libcaca/cucul/import.c

/*
 *  libcucul      Canvas for ultrafast compositing of Unicode letters
 *  Copyright (c) 2002-2006 Sam Hocevar <sam@zoy.org>
 *                All Rights Reserved
 *
 *  $Id$
 *
 *  This library is free software; 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 import functions.
 */

#include "config.h"
#include "common.h"

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

#include "cucul.h"
#include "cucul_internals.h"

/* ANSI Graphic Rendition Combination Mode */
struct ansi_grcm
{
    uint8_t fg, bg;
    uint8_t bold, negative, concealed;
};

static cucul_canvas_t *import_caca(void const *, unsigned int);
static cucul_canvas_t *import_text(void const *, unsigned int);
static cucul_canvas_t *import_ansi(void const *, unsigned int);

static void ansi_parse_grcm(cucul_canvas_t *, struct ansi_grcm *,
                            unsigned int, unsigned int const *);

/** \brief Import a buffer into a canvas
 *
 *  This function imports a libcucul buffer (cucul_load_memory()/cucul_load_file())
 *  into an internal libcucul canvas.
 *
 *  Valid values for \c format are:
 *
 *  \li \c "": attempt to autodetect the file format.
 *
 *  \li \c "ansi": import ANSI files.
 *
 *  \li \c "caca": import native libcaca files.
 *
 *  \param buffer A \e libcucul buffer containing the data to be loaded
 *         into a canvas.
 *  \param format A string describing the input format.
 *  \return A libcucul canvas, or NULL in case of error.
 */
cucul_canvas_t * cucul_import_canvas(cucul_buffer_t *buffer, char const *format)
{
    char const *buf = (char const*)buffer->data;

    if(buffer->size == 0 || buffer->data == NULL)
        return NULL;

    if(!strcasecmp("caca", format))
        return import_caca(buffer->data, buffer->size);
    if(!strcasecmp("text", format))
        return import_text(buffer->data, buffer->size);
    if(!strcasecmp("ansi", format))
        return import_ansi(buffer->data, buffer->size);

    /* Autodetection */
    if(!strcasecmp("", format))
        {
            unsigned int i=0;
            /* if 4 first letters are CACA */
            if(buffer->size >= 4 &&
               buf[0] == 'C' && buf[1] == 'A' && buf[2] == 'C' && buf[3] != 'A')
                return import_caca(buffer->data, buffer->size);

            /* If we find ESC[ argv, we guess it's an ANSI file */
            while(i < buffer->size - 1)
                {
                    if((buf[i] == 0x1b) && (buf[i+1] == '['))
                        return import_ansi(buffer->data, buffer->size);
                    i++;
                }

            /* Otherwise, import it as text */
            return import_text(buffer->data, buffer->size);
        }
    return NULL;
}

/** \brief Get available import formats
 *
 *  Return a list of available import formats. The list is a NULL-terminated
 *  array of strings, interleaving a string containing the internal value for
 *  the import format, to be used with cucul_import_canvas(), and a string
 *  containing the natural language description for that import format.
 *
 *  \return An array of strings.
 */
char const * const * cucul_get_import_list(void)
{
    static char const * const list[] =
        {
            "", "autodetect",
            "text", "plain text",
            "caca", "native libcaca format",
            "ansi", "ANSI coloured text",
            NULL, NULL
        };

    return list;
}

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

static cucul_canvas_t *import_caca(void const *data, unsigned int size)
{
    cucul_canvas_t *cv;
    uint8_t const *buf = (uint8_t const *)data;
    unsigned int width, height, n;

    if(size < 16)
        return NULL;

    if(buf[0] != 'C' || buf[1] != 'A' || buf[2] != 'C' || buf[3] != 'A')
        return NULL;

    if(buf[4] != 'C' || buf[5] != 'A' || buf[6] != 'N' || buf[7] != 'V')
        return NULL;

    width = ((uint32_t)buf[8] << 24) | ((uint32_t)buf[9] << 16)
        | ((uint32_t)buf[10] << 8) | (uint32_t)buf[11];
    height = ((uint32_t)buf[12] << 24) | ((uint32_t)buf[13] << 16)
        | ((uint32_t)buf[14] << 8) | (uint32_t)buf[15];

    if(!width || !height)
        return NULL;

    if(size != 16 + width * height * 8)
        return NULL;

    cv = cucul_create_canvas(width, height);

    if(!cv)
        return NULL;

    for(n = height * width; n--; )
        {
            cv->chars[n] = ((uint32_t)buf[16 + 0 + 8 * n] << 24)
                | ((uint32_t)buf[16 + 1 + 8 * n] << 16)
                | ((uint32_t)buf[16 + 2 + 8 * n] << 8)
                | (uint32_t)buf[16 + 3 + 8 * n];
            cv->attr[n] = ((uint32_t)buf[16 + 4 + 8 * n] << 24)
                | ((uint32_t)buf[16 + 5 + 8 * n] << 16)
                | ((uint32_t)buf[16 + 6 + 8 * n] << 8)
                | (uint32_t)buf[16 + 7 + 8 * n];
        }

