libcaca-migrating - Migrating from libcaca 0.x to the 1.0 API This
section will guide you through the migration of a libcaca 0.x
application to the latest API version.
The most important change in the 1.0 API of libcaca is the
object-oriented design. See these two examples for a rough idea of what
changed:
#include <caca.h>
/* libcaca program - 0.x API */
int main(void)
{
/* Initialise libcaca */
caca_init();
/* Set window title */
caca_set_window_title("Window");
/* Choose drawing colours */
caca_set_color(CACA_COLOR_BLACK,
CACA_COLOR_WHITE);
/* Draw a string at (0, 0) */
caca_putstr(0, 0, "Hello world!");
/* Refresh display */
caca_refresh();
/* Wait for a key press event */
caca_wait_event(CACA_EVENT_KEY_PRESS);
/* Clean up library */
caca_end();
return 0;
}
#include <caca.h>
/* libcaca program - 1.0 API */
int main(void)
{
/* Initialise libcaca */
caca_canvas_t *cv;
caca_display_t *dp;
dp = caca_create_display(NULL);
cv = caca_get_canvas(dp);
/* Set window title */
caca_set_display_title(dp, "Window");
/* Choose drawing colours */
caca_set_color_ansi(cv, CACA_BLACK,
CACA_WHITE);
/* Draw a string at (0, 0) */
caca_put_str(cv, 0, 0, "Hello world!");
/* Refresh display */
caca_refresh_display();
/* Wait for a key press event */
caca_get_event(dp, CACA_EVENT_KEY_PRESS,
NULL, -1);
/* Clean up library */
caca_free_display(dp);
return 0;
}
Note the following important things:
- •
- Most functions now take an object handle as their first argument.
You have two ways to migrate your application to use
libcaca 1.x:
- Port your code using the function equivalence list. This is the preferred
way because new functions are thread safe and offer much more features to
both the programmer and the end user.
- Use the legacy compatibility layer.
Using the compatibility layer is as easy as adding the following
three lines:
#include <caca.h>
/* libcaca program - 0.x API */
...
#include <caca.h>
#ifdef CACA_API_VERSION_1
# include <caca0.h>
#endif
/* libcaca program - 0.x API */
...
The modified code is guaranteed to build both with libcaca
0.x and libcaca 1.0.
- caca_init(): use caca_create_canvas() to create a
libcaca canvas, followed by caca_create_display() to attach
a libcaca display to it. Alternatively,
caca_create_display() with a NULL argument will create a canvas
automatically.
- caca_set_delay(): use caca_set_display_time().
- caca_get_feature(): deprecated.
- caca_set_feature(): deprecated, see
caca_set_dither_antialias(), caca_set_dither_color() and
caca_set_dither_mode() instead.
- caca_get_feature_name(): deprecated, see
caca_get_dither_mode_list(), caca_get_dither_antialias_list() and
caca_get_dither_color_list() instead.
- caca_get_rendertime(): use caca_get_display_time().
- caca_get_width(): use caca_get_canvas_width().
- caca_get_height(): use caca_get_canvas_height().
- caca_set_window_title(): use caca_set_display_title().
- caca_get_window_width(): use caca_get_display_width().
- caca_get_window_height(): use
caca_get_display_height().
- caca_refresh(): use caca_refresh_display().
- caca_end(): use caca_free_display() to detach the
libcaca display, followed by caca_free_canvas() to free the
underlying libcaca canvas. Alternatively, if the canvas was created
by caca_create_display(), it will be automatically destroyed by
caca_free_display().
- caca_get_event(): unchanged, but the event
information retrieval changed a lot.
- caca_wait_event(): use caca_get_event() with a timeout
argument of -1.
- caca_get_mouse_x(): unchanged.
- caca_get_mouse_y(): unchanged.
- caca_set_color(): use caca_set_color_ansi() or
caca_set_color_argb().
- caca_get_fg_color(): use caca_get_attr().
- caca_get_bg_color(): use caca_get_attr().
- caca_get_color_name(): this function is now deprecated due to major
uselessness.
- caca_putchar(): use caca_put_char().
- caca_putstr(): use caca_put_str().
- caca_printf(): unchanged.
- caca_clear(): use caca_clear_canvas().
These functions are almost unchanged, except for Unicode support
and the fact that they now act on a given canvas.
- caca_draw_line(): unchanged.
- caca_draw_polyline(): unchanged.
- caca_draw_thin_line(): unchanged.
- caca_draw_thin_polyline(): unchanged.
- caca_draw_circle(): unchanged.
- caca_draw_ellipse(): unchanged.
- caca_draw_thin_ellipse(): unchanged.
- caca_fill_ellipse(): unchanged.
- caca_draw_box(): unchanged, but the argument
meaning changed (width and height instead of corner coordinates).
- caca_draw_thin_box(): use
caca_draw_thin_box() or caca_draw_cp437_box(),
also the argument meaning changed (width and height instead of corner
coordinates).
- caca_fill_box(): unchanged, but the argument
meaning changed (width and height instead of corner coordinates).
- caca_draw_triangle(): unchanged.
- caca_draw_thin_triangle(): unchanged.
- caca_fill_triangle(): unchanged.
- caca_rand(): unchanged, but the second argument is different, make
sure you take that into account.
- caca_sqrt(): this function is now deprecated, use your system's
sqrt() call instead.
The newly introduced canvases can have several frames. Sprites are
hence completely deprecated.
- caca_load_sprite(): use caca_import_file().
- caca_get_sprite_frames(): use caca_get_frame_count().
- caca_get_sprite_width(): use caca_get_canvas_width().
- caca_get_sprite_height(): use caca_get_canvas_height().
- caca_get_sprite_dx(): use caca_get_canvas_handle_x().
- caca_get_sprite_dy(): use caca_get_canvas_handle_y().
- caca_draw_sprite(): use caca_set_frame() and
caca_blit().
- caca_free_sprite(): use caca_free_canvas().
Bitmaps have been renamed to dithers, because these objects do not
in fact store any pixels, they just have information on how bitmaps will be
dithered.
- caca_create_bitmap(): use caca_create_dither().
- caca_set_bitmap_palette(): use
caca_set_dither_palette().
- caca_draw_bitmap(): use caca_dither_bitmap().
- caca_free_bitmap(): use caca_free_dither().
The caca-config utility is deprecated in favour of the standard
pkg-config interface:
gcc -c foobar.c -o foobar.o `pkg-config --cflags caca`
gcc foobar.o -o foobar `pkg-config --libs caca`
caca-config is still provided as a convenience tool but may be
removed in the future.