notcurses_direct(3)

NAME
notcurses_direct - the Direct Mode API

SYNOPSIS

        #include <notcurses/direct.h>
        #define NCDIRECT_OPTION_INHIBIT_SETLOCALE   0x0001ull
        #define NCDIRECT_OPTION_INHIBIT_CBREAK      0x0002ull
        #define NCDIRECT_OPTION_NO_QUIT_SIGHANDLERS 0x0008ull
        #define NCDIRECT_OPTION_VERBOSE             0x0010ull
        #define NCDIRECT_OPTION_VERY_VERBOSE        0x0020ull

struct ncdirect* ncdirect_init(const char* termtype, FILE* fp, uint64_t flags);

unsigned ncdirect_palette_size(const struct ncdirect* nc);

int ncdirect_set_bg_rgb8(struct ncdirect* nc, unsigned r, unsigned g, unsigned b);

int ncdirect_set_fg_rgb8(struct ncdirect* nc, unsigned r, unsigned g, unsigned b);

int ncdirect_set_fg_rgb(struct ncdirect* nc, unsigned rgb);

int ncdirect_set_bg_rgb(struct ncdirect* nc, unsigned rgb);

int ncdirect_set_fg_default(struct ncdirect* nc);

int ncdirect_set_bg_default(struct ncdirect* nc);

int ncdirect_set_fg_palindex(struct ncdirect* nc, int pidx);

int ncdirect_set_bg_palindex(struct ncdirect* nc, int pidx);

unsigned ncdirect_dim_x(const struct ncdirect* nc);

unsigned ncdirect_dim_y(const struct ncdirect* nc);

unsigned ncdirect_supported_styles(const struct ncdirect* nc);

int ncdirect_styles_set(struct ncdirect* n, unsigned stylebits);

int ncdirect_styles_on(struct ncdirect* n, unsigned stylebits);

int ncdirect_styles_off(struct ncdirect* n, unsigned stylebits);

unsigned ncdirect_styles(struct ncdirect* n);

int ncdirect_clear(struct ncdirect* nc)

int ncdirect_stop(struct ncdirect* nc);

int ncdirect_cursor_move_yx(struct ncdirect* n, int y, int x);

int ncdirect_cursor_yx(struct ncdirect* n, unsigned* y, unsigned* x);

int ncdirect_cursor_enable(struct ncdirect* nc);

int ncdirect_cursor_disable(struct ncdirect* nc);

int ncdirect_cursor_up(struct ncdirect* nc, int num);

int ncdirect_cursor_left(struct ncdirect* nc, int num);

int ncdirect_cursor_right(struct ncdirect* nc, int num);

int ncdirect_cursor_down(struct ncdirect* nc, int num);

int ncdirect_putstr(struct ncdirect* nc, uint64_t channels, const char* utf8);

int ncdirect_putegc(struct ncdirect* nc, uint64_t channels, const char* utf8, int* sbytes);

int ncdirect_printf_aligned(struct ncdirect* n, int y, ncalign_e align, const char* fmt, ...);

const char* ncdirect_detected_terminal(const struct ncdirect* n);

int ncdirect_hline_interp(struct ncdirect* n, const char* egc, unsigned len, uint64_t h1, uint64_t h2);

int ncdirect_vline_interp(struct ncdirect* n, const char* egc, unsigned len, uint64_t h1, uint64_t h2);

int ncdirect_box(struct ncdirect* n, uint64_t ul, uint64_t ur, uint64_t ll, uint64_t lr, const wchar_t* wchars, int ylen, int xlen, unsigned ctlword);

int ncdirect_rounded_box(struct ncdirect* n, uint64_t ul, uint64_t ur, uint64_t ll, uint64_t lr, int ylen, int xlen, unsigned ctlword);

int ncdirect_double_box(struct ncdirect* n, uint64_t ul, uint64_t ur, uint64_t ll, uint64_t lr, int ylen, int xlen, unsigned ctlword);

ncdirectv* ncdirect_render_frame(struct ncdirect* n, const char* filename, ncblitter_e blitter, ncscale_e scale, int maxy, int maxx);

char* ncdirect_readline(struct ncdirect* n, const char* prompt);

bool ncdirect_cantruecolor(const struct ncdirect* nc);

bool ncdirect_canchangecolor(const struct ncdirect* nc);

bool ncdirect_canfade(const struct ncdirect* nc);

bool ncdirect_canopen_images(const struct ncdirect* nc);

bool ncdirect_canopen_videos(const struct ncdirect* nc);

bool ncdirect_canutf8(const struct ncdirect* nc);

int ncdirect_check_pixel_support(const struct ncdirect* nc);

bool ncdirect_canhalfblock(const struct ncdirect* nc);

bool ncdirect_canquadrant(const struct ncdirect* nc);

bool ncdirect_cansextant(const struct ncdirect* nc);

bool ncdirect_canoctant(const struct ncdirect* nc);

bool ncdirect_canbraille(const struct ncdirect* nc);

bool ncdirect_canget_cursor(const struct ncdirect* nc);

uint32_t ncdirect_get(struct ncdirect* n, const struct timespec* absdl, ncinput* ni);

        typedef struct ncvgeom {
          int pixy, pixx;     // true pixel geometry of ncvisual data
          int cdimy, cdimx;   // terminal cell geometry when this was calculated
          int rpixy, rpixx;   // rendered pixel geometry
          int rcelly, rcellx; // rendered cell geometry
          int scaley, scalex; // pixels per filled cell
          // only defined for NCBLIT_PIXEL
          int maxpixely, maxpixelx;
        } ncvgeom;

int ncdirect_render_image(struct ncdirect* n, const char* filename, ncblitter_e blitter, ncscale_e scale);

int ncdirect_raster_frame(struct ncdirect* n, ncdirectv* ncdv, ncalign_e align);

int ncdirect_stream(struct ncdirect* n, const char* filename, ncstreamcb streamer, struct ncvisual_options* vopts, void* curry);

int ncdirect_raster_frame(struct ncdirect* n, ncdirectv* ncdv, ncalign_e align);

struct ncdirectf* ncdirectf_from_file(struct ncdirect* n, const char* filename);*

void ncdirectf_free(struct ncdirectf* frame);

ncdirectv* ncdirectf_render(struct ncdirect* n, struct ncdirectf* frame, const struct ncvisual_options vopts);

int ncdirectf_geom(struct ncdirect* n, struct ncdirectf* frame, const struct ncvisual_options vopts, ncvgeom* geom);

