[ot-color/png] Consider strike ppem on scaling

This commit is contained in:
Ebrahim Byagowi 2018-10-29 08:41:13 +03:30 committed by Behdad Esfahbod
parent a8c9facf7a
commit c929ccfcea
5 changed files with 26 additions and 10 deletions

View File

@ -402,9 +402,10 @@ struct CBDT
hb_blob_destroy (this->cbdt_blob);
}
inline bool get_extents (hb_codepoint_t glyph, hb_glyph_extents_t *extents) const
inline bool get_extents (hb_font_t *font, hb_codepoint_t glyph,
hb_glyph_extents_t *extents) const
{
unsigned int x_ppem = upem, y_ppem = upem; /* TODO Use font ppem if available. */
unsigned int x_ppem = font->x_ppem, y_ppem = font->y_ppem;
if (!cblc)
return false; // Not a color bitmap font.

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@ -74,7 +74,8 @@ struct SBIXStrike
hb_tag_t file_type,
int *x_offset,
int *y_offset,
unsigned int num_glyphs) const
unsigned int num_glyphs,
unsigned int *strike_ppem) const
{
if (unlikely (!ppem)) return hb_blob_get_empty (); /* To get Null() object out of the way. */
@ -109,6 +110,7 @@ struct SBIXStrike
if (unlikely (file_type != glyph->graphicType))
return hb_blob_get_empty ();
if (strike_ppem) *strike_ppem = ppem;
if (x_offset) *x_offset = glyph->xOffset;
if (y_offset) *y_offset = glyph->yOffset;
return hb_blob_create_sub_blob (sbix_blob, glyph_offset, glyph_length);
@ -167,12 +169,13 @@ struct sbix
inline hb_blob_t *reference_png (hb_font_t *font,
hb_codepoint_t glyph_id,
int *x_offset,
int *y_offset) const
int *y_offset,
unsigned int *available_ppem) const
{
return get_strike (font).get_glyph_blob (glyph_id, sbix_blob,
HB_TAG ('p','n','g',' '),
x_offset, y_offset,
num_glyphs);
num_glyphs, available_ppem);
}
private:
@ -236,7 +239,8 @@ struct sbix
return false;
int x_offset = 0, y_offset = 0;
hb_blob_t *blob = reference_png (font, glyph, &x_offset, &y_offset);
unsigned int strike_ppem = 0;
hb_blob_t *blob = reference_png (font, glyph, &x_offset, &y_offset, &strike_ppem);
if (unlikely (blob->length < sizeof (PNGHeader)))
return false;
@ -247,6 +251,17 @@ struct sbix
extents->y_bearing = y_offset;
extents->width = png.IHDR.width;
extents->height = png.IHDR.height;
/* Convert to the font units. */
if (strike_ppem)
{
unsigned int upem = font->face->upem;
extents->x_bearing *= upem / (float) strike_ppem;
extents->y_bearing *= upem / (float) strike_ppem;
extents->width *= upem / (float) strike_ppem;
extents->height *= upem / (float) strike_ppem;
}
hb_blob_destroy (blob);
return true;

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@ -318,7 +318,7 @@ hb_ot_color_glyph_reference_png (hb_font_t *font, hb_codepoint_t glyph)
hb_blob_t *blob = hb_blob_get_empty ();
if (_get_sbix (font->face).has_data ())
blob = _get_sbix (font->face).reference_png (font, glyph, nullptr, nullptr);
blob = _get_sbix (font->face).reference_png (font, glyph, nullptr, nullptr, nullptr);
if (!blob->length && _get_cbdt (font->face).has_data ())
blob = _get_cbdt (font->face).reference_png (glyph, font->x_ppem, font->y_ppem);

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@ -187,7 +187,7 @@ hb_ot_get_glyph_extents (hb_font_t *font,
if (!ret)
ret = ot_face->glyf->get_extents (glyph, extents);
if (!ret)
ret = ot_face->CBDT->get_extents (glyph, extents);
ret = ot_face->CBDT->get_extents (font, glyph, extents);
// TODO Hook up side-bearings variations.
extents->x_bearing = font->em_scale_x (extents->x_bearing);
extents->y_bearing = font->em_scale_y (extents->y_bearing);

View File

@ -427,8 +427,8 @@ test_hb_ot_color_png (void)
hb_font_get_glyph_extents (sbix_font, 1, &extents);
g_assert_cmpint (extents.x_bearing, ==, 0);
g_assert_cmpint (extents.y_bearing, ==, 0);
g_assert_cmpint (extents.width, ==, 300);
g_assert_cmpint (extents.height, ==, 300);
g_assert_cmpint (extents.width, ==, 800);
g_assert_cmpint (extents.height, ==, 800);
hb_blob_destroy (blob);
hb_font_destroy (sbix_font);