libcaca(3caca) libcaca libcaca(3caca)
NAME
libcaca - libcaca basic functions
SYNOPSIS
Modules
libcaca canvas drawing
Functions
__extern caca_canvas_t * caca_create_canvas (int, int)
Initialise a libcaca canvas.
__extern int caca_manage_canvas (caca_canvas_t *, int(*)(void *), void
*)
Manage a canvas.
__extern int caca_unmanage_canvas (caca_canvas_t *, int(*)(void *),
void *)
unmanage a canvas.
__extern int caca_set_canvas_size (caca_canvas_t *, int, int)
Resize a canvas.
__extern int caca_get_canvas_width (caca_canvas_t const *)
Get the canvas width.
__extern int caca_get_canvas_height (caca_canvas_t const *)
Get the canvas height.
__extern uint32_t const * caca_get_canvas_chars (caca_canvas_t const
*)
Get the canvas character array.
__extern uint32_t const * caca_get_canvas_attrs (caca_canvas_t const
*)
Get the canvas attribute array.
__extern int caca_free_canvas (caca_canvas_t *)
Free a libcaca canvas.
__extern int caca_rand (int, int)
__extern char const * caca_get_version (void)
Return the libcaca version.
Detailed Description
These functions provide the basic libcaca routines for library
initialisation, system information retrieval and configuration.
Function Documentation
__extern caca_canvas_t* caca_create_canvas (int width, int height)
Initialise internal libcaca structures and the backend that will be
used for subsequent graphical operations. It must be the first libcaca
function to be called in a function. caca_free_canvas() should be
called at the end of the program to free all allocated resources.
Both the cursor and the canvas' handle are initialised at the top-left
corner.
If an error occurs, NULL is returned and errno is set accordingly:
• EINVAL Specified width or height is invalid.
• EOVERFLOW Specified width and height overflowed.
• ENOMEM Not enough memory for the requested canvas size.
Parameters
width The desired canvas width
height The desired canvas height
Returns
A libcaca canvas handle upon success, NULL if an error occurred.
References CACA_DEFAULT, caca_set_color_ansi(), and CACA_TRANSPARENT.
Referenced by caca_conio_movetext(), caca_create_display_with_driver(),
caca_export_area_to_memory(), caca_import_area_from_file(),
caca_import_area_from_memory(), and caca_set_canvas_boundaries().
__extern int caca_manage_canvas (caca_canvas_t * cv, int(*)(void *)
callback, void * p)
Lock a canvas to prevent it from being resized. If non-NULL, the
callback function pointer will be called upon each caca_set_canvas_size
call and if the returned value is zero, the canvas resize request will
be denied.
This function is only useful for display drivers such as the libcaca
library.
If an error occurs, -1 is returned and errno is set accordingly:
• EBUSY The canvas is already being managed.
Parameters
cv A libcaca canvas.
callback An optional callback function pointer.
p The argument to be passed to callback.
Returns
0 in case of success, -1 if an error occurred.
Referenced by caca_create_display_with_driver().
__extern int caca_unmanage_canvas (caca_canvas_t * cv, int(*)(void *)
callback, void * p)
unlock a canvas previously locked by caca_manage_canvas(). for safety
reasons, the callback and callback data arguments must be the same as
for the caca_manage_canvas() call.
this function is only useful for display drivers such as the libcaca
library.
if an error occurs, -1 is returned and errno is set accordingly:
• einval the canvas is not managed, or the callback arguments do not
match.
Parameters
cv a libcaca canvas.
callback the callback argument previously passed to
caca_manage_canvas().
p the p argument previously passed to caca_manage_canvas().
Returns
0 in case of success, -1 if an error occurred.
Referenced by caca_create_display_with_driver(), and
caca_free_display().
__extern int caca_set_canvas_size (caca_canvas_t * cv, int width, int
height)
Set the canvas' width and height, in character cells.
The contents of the canvas are preserved to the extent of the new
canvas size. Newly allocated character cells at the right and/or at the
bottom of the canvas are filled with spaces.
If as a result of the resize the cursor coordinates fall outside the
new canvas boundaries, they are readjusted. For instance, if the
current X cursor coordinate is 11 and the requested width is 10, the
new X cursor coordinate will be 10.
It is an error to try to resize the canvas if an output driver has been
attached to the canvas using caca_create_display(). You need to remove
the output driver using caca_free_display() before you can change the
canvas size again. However, the caca output driver can cause a canvas
resize through user interaction. See the caca_event() documentation for
more about this.
If an error occurs, -1 is returned and errno is set accordingly:
• EINVAL Specified width or height is invalid.
• EOVERFLOW Specified width and height overflowed.
• EBUSY The canvas is in use by a display driver and cannot be resized.
• ENOMEM Not enough memory for the requested canvas size. If this
happens, the canvas handle becomes invalid and should not be used.
Parameters
cv A libcaca canvas.
width The desired canvas width.
height The desired canvas height.
Returns
0 in case of success, -1 if an error occurred.
Referenced by caca_canvas_set_figfont(), caca_flush_figlet(), and
caca_put_figchar().
__extern int caca_get_canvas_width (caca_canvas_t const * cv)
Return the current canvas' width, in character cells.
This function never fails.
Parameters
cv A libcaca canvas.
Returns
The canvas width.
Referenced by caca_conio_clreol(), caca_conio_movetext(), and
caca_get_mouse_x().
__extern int caca_get_canvas_height (caca_canvas_t const * cv)
Returns the current canvas' height, in character cells.
This function never fails.
Parameters
cv A libcaca canvas.
Returns
The canvas height.
Referenced by caca_flush_figlet(), and caca_get_event_type().
__extern uint32_t const* caca_get_canvas_chars (caca_canvas_t const * cv)
Return the current canvas' internal character array. The array elements
consist in native endian 32-bit Unicode values as returned by
caca_get_char().
This function is probably only useful for libcaca 's internal display
drivers.
This function never fails.
Parameters
cv A libcaca canvas.
Returns
The canvas character array.
__extern uint32_t const* caca_get_canvas_attrs (caca_canvas_t const * cv)
Returns the current canvas' internal attribute array. The array
elements consist in native endian 32-bit attribute values as returned
by caca_get_attr().
This function is probably only useful for libcaca 's internal display
drivers.
This function never fails.
Parameters
cv A libcaca canvas.
Returns
The canvas attribute array.
__extern int caca_free_canvas (caca_canvas_t * cv)
Free all resources allocated by caca_create_canvas(). The canvas
pointer becomes invalid and must no longer be used unless a new call to
caca_create_canvas() is made.
If an error occurs, -1 is returned and errno is set accordingly:
• EBUSY The canvas is in use by a display driver and cannot be freed.
Parameters
cv A libcaca canvas.
Returns
0 in case of success, -1 if an error occurred.
References caca_canvas_set_figfont().
Referenced by caca_canvas_set_figfont(),
caca_create_display_with_driver(), caca_export_area_to_memory(),
caca_free_display(), caca_import_area_from_file(), and
caca_import_area_from_memory().
__extern char const* caca_get_version (void)
Return a read-only string with the libcaca version information.
This function never fails.
Returns
The libcaca version information.
Author
Generated automatically by Doxygen for libcaca from the source code.
Version 0.99.beta20 Tue Jul 12 2022 libcaca(3caca)
Generated by dwww version 1.15 on Wed Jun 26 18:05:40 CEST 2024.