Mathematical Functions

Most shader languages are based on some kind of C and thereby seem to inherit a good bunch of the well known math.h functions. On the other hand does GLSL define additional functions which don't come with the C standard libraries, or it uses features like overloading, which leads to problems when a function like sin() is defined as sin(float) as well as for sin(double) - in these cases DCTL avoids the ambiguity by providing explicit functions to determine the required variant - in the example a _sinf() works for a float parameter and only a float parameter.

Function	Remark
cos()	Replace with DCTL's _cosf(float)
fract()	Implementation needed for Cuda
pow()	Corrected version needed for some shaders
max()	Replace with _fmaxf()
min()	Replace with _fmixf()
mod()	Replace with mod_f()
sign()	Implementation needed for Cuda
sin()	Replace with DCTL's _sinf(float)

See also WebGL to DCTL for a differently formatted overview on how to convert which of these functions.

Functions that do not come with math.h and must be implemented separately - if they don't come with the Graphics API or DCTL already.

Function	Description
clamp()	Exists (at least clamp(float,float,float)
dot()	Exists (at least dot(float,float); we'll have to check for Vector types
radians()	Implement as radians(float) (missing in Cuda - maybe better radians_f())
distance()	Implement as distance_f and distance_fx (missing in Cuda)
reflect()	Missing in OpenCL (metal ? don't know exactly-please check)

External links

• C Mathematical Functions on Wikipedia
• Common Mathematical Functions on cppreference.co
• Cuda Math API on docs.nvidia.com
• OpenGL Reference at khronos.org