Libfixmath

libfixmath
Developer(s)	Ben Brewer
Stable release	r64 / February 2, 2012; 13 years ago
Repository	code.google.com/archive/p/libfixmath/source/default/source ;
Written in	C99
Operating system	Cross-platform
Type	fixed-point math library
License	MIT
Website	code.google.com/p/libfixmath

libfixmath is a platform-independent fixed-point math library aimed at developers wanting to perform fast non-integer math on platforms lacking a (or with a low performance) FPU. It offers developers a similar interface to the standard math.h functions for use on Q16.16 fixed-point numbers. libfixmath has no external dependencies other than stdint.h and a compiler which supports 64-bit integer arithmetic (such as GCC).^[1] Conditional compilation options exist to remove the requirement for a 64-bit capable compiler as many compilers for microcontrollers and DSPs do not support 64-bit arithmetic.^[2]

History

libfixmath was developed by Ben Brewer and first released publicly as part of the Dingoo SDK.^[3] It has since been used to implement a software 3D graphics library called FGL.^[4]

Q16.16 functions

Name	Description
`fix16_acos`	inverse cosine
`fix16_asin`	inverse sine
`fix16_atan`	one-parameter inverse tangent
`fix16_atan2`	two-parameter inverse tangent
`fix16_cos`	cosine
`fix16_exp`	exponential function
`fix16_sin`	sine
`fix16_sqrt`	square root
`fix16_tan`	tangent
`fix16_mul`	multiplication
`fix16_div`	division
`fix16_sadd`	saturated addition
`fix16_smul`	saturated multiplication
`fix16_sdiv`	saturated division

Other functions

Name	Description
`fix16_to_dbl`	Convert Q16.16 to a double
`fix16_to_float`	Convert Q16.16 to a float
`fix16_to_int`	Convert Q16.16 to an integer
`fix16_from_dbl`	Convert double to a Q16.16
`fix16_from_float`	Convert float to a Q16.16
`fix16_from_int`	Convert integer to a Q16.16