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52 lines
1.3 KiB
C
52 lines
1.3 KiB
C
#ifndef WIN32 /* currently we support fast acosf computation only on UNIX/Linux */
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/*
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* @brief Fast arithmetic using precomputed arc cosine table.
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*
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* Contributor(s):
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*
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* Eric des Courtis <eric.des.courtis@benbria.com>
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* Piotr Gregor <piotrgregor@rsyncme.org>
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*/
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#ifndef __AVMD_FAST_ACOSF_H__
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#define __AVMD_FAST_ACOSF_H__
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#define ACOS_TABLE_FILENAME "/tmp/acos_table.dat"
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/*! \brief Arc cosine table initialization.
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*
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* @return 0 on success, negative value otherwise:
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* -1 can't access arc cos table with error != NOENT,
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* -2 table creation failed (compute_table)
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* -3 can access table but fopen failed
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* -4 mmap failed
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*/
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extern int init_fast_acosf(void);
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/*! \brief Arc cosine table deinitialization.
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*
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* @return 0 on success, negative value otherwise:
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* -1 munmap failed,
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* -2 close failed
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*/
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extern int destroy_fast_acosf(void);
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/*! \brief Return arc cos for this argument.
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* @details Uses previously created and mmapped file.
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*/
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extern float fast_acosf(float x);
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/*! \brief Arc cosine table creation.
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*
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* @return 0 on success, negative value otherwise:
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* -1 fwrite failed,
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* -2 fclose failed
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*/
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extern int compute_table(void);
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#endif /* __AVMD_FAST_ACOSF_H__ */
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#endif
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