libcaca/caca/export.c

/*
 *  libcaca       Colour ASCII-Art library
 *  Copyright (c) 2002-2006 Sam Hocevar <sam@zoy.org>
 *                2006 Jean-Yves Lamoureux <jylam@lnxscene.org>
 *                All Rights Reserved
 *
 *  $Id$
 *
 *  This library is free software. It comes without any warranty, to
 *  the extent permitted by applicable law. You can redistribute it
 *  and/or modify it under the terms of the Do What The Fuck You Want
 *  To Public License, Version 2, as published by Sam Hocevar. See
 *  http://sam.zoy.org/wtfpl/COPYING for more details.
 */

/*
 *  This file contains various export functions
 */

#include "config.h"

#if !defined(__KERNEL__)
#   include <stdlib.h>
#   include <stdio.h>
#   include <string.h>
#endif

#include "caca.h"
#include "caca_internals.h"

static inline int sprintu32(char *s, uint32_t x)
{
    s[0] = (uint8_t)(x >> 24);
    s[1] = (uint8_t)(x >> 16) & 0xff;
    s[2] = (uint8_t)(x >>  8) & 0xff;
    s[3] = (uint8_t)(x      ) & 0xff;
    return 4;
}

static inline int sprintu16(char *s, uint16_t x)
{
    s[0] = (uint8_t)(x >>  8) & 0xff;
    s[1] = (uint8_t)(x      ) & 0xff;
    return 2;
}

static void *export_caca(caca_canvas_t const *, size_t *);
static void *export_ansi(caca_canvas_t const *, size_t *);
static void *export_utf8(caca_canvas_t const *, size_t *, int);
static void *export_html(caca_canvas_t const *, size_t *);
static void *export_html3(caca_canvas_t const *, size_t *);
static void *export_bbfr(caca_canvas_t const *, size_t *);
static void *export_irc(caca_canvas_t const *, size_t *);
static void *export_ps(caca_canvas_t const *, size_t *);
static void *export_svg(caca_canvas_t const *, size_t *);
static void *export_tga(caca_canvas_t const *, size_t *);

/** \brief Export a canvas into a foreign format.
 *
 *  This function exports a libcaca canvas into various foreign formats such
 *  as ANSI art, HTML, IRC colours, etc. The returned pointer should be passed
 *  to free() to release the allocated storage when it is no longer needed.
 *
 *  Valid values for \c format are:
 *  - \c "caca": export native libcaca files.
 *  - \c "ansi": export ANSI art (CP437 charset with ANSI colour codes).
 *  - \c "html": export an HTML page with CSS information.
 *  - \c "html3": export an HTML table that should be compatible with
 *    most navigators, including textmode ones.
 *  - \c "irc": export UTF-8 text with mIRC colour codes.
 *  - \c "ps": export a PostScript document.
 *  - \c "svg": export an SVG vector image.
 *  - \c "tga": export a TGA image.
 *
 *  If an error occurs, NULL is returned and \b errno is set accordingly:
 *  - \c EINVAL Unsupported format requested.
 *  - \c ENOMEM Not enough memory to allocate output buffer.
 *
 *  \param cv A libcaca canvas
 *  \param format A string describing the requested output format.
 *  \param bytes A pointer to a size_t where the number of allocated bytes
 *         will be written.
 *  \return A pointer to the exported memory area, or NULL in case of error.
 */
void *caca_export_memory(caca_canvas_t const *cv, char const *format,
                          size_t *bytes)
{
    if(!strcasecmp("caca", format))
        return export_caca(cv, bytes);

    if(!strcasecmp("ansi", format))
        return export_ansi(cv, bytes);

    if(!strcasecmp("utf8", format))
        return export_utf8(cv, bytes, 0);

    if(!strcasecmp("utf8cr", format))
        return export_utf8(cv, bytes, 1);

    if(!strcasecmp("html", format))
        return export_html(cv, bytes);

    if(!strcasecmp("html3", format))
        return export_html3(cv, bytes);

    if(!strcasecmp("bbfr", format))
        return export_bbfr(cv, bytes);

    if(!strcasecmp("irc", format))
        return export_irc(cv, bytes);

    if(!strcasecmp("ps", format))
        return export_ps(cv, bytes);

