walkero
/
harfbuzz
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[API] Allow negative font x_scale/y_scale 

I was reconsidering whether y should grow down, since all three/four
times I've used this API I was tricked and got that wrong in my use.
So I was very inclined to make y grow down instead of up.  However,
considering that the font space has y up and it would be very confusing
for callbacks to work against that, I decided that what I really want
is for the user to be able to set y_scale to a negative number to imply
that user-space y grows down.

Changing x_scale/y_scale from unsigned int to int allows that, and I've
made pango to use that instead of negating glyph y_offset later.  hb-ft
however still has y group up.  I *guess* that's how FreeType works?
I'm not sure, FreeType docs don't make this clear...

I'm happy with the resolution :-).
This commit is contained in:
Behdad Esfahbod 2011-04-21 15:08:01 -04:00
parent 4d559cddbb
commit da97541988
4 changed files with 10 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/hb-font.cc
View File

@ -523,8 +523,8 @@ hb_font_unset_funcs (hb_font_t *font,
void void
hb_font_set_scale (hb_font_t *font, hb_font_set_scale (hb_font_t *font,
unsigned int x_scale, int x_scale,
unsigned int y_scale) int y_scale)
{ {
if (HB_OBJECT_IS_INERT (font)) if (HB_OBJECT_IS_INERT (font))
return; return;
@ -535,8 +535,8 @@ hb_font_set_scale (hb_font_t *font,
void void
hb_font_get_scale (hb_font_t *font, hb_font_get_scale (hb_font_t *font,
unsigned int *x_scale, int *x_scale,
unsigned int *y_scale) int *y_scale)
{ {
if (x_scale) *x_scale = font->x_scale; if (x_scale) *x_scale = font->x_scale;
if (y_scale) *y_scale = font->y_scale; if (y_scale) *y_scale = font->y_scale;

8
src/hb-font.h
View File

@ -231,13 +231,13 @@ hb_font_unset_funcs (hb_font_t *font,
*/ */
void void
hb_font_set_scale (hb_font_t *font, hb_font_set_scale (hb_font_t *font,
unsigned int x_scale, int x_scale,
unsigned int y_scale); int y_scale);
void void
hb_font_get_scale (hb_font_t *font, hb_font_get_scale (hb_font_t *font,
unsigned int *x_scale, int *x_scale,
unsigned int *y_scale); int *y_scale);
/* /*
* A zero value means "no hinting in that direction" * A zero value means "no hinting in that direction"

6
src/hb-ot-layout-common-private.hh
View File

@ -532,7 +532,7 @@ struct Device
inline hb_position_t get_y_delta (hb_ot_layout_context_t *c) const inline hb_position_t get_y_delta (hb_ot_layout_context_t *c) const
{ return get_delta (c->font->y_ppem, c->font->y_scale); } { return get_delta (c->font->y_ppem, c->font->y_scale); }
inline int get_delta (unsigned int ppem, unsigned int scale) const inline int get_delta (unsigned int ppem, int scale) const
{ {
if (!ppem) return 0; if (!ppem) return 0;
@ -540,10 +540,6 @@ struct Device
if (!pixels) return 0; if (!pixels) return 0;
/* pixels is at most in the -8..7 range. So 64-bit arithmetic is
* not really necessary here. A simple cast to int may just work
* as well. But since this code is not reached that often and
* for the sake of correctness, we do a 64bit operation. */
return pixels * (int64_t) scale / ppem; return pixels * (int64_t) scale / ppem;
} }

2
src/hb-ot-layout-private.hh
View File

@ -77,7 +77,7 @@ struct hb_ot_layout_context_t
inline hb_position_t scale_y (int16_t v) { return scale (v, this->font->y_scale); } inline hb_position_t scale_y (int16_t v) { return scale (v, this->font->y_scale); }
private: private:
inline hb_position_t scale (int16_t v, unsigned int scale) { return v * (int64_t) scale / this->face->head_table->get_upem (); } inline hb_position_t scale (int16_t v, int scale) { return v * (int64_t) scale / this->face->head_table->get_upem (); }
}; };