() function for indexing safely into its internal array. This allows the checking and computing of the correct indexes to be done internally. The indexing in allows cos/sine of 0 to 2pi to be obtained. The values returned by getTable are the same as before. Comments that describe the values that the table contains has been modified to line up with what the code is doing.
73 lines
2.1 KiB
C++
73 lines
2.1 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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*/
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#ifndef COMMON_SINETABLES_H
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#define COMMON_SINETABLES_H
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namespace Common {
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class SineTable {
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public:
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/**
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* Construct a sine table with the specified bit precision
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*
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* @param bitPrecision Precision of the table, which must be in range [4, 16]
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*/
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SineTable(int bitPrecision);
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~SineTable();
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/**
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* Get pointer to table
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*
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* This table contains 2^bitPrecision/2 entries.
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* Prefer to use at()
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* The layout of this table is as follows:
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* - Entries 0 up to (excluding) 2^bitPrecision/4:
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* sin(0) till (excluding) sin(1/2*pi)
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* - Entries 2^bitPrecision/4 up to 2^bitPrecision/2:
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* sin(pi) till (excluding) sin(3/2*pi)
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*/
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const float *getTable() { return _table; }
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/**
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* Returns sin(2*pi * index / 2^bitPrecision )
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* Index must be in range [0,2^bitPrecision-1]
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*/
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float at(int index) const;
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/**
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* Get bit precision
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*/
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int getBitPrecision() { return _bitPrecision; }
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private:
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float *_table;
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int _bitPrecision;
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double _radResolution; // Smallest radian increment
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int _refSize; // _nPoints / 4
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int _nPoints; // range of operator[]
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};
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} // End of namespace Common
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#endif // COMMON_SINETABLES_H
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