    if(!strcasecmp("svg", format))
        return export_svg(cv, bytes);

    if(!strcasecmp("tga", format))
        return export_tga(cv, bytes);

    seterrno(EINVAL);
    return NULL;
}

/** \brief Get available export formats
 *
 *  Return a list of available export formats. The list is a NULL-terminated
 *  array of strings, interleaving a string containing the internal value for
 *  the export format, to be used with caca_export_memory(), and a string
 *  containing the natural language description for that export format.
 *
 *  This function never fails.
 *
 *  \return An array of strings.
 */
char const * const * caca_get_export_list(void)
{
    static char const * const list[] =
    {
        "caca", "native libcaca format",
        "ansi", "ANSI",
        "utf8", "UTF-8 with ANSI escape codes",
        "utf8cr", "UTF-8 with ANSI escape codes and MS-DOS \\r",
        "html", "HTML",
        "html3", "backwards-compatible HTML",
        "bbfr", "BBCode (French)",
        "irc", "IRC with mIRC colours",
        "ps", "PostScript document",
        "svg", "SVG vector image",
        "tga", "TGA image",
        NULL, NULL
    };

    return list;
}

/*
 * XXX: the following functions are local.
 */

/* Generate a native libcaca canvas file. */
static void *export_caca(caca_canvas_t const *cv, size_t *bytes)
{
    char *data, *cur;
    int f, n;

    /* 52 bytes for the header:
     *  - 4 bytes for "\xCA\xCA" + "CV"
     *  - 16 bytes for the canvas header
     *  - 32 bytes for the frame info
     * 8 bytes for each character cell */
    *bytes = 20 + (32 + 8 * cv->width * cv->height) * cv->framecount;
    cur = data = malloc(*bytes);

    /* magic */
    cur += sprintf(cur, "%s", "\xCA\xCA" "CV");

    /* canvas_header */
    cur += sprintu32(cur, 16 + 32 * cv->framecount);
    cur += sprintu32(cur, cv->width * cv->height * 8 * cv->framecount);
    cur += sprintu16(cur, 0x0001);
    cur += sprintu32(cur, cv->framecount);
    cur += sprintu16(cur, 0x0000);

    /* frame_info */
    for(f = 0; f < cv->framecount; f++)
    {
        cur += sprintu32(cur, cv->width);
        cur += sprintu32(cur, cv->height);
        cur += sprintu32(cur, 0);
        cur += sprintu32(cur, cv->curattr);
        cur += sprintu32(cur, cv->frames[f].x);
        cur += sprintu32(cur, cv->frames[f].y);
        cur += sprintu32(cur, cv->frames[f].handlex);
        cur += sprintu32(cur, cv->frames[f].handley);
    }

    /* canvas_data */
    for(f = 0; f < cv->framecount; f++)
    {
        uint32_t *attrs = cv->frames[f].attrs;
        uint32_t *chars = cv->frames[f].chars;

        for(n = cv->height * cv->width; n--; )
        {
            cur += sprintu32(cur, *chars++);
            cur += sprintu32(cur, *attrs++);
        }
    }

    return data;
}

/* Generate UTF-8 representation of current canvas. */
static void *export_utf8(caca_canvas_t const *cv, size_t *bytes,
                         int cr)
{
    static uint8_t const palette[] =
    {
        0,  4,  2,  6, 1,  5,  3,  7,
        8, 12, 10, 14, 9, 13, 11, 15
    };

    char *data, *cur;
    int x, y;

    /* 23 bytes assumed for max length per pixel ('\e[5;1;3x;4y;9x;10ym' plus
     * 4 max bytes for a UTF-8 character).
     * Add height*9 to that (zeroes color at the end and jump to next line) */
    *bytes = (cv->height * 9) + (cv->width * cv->height * 23);
    cur = data = malloc(*bytes);

    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        uint8_t prevfg = 0x10;
        uint8_t prevbg = 0x10;

        for(x = 0; x < cv->width; x++)
        {
            uint32_t attr = lineattr[x];
            uint32_t ch = linechar[x];
            uint8_t ansifg, ansibg, fg, bg;

            if(ch == CACA_MAGIC_FULLWIDTH)
                continue;

            ansifg = caca_attr_to_ansi_fg(attr);
            ansibg = caca_attr_to_ansi_bg(attr);

            fg = ansifg < 0x10 ? palette[ansifg] : 0x10;
            bg = ansibg < 0x10 ? palette[ansibg] : 0x10;

