/*
* Copyright (C) 2009 Red Hat, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
*/
#include "hb-private.h"
#include "hb-shape.h"
#include "hb-buffer-private.h"
#include "hb-ot-shape-private.h"
/* Prepare */
static inline hb_bool_t
is_variation_selector (hb_codepoint_t unicode)
{
return HB_UNLIKELY ((unicode >= 0x180B && unicode <= 0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
(unicode >= 0xFE00 && unicode <= 0xFE0F) || /* VARIATION SELECTOR-1..16 */
(unicode >= 0xE0100 && unicode <= 0xE01EF)); /* VARIATION SELECTOR-17..256 */
}
static void
hb_form_clusters (hb_buffer_t *buffer)
{
unsigned int count;
count = buffer->in_length;
for (buffer->in_pos = 1; buffer->in_pos < count; buffer->in_pos++)
if (buffer->unicode->get_general_category (IN_CURGLYPH()) == HB_CATEGORY_NON_SPACING_MARK)
IN_CLUSTER (buffer->in_pos) = IN_CLUSTER (buffer->in_pos - 1);
}
static hb_direction_t
hb_ensure_native_direction (hb_buffer_t *buffer)
{
hb_direction_t original_direction = buffer->direction;
/* TODO vertical */
if (HB_DIRECTION_IS_HORIZONTAL (original_direction) &&
original_direction != _hb_script_get_horizontal_direction (buffer->script))
{
hb_buffer_reverse_clusters (buffer);
buffer->direction ^= 1;
}
return original_direction;
}
/* Substitute */
static void
hb_mirror_chars (hb_buffer_t *buffer)
{
unsigned int count;
hb_unicode_get_mirroring_func_t get_mirroring = buffer->unicode->get_mirroring;
if (HB_DIRECTION_IS_FORWARD (buffer->direction))
return;
count = buffer->in_length;
for (buffer->in_pos = 0; buffer->in_pos < count; buffer->in_pos++) {
IN_CURGLYPH() = get_mirroring (IN_CURGLYPH());
}
}
static void
hb_map_glyphs (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer)
{
unsigned int count;
if (HB_UNLIKELY (!buffer->in_length))
return;
count = buffer->in_length - 1;
for (buffer->in_pos = 0; buffer->in_pos < count; buffer->in_pos++) {
if (HB_UNLIKELY (is_variation_selector (IN_NEXTGLYPH()))) {
IN_CURGLYPH() = hb_font_get_glyph (font, face, IN_CURGLYPH(), IN_NEXTGLYPH());
buffer->in_pos++;
} else {
IN_CURGLYPH() = hb_font_get_glyph (font, face, IN_CURGLYPH(), 0);
}
}
IN_CURGLYPH() = hb_font_get_glyph (font, face, IN_CURGLYPH(), 0);
}
static void
hb_substitute_default (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
hb_mirror_chars (buffer);
hb_map_glyphs (font, face, buffer);
}
static hb_bool_t
hb_substitute_complex (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
return _hb_ot_substitute_complex (font, face, buffer, features, num_features);
}
static void
hb_substitute_fallback (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
/* TODO Arabic */
}
/* Position */
static void
hb_position_default (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
unsigned int count;
hb_buffer_clear_positions (buffer);
count = buffer->in_length;
for (buffer->in_pos = 0; buffer->in_pos < count; buffer->in_pos++) {
hb_glyph_metrics_t metrics;
hb_font_get_glyph_metrics (font, face, IN_CURGLYPH(), &metrics);
CURPOSITION()->x_advance = metrics.x_advance;
CURPOSITION()->y_advance = metrics.y_advance;
}
}
static hb_bool_t
hb_position_complex (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
return _hb_ot_position_complex (font, face, buffer, features, num_features);
}
static void
hb_position_fallback (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
/* TODO Mark pos */
}
static void
hb_truetype_kern (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
unsigned int count;
/* TODO Check for kern=0 */
count = buffer->in_length;
for (buffer->in_pos = 1; buffer->in_pos < count; buffer->in_pos++) {
hb_position_t kern, kern1, kern2;
kern = hb_font_get_kerning (font, face, IN_GLYPH(buffer->in_pos - 1), IN_CURGLYPH());
kern1 = kern >> 1;
kern2 = kern - kern1;
POSITION(buffer->in_pos - 1)->x_advance += kern1;
CURPOSITION()->x_advance += kern2;
CURPOSITION()->x_offset += kern2;
}
}
static void
hb_position_fallback_visual (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
hb_truetype_kern (font, face, buffer, features, num_features);
}
/* Shape */
void
hb_shape (hb_font_t *font,
hb_face_t *face,
hb_buffer_t *buffer,
hb_feature_t *features,
unsigned int num_features)
{
hb_direction_t original_direction;
hb_bool_t substitute_fallback, position_fallback;
hb_form_clusters (buffer);
original_direction = hb_ensure_native_direction (buffer);
hb_substitute_default (font, face, buffer, features, num_features);
substitute_fallback = !hb_substitute_complex (font, face, buffer, features, num_features);
if (substitute_fallback)
hb_substitute_fallback (font, face, buffer, features, num_features);
hb_position_default (font, face, buffer, features, num_features);
position_fallback = !hb_position_complex (font, face, buffer, features, num_features);
if (position_fallback)
hb_position_fallback (font, face, buffer, features, num_features);
if (HB_DIRECTION_IS_BACKWARD (buffer->direction))
hb_buffer_reverse (buffer);
if (position_fallback)
hb_position_fallback_visual (font, face, buffer, features, num_features);
buffer->direction = original_direction;
}
