netsurf/framebuffer/font_internal.c

/*
 * Copyright 2005 James Bursa <bursa@users.sourceforge.net>
 *           2008 Vincent Sanders <vince@simtec.co.uk>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <inttypes.h>
#include <string.h>

#include <assert.h>
#include "css/css.h"
#include "render/font.h"
#include "desktop/options.h"
#include "utils/utf8.h"

#include "framebuffer/gui.h"
#include "framebuffer/font.h"

bool fb_font_init(void)
{
        return true;
}

const struct fb_font_desc*
fb_get_font(const plot_font_style_t *fstyle)
{
	if (fstyle->weight >= 700) {
		if ((fstyle->flags & FONTF_ITALIC) ||
				(fstyle->flags & FONTF_OBLIQUE)) {
			return &font_italic_bold;
		} else {
			return &font_bold;
		}
	} else {
		if ((fstyle->flags & FONTF_ITALIC) ||
				(fstyle->flags & FONTF_OBLIQUE)) {
			return &font_italic;
		} else {
			return &font_regular;
		}
	}
}

utf8_convert_ret utf8_to_font_encoding(const struct fb_font_desc* font,
				       const char *string,
				       size_t len,
				       char **result)
{
	return utf8_to_enc(string, font->encoding, len, result);

}

utf8_convert_ret utf8_to_local_encoding(const char *string,
				       size_t len,
				       char **result)
{
	return utf8_to_enc(string, "CP1252", len, result);

}

utf8_convert_ret utf8_from_local_encoding(const char *string,
					size_t len,
					char **result)
{
	*result = malloc(len + 1);
	if (*result == NULL) {
		return UTF8_CONVERT_NOMEM;
	}

	memcpy(*result, string, len);

	(*result)[len] = '\0';

	return UTF8_CONVERT_OK;
}

static bool nsfont_width(const plot_font_style_t *fstyle,
                         const char *string, size_t length,
                         int *width)
{
        const struct fb_font_desc* fb_font = fb_get_font(fstyle);
        *width = fb_font->width * utf8_bounded_length(string, length);
	return true;
}

/**
 * Find the position in a string where an x coordinate falls.
 *
 * \param  fstyle       style for this text
 * \param  string       UTF-8 string to measure
 * \param  length       length of string
 * \param  x            x coordinate to search for
 * \param  char_offset  updated to offset in string of actual_x, [0..length]
 * \param  actual_x     updated to x coordinate of character closest to x
 * \return  true on success, false on error and error reported
 */

static bool nsfont_position_in_string(const plot_font_style_t *fstyle,
		const char *string, size_t length,
		int x, size_t *char_offset, int *actual_x)
{
        const struct fb_font_desc* fb_font = fb_get_font(fstyle);
        *char_offset = (x + fb_font->width / 2) / fb_font->width;
        if (*char_offset > length)
                *char_offset = length;
        *actual_x = *char_offset * fb_font->width;
	return true;
}



/**
 * Find where to split a string to make it fit a width.
 *
 * \param  fstyle       style for this text
 * \param  string       UTF-8 string to measure
 * \param  length       length of string, in bytes
 * \param  x            width available
 * \param  char_offset  updated to offset in string of actual_x, [1..length]
 * \param  actual_x     updated to x coordinate of character closest to x
 * \return  true on success, false on error and error reported
 *
 * On exit, char_offset indicates first character after split point.
 *
 * Note: char_offset of 0 should never be returned.
 *
 *   Returns:
 *     char_offset giving split point closest to x, where actual_x <= x
 *   else
 *     char_offset giving split point closest to x, where actual_x > x
 *
 * Returning char_offset == length means no split possible
 */

static bool nsfont_split(const plot_font_style_t *fstyle,
		const char *string, size_t length,
		int x, size_t *char_offset, int *actual_x)
{

        const struct fb_font_desc* fb_font = fb_get_font(fstyle);
        int c_off = *char_offset = x / fb_font->width;
        if (*char_offset > length) {
                *char_offset = length;
        } else {
                while (*char_offset > 0) {
                        if (string[*char_offset] == ' ')
                                break;
                        (*char_offset)--;
                }
                if (*char_offset == 0) {
                        *char_offset = c_off;
                        while (*char_offset < length &&
                                        string[*char_offset] != ' ') {
                                (*char_offset)++;
                        }
                }
        }
        *actual_x = *char_offset * fb_font->width;
	return true;
}

const struct font_functions nsfont = {
	nsfont_width,
	nsfont_position_in_string,
	nsfont_split
};

/*
 * Local Variables:
 * c-basic-offset:8
 * End:
 */