netsurf/framebuffer/font_internal.c

186 lines
5.1 KiB
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:
*/