[cairo-commit] src/cairo-surface.c

[Behdad Esfahbod]

 src/cairo-surface.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

New commits:
commit 99427c3f4f6ce7ce3c95c4caa4d2b8ff7c0093d9
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Tue Sep 12 01:35:15 2017 -0400

    Handle SOURCE and CLEAR operators when painting color glyphs
    
    In cairo, most operators are composited this way:
    
      ((src IN mask) OP dst) LERP_clip dst
    
    but SOURCE and CLEAR operators are composited this way:
    
      (src OP dst) LERP_(clip IN mask) dst
    
    (why is this not specified anywhere in the docs or source tree?)
    
    With color glyphs, we were not special-casing SOURCE and CLEAR.
    We do now.
    
    Fixes https://bugs.freedesktop.org/show_bug.cgi?id=102661

diff --git a/src/cairo-surface.c b/src/cairo-surface.c
index 6f25bd7c..35c63d7b 100644
--- a/src/cairo-surface.c
+++ b/src/cairo-surface.c
@@ -2571,7 +2571,10 @@ composite_one_color_glyph (cairo_surface_t       *surface,
         pattern = cairo_pattern_create_for_surface ((cairo_surface_t *)glyph_surface);
         cairo_matrix_init_translate (&matrix, - x, - y);
         cairo_pattern_set_matrix (pattern, &matrix);
-        status = surface->backend->paint (surface, op, pattern, clip);
+	if (op == CAIRO_OPERATOR_SOURCE || op == CAIRO_OPERATOR_CLEAR)
+	  status = surface->backend->mask (surface, op, pattern, pattern, clip);
+	else
+	  status = surface->backend->paint (surface, op, pattern, clip);
     }
 
     return status;