            /* TODO: the [0 could be omitted in some cases */
            if(fg != prevfg || bg != prevbg)
            {
                cur += sprintf(cur, "\033[0");

                if(fg < 8)
                    cur += sprintf(cur, ";3%d", fg);
                else if(fg < 16)
                    cur += sprintf(cur, ";1;3%d;9%d", fg - 8, fg - 8);

                if(bg < 8)
                    cur += sprintf(cur, ";4%d", bg);
                else if(bg < 16)
                    cur += sprintf(cur, ";5;4%d;10%d", bg - 8, bg - 8);

                cur += sprintf(cur, "m");
            }

            cur += caca_utf32_to_utf8(cur, ch);

            prevfg = fg;
            prevbg = bg;
        }

        if(prevfg != 0x10 || prevbg != 0x10)
            cur += sprintf(cur, "\033[0m");

        cur += sprintf(cur, cr ? "\r\n" : "\n");
    }

    /* Crop to really used size */
    debug("utf8 export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Generate ANSI representation of current canvas. */
static void *export_ansi(caca_canvas_t const *cv, size_t *bytes)
{
    static uint8_t const palette[] =
    {
        0,  4,  2,  6, 1,  5,  3,  7,
        8, 12, 10, 14, 9, 13, 11, 15
    };

    char *data, *cur;
    int x, y;

    uint8_t prevfg = -1;
    uint8_t prevbg = -1;

    /* 16 bytes assumed for max length per pixel ('\e[5;1;3x;4ym' plus
     * 1 byte for a CP437 character).
     * Add height*9 to that (zeroes color at the end and jump to next line) */
    *bytes = (cv->height * 9) + (cv->width * cv->height * 16);
    cur = data = malloc(*bytes);

    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        for(x = 0; x < cv->width; x++)
        {
            uint8_t ansifg = caca_attr_to_ansi_fg(lineattr[x]);
            uint8_t ansibg = caca_attr_to_ansi_bg(lineattr[x]);
            uint8_t fg = ansifg < 0x10 ? palette[ansifg] : CACA_LIGHTGRAY;
            uint8_t bg = ansibg < 0x10 ? palette[ansibg] : CACA_BLACK;
            uint32_t ch = linechar[x];

            if(ch == CACA_MAGIC_FULLWIDTH)
                ch = '?';

            if(fg != prevfg || bg != prevbg)
            {
                cur += sprintf(cur, "\033[0;");

                if(fg < 8)
                    if(bg < 8)
                        cur += sprintf(cur, "3%d;4%dm", fg, bg);
                    else
                        cur += sprintf(cur, "5;3%d;4%dm", fg, bg - 8);
                else
                    if(bg < 8)
                        cur += sprintf(cur, "1;3%d;4%dm", fg - 8, bg);
                    else
                        cur += sprintf(cur, "5;1;3%d;4%dm", fg - 8, bg - 8);
            }

            *cur++ = caca_utf32_to_cp437(ch);

            prevfg = fg;
            prevbg = bg;
        }

        if(cv->width == 80)
        {
            cur += sprintf(cur, "\033[s\n\033[u");
        }
        else
        {
            cur += sprintf(cur, "\033[0m\r\n");
            prevfg = -1;
            prevbg = -1;
        }
    }

    /* Crop to really used size */
    debug("ansi export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Generate HTML representation of current canvas. */
static void *export_html(caca_canvas_t const *cv, size_t *bytes)
{
    char *data, *cur;
    int x, y, len;

    /* The HTML header: less than 1000 bytes
     * A line: 7 chars for "<br />\n"
     * A glyph: 47 chars for "<span style="color:#xxx;background-color:#xxx">"
     *          83 chars for ";font-weight..."
     *          up to 9 chars for "&#xxxxxx;", far less for pure ASCII
     *          7 chars for "</span>" */
    *bytes = 1000 + cv->height * (7 + cv->width * (47 + 83 + 9 + 7));
    cur = data = malloc(*bytes);

