[cairo] Add separate x/y scale factors
diff --git a/src/hb-cairo.cc b/src/hb-cairo.cc
index 6e18228..3839fe1 100644
--- a/src/hb-cairo.cc
+++ b/src/hb-cairo.cc
@@ -458,11 +458,9 @@
hb_buffer_guess_segment_properties (buffer);
hb_shape (font, buffer, nullptr, 0);
- double scale_factor = font->x_scale;
-
hb_cairo_glyphs_from_buffer (buffer,
true,
- scale_factor,
+ font->x_scale, font->y_scale,
0., 0.,
utf8, utf8_len,
glyphs, (unsigned *) num_glyphs,
@@ -710,17 +708,17 @@
* When using the hb_cairo_glyphs_from_buffer() API to convert
* HarfBuzz glyph buffer resulted from shaping with such a hb_font_t,
* if the scale-factor was non-zero, you can pass it directly to
- * that API. If the scale-factor was zero however, you need to
- * calculate the correct scale-factor to pass to that API by
- * dividing the #hb_font_t scale-factor by the cairo scaled-font's
- * scale-matrix scale-factor. This assumes a uniform scale.
+ * that API as both X and Y scale factors.
*
- * If the cairo-face was created using the alternative constructor
- * hb_cairo_font_face_create_for_font(), you are on your own
- * computing the correct scale-factor to pass to
- * hb_cairo_glyphs_from_buffer(), but it is generally the x_scale
- * of the #hb_font_t divided by the xx factor of the scaled-font's
- * scale-matrix.
+ * If the scale-factor was zero however, or the cairo face was
+ * created using the alternative constructor
+ * hb_cairo_font_face_create_for_font(), you need to calculate the
+ * correct X/Y scale-factors to pass to hb_cairo_glyphs_from_buffer()
+ * by dividing the #hb_font_t X/Y scale-factors by the
+ * cairo scaled-font's scale-matrix XX/YY components respectively
+ * and use those values. Or if you know that relationship offhand
+ * (because you set the scale of the #hb_font_t yourself), use
+ * the conversation rate involved.
*
* Since: REPLACEME
*/
@@ -758,7 +756,8 @@
* hb_cairo_glyphs_from_buffer:
* @buffer: a #hb_buffer_t containing glyphs
* @utf8_clusters: `true` to if @buffer clusters are in bytes, instead of characters
- * @scale_factor: scale factor to divide hb_positions_t values by
+ * @x_scale_factor: scale factor to divide hb_positions_t Y values by
+ * @y_scale_factor: scale factor to divide hb_positions_t X values by
* @x: X position to place first glyph
* @y: Y position to place first glyph
* @utf8: (nullable): the text that was shaped in @buffer
@@ -787,7 +786,8 @@
void
hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer,
hb_bool_t utf8_clusters,
- double scale_factor,
+ double x_scale_factor,
+ double y_scale_factor,
double x,
double y,
const char *utf8,
@@ -834,22 +834,23 @@
return;
}
- double iscale = scale_factor ? 1. / scale_factor : 0.;
+ double x_scale = x_scale_factor ? 1. / x_scale_factor : 0.;
+ double y_scale = y_scale_factor ? 1. / y_scale_factor : 0.;
hb_position_t hx = 0, hy = 0;
int i;
for (i = 0; i < (int) *num_glyphs; i++)
{
(*glyphs)[i].index = hb_glyph[i].codepoint;
- (*glyphs)[i].x = x + (+hb_position->x_offset + hx) * iscale;
- (*glyphs)[i].y = y + (-hb_position->y_offset + hy) * iscale;
+ (*glyphs)[i].x = x + (+hb_position->x_offset + hx) * x_scale;
+ (*glyphs)[i].y = y + (-hb_position->y_offset + hy) * y_scale;
hx += hb_position->x_advance;
hy += -hb_position->y_advance;
hb_position++;
}
(*glyphs)[i].index = -1;
- (*glyphs)[i].x = round (hx * iscale);
- (*glyphs)[i].y = round (hy * iscale);
+ (*glyphs)[i].x = round (hx * x_scale);
+ (*glyphs)[i].y = round (hy * y_scale);
if (clusters && *num_clusters)
{
diff --git a/src/hb-cairo.h b/src/hb-cairo.h
index cb7e53e..8663147 100644
--- a/src/hb-cairo.h
+++ b/src/hb-cairo.h
@@ -82,7 +82,8 @@
HB_EXTERN void
hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer,
hb_bool_t utf8_clusters,
- double scale_factor,
+ double x_scale_factor,
+ double y_scale_factor,
double x,
double y,
const char *utf8,
diff --git a/util/helper-cairo.hh b/util/helper-cairo.hh
index 82fe040..d834cc8 100644
--- a/util/helper-cairo.hh
+++ b/util/helper-cairo.hh
@@ -606,7 +606,7 @@
hb_cairo_glyphs_from_buffer (buffer,
utf8_clusters,
- 1 << -scale_bits,
+ 1 << -scale_bits, 1 << -scale_bits,
0., 0.,
l->utf8, l->utf8_len,
&l->glyphs, &l->num_glyphs,
