gfx/cairo/win32-cleartype-clipping.patch@b8a032363ba2 (annotated)
gfx/cairo/win32-cleartype-clipping.patch
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
| michael@0 | 1 | diff --git a/gfx/cairo/cairo/src/cairo-win32-font.c b/gfx/cairo/cairo/src/cairo-win32-font.c |
| michael@0 | 2 | --- a/gfx/cairo/cairo/src/cairo-win32-font.c |
| michael@0 | 3 | +++ b/gfx/cairo/cairo/src/cairo-win32-font.c |
| michael@0 | 4 | @@ -986,6 +986,19 @@ _cairo_win32_scaled_font_init_glyph_metr |
| michael@0 | 5 | &metrics, 0, NULL, &matrix) == GDI_ERROR) { |
| michael@0 | 6 | status = _cairo_win32_print_gdi_error ("_cairo_win32_scaled_font_init_glyph_metrics:GetGlyphOutlineW"); |
| michael@0 | 7 | memset (&metrics, 0, sizeof (GLYPHMETRICS)); |
| michael@0 | 8 | + } else { |
| michael@0 | 9 | + if (metrics.gmBlackBoxX > 0 && scaled_font->base.options.antialias != CAIRO_ANTIALIAS_NONE) { |
| michael@0 | 10 | + /* The bounding box reported by Windows supposedly contains the glyph's "black" area; |
| michael@0 | 11 | + * however, antialiasing (especially with ClearType) means that the actual image that |
| michael@0 | 12 | + * needs to be rendered may "bleed" into the adjacent pixels, mainly on the right side. |
| michael@0 | 13 | + * To avoid clipping the glyphs when drawn by _cairo_surface_fallback_show_glyphs, |
| michael@0 | 14 | + * for example, or other code that uses glyph extents to determine the area to update, |
| michael@0 | 15 | + * we add a pixel of "slop" to left side of the nominal "black" area returned by GDI, |
| michael@0 | 16 | + * and two pixels to the right (as tests show some glyphs bleed into this column). |
| michael@0 | 17 | + */ |
| michael@0 | 18 | + metrics.gmptGlyphOrigin.x -= 1; |
| michael@0 | 19 | + metrics.gmBlackBoxX += 3; |
| michael@0 | 20 | + } |
| michael@0 | 21 | } |
| michael@0 | 22 | cairo_win32_scaled_font_done_font (&scaled_font->base); |
| michael@0 | 23 | if (status) |