    /* HTML header */
    cur += sprintf(cur, "<html><head>\n");
    cur += sprintf(cur, "<title>Generated by libcaca %s</title>\n",
                        caca_get_version());
    cur += sprintf(cur, "</head><body>\n");

    cur += sprintf(cur, "<div cellpadding='0' cellspacing='0' style='%s'>\n",
                        "font-family: monospace, fixed; font-weight: bold;");

    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        for(x = 0; x < cv->width; x += len)
        {
            cur += sprintf(cur, "<span style=\"");
            if(caca_attr_to_ansi_fg(lineattr[x]) < 0x10)
                cur += sprintf(cur, ";color:#%.03x",
                               caca_attr_to_rgb12_fg(lineattr[x]));
            if(caca_attr_to_ansi_bg(lineattr[x]) < 0x10)
                cur += sprintf(cur, ";background-color:#%.03x",
                               caca_attr_to_rgb12_bg(lineattr[x]));
            if(lineattr[x] & CACA_BOLD)
                cur += sprintf(cur, ";font-weight:bold");
            if(lineattr[x] & CACA_ITALICS)
                cur += sprintf(cur, ";font-style:italic");
            if(lineattr[x] & CACA_UNDERLINE)
                cur += sprintf(cur, ";text-decoration:underline");
            if(lineattr[x] & CACA_BLINK)
                cur += sprintf(cur, ";text-decoration:blink");
            cur += sprintf(cur, "\">");

            for(len = 0;
                x + len < cv->width && lineattr[x + len] == lineattr[x];
                len++)
            {
                if(linechar[x + len] == CACA_MAGIC_FULLWIDTH)
                    ;
                else if(linechar[x + len] <= 0x00000020)
                    cur += sprintf(cur, "&nbsp;");
                else if(linechar[x + len] < 0x00000080)
                    cur += sprintf(cur, "%c", (uint8_t)linechar[x + len]);
                else
                    cur += sprintf(cur, "&#%i;",
                                   (unsigned int)linechar[x + len]);
            }
            cur += sprintf(cur, "</span>");
        }
        /* New line */
        cur += sprintf(cur, "<br />\n");
    }

    cur += sprintf(cur, "</div></body></html>\n");

    /* Crop to really used size */
    debug("html export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Export an HTML3 document. This function is way bigger than export_html(),
 * but permits viewing in old browsers (or limited ones such as links). It
 * will not work under gecko (mozilla rendering engine) unless you set a
 * correct header. */
static void *export_html3(caca_canvas_t const *cv, size_t *bytes)
{
    char *data, *cur;
    int x, y, len;

    /* The HTML table markup: less than 1000 bytes
     * A line: 10 chars for "<tr></tr>\n"
     * A glyph: 40 chars for "<td bgcolor=#xxxxxx><font color=#xxxxxx>"
     *          up to 36 chars for "<b><i><u><blink></blink></u></i></b>"
     *          up to 9 chars for "&#xxxxxx;", far less for pure ASCII
     *          12 chars for "</font></td>" */
    *bytes = 1000 + cv->height * (10 + cv->width * (40 + 36 + 9 + 12));
    cur = data = malloc(*bytes);

    /* Table */
    cur += sprintf(cur, "<table cols='%d' cellpadding='0' cellspacing='0'>\n",
                        cv->height);

    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        cur += sprintf(cur, "<tr>");

        for(x = 0; x < cv->width; x += len)
        {
            int i, needfont;

            /* Use colspan option to factor cells with same attributes
             * (see below) */
            len = 1;
            while(x + len < cv->width && lineattr[x + len] == lineattr[x])
                len++;

            cur += sprintf(cur, "<td");

            if(caca_attr_to_ansi_fg(lineattr[x]) < 0x10)
                cur += sprintf(cur, " bgcolor=#%.06lx", (unsigned long int)
                               _caca_attr_to_rgb24bg(lineattr[x]));

            if(len > 1)
                cur += sprintf(cur, " colspan=%d", len);

            cur += sprintf(cur, ">");

            needfont = caca_attr_to_ansi_bg(lineattr[x]) < 0x10;

