notcurses/doc/man/man3/notcurses_output.3.md

% notcurses_output(3)
% nick black <nickblack@linux.com>
% v1.3.1

# NAME

notcurses_output - output to ncplanes

# SYNOPSIS

**#include <notcurses.h>**

**static inline int
ncplane_putc(struct ncplane* n, const cell* c);**

**int ncplane_putc_yx(struct ncplane* n, int y, int x, const cell* c);**

**static inline int
ncplane_putsimple(struct ncplane* n, char c);**

**static inline int
ncplane_putsimple_yx(struct ncplane* n, int y, int x, char c);**

**int ncplane_putsimple_stainable(struct ncplane* n, char c);**

**static inline int
ncplane_putwc(struct ncplane* n, wchar_t w);**

**int ncplane_putwc_yx(struct ncplane* n, int y, int x, wchar_t w);**

**static inline int
ncplane_putegc(struct ncplane* n, const char* gclust, int* sbytes);**

**int ncplane_putegc_yx(struct ncplane* n, int y, int x, const char* gclust, int* sbytes);**

**int ncplane_putegc_stainable(struct ncplane* n, const char* gclust, int* sbytes);**

**static inline int
ncplane_putwegc(struct ncplane* n, const wchar_t* gclust, int* sbytes);**

**static inline int
ncplane_putwegc_yx(struct ncplane* n, int y, int x, const wchar_t* gclust, int* sbytes);**

**int ncplane_putwegc_stainable(struct ncplane* n, const wchar_t* gclust, int* sbytes);**

**static inline int
ncplane_putstr_yx(struct ncplane* n, int y, int x, const char* gclustarr);**

**static inline int
ncplane_putstr(struct ncplane* n, const char* gclustarr);**

**int ncplane_putstr_aligned(struct ncplane* n, int y, ncalign_e align,
                               const char* s);**

**int ncplane_putwstr_yx(struct ncplane* n, int y, int x, const wchar_t* gclustarr);**

**static inline int
ncplane_putwstr_aligned(struct ncplane* n, int y, ncalign_e align,
                        const wchar_t* gclustarr);**

**static inline int
ncplane_putwstr(struct ncplane* n, const wchar_t* gclustarr);**

**int ncplane_vprintf_aligned(struct ncplane* n, int y, ncalign_e align,
                                const char* format, va_list ap);**

**int ncplane_vprintf_yx(struct ncplane* n, int y, int x,
                           const char* format, va_list ap);**

**static inline int
ncplane_vprintf(struct ncplane* n, const char* format, va_list ap);**

**static inline int
ncplane_printf(struct ncplane* n, const char* format, ...);**

**static inline int
ncplane_printf_yx(struct ncplane* n, int y, int x, const char* format, ...);**

**static inline int
ncplane_printf_aligned(struct ncplane* n, int y, ncalign_e align, const char* format, ...);**

**int ncplane_cursor_move_yx(struct ncplane* n, int y, int x);**

# DESCRIPTION

These functions write EGCs (Extended Grapheme Clusters) to the specified
**struct ncplane**s. The following inputs are supported:

* **ncplane_putc(3)**: writes a single cell (see **notcurses_cell(3)**)
* **ncplane_put_simple(3)**: writes a single 7-bit ASCII character
* **ncplane_putwc(3)**: writes a single **wchar_t** (following UTF-8 conversion)
* **ncplane_putwegc(3)**: writes a single EGC from an array of **wchar_t**
* **ncplane_putegc(3)**: writes a single EGC from an array of UTF-8
* **ncplane_putstr(3)**: writes a set of EGCs from an array of UTF-8
* **ncplane_putwstr(3)**: writes a set of EGCs from an array of **wchar_t**
* **ncplane_vprintf(3)**: formatted output using **va_list**
* **ncplane_printf(3)**: formatted output using variadic arguments

All of these use the **ncplane**'s active styling, save **notcurses_putc(3)**,
which uses the cell's styling. Functions accepting a single EGC expect a series
of **wchar_t** terminated by **L'\0'** or a series of UTF-8 **char** terminated
by **'\0'**. The EGC must be well-formed, and must not contain any cluster
breaks. For more information, consult [Unicode® Standard Annex #29](https://unicode.org/reports/tr29/).
Functions accepting a set of EGCs must consist of a series of well-formed EGCs,
broken by cluster breaks, terminated by the appropriate NUL terminator.

These functions output to the `ncplane`'s current cursor location. They *do not*
move to the next line upon reaching the right extreme of the containing plane.
If the entirety of the content cannot be output, they will output as much as
possible.

Each of these base functions has two additional forms:

* **ncplane_putc_aligned()**, etc.: accepts a row and an alignment type
* **ncplane_putc_yx()**, etc.: accepts a row and column

If a positional parameter is -1, no movement will be made along that axis.
Passing **-1, -1** to e.g. **ncplane_putc_yx()** is equivalent to calling the
base form. These functions are implemented by moving the cursor, and then
performing the output. The two steps are *atomic* on success (it is not possible
for another caller to move the cursor between when it is positioned, and when
output begins), and thus these functions ought generally be preferred to an
explicit **ncplane_cursor_move_yx()**.

Upon successful return, the cursor will follow the last cell output.

# RETURN VALUES

**ncplane_cursor_move_yx()** returns -1 on error (invalid coordinate), or 0
on success.

For output functions, a negative return indicates an error with the inputs.
Otherwise, the number of *screen columns* output is returned. It is entirely
possible to get a short return, if there was insufficient room to output all
EGCs.

# SEE ALSO

**fprintf(3)**
**notcurses(3)**, **notcurses_cell(3)**, **notcurses_ncplane(3)**,
**stdarg(3)**,
**ascii(7)**,
**unicode(7)**,
**utf-8(7)**