DESCRIPTION
ncdirect_init prepares the FILE provided as fp for colorizing and styling. On success, a pointer to a valid struct ncdirect is returned. NULL is returned on failure. Before the process exits, ncdirect_stop should be called to reset the terminal and free up resources. ncdirect_init places the terminal into "cbreak" (also known as "rare") mode, disabling line-buffering and echo of input. ncdirect_stop restores the terminal state as it was when the corresponding ncdirect_init call was made. A process can have only one context active at once.

The following flags are defined:

•   NCDIRECT_OPTION_INHIBIT_SETLOCALE: Unless this flag is set, ncdirect_init will call setlocale(LC_ALL, NULL). If the result is either "C" or "POSIX", it will print a diagnostic to stderr, and then call setlocale(LC_ALL, ""). This will attempt to set the locale based off the LANG environment variable. Your program should call setlocale(3) itself, usually as one of the first lines.

•   NCDIRECT_OPTION_INHIBIT_CBREAK: Unless this flag is set, ncdirect_init will place the terminal into cbreak mode (i.e. disabling echo and line buffering; see tcgetattr(3)).

•   NCDIRECT_OPTION_DRAIN_INPUT: Standard input may be freely discarded. If you do not intend to process input, pass this flag. Otherwise, input can buffer up, eventually preventing Notcurses from processing terminal messages. It will furthermore avoid wasting time processing useless input.

•   NCDIRECT_OPTION_NO_QUIT_SIGHANDLERS: A signal handler will usually be installed for SIGABRT, SIGBUS, SIGFPE, SIGILL, SIGINT, SIGQUIT, SIGSEGV, and SIGTERM, cleaning up the terminal on such exceptions. With this flag, the handler will not be installed.

•   NCDIRECT_OPTION_VERBOSE: Enable diagnostics to stderr at the level of NCLOGLEVEL_WARNING.

•   NCDIRECT_OPTION_VERY_VERBOSE: Enable all diagnostics (equivalent to NCLOGLEVEL_TRACE). Implies NCDIRECT_OPTION_VERBOSE.

The loglevel can also be set externally using the NOTCURSES_LOGLEVEL environment variable. See notcurses_init(3) for more information.

An appropriate terminfo(5) entry must exist for the terminal. This entry is usually selected using the value of the TERM environment variable (see getenv(3)), but a non-NULL value for termtype will override this. An invalid terminfo specification can lead to reduced performance, reduced display capabilities, and/or display errors. notcurses natively targets 24bpp/8bpc RGB color, and it is thus desirable to use a terminal with the rgb capability (e.g. xterm's xterm-direct).

ncdirect_dim_x returns the current number of columns, and ncdirect_dim_y the current number of rows.

ncdirect_clear clears the screen using a control code if one exists in terminfo. Otherwise, it prints successive newlines to scroll everything off.

ncdirect_cursor_move_yx moves the cursor to the specified coordinate. -1 can be specified for either y or x to leave that axis unchanged.

ncdirect_enable_cursor and ncdirect_disable_cursor always flush the output stream, taking effect immediately.

ncdirect_cursor_up and friends all move relative to the current position. Attempting to e.g. move up while on the top row will return 0, but have no effect.

ncdirect_readline reads a (heap-allocated) line of arbitrary length, supporting some libreadline-style line-editing controls. NCDIRECT_OPTION_INHIBIT_CBREAK should not be used if you intend to use ncdirect_readline; if used, line-editing keybindings cannot be implemented. Input will be echoed whether this option is used or not.

ncdirect_check_pixel_support must be called (and successfully return) before NCBLIT_PIXEL can be used to render images; see notcurses_visual(3) for more details.

When rendering an image, maxy and maxx specify a maximum number of (cell) rows and columns to use, respectively. Passing 0 means "use as much space as is necessary". It is an error to pass a negative number for either.

RETURN VALUES
ncdirect_init returns NULL on failure. Otherwise, the return value points to a valid struct ncdirect, which can be used until it is provided to ncdirect_stop.

ncdirect_printf_aligned returns the number of bytes written on success. On failure, it returns some negative number.

ncdirect_putstr returns a nonnegative number on success, and EOF on failure.

ncdirect_putegc returns the number of columns consumed on success, or -1 on failure. If sbytes is not NULL, the number of bytes consumed will be written to it.

ncdirect_check_pixel_support returns -1 on error, 0 if there is no pixel support, and 1 if pixel support is successfully detected.

ncdirect_styles returns the current styling, a bitmask over the various NCSTYLE_ constants.

All other functions return 0 on success, and non-zero on error.

NOTES
You are recommended to accept -v and -vv as command-line options, mapping them to NCDIRECT_OPTION_VERBOSE and NCDIRECT_OPTION_VERY_VERBOSE respectively.

SEE ALSO
getenv(3), notcurses(3), notcurses_init(3), notcurses_plane(3), notcurses_visual(3), terminfo(5), termios(3)

AUTHORS
nick black nickblack@linux.com