            if(needfont)
                cur += sprintf(cur, "<font color=#%.06lx>", (unsigned long int)
                               _caca_attr_to_rgb24fg(lineattr[x]));

            if(lineattr[x] & CACA_BOLD)
                cur += sprintf(cur, "<b>");
            if(lineattr[x] & CACA_ITALICS)
                cur += sprintf(cur, "<i>");
            if(lineattr[x] & CACA_UNDERLINE)
                cur += sprintf(cur, "<u>");
            if(lineattr[x] & CACA_BLINK)
                cur += sprintf(cur, "<blink>");

            for(i = 0; i < len; i++)
            {
                if(linechar[x + i] == CACA_MAGIC_FULLWIDTH)
                    ;
                else if(linechar[x + i] <= 0x00000020)
                    cur += sprintf(cur, "&nbsp;");
                else if(linechar[x + i] < 0x00000080)
                    cur += sprintf(cur, "%c", (uint8_t)linechar[x + i]);
                else
                    cur += sprintf(cur, "&#%i;", (unsigned int)linechar[x + i]);
            }

            if(lineattr[x] & CACA_BLINK)
                cur += sprintf(cur, "</blink>");
            if(lineattr[x] & CACA_UNDERLINE)
                cur += sprintf(cur, "</u>");
            if(lineattr[x] & CACA_ITALICS)
                cur += sprintf(cur, "</i>");
            if(lineattr[x] & CACA_BOLD)
                cur += sprintf(cur, "</b>");

            if(needfont)
                cur += sprintf(cur, "</font>");
            cur += sprintf(cur, "</td>");
        }
        cur += sprintf(cur, "</tr>\n");
    }

    /* Footer */
    cur += sprintf(cur, "</table>\n");

    /* Crop to really used size */
    debug("html3 export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

static void *export_bbfr(caca_canvas_t const *cv, size_t *bytes)
{
    char *data, *cur;
    int x, y, len;

    /* The font markup: less than 100 bytes
     * A line: 1 char for "\n"
     * A glyph: 22 chars for "[f=#xxxxxx][c=#xxxxxx]"
     *          up to 21 chars for "[g][i][s][/s][/i][/g]"
     *          up to 6 chars for the UTF-8 glyph
     *          8 chars for "[/c][/f]" */
    *bytes = 100 + cv->height * (1 + cv->width * (22 + 21 + 6 + 8));
    cur = data = malloc(*bytes);

    /* Table */
    cur += sprintf(cur, "[font=Courier New]");

    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        for(x = 0; x < cv->width; x += len)
        {
            int i, needback, needfront;

            /* Use colspan option to factor cells with same attributes
             * (see below) */
            len = 1;
            if(linechar[x] == ' ')
                while(x + len < cv->width && lineattr[x + len] == lineattr[x]
                        && linechar[x] == ' ')
                    len++;
            else
                while(x + len < cv->width && lineattr[x + len] == lineattr[x]
                        && linechar[x] != ' ')
                    len++;

            needback = caca_attr_to_ansi_bg(lineattr[x]) < 0x10;
            needfront = caca_attr_to_ansi_fg(lineattr[x]) < 0x10;

            if(needback)
                cur += sprintf(cur, "[f=#%.06lx]", (unsigned long int)
                               _caca_attr_to_rgb24bg(lineattr[x]));

            if(linechar[x] == ' ')
                cur += sprintf(cur, "[c=#%.06lx]", (unsigned long int)
                               _caca_attr_to_rgb24bg(lineattr[x]));
            else if(needfront)
                cur += sprintf(cur, "[c=#%.06lx]", (unsigned long int)
                               _caca_attr_to_rgb24fg(lineattr[x]));

            if(lineattr[x] & CACA_BOLD)
                cur += sprintf(cur, "[g]");
            if(lineattr[x] & CACA_ITALICS)
                cur += sprintf(cur, "[i]");
            if(lineattr[x] & CACA_UNDERLINE)
                cur += sprintf(cur, "[s]");
            if(lineattr[x] & CACA_BLINK)
                ; /* FIXME */

            for(i = 0; i < len; i++)
            {
                if(linechar[x + i] == CACA_MAGIC_FULLWIDTH)
                    ;
                else if(linechar[x + i] == ' ')
                    *cur++ = '_';
                else
                    cur += caca_utf32_to_utf8(cur, linechar[x + i]);
            }

