.TH LIBCOLOUR_CONVERT_EN_MASSE 3 libcolour
.SH NAME
libcolour_convert_en_masse - Colour space and colour model conversion for many colours
.SH SYNOPSIS
.nf
#include <libcolour.h>

int \fBlibcolour_convert_en_masse_f\fP(const libcolour_colour_f_t *restrict \fIfrom\fP,
                                 const libcolour_colour_f_t *restrict \fIto\fP,
                                 libcolour_convert_en_masse_mode_t \fImode\fP,
                                 size_t \fIn\fP, ...);
int \fBlibcolour_convert_en_masse_lf\fP(const libcolour_colour_lf_t *restrict \fIfrom\fP,
                                  const libcolour_colour_lf_t *restrict \fIto\fP,
                                  libcolour_convert_en_masse_mode_t \fImode\fP,
                                  size_t \fIn\fP, ...);
int \fBlibcolour_convert_en_masse_llf\fP(const libcolour_colour_llf_t *restrict \fIfrom\fP,
                                   const libcolour_colour_llf_t *restrict \fIto\fP,
                                   libcolour_convert_en_masse_mode_t \fImode\fP,
                                   size_t \fIn\fP, ...);

#define \fBlibcolour_convert_en_masse\fP(\fIfrom\fP, \fIto\fP, \fImode\fP, \fIn\fP, ...)\\
	(_Generic((\fIfrom\fP),\\
	          const libcolour_colour_f_t *:\\
                          \fBlibcolour_convert_en_masse_f\fP(\fIfrom\fP, \fIto\fP, \fImode\fP, \fIn\fP, __VA_ARGS__),\\
	          const libcolour_colour_lf_t *:\\
                          \fBlibcolour_convert_en_masse_lf\fP(\fIfrom\fP, \fIto\fP, \fImode\fP, \fIn\fP, __VA_ARGS__),\\
	          const libcolour_colour_llf_t *:\\
                          \fBlibcolour_convert_en_masse_llf\fP(\fIfrom\fP, \fIto\fP, \fImode\fP, \fIn\fP, __VA_ARGS__)))
	          /* list is incomplete */
.fi
.SH DESCRIPTION
.B libcolour_convert_en_masse
and its non-generic functions converts
.I n
colours from the colour space and transfer function
specified in
.I from
to the colour space and transfer function specified in
.IR to .
.I mode
specifies the behaviour of the functions. It shall
be the
.B OR
the any, or none, of the following values:
.TP
.B LIBCOLOUR_CONVERT_EN_MASSE_ON_CPU
Perform convertion on CPU rather than on GPU.
.TP
.B LIBCOLOUR_CONVERT_EN_MASSE_NO_OVERRIDE
Output parameters are listed after input parameters,
rather than using the input parametrs as the
output parameters. These will have the same type
as the input parameters.
.P
and one of the following values:
.TP
.B LIBCOLOUR_CONVERT_EN_MASSE_NO_ALPHA
The parameter after
.I n
is
.BR float\ * ,
.BR double\ * ,
or
.BR long\ double\ * ,
depending of the which function is called.
The argument shall be the values of the colour,
without any alpha channel, repeated
.I n
times (once per colour).
For example, if
.BI ( from->model ==LIBCOLOUR_RGB)
and if
.BI ( n ==2)
the values in the pointer shall be
.BI { colour[0].red ,
.IB colour[0].green ,
.IB colour[0].blue ,
.IB colour[1].red ,
.IB colour[1].green ,
.IB colour[1].blue }
for an imaginary
.BR libcolour_rgb_f_t \ \fIcolour[2]\fP,
.BR libcolour_rgb_lf_t \ \fIcolour[2]\fP,
or
.BR libcolour_rgb_llf_t \ \fIcolour[2]\fP,
depending on which function is called.
.TP
.B LIBCOLOUR_CONVERT_EN_MASSE_ALPHA_FIRST
Same as
.BR LIBCOLOUR_CONVERT_EN_MASSE_NO_ALPHA ,
except before each red channel value (in the
case of RGB that is, the first channel value in
general) there is an alpha channel value that
will not be modified.
.TP
.B LIBCOLOUR_CONVERT_EN_MASSE_ALPHA_LAST
Same as
.BR LIBCOLOUR_CONVERT_EN_MASSE_NO_ALPHA ,
except after each blue channel value (in the
case of RGB that is, the last cannel value in
general) there is an alpha channel value that
will not be modified.
.TP
.B LIBCOLOUR_CONVERT_EN_MASSE_SEPARATED
After the parameter
.I n
there is one parameter per channel, these
parameters are of the type
.BR float\ * ,
.BR double\ * ,
or
.BR long\ double\ * ,
depending of the which function is called.
Each parameter shall be a pointer with
.I n
elements, one per colour to convert.
.SH RETURN VALUES
Upon successful completion, the functions returns 0.
Otherwise the function return -1 with
.I errno
set to indicate the error.
.SH ERRORS
.TP
.B EINVAL
.I from->model
or
.I to->model
does not refer to a recognised colour model.
.SH NOTES
.B libcolour_convert_en_masse
cannot convert between
.BR float ,
.BR double ,
and
.BR long\ double ,
.I from
and
.I to
most use the same floating-point type.
.P
GPU acceleration is currently not implemented.
.SH SEE ALSO
.BR libcolour (7),
.BR libcolour_convert (3)
.SH AUTHORS
Mattias Andrée
.RI < maandree@kth.se >