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Diffstat (limited to '')
-rw-r--r-- | src/PcmUtils.hxx | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/src/PcmUtils.hxx b/src/PcmUtils.hxx new file mode 100644 index 000000000..d77c4194a --- /dev/null +++ b/src/PcmUtils.hxx @@ -0,0 +1,66 @@ +/* + * Copyright (C) 2003-2011 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef MPD_PCM_UTILS_H +#define MPD_PCM_UTILS_H + +#include "gcc.h" + +#include <limits> + +#include <stdint.h> + +/** + * Add a byte count to the specified pointer. This is a utility + * function to convert a source pointer and a byte count to an "end" + * pointer for use in loops. + */ +template<typename T> +static inline const T * +pcm_end_pointer(const T *p, size_t size) +{ + return (const T *)((const uint8_t *)p + size); +} + +/** + * Check if the value is within the range of the provided bit size, + * and caps it if necessary. + */ +template<typename T, typename U, unsigned bits> +gcc_const +static inline T +PcmClamp(U x) +{ + constexpr U MIN_VALUE = -(U(1) << (bits - 1)); + constexpr U MAX_VALUE = (U(1) << (bits - 1)) - 1; + + typedef std::numeric_limits<T> limits; + static_assert(MIN_VALUE >= limits::min(), "out of range"); + static_assert(MAX_VALUE <= limits::max(), "out of range"); + + if (gcc_unlikely(x < MIN_VALUE)) + return T(MIN_VALUE); + + if (gcc_unlikely(x > MAX_VALUE)) + return T(MAX_VALUE); + + return T(x); +} + +#endif |