libcaca/doc/migrating.dox

/* $Id$ */

/** \page migrating Migrating from libcaca 0.x to the 1.0 API

 This section will guide you through the migration of a \e libcaca 0.x
 application to the latest API version.

 \section foo1 Overview

 The most important changes in the 1.0 API of \e libcaca are the
 \e libcaca / \e libcucul split and the object-oriented design. See these
 two examples for a rough idea of what changed:

<table border="0"><tr><td valign="top">
\code
#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;
}
\endcode
</td><td>
\code
#include <cucul.h>
#include <caca.h>

/* libcaca program - 1.0 API */
int main(void)
{
    /* Initialise libcaca */
    cucul_canvas_t *cv;
    caca_display_t *dp;
    cv = cucul_create_canvas(0, 0);
    dp = caca_create_display(cv);
    /* Set window title */
    caca_set_display_title(dp, "Window");
    /* Choose drawing colours */
    cucul_set_color(cv, CUCUL_COLOR_BLACK,
                        CUCUL_COLOR_WHITE);
    /* Draw a string at (0, 0) */
    cucul_putstr(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);
    cucul_free_canvas(cv);

    return 0;
}
\endcode
</td></tr></table>

 Note the following important things:

 - Functions now take an object handle as their first argument.
 - All input/output functions start with \b caca_ and all
   drawing and text handling functions start with \b cucul_ .

 \section foo2 Migration strategy

 You have two ways to migrate your application to use \e 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:

<table border="0"><tr><td valign="top">
\code
#include <caca.h>

/* libcaca program - 0.x API */
...
\endcode
</td><td>
\code
#include <caca.h>
#ifdef CACA_API_VERSION_1
#   include <caca0.h>
#endif

/* libcaca program - 0.x API */
...
\endcode
</td></tr></table>

 \section foo3 Function equivalence list

 \subsection bar1 Basic functions

 - \b caca_init(): use cucul_create_canvas() to create a \e libcucul canvas,
   followed by caca_create_display() to attach a \e libcaca display to it.
 - \b caca_set_delay(): use caca_set_display_time().
 - \b caca_get_feature(): deprecated.
 - \b caca_set_feature(): deprecated, see cucul_set_dither_antialias(),
   cucul_set_dither_color() and cucul_set_dither_mode() instead.
 - \b caca_get_feature_name(): deprecated, see cucul_get_dither_mode_list(),
   cucul_get_dither_antialias_list() and cucul_get_dither_color_list()
   instead.
 - \b caca_get_rendertime(): use caca_get_display_time().
 - \b caca_get_width(): use cucul_get_canvas_width().
 - \b caca_get_height(): use cucul_get_canvas_height().
 - \b caca_set_window_title(): use caca_set_display_title().
 - \b caca_get_window_width(): use caca_get_display_width().
 - \b caca_get_window_height(): use caca_get_display_height().
 - \b caca_refresh(): use caca_refresh_display().
 - \b caca_end(): use caca_free_display() to detach the \e libcaca display,
   followed by cucul_free_canvas() to free the underlying \e libcucul canvas.

 \subsection bar2 Event handling

 - \b caca_get_event(): unchanged, but the event information retrieval
   changed a lot.
 - \b caca_wait_event(): use caca_get_event() with a \c timeout argument
   of \b -1.
 - \b caca_get_mouse_x(): unchanged.
 - \b caca_get_mouse_y(): unchanged.

 \subsection bar3 Character printing

 - \b caca_set_color(): use cucul_set_color() or cucul_set_truecolor().
 - \b caca_get_fg_color(): deprecated.
 - \b caca_get_bg_color(): deprecated.
 - \b caca_get_color_name(): use cucul_get_color_name().
 - \b caca_putchar(): use cucul_putchar().
 - \b caca_putstr(): use cucul_putstr().
 - \b caca_printf(): use cucul_printf().
 - \b caca_clear(): use cucul_clear_canvas().

 \subsection bar4 Primitives drawing

 These functions are almost unchanged, except for Unicode support and the
 fact that they now act on a given canvas.

 - \b caca_draw_line(): use cucul_draw_line().
 - \b caca_draw_polyline(): use cucul_draw_polyline().
 - \b caca_draw_thin_line(): use cucul_draw_thin_line().
 - \b caca_draw_thin_polyline(): use cucul_draw_thin_polyline().

 - \b caca_draw_circle(): use cucul_draw_circle().
 - \b caca_draw_ellipse(): use cucul_draw_ellipse().
 - \b caca_draw_thin_ellipse(): use cucul_draw_thin_ellipse().
 - \b caca_fill_ellipse(): use cucul_fill_ellipse().

 - \b caca_draw_box(): use cucul_draw_box().
 - \b caca_draw_thin_box(): use cucul_draw_thin_box().
 - \b caca_fill_box(): use cucul_fill_box().

 - \b caca_draw_triangle(): use cucul_draw_triangle().
 - \b caca_draw_thin_triangle(): use cucul_draw_thin_triangle().
 - \b caca_fill_triangle(): use cucul_fill_triangle().

 \subsection bar5 Mathematical functions

 - \b caca_rand(): use cucul_rand(). The second argument is different, make
   sure you take that into account.
 - \b caca_sqrt(): this function is now deprecated, use your system's
   \b sqrt() call instead.

 \subsection bar6 Sprite handling

 The newly introduced canvases can have several frames. Sprites are hence
 completely deprecated.

 - \b caca_load_sprite(): use cucul_import_canvas().
 - \b caca_get_sprite_frames(): use cucul_get_canvas_frame_count().
 - \b caca_get_sprite_width(): use cucul_get_canvas_width().
 - \b caca_get_sprite_height(): use cucul_get_canvas_height().
 - \b caca_get_sprite_dx(): this function is now deprecated.
 - \b caca_get_sprite_dy(): this function is now deprecated.
 - \b caca_draw_sprite(): use cucul_set_canvas_frame() and cucul_blit().
 - \b caca_free_sprite(): use cucul_free_canvas().

 \subsection bar7 Bitmap handling

 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.

 - \b caca_create_bitmap(): use cucul_create_dither().
 - \b caca_set_bitmap_palette(): use cucul_set_dither_palette().
 - \b caca_draw_bitmap(): use cucul_dither_bitmap().
 - \b caca_free_bitmap(): use cucul_free_dither().

 \section foo4 Compilation

 The \c caca-config utility is deprecated in favour of the standard
 \c pkg-config interface:

\code
gcc -c foobar.c -o foobar.o `pkg-config --cflags caca`
gcc foobar.o -o foobar `pkg-config --libs caca`
\endcode

 \c caca-config is still provided as a convenience tool but will be removed
 in the future.

*/