    return cv;
}

static cucul_canvas_t *import_text(void const *data, unsigned int size)
{
    cucul_canvas_t *cv;
    char const *text = (char const *)data;
    unsigned int width = 1, height = 1, x = 0, y = 0, i;

    cv = cucul_create_canvas(width, height);
    cucul_set_color(cv, CUCUL_COLOR_DEFAULT, CUCUL_COLOR_TRANSPARENT);

    for(i = 0; i < size; i++)
        {
            unsigned char ch = *text++;

            if(ch == '\r')
                continue;

            if(ch == '\n')
                {
                    x = 0;
                    y++;
                    continue;
                }

            if(x >= width || y >= height)
                {
                    if(x >= width)
                        width = x + 1;

                    if(y >= height)
                        height = y + 1;

                    cucul_set_canvas_size(cv, width, height);
                }

            cucul_putchar(cv, x, y, ch);
            x++;
        }

    return cv;
}

static cucul_canvas_t *import_ansi(void const *data, unsigned int size)
{
    struct ansi_grcm grcm;
    unsigned char const *buffer = (unsigned char const*)data;
    cucul_canvas_t *cv;
    unsigned int i, j, skip, dummy = 0;
    unsigned int width = 80, height = 25;
    int x = 0, y = 0, save_x = 0, save_y = 0;

    cv = cucul_create_canvas(width, height);
    ansi_parse_grcm(cv, &grcm, 1, &dummy);

    for(i = 0; i < size; i += skip)
        {
            skip = 1;

            /* Wrap long lines */
            if((unsigned int)x >= width)
                {
                    x = 0;
                    y++;
                }

            if(buffer[i] == '\x1a' && size - i >= 8
               && !memcmp(buffer + i + 1, "SAUCE00", 7))
                break; /* End before SAUCE data */

            if(buffer[i] == '\r')
                continue; /* DOS sucks */

            if(buffer[i] == '\n')
                {
                    x = 0;
                    y++;
                    continue;
                }

            /* Interpret escape commands, as per Standard ECMA-48 "Control
             * Functions for Coded Character Sets", 5.4. Control sequences. */
            if(buffer[i] == '\x1b' && buffer[i + 1] == '[')
                {
                    unsigned int argc = 0, argv[101];
                    unsigned int param, inter, final;

                    /* Compute offsets to parameter bytes, intermediate bytes and
                     * to the final byte. Only the final byte is mandatory, there
                     * can be zero of the others.
                     * 0  param=2             inter                 final           final+1
                     * +-----+------------------+---------------------+-----------------+
                     * | CSI | parameter bytes  | intermediate bytes  |   final byte    |
                     * |     |   0x30 - 0x3f    |    0x20 - 0x2f      |   0x40 - 0x7e   |
                     * | ^[[ | 0123456789:;<=>? | SPC !"#$%&'()*+,-./ | azAZ@[\]^_`{|}~ |
                     * +-----+------------------+---------------------+-----------------+
                     */
                    param = 2;

                    for(inter = param; i + inter < size; inter++)
                        if(buffer[i + inter] < 0x30 || buffer[i + inter] > 0x3f)
                            break;

                    for(final = inter; i + final < size; final++)
                        if(buffer[i + final] < 0x20 || buffer[i + final] > 0x2f)
                            break;

                    if(buffer[i + final] < 0x40 || buffer[i + final] > 0x7e)
                        break; /* Invalid Final Byte */

                    skip += final;

                    /* Sanity checks */
                    if(param < inter && buffer[i + param] >= 0x3c)
                        {
                            fprintf(stderr, "private sequence \"^[[%.*s\"\n",
                                    final - param + 1, buffer + i + param);
                            continue; /* Private sequence, skip it entirely */
                        }

                    if(final - param > 100)
                        continue; /* Suspiciously long sequence, skip it */

                    /* Parse parameter bytes as per ECMA-48 5.4.2: Parameter string
                     * format */
                    if(param < inter)
                        {
                            argv[0] = 0;
                            for(j = param; j < inter; j++)
                                {
                                    if(buffer[i + j] == ';')
                                        argv[++argc] = 0;
                                    else if(buffer[i + j] >= '0' && buffer[i + j] <= '9')
                                        argv[argc] = 10 * argv[argc] + (buffer[i + j] - '0');
                                }
                            argc++;
                        }