            if(lineattr[x] & CACA_BLINK)
                ; /* FIXME */
            if(lineattr[x] & CACA_UNDERLINE)
                cur += sprintf(cur, "[/s]");
            if(lineattr[x] & CACA_ITALICS)
                cur += sprintf(cur, "[/i]");
            if(lineattr[x] & CACA_BOLD)
                cur += sprintf(cur, "[/g]");

            if(linechar[x] == ' ' || needfront)
                cur += sprintf(cur, "[/c]");
            if(needback)
                cur += sprintf(cur, "[/f]");
        }
        cur += sprintf(cur, "\n");
    }

    /* Footer */
    cur += sprintf(cur, "[/font]\n");

    /* Crop to really used size */
    debug("bbfr export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Export a text file with IRC colours */
static void *export_irc(caca_canvas_t const *cv, size_t *bytes)
{
    static uint8_t const palette[] =
    {
        1, 2, 3, 10, 5, 6, 7, 15, /* Dark */
        14, 12, 9, 11, 4, 13, 8, 0, /* Light */
    };

    char *data, *cur;
    int x, y;

    /* 14 bytes assumed for max length per pixel. Worst case scenario:
     * ^Cxx,yy   6 bytes
     * ^B^B      2 bytes
     * ch        6 bytes
     * 3 bytes for max length per line. Worst case scenario:
     * <spc>     1 byte (for empty lines)
     * \r\n      2 bytes
     * In real life, the average bytes per pixel value will be around 5.
     */

    *bytes = 2 + cv->height * (3 + cv->width * 14);
    cur = data = malloc(*bytes);

    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        uint8_t prevfg = 0x10;
        uint8_t prevbg = 0x10;

        for(x = 0; x < cv->width; x++)
        {
            uint32_t attr = lineattr[x];
            uint32_t ch = linechar[x];
            uint8_t ansifg, ansibg, fg, bg;

            if(ch == CACA_MAGIC_FULLWIDTH)
                continue;

            ansifg = caca_attr_to_ansi_fg(attr);
            ansibg = caca_attr_to_ansi_bg(attr);

            fg = ansifg < 0x10 ? palette[ansifg] : 0x10;
            bg = ansibg < 0x10 ? palette[ansibg] : 0x10;

            /* TODO: optimise series of same fg / same bg
             *       don't change fg value if ch == ' '
             *       make sure the \x03,%d trick works everywhere */
            if(bg != prevbg || fg != prevfg)
            {
                int need_escape = 0;

                if(bg == 0x10)
                {
                    if(fg == 0x10)
                        cur += sprintf(cur, "\x0f");
                    else
                    {
                        if(prevbg == 0x10)
                            cur += sprintf(cur, "\x03%d", fg);
                        else
                            cur += sprintf(cur, "\x0f\x03%d", fg);

                        if(ch == (uint32_t)',')
                            need_escape = 1;
                    }
                }
                else
                {
                    if(fg == 0x10)
                        cur += sprintf(cur, "\x0f\x03,%d", bg);
                    else
                        cur += sprintf(cur, "\x03%d,%d", fg, bg);
                }

                if(ch >= (uint32_t)'0' && ch <= (uint32_t)'9')
                    need_escape = 1;

                if(need_escape)
                    cur += sprintf(cur, "\x02\x02");
            }

            cur += caca_utf32_to_utf8(cur, ch);
            prevfg = fg;
            prevbg = bg;
        }

        /* TODO: do the same the day we optimise whole lines above */
        if(!cv->width)
            *cur++ = ' ';

        *cur++ = '\r';
        *cur++ = '\n';
    }

    /* Crop to really used size */
    debug("IRC export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Export a PostScript document. */
static void *export_ps(caca_canvas_t const *cv, size_t *bytes)
{
    static char const *ps_header =
        "%!\n"
        "%% libcaca PDF export\n"
        "%%LanguageLevel: 2\n"
        "%%Pages: 1\n"
        "%%DocumentData: Clean7Bit\n"
        "/csquare {\n"
        "  newpath\n"
        "  0 0 moveto\n"
        "  0 1 rlineto\n"
        "  1 0 rlineto\n"
        "  0 -1 rlineto\n"
        "  closepath\n"
        "  setrgbcolor\n"
        "  fill\n"
        "} def\n"
        "/S {\n"
        "  Show\n"
        "} bind def\n"
        "/Courier-Bold findfont\n"
        "8 scalefont\n"
        "setfont\n"
        "gsave\n"
        "6 10 scale\n";

    char *data, *cur;
    int x, y;

