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diff --git a/doc/info/chap/functions.texinfo b/doc/info/chap/functions.texinfo new file mode 100644 index 0000000..9f98353 --- /dev/null +++ b/doc/info/chap/functions.texinfo @@ -0,0 +1,75 @@ +@node Functions +@chapter Functions + +The following functions are available in @command{libcolour}: + +@table @code +@item int libcolour_convert(const libcolour_colour_t* restrict, libcolour_colour_t* restrict) +Colour space and colour model conversion. +Described in @ref{Colour Spaces}. + +@item double libcolour_srgb_encode(double) +Apply the sRGB transfer function. +Described in @ref{sRGB}. + +@item double libcolour_srgb_decode(double) +Unapply the sRGB transfer function. +Described in @ref{sRGB}. + +@item int libcolour_delta_e(const libcolour_colour_t*, const libcolour_colour_t*, double*) +Calculates the @math{\Delta e^*_{ab}} distance +(the distance in CIE L*a*b*) of two colours. + +@item int libcolour_proper(libcolour_colour_t*) +Sets any member or submember that may be +incorrectly set. Returns 0 on success, and +@math{-1} on error. On error @code{errno} +set appropriately. Error is only possible +is there is something wrong with the described +colour space that cannot be fixed. + +@item int libcolour_get_rgb_colour_space(libcolour_rgb_t*, libcolour_rgb_colour_space_t) +Selects RGB colour space. +Described in @ref{RGB}. + +@item size_t libcolour_marshal(const libcolour_colour_t*, void*) +Store a colour into a buffer, and returns the number +of bytes written. If @code{NULL} is given instead of +a buffer, the number of bytes that would have been +written is returned. + +This function will always write an @code{int} that +is used to identify the version of @command{libcolour} +so it can be decoded by future versions. + +In addition to this @code{int}, all the content of +the structure is copied, so uninitialised values +can be copied. However, it will never copy more than +the size of the structure used to represent colours +with used colour model. For example, is the @code{.model} +member if the colour is set to @code{LIBCOLOUR_SRGB}, +no more than @code{sizeof(libcolour_srgb_t)} is written +in addition to the initial @code{int}. If the value +of @code{.model} is invalid, 0 is returned and +@code{errno} is set to @code{EINVAL}. + +The written data is machine architecture specific. + +@item size_t libcolour_unmarshal(libcolour_colour_t*, const void*) +Restores a colour from a buffer, and returns the number +of bytes read. If @code{NULL} is given instead of +an output pointer for the colour, the number of bytes +that would have been read is returned. + +If the stored @code{int} at the beginning does +not match a recognised version of @command{libcolour}, +0 is returned and errno is set to @code{EINVAL}, this +also happens if the stored colour does not used +a recognised colour model. + +If the stored colour uses a custom (not pre-defined) +RGB colour space with custom a transfer function, the +user must set them after calling @code{libcolour_unmarshal}. + +@end table + diff --git a/doc/info/content.texinfo b/doc/info/content.texinfo index eee47a3..4ad71d5 100644 --- a/doc/info/content.texinfo +++ b/doc/info/content.texinfo @@ -11,6 +11,7 @@ * Overview:: Brief overview of @command{libcolour}. * Colour Spaces:: Colour-space conversion. * Illuminants:: Illuminant initialisers. +* Functions:: Functions available in @command{libcolour}. * Free Software Needs Free Documentation:: Why free documentation is important. * GNU General Public License:: Copying and sharing @command{libcolour}. @@ -39,6 +40,7 @@ Colour Spaces Illuminants +Functions Free Software Needs Free Documentation @@ -53,6 +55,7 @@ GNU Free Documentation License @include chap/overview.texinfo @include chap/colour-spaces.texinfo @include chap/illuminants.texinfo +@include chap/functions.texinfo @include appx/free-software-needs-free-documentation.texinfo |