                    /* Interpret final byte. The code representations are given in
                     * ECMA-48 5.4: Control sequences, and the code definitions are
                     * given in ECMA-48 8.3: Definition of control functions. */
                    switch(buffer[i + final])
                        {
                        case 'f': /* CUP - Cursor Position */
                        case 'H': /* HVP - Character And Line Position */
                            x = (argc > 1) ? argv[1] - 1 : 0;
                            y = (argc > 0) ? argv[0] - 1 : 0;
                            break;
                        case 'A': /* CUU - Cursor Up */
                            y -= argc ? argv[0] : 1;
                            if(y < 0)
                                y = 0;
                            break;
                        case 'B': /* CUD - Cursor Down */
                            y += argc ? argv[0] : 1;
                            break;
                        case 'C': /* CUF - Cursor Right */
                            x += argc ? argv[0] : 1;
                            break;
                        case 'D': /* CUB - Cursor Left */
                            x -= argc ? argv[0] : 1;
                            if(x < 0)
                                x = 0;
                            break;
                        case 's': /* Private (save cursor position) */
                            save_x = x;
                            save_y = y;
                            break;
                        case 'u': /* Private (reload cursor positin) */
                            x = save_x;
                            y = save_y;
                            break;
                        case 'J': /* ED - Erase In Page */
                            if(argv[0] == 2)
                                x = y = 0;
                            break;
                        case 'K': /* EL - Erase In Line */
                            for(j = x; j < width; j++)
                                _cucul_putchar32(cv, j, y, (uint32_t)' ');
                            x = width;
                            break;
                        case 'm': /* SGR - Select Graphic Rendition */
                            ansi_parse_grcm(cv, &grcm, argc, argv);
                            break;
                        default:
                            fprintf(stderr, "unknown command %c\n", buffer[i + final]);
                            break;
                        }

                    continue;
                }

            /* We're going to paste a character. First make sure the canvas
             * is big enough. */
            if((unsigned int)y >= height)
                {
                    height = y + 1;
                    cucul_set_canvas_size(cv, width, height);
                }

            /* Now paste our character */
            _cucul_putchar32(cv, x, y, _cucul_cp437_to_utf32(buffer[i]));
            x++;
        }

    return cv;
}

/* XXX : ANSI loader helper */

static void ansi_parse_grcm(cucul_canvas_t *cv, struct ansi_grcm *g,
                            unsigned int argc, unsigned int const *argv)
{
    static uint8_t const ansi2cucul[] =
        {
            CUCUL_COLOR_BLACK, CUCUL_COLOR_RED,
            CUCUL_COLOR_GREEN, CUCUL_COLOR_BROWN,
            CUCUL_COLOR_BLUE, CUCUL_COLOR_MAGENTA,
            CUCUL_COLOR_CYAN, CUCUL_COLOR_LIGHTGRAY
        };

    unsigned int j;
    uint8_t myfg, mybg;

    for(j = 0; j < argc; j++)
        {
            /* Defined in ECMA-48 8.3.117: SGR - SELECT GRAPHIC RENDITION */
            if(argv[j] >= 30 && argv[j] <= 37)
                g->fg = ansi2cucul[argv[j] - 30];
            else if(argv[j] >= 40 && argv[j] <= 47)
                g->bg = ansi2cucul[argv[j] - 40];
            else if(argv[j] >= 90 && argv[j] <= 97)
                g->fg = ansi2cucul[argv[j] - 90] + 8;
            else if(argv[j] >= 100 && argv[j] <= 107)
                g->bg = ansi2cucul[argv[j] - 100] + 8;
            else switch(argv[j])
                {
                case 0: /* default rendition */
                    g->fg = CUCUL_COLOR_DEFAULT;
                    g->bg = CUCUL_COLOR_DEFAULT;
                    g->bold = g->negative = g->concealed = 0;
                    break;
                case 1: /* bold or increased intensity */
                    g->bold = 1;
                    break;
                case 4: /* singly underlined */
                    break;
                case 5: /* slowly blinking (less then 150 per minute) */
                    break;
                case 7: /* negative image */
                    g->negative = 1;
                    break;
                case 8: /* concealed characters */
                    g->concealed = 1;
                    break;
                case 22: /* normal colour or normal intensity (neither bold nor faint) */
                    g->bold = 0;
                    break;
                case 28: /* revealed characters */
                    g->concealed = 0;
                    break;
                case 39: /* default display colour (implementation-defined) */
                    g->fg = CUCUL_COLOR_DEFAULT;
                    break;
                case 49: /* default background colour (implementation-defined) */
                    g->bg = CUCUL_COLOR_DEFAULT;
                    break;
                default:
                    fprintf(stderr, "unknown sgr %i\n", argv[j]);
                    break;
                }
        }

    if(g->concealed)
        {
            myfg = mybg = CUCUL_COLOR_TRANSPARENT;
        }
    else
        {
            myfg = g->negative ? g->bg : g->fg;
            mybg = g->negative ? g->fg : g->bg;

            if(g->bold)
                {
                    if(myfg < 8)
                        myfg += 8;
                    else if(myfg == CUCUL_COLOR_DEFAULT)
                        myfg = CUCUL_COLOR_WHITE;
                }
        }

    cucul_set_color(cv, myfg, mybg);
}