    /* 200 is arbitrary but should be ok */
    *bytes = strlen(ps_header) + 100 + cv->height * (32 + cv->width * 200);
    cur = data = malloc(*bytes);

    /* Header */
    cur += sprintf(cur, "%s", ps_header);
    cur += sprintf(cur, "0 %d translate\n", cv->height);

    /* Background, drawn using csquare macro defined in header */
    for(y = cv->height; y--; )
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;

        for(x = 0; x < cv->width; x++)
        {
            uint8_t argb[8];
            caca_attr_to_argb64(*lineattr++, argb);
            cur += sprintf(cur, "1 0 translate\n %f %f %f csquare\n",
                           (float)argb[1] * (1.0 / 0xf),
                           (float)argb[2] * (1.0 / 0xf),
                           (float)argb[3] * (1.0 / 0xf));
        }

        /* Return to beginning of the line, and jump to the next one */
        cur += sprintf(cur, "-%d 1 translate\n", cv->width);
    }

    cur += sprintf(cur, "grestore\n"); /* Restore transformation matrix */
    cur += sprintf(cur, "0 %d translate\n", cv->height*10);

    for(y = cv->height; y--; )
    {
        uint32_t *lineattr = cv->attrs + (cv->height - y - 1) * cv->width;
        uint32_t *linechar = cv->chars + (cv->height - y - 1) * cv->width;

        for(x = 0; x < cv->width; x++)
        {
            uint8_t argb[8];
            uint32_t ch = *linechar++;

            caca_attr_to_argb64(*lineattr++, argb);

            cur += sprintf(cur, "newpath\n");
            cur += sprintf(cur, "%d %d moveto\n", (x + 1) * 6, y * 10 + 2);
            cur += sprintf(cur, "%f %f %f setrgbcolor\n",
                           (float)argb[5] * (1.0 / 0xf),
                           (float)argb[6] * (1.0 / 0xf),
                           (float)argb[7] * (1.0 / 0xf));

            if(ch < 0x00000020)
                cur += sprintf(cur, "(?) show\n");
            else if(ch >= 0x00000080)
                cur += sprintf(cur, "(?) show\n");
            else switch((uint8_t)(ch & 0x7f))
            {
                case '\\':
                case '(':
                case ')':
                    cur += sprintf(cur, "(\\%c) show\n", (uint8_t)ch);
                    break;
                default:
                    cur += sprintf(cur, "(%c) show\n", (uint8_t)ch);
                    break;
            }
        }
    }

    cur += sprintf(cur, "showpage\n");

    /* Crop to really used size */
    debug("PS export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Export an SVG vector image */
static void *export_svg(caca_canvas_t const *cv, size_t *bytes)
{
    static char const svg_header[] =
        "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
        "<svg width=\"%d\" height=\"%d\" viewBox=\"0 0 %d %d\""
        " xmlns=\"http://www.w3.org/2000/svg\""
        " xmlns:xlink=\"http://www.w3.org/1999/xlink\""
        " xml:space=\"preserve\" version=\"1.1\"  baseProfile=\"full\">\n";

    char *data, *cur;
    int x, y;

    /* 200 is arbitrary but should be ok */
    *bytes = strlen(svg_header) + 128 + cv->width * cv->height * 200;
    cur = data = malloc(*bytes);

    /* Header */
    cur += sprintf(cur, svg_header, cv->width * 6, cv->height * 10,
                                    cv->width * 6, cv->height * 10);

    cur += sprintf(cur, " <g id=\"mainlayer\" font-size=\"10\""
                        " style=\"font-family: monospace\">\n");

