diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2009-10-16 16:48:54 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2009-10-21 11:37:16 +0100 |
| commit | df357f26ff72571acb840715efa4930054d4fdbe (patch) | |
| tree | 66e9174c24c52564a5d691a21653c8b31a3b7156 /src/cairo-scaled-font.c | |
| parent | f0cd20e6cec445eb627c2708c2230c8bad1b64ce (diff) | |
Support component-alpha.
Within our code base we carried a few hacks to utilize the component
alpha capabilities of pixman, whilst not supporting the concept for our
own masks. Thus we were setting it upon the pixman_image_t that we
passed around through code that was blissfully unaware and indeed the
component-alpha property was forgotten (e.g. upgrading glyph masks).
The real issue is that without explicit support that a pattern carries
subpixel masking information, that information is lost when using that
pattern with composite. Again we can look at the example of compositing
a sub-pixel glyph mask onto a remote xlib surface for further failure.
Diffstat (limited to 'src/cairo-scaled-font.c')
| -rw-r--r-- | src/cairo-scaled-font.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/src/cairo-scaled-font.c b/src/cairo-scaled-font.c index 199ad39e..179844fc 100644 --- a/src/cairo-scaled-font.c +++ b/src/cairo-scaled-font.c @@ -2169,8 +2169,10 @@ _cairo_scaled_font_show_glyphs (cairo_scaled_font_t *scaled_font, } _cairo_pattern_init_for_surface (&mask_pattern, mask); - - status = _cairo_surface_composite (CAIRO_OPERATOR_ADD, + /* Note that we only upgrade masks, i.e. A1 -> A8 -> ARGB32, so there is + * never any component alpha here. + */ + status = _cairo_surface_composite (CAIRO_OPERATOR_SOURCE, &white_pattern.base, &mask_pattern.base, new_mask, @@ -2203,6 +2205,8 @@ _cairo_scaled_font_show_glyphs (cairo_scaled_font_t *scaled_font, _cairo_pattern_init_for_surface (&glyph_pattern, &glyph_surface->base); + if (mask_format == CAIRO_FORMAT_ARGB32) + glyph_pattern.base.has_component_alpha = TRUE; status = _cairo_surface_composite (CAIRO_OPERATOR_ADD, &white_pattern.base, @@ -2222,11 +2226,9 @@ _cairo_scaled_font_show_glyphs (cairo_scaled_font_t *scaled_font, } } - if (mask_format == CAIRO_FORMAT_ARGB32) { - pixman_image_set_component_alpha (((cairo_image_surface_t*) mask)-> - pixman_image, TRUE); - } _cairo_pattern_init_for_surface (&mask_pattern, mask); + if (mask_format == CAIRO_FORMAT_ARGB32) + mask_pattern.base.has_component_alpha = TRUE; status = _cairo_surface_composite (op, pattern, &mask_pattern.base, surface, |