Small numbers of traps are frequently generated from either a path of a
single line, or that of a rectangle. Therefore should embed sufficient
storage with cairo_traps_t to accommodate the stroke of a single rectangle
(e.g. a pango unknown glyph hexbox) to avoid frequent allocations.
First try to use a stack buffer for the glyphs and clusters if the user
calls cairo_show_text() - for example, as pango does to draw the unknown hex
box.
By using a NULL backend for the error surfaces, instead of a pointer to
the image surface backend end, we save a few lookup/redirections during
dynamic linking.
Ginn Chen reported a regression with Firefox where "the whole area of web
page is transparent until it redraws", and bisected it to the change to
lazily clear the clip.
The bug would appears to be when we have an inconsistent GC clip - i.e.
the clip on the surface has been cleared, but we have not yet used and
thus cleared the GC, so that we did not mark the GC as having a clip set
when we freed it.
Behdad prefers these to be upper-case to be consistent with G_UNLIKELY and
friends. However, as I intend to use these for nearly all instances of
if(status), I suggest that we keep to the short and not so loud:
if (unlikely (status))
return status;
The spline decomposition code allocates and stores points in a temporary
buffer which is immediately consumed by the caller. If the caller supplies
a callback that handles each point computed along the spline, then we can
use the point immediately and avoid the allocation.
When discussing the implications of snapshot cow, one of the questions
that we raised was what happens on cairo_destroy()? The lifetime of the
context implicitly marks the extents of the drawing operations, typically
the expose event (or perhaps one phase of it). Therefore at the end of the
sequence we implicitly wish to flush the graphics events to the surface.
The previous LFSR generator used a large table to be speedy. The
replacement generator is the single stage generator (1) from section
5.4 of [HP2007], requires no tables or extra state. I've run the
generator through Rob Brown's extended Dieharder test suite and it
passes all but one self-proclaimed buggy test (-d2) and the 2D sphere
minimum distance test (-d12).
[HP2007] Hars L. and Petruska G., ``Pseudorandom Recursions: Small and Fast Pseurodandom Number Generators for Embedded Applications'',
Hindawi Publishing Corporation
EURASIP Journal on Embedded Systems
Volume 2007, Article ID 98417, 13 pages
doi:10.1155/2007/98417
http://www.hindawi.com/getarticle.aspx?doi=10.1155/2007/98417&e=cta
A new meta-surface backend for serialising drawing operations to a
CairoScript file. The principal use (as currently envisaged) is to provide
a round-trip testing mechanism for CairoScript - i.e. we can generate
script files for every test in the suite and check that we can replay them
with perfect fidelity. (Obviously this does not provide complete coverage
of CairoScript's syntax, but should give reasonable coverage over the
operators.)
Benjamin Otte noticed that the top-left vertex was now included within the
fill extents. Having updated the test case to check the insideness
conditions as defined by flash, fix the edge handling to match.
7944601864 broke the quartz backend.
Fix it by adding const to the appropriate parameters in the function
declarations and copying the pattern when needed.
Use the return value to return the result from _cairo_hash_table_lookup()
(as opposed to filling an output parameter on the stack) as this (a)
results in cleaner code (no strict-alias breaking pointer casts), (b)
produces a smaller binary and (c) is measurably faster.
As we obey the rule in Cairo that we only insert if we know that there is
no existing entry in the hash table, we can therefore perform a much quicker
search knowing that the key is unique.
A limitation of the current API was that the destroy notifier was called
on the mime-data block. This prevents the user from passing in a pointer
to a managed block, for example a mime-data block belonging to a
ref-counted object. We can overcome this by allowing the user to specify
the closure to be used with the destroy notifier.
Benjamin Otte reports that in one particular benchmark cairo_in_fill() is
a hotspot in the profile. Currently we tessellate the entire path and then
search for a containing trapezoid. This is very expensive compared to the
simple method of counting the number of edge crossing between the point of
interest and x=-∞. For example, this speeds tessellate-256 up by almost 3
orders of magnitude.
Write out the original PNG mime-data if attached to the surface during
cairo_surface_write_to_png(). Similar to how the compressed alternate
representations are handled by the other backends.
Note: by automatically attaching and using the mime-data in preference to
the image data, we break the read_from_png(); draw(); write_to_png()
cycle.
I moved the pixel centre to xc,yc but forgot to remove it during
compensation - as caught by the test suite.
Refresh a couple of reference images that depend upon exact pixel-centre
rounding conditions.
