% notcurses_channels(3)
% nick black <nickblack@linux.com>
% v1.6.17

# NAME

notcurses_channels - operations on notcurses channels

# SYNOPSIS

**#include <notcurses/notcurses.h>**

```c
#define CHANNELS_RGB_INITIALIZER(fr, fg, fb, br, bg, bb) \
  (((((uint64_t)(fr) << 16u) + ((uint64_t)(fg) << 8u) + (uint64_t)(fb)) << 32ull) + \
   (((br) << 16u) + ((bg) << 8u) + (bb)) + CELL_BGDEFAULT_MASK + CELL_FGDEFAULT_MASK)

#define CHANNEL_RGB_INITIALIZER(r, g, b) \
  (((uint32_t)r << 16u) + ((uint32_t)g << 8u) + (b) + CELL_BGDEFAULT_MASK)
```

**unsigned channel_r(unsigned channel);**

**unsigned channel_g(unsigned channel);**

**unsigned channel_b(unsigned channel);**

**unsigned channel_rgb(unsigned channel, unsigned* restrict r, unsigned* restrict g, unsigned* restrict b);**

**int channel_set_rgb(unsigned* channel, int r, int g, int b);**

**int channel_set(unsigned* channel, unsigned rgb);**

**unsigned channel_alpha(unsigned channel);**

**int channel_set_alpha(unsigned* channel, int alpha);**

**bool channel_default_p(unsigned channel);**

**unsigned channel_set_default(unsigned* channel);**

**unsigned channels_bchannel(uint64_t channels);**

**unsigned channels_fchannel(uint64_t channels);**

**uint64_t channels_set_bchannel(uint64_t* channels, uint32_t channel);**

**uint64_t channels_set_fchannel(uint64_t* channels, uint32_t channel);**

**unsigned channels_fg(uint64_t channels);**

**unsigned channels_bg(uint64_t channels);**

**unsigned channels_fg_alpha(uint64_t channels);**

**unsigned channels_bg_alpha(uint64_t channels);**

**unsigned channels_fg_rgb(uint64_t channels, unsigned* r, unsigned* g, unsigned* b);**

**unsigned channels_bg_rgb(uint64_t channels, unsigned* r, unsigned* g, unsigned* b);**

**int channels_set_fg_rgb(uint64_t* channels, int r, int g, int b);**

**int channels_set_bg_rgb(uint64_t* channels, int r, int g, int b);**

**int channels_set_fg(uint64_t* channels, unsigned rgb);**

**int channels_set_bg(uint64_t* channels, unsigned rgb);**

**int channels_set_fg_alpha(uint64_t* channels, int alpha);**

**int channels_set_bg_alpha(uint64_t* channels, int alpha);**

**bool channels_fg_default_p(uint64_t channels);**

**bool channels_bg_default_p(uint64_t channels);**

**uint64_t channels_set_fg_default(uint64_t* channels);**

**uint64_t channels_set_bg_default(uint64_t* channels);**

**unsigned channels_blend(unsigned c1, unsigned c2, unsigned blends);**

# DESCRIPTION


# RETURN VALUES

Functions returning `int` return -1 on failure, or 0 on success. Failure is
always due to invalid inputs. Functions returning `bool` are predicates, and
return the requested value. Functions returning `unsigned` forms return the
input, modified as requested.

# SEE ALSO

**notcurses(3)**,
**notcurses_cell(3)**,
**notcurses_plane(3)**,
**notcurses_output(3)**