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/*
* Copyright (C) 2011 Grigori Goronzy <greg@chown.ath.cx>
*
* This file is part of libass.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <fribidi/fribidi.h>
#include "ass_render.h"
#include "ass_shaper.h"
/**
* \brief Print version information
*/
void ass_shaper_info(ASS_Library *lib)
{
ass_msg(lib, MSGL_V, "Complex text layout enabled, using FriBidi "
FRIBIDI_VERSION);
}
/**
* \brief Shape an event's text. Calculates directional runs and shapes them.
* \param text_info event's text
* \param ctypes returns character types
* \param emblevels returns embedding levels (directional runs)
*/
void ass_shaper_shape(TextInfo *text_info, FriBidiCharType *ctypes,
FriBidiLevel *emblevels)
{
int i, last_break;
FriBidiParType dir;
FriBidiChar *event_text = calloc(sizeof(*event_text), text_info->length);
GlyphInfo *glyphs = text_info->glyphs;
// Get bidi character types and embedding levels
last_break = 0;
for (i = 0; i < text_info->length; i++) {
event_text[i] = glyphs[i].symbol;
// embedding levels should be calculated paragraph by paragraph
if (glyphs[i].symbol == '\n' || i == text_info->length - 1) {
//printf("paragraph from %d to %d\n", last_break, i);
dir = FRIBIDI_PAR_ON;
fribidi_get_bidi_types(event_text + last_break, i - last_break + 1,
ctypes + last_break);
fribidi_get_par_embedding_levels(ctypes + last_break,
i - last_break + 1, &dir, emblevels + last_break);
last_break = i + 1;
}
}
#if 0
printf("levels ");
for (i = 0; i < text_info->length; i++) {
printf("%d:%d ", ctypes[i], emblevels[i]);
}
printf("\n");
#endif
// Call FriBidi's glyph mirroring shaper.
// This shaper implements rule L4 of the bidi algorithm
fribidi_shape_mirroring(emblevels, text_info->length, event_text);
for (i = 0; i < text_info->length; i++) {
glyphs[i].symbol = event_text[i];
}
// XXX: insert HarfBuzz shaper here
// Skip direction override characters
// NOTE: Behdad said HarfBuzz is supposed to remove these, but this hasn't
// been implemented yet
for (i = 0; i < text_info->length; i++) {
if (glyphs[i].symbol <= 0x202F && glyphs[i].symbol >= 0x202a) {
glyphs[i].symbol = 0;
glyphs[i].skip++;
}
}
free(event_text);
}
void ass_shaper_reorder(TextInfo *text_info, FriBidiCharType *ctypes,
FriBidiLevel *emblevels, FriBidiStrIndex *cmap)
{
int i;
FriBidiParType dir = FRIBIDI_PAR_LTR;
// Initialize reorder map
for (i = 0; i < text_info->length; i++)
cmap[i] = i;
// Create reorder map line-by-line
for (i = 0; i < text_info->n_lines; i++) {
LineInfo *line = text_info->lines + i;
int level;
// FIXME: we should actually specify
// the correct paragraph base direction
level = fribidi_reorder_line(FRIBIDI_FLAGS_DEFAULT,
ctypes + line->offset, line->len, 0, dir,
emblevels + line->offset, NULL, cmap + line->offset);
//printf("reorder line %d to level %d\n", i, level);
}
#if 0
printf("map ");
for (i = 0; i < text_info->length; i++) {
printf("%d ", cmap[i]);
}
printf("\n");
#endif
}
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