[Vertical] fix vertical gpos

Wow, it took me a few days to find the right fix!

We now set the advance for attached marks to zero, but we
do this in the _finish() state of gpos, so it shouldn't
regress with fonts like DejaVuSansMono that explicitly
decrease the mark advance width to set it to zero.
This commit is contained in:
Behdad Esfahbod 2011-05-24 21:04:15 -04:00
parent ff7cbd0219
commit 7403e055cd
2 changed files with 103 additions and 73 deletions

View File

@ -873,38 +873,57 @@ struct CursivePosFormat1
(this+this_record.exitAnchor).get_anchor (c->font, c->buffer->info[i].codepoint, &exit_x, &exit_y);
(this+next_record.entryAnchor).get_anchor (c->font, c->buffer->info[j].codepoint, &entry_x, &entry_y);
/* Align the exit anchor of the left/top glyph with the entry anchor of the right/bottom glyph
* by adjusting advance of the left/top glyph. */
if (HB_DIRECTION_IS_BACKWARD (c->direction))
{
if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
c->buffer->pos[j].x_advance = c->buffer->pos[j].x_offset + entry_x - exit_x;
else
c->buffer->pos[j].y_advance = c->buffer->pos[j].y_offset + entry_y - exit_y;
}
else
{
if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
c->buffer->pos[i].x_advance = c->buffer->pos[i].x_offset + exit_x - entry_x;
else
c->buffer->pos[i].y_advance = c->buffer->pos[i].y_offset + exit_y - entry_y;
hb_glyph_position_t *pos = c->buffer->pos;
hb_position_t d;
/* Main-direction adjustment */
switch (c->direction) {
case HB_DIRECTION_LTR:
pos[i].x_advance = exit_x + pos[i].x_offset;
d = entry_x + pos[j].x_offset;
pos[j].x_advance -= d;
pos[j].x_offset -= d;
break;
case HB_DIRECTION_RTL:
d = exit_x + pos[i].x_offset;
pos[i].x_advance -= d;
pos[i].x_offset -= d;
pos[j].x_advance = entry_x + pos[j].x_offset;
break;
case HB_DIRECTION_TTB:
pos[i].y_advance = exit_y + pos[i].y_offset;
d = entry_y + pos[j].y_offset;
pos[j].y_advance -= d;
pos[j].y_offset -= d;
break;
case HB_DIRECTION_BTT:
d = exit_y + pos[i].y_offset;
pos[i].y_advance -= d;
pos[i].y_offset -= d;
pos[j].y_advance = entry_y;
break;
case HB_DIRECTION_INVALID:
default:
break;
}
if (c->lookup_props & LookupFlag::RightToLeft)
{
c->buffer->pos[i].cursive_chain() = j - i;
/* Cross-direction adjustment */
if (c->lookup_props & LookupFlag::RightToLeft) {
pos[i].cursive_chain() = j - i;
if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
c->buffer->pos[i].y_offset = entry_y - exit_y;
pos[i].y_offset = entry_y - exit_y;
else
c->buffer->pos[i].x_offset = entry_x - exit_x;
}
else
{
c->buffer->pos[j].cursive_chain() = i - j;
pos[i].x_offset = entry_x - exit_x;
} else {
pos[j].cursive_chain() = i - j;
if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
c->buffer->pos[j].y_offset = exit_y - entry_y;
pos[j].y_offset = exit_y - entry_y;
else
c->buffer->pos[j].x_offset = exit_x - entry_x;
pos[j].x_offset = exit_x - entry_x;
}
c->buffer->i = j;
@ -1500,61 +1519,69 @@ struct GPOS : GSUBGPOS
DEFINE_SIZE_STATIC (10);
};
static void
fix_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
{
unsigned int j = pos[i].cursive_chain();
if (likely (!j))
return;
j += i;
pos[i].cursive_chain() = 0;
fix_cursive_minor_offset (pos, j, direction);
if (HB_DIRECTION_IS_HORIZONTAL (direction))
pos[i].y_offset += pos[j].y_offset;
else
pos[i].x_offset += pos[j].x_offset;
}
static void
fix_mark_attachment (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
{
if (likely (!(pos[i].attach_lookback())))
return;
unsigned int j = i - pos[i].attach_lookback();
pos[i].x_advance = 0;
pos[i].y_advance = 0;
pos[i].x_offset += pos[j].x_offset;
pos[i].y_offset += pos[j].y_offset;
if (HB_DIRECTION_IS_FORWARD (direction))
for (unsigned int k = j; k < i; j++) {
pos[i].x_offset -= pos[k].x_advance;
pos[i].y_offset -= pos[k].y_advance;
}
else
for (unsigned int k = j + 1; k < i + 1; j++) {
pos[i].x_offset += pos[k].x_advance;
pos[i].y_offset += pos[k].y_advance;
}
}
void
GPOS::position_finish (hb_buffer_t *buffer)
{
unsigned int i, j;
unsigned int len;
hb_glyph_position_t *pos = hb_buffer_get_glyph_positions (buffer, &len);
hb_direction_t direction = buffer->props.direction;
/* Handle cursive connections:
* First handle all chain-back connections, then handle all chain-forward connections. */
if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
/* Handle cursive connections */
for (unsigned int i = 0; i < len; i++)
{
for (j = 0; j < len; j++) {
if (pos[j].cursive_chain() < 0)
pos[j].y_offset += pos[j + pos[j].cursive_chain()].y_offset;
}
for (i = len; i > 0; i--) {
j = i - 1;
if (pos[j].cursive_chain() > 0)
pos[j].y_offset += pos[j + pos[j].cursive_chain()].y_offset;
}
fix_cursive_minor_offset (pos, i, direction);
}
else
{
for (j = 0; j < len; j++) {
if (pos[j].cursive_chain() < 0)
pos[j].x_offset += pos[j + pos[j].cursive_chain()].x_offset;
}
for (i = len; i > 0; i--) {
j = i - 1;
if (pos[j].cursive_chain() > 0)
pos[j].x_offset += pos[j + pos[j].cursive_chain()].x_offset;
}
}
/* Handle attachments */
for (i = 0; i < len; i++)
if (pos[i].attach_lookback())
{
unsigned int back = i - pos[i].attach_lookback();
pos[i].x_offset += pos[back].x_offset;
pos[i].y_offset += pos[back].y_offset;
if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
for (j = back + 1; j < i + 1; j++) {
pos[i].x_offset += pos[j].x_advance;
pos[i].y_offset += pos[j].y_advance;
}
else
for (j = back; j < i; j++) {
pos[i].x_offset -= pos[j].x_advance;
pos[i].y_offset -= pos[j].y_advance;
}
}
for (unsigned int i = 0; i < len; i++)
{
fix_mark_attachment (pos, i, direction);
}
}

View File

@ -184,9 +184,12 @@ hb_ensure_native_direction (hb_ot_shape_context_t *c)
{
hb_direction_t direction = c->buffer->props.direction;
/* XXX vertical */
if (HB_DIRECTION_IS_HORIZONTAL (direction) &&
direction != hb_script_get_horizontal_direction (c->buffer->props.script))
/* TODO vertical:
* The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
* Ogham fonts are supposed to be implemented BTT or not. Need to research that
* first. */
if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (c->buffer->props.script)) ||
(HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB))
{
hb_buffer_reverse_clusters (c->buffer);
c->buffer->props.direction = HB_DIRECTION_REVERSE (c->buffer->props.direction);