    /* Background */
    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;

        for(x = 0; x < cv->width; x++)
        {
            cur += sprintf(cur, "<rect style=\"fill:#%.03x\" x=\"%d\" y=\"%d\""
                                " width=\"6\" height=\"10\"/>\n",
                                caca_attr_to_rgb12_bg(*lineattr++),
                                x * 6, y * 10);
        }
    }

    /* Text */
    for(y = 0; y < cv->height; y++)
    {
        uint32_t *lineattr = cv->attrs + y * cv->width;
        uint32_t *linechar = cv->chars + y * cv->width;

        for(x = 0; x < cv->width; x++)
        {
            uint32_t ch = *linechar++;

            if(ch == ' ' || ch == CACA_MAGIC_FULLWIDTH)
            {
                lineattr++;
                continue;
            }

            cur += sprintf(cur, "<text style=\"fill:#%.03x\" "
                                "x=\"%d\" y=\"%d\">",
                                caca_attr_to_rgb12_fg(*lineattr++),
                                x * 6, (y * 10) + 8);

            if(ch < 0x00000020)
                *cur++ = '?';
            else if(ch > 0x0000007f)
                cur += caca_utf32_to_utf8(cur, ch);
            else switch((uint8_t)ch)
            {
                case '>': cur += sprintf(cur, "&gt;"); break;
                case '<': cur += sprintf(cur, "&lt;"); break;
                case '&': cur += sprintf(cur, "&amp;"); break;
                default: *cur++ = ch; break;
            }
            cur += sprintf(cur, "</text>\n");
        }
    }

    cur += sprintf(cur, " </g>\n");
    cur += sprintf(cur, "</svg>\n");

    /* Crop to really used size */
    debug("SVG export: alloc %lu bytes, realloc %lu",
          (unsigned long int)*bytes, (unsigned long int)(cur - data));
    *bytes = (uintptr_t)(cur - data);
    data = realloc(data, *bytes);

    return data;
}

/* Export a TGA image */
static void *export_tga(caca_canvas_t const *cv, size_t *bytes)
{
    char const * const *fontlist;
    char *data, *cur;
    caca_font_t *f;
    int i, w, h;

    fontlist = caca_get_font_list();
    if(!fontlist[0])
    {
        seterrno(EINVAL);
        return NULL;
    }

    f = caca_load_font(fontlist[0], 0);

    w = caca_get_canvas_width(cv) * caca_get_font_width(f);
    h = caca_get_canvas_height(cv) * caca_get_font_height(f);

    *bytes = w * h * 4 + 18; /* 32 bpp + 18 bytes for the header */
    cur = data = malloc(*bytes);

    /* ID Length */
    cur += sprintf(cur, "%c", 0);
    /* Color Map Type: no colormap */
    cur += sprintf(cur, "%c", 0);
    /* Image Type: uncompressed truecolor */
    cur += sprintf(cur, "%c", 2);
    /* Color Map Specification: no color map */
    memset(cur, 0, 5); cur += 5;

    /* Image Specification */
    cur += sprintf(cur, "%c%c", 0, 0); /* X Origin */
    cur += sprintf(cur, "%c%c", 0, 0); /* Y Origin */
    cur += sprintf(cur, "%c%c", w & 0xff, w >> 8); /* Width */
    cur += sprintf(cur, "%c%c", h & 0xff, h >> 8); /* Height */
    cur += sprintf(cur, "%c", 32); /* Pixel Depth */
    cur += sprintf(cur, "%c", 40); /* Image Descriptor */

    /* Image ID: no ID */
    /* Color Map Data: no colormap */

    /* Image Data */
    caca_render_canvas(cv, f, cur, w, h, 4 * w);

    /* Swap bytes. What a waste of time. */
    for(i = 0; i < w * h * 4; i += 4)
    {
        char c;
        c = cur[i]; cur[i] = cur[i + 3]; cur[i + 3] = c;
        c = cur[i + 1]; cur[i + 1] = cur[i + 2]; cur[i + 2] = c;
    }

    caca_free_font(f);

    return data;
}

/*
 * XXX: The following functions are aliases.
 */

void *cucul_export_memory(cucul_canvas_t const *, char const *,
                          size_t *) CACA_ALIAS(caca_export_memory);
char const * const * cucul_get_export_list(void)
         CACA_ALIAS(caca_get_export_list);