diff options
Diffstat (limited to 'man/curs_color.3x')
| -rw-r--r-- | man/curs_color.3x | 72 |
1 files changed, 60 insertions, 12 deletions
diff --git a/man/curs_color.3x b/man/curs_color.3x index b3521cb..2b8b607 100644 --- a/man/curs_color.3x +++ b/man/curs_color.3x @@ -1,5 +1,5 @@ .\"*************************************************************************** -.\" Copyright 2018-2019,2020 Thomas E. Dickey * +.\" Copyright 2018-2020,2021 Thomas E. Dickey * .\" Copyright 1998-2016,2017 Free Software Foundation, Inc. * .\" * .\" Permission is hereby granted, free of charge, to any person obtaining a * @@ -27,7 +27,7 @@ .\" authorization. * .\"*************************************************************************** .\" -.\" $Id: curs_color.3x,v 1.62 2020/02/02 23:34:34 tom Exp $ +.\" $Id: curs_color.3x,v 1.66 2021/09/04 19:42:20 tom Exp $ .TH curs_color 3X "" .ie \n(.g .ds `` \(lq .el .ds `` `` @@ -66,31 +66,31 @@ .br \fBbool can_change_color(void);\fR .sp -\fBint init_pair(short pair, short f, short b);\fR +\fBint init_pair(short \fP\fIpair\fP\fB, short \fP\fIf\fP\fB, short \fP\fIb\fP\fB);\fR .br -\fBint init_color(short color, short r, short g, short b);\fR +\fBint init_color(short \fP\fIcolor\fP\fB, short \fP\fIr\fP\fB, short \fP\fIg\fP\fB, short \fP\fIb\fP\fB);\fR .br /* extensions */ .br -\fBint init_extended_pair(int pair, int f, int b);\fR +\fBint init_extended_pair(int \fP\fIpair\fP\fB, int \fP\fIf\fP\fB, int \fP\fIb\fP\fB);\fR .br -\fBint init_extended_color(int color, int r, int g, int b);\fR +\fBint init_extended_color(int \fP\fIcolor\fP\fB, int \fP\fIr\fP\fB, int \fP\fIg\fP\fB, int \fP\fIb\fP\fB);\fR .sp -\fBint color_content(short color, short *r, short *g, short *b);\fR +\fBint color_content(short \fP\fIcolor\fP\fB, short *\fP\fIr\fP\fB, short *\fP\fIg\fP\fB, short *\fP\fIb\fP\fB);\fR .br -\fBint pair_content(short pair, short *f, short *b);\fR +\fBint pair_content(short \fP\fIpair\fP\fB, short *\fP\fIf\fP\fB, short *\fP\fIb\fP\fB);\fR .br /* extensions */ .br -\fBint extended_color_content(int color, int *r, int *g, int *b);\fR +\fBint extended_color_content(int \fP\fIcolor\fP\fB, int *\fP\fIr\fP\fB, int *\fP\fIg\fP\fB, int *\fP\fIb\fP\fB);\fR .br -\fBint extended_pair_content(int pair, int *f, int *b);\fR +\fBint extended_pair_content(int \fP\fIpair\fP\fB, int *\fP\fIf\fP\fB, int *\fP\fIb\fP\fB);\fR .sp /* extensions */ .br \fBvoid reset_color_pairs(void);\fR .sp -\fBint COLOR_PAIR(int n);\fR +\fBint COLOR_PAIR(int \fP\fIn\fP\fB);\fR .br \fBPAIR_NUMBER(\fR\fIattrs\fR\fB);\fP .br @@ -422,7 +422,7 @@ if \fBstart_color\fP was not called. SVr4 does much the same, except that it returns \fBERR\fP from \fBpair_content\fP if the pair was not initialized using \fBinit_pairs\fP -and +and it returns \fBERR\fP from \fBcolor_content\fP if the terminal does not support changing colors. .IP @@ -467,6 +467,54 @@ Paradise and compatibles) do the wrong thing when you try to set a bright \*(``yellow\*('' background (you get a blinking yellow foreground instead). .bP Color RGB values are not settable. +.SH HISTORY +.PP +SVr3.2 introduced color support to curses in 1987. +.PP +SVr4 made internal changes, +e.g., moving the storage for the color state +from \fBSP\fP (the \fBSCREEN\fP structure) +to \fBcur_term\fP (the \fBTERMINAL\fP structure), +but provided the same set of library functions. +.PP +SVr4 curses limits the number of color pairs to 64, +reserving color pair zero (0) as the terminal's initial uncolored state. +This limit arises because the color pair information is a bitfield +in the \fBchtype\fP data type (denoted by \fBA_COLOR\fP). +.PP +Other implementations of curses had different limits: +.bP +PCCurses (1987-1990) provided for only eight (8) colors. +.bP +PDCurses (1992-present) inherited the 8-color limitation from PCCurses, +but changed this to 256 in version 2.5 (2001), +along with changing \fBchtype\fP from 16-bits to 32-bits. +.bP +X/Open Curses (1992-present) +added a new structure \fBcchar_t\fP to store the character, +attributes and color-pair values, allowing increased range of color-pairs. +Both color-pairs and color-values used a signed \fBshort\fP, +limiting values to 15 bits. +.bP +ncurses (1992-present) uses eight bits for \fBA_COLOR\fP in \fBchtype\fP values. +.IP +Version 5.3 provided a wide-character interface (2002), +but left color-pairs as part of the attributes-field. +.IP +Since version 6 (2015), +ncurses uses a separate \fBint\fP for color-pairs in the \fBcchar_t\fP values. +When those color-pair values fit in 8 bits, +ncurses allows color-pairs to be manipulated +via the functions using \fBchtype\fP values. +.bP +NetBSD curses used 6 bits from +2000 (when colors were first supported) until 2004. +At that point, NetBSD changed to use 10 bits. +As of 2021, that size is unchanged. +Like ncurses before version 6, +the NetBSD color-pair information is stored in +the attributes field of \fBcchar_t\fP, limiting the number of color-pairs +by the size of the bitfield. .SH PORTABILITY This implementation satisfies XSI Curses's minimum maximums for \fBCOLORS\fR and \fBCOLOR_PAIRS\fR. |