NEWS: Add notes for 1.3.2 snapshot

1 files changed, 179 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index a816bd35f..01333f143 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,182 @@
+Snapshot 1.3.2 (2006-11-14 Carl Worth <cworth@cworth.org>)
+==========================================================
+This is the first development snapshot since the 1.2 stable series
+branched off shortly after the 1.2.4 release in August 2006.
+
+This snapshot includes all the bug fixes from the 1.2.6 release,
+(since they originated here on the 1.3 branch first and were
+cherry-picked over to 1.2). But more importantly, it contains some new
+API in preparation for a future 1.4 release, and most importantly, it
+contains several performance improvements.
+
+The bug fixes will not be reviewed here, as most of them are already
+described in the 1.2.6 release notes. But details for the new API and
+some performance improvements are included here.
+
+As with all snapshots, this is experimental code, and the new API
+added here is still experimental and is not guaranteed to appear
+unchanged in any future release of cairo.
+
+API additions
+-------------
+Several new API additions are available in this release. There is a
+common theme among all the additions in that they allow cairo to
+advertise information about its state that it was refusing to
+volunteer earlier. So this isn't groundbreaking new functionality, but
+it is essential for easily achieving several tasks.
+
+The new functions can be divided into three categories:
+
+	Getting information about the current clip region
+	-------------------------------------------------
+	cairo_clip_extents
+	cairo_copy_clip_rectangles
+	cairo_rectangle_list_destroy
+
+	Getting information about the current dash setting
+	--------------------------------------------------
+	cairo_get_dash_count
+	cairo_get_dash
+
+	Getting information from a pattern
+	----------------------------------
+	cairo_pattern_get_rgba
+	cairo_pattern_get_surface
+	cairo_pattern_get_color_stop_rgba
+	cairo_pattern_get_color_stop_count
+	cairo_pattern_get_linear_points
+	cairo_pattern_get_radial_circles
+
+In each of these areas, we have new API for providing a list of
+uniform values from cairo. The closest thing we had to this before was
+cairo_copy_path, (which is rather unique in providing a list of
+non-uniform data).
+
+The copy_clip_rectangles/rectangle_list_destroy functions follow a
+style similar to that of cairo_copy_path. Meanwhile, the dash and
+pattern color stop functions introduce a new style in which there is a
+single call to return the number of elements available (get_dash_count
+and get_color_stop_count) and then a function to be called once to get
+each element (get_dash and get_color_stop_rgba).
+
+I'm interested in hearing feedback from users of these new API
+functions, particularly from people writing language bindings. One
+open question is whether the clip "getter" functionality should adopt
+a style similar to that of the new dash and color_stop interfaces.
+
+API deprecation
+---------------
+The CAIRO_FORMAT_RGB16_565 enum value has been deprecated. It never
+worked as a format value for cairo_image_surface_create, and it wasn't
+necessary for supporting 16-bit 565 X server visuals.
+
+XCB backend changes
+-------------------
+The XCB backend has been updated to track the latest XCB API (which
+recently had a 1.0 release).
+
+New quartz backend
+------------------
+Vladimir Vukicevic has written a new "native quartz" backend which
+will eventually replace the current "image-surface wrapping" quartz
+backend. For now, both backends are available, (the old one is
+"quartz" and the new one is "nquartz"). But it is anticipated that the
+new backend will replace the old one and take on the "quartz" name
+before this backend is marked as supported in a release of cairo.
+
+New OS/2 backend
+----------------
+Doodle and Peter Weilbacher have contributed a new, experimental
+backend for using cairo on OS/2 systems.
+
+Performance improvements
+------------------------
+Here are some highlights from cairo's performance suite showing
+improvements from cairo 1.2.6 to cairo 1.3.2. The command used to
+generate this data is:
+
+	./cairo-perf-diff 1.2.6 HEAD
+
+available in the perf/ directory of a recent checkout of cairo's
+source, (the cairo-perf-diff script does require a git checkout and
+will not work from a tar file---though ./cairo-perf can still be used
+to generate a single report there and ./cairo-perf-diff-files can be
+used to compare two reports).
+
+Results are described below both for an x86 laptop (with an old Radeon
+video card, recent X.org build, XAA, free software drivers), as well
+as for a Nokia 770. First the x86 results with comments on each, (all
+times are reported in milliseconds).
+
+Copying subsets of an image surface to an xlib surface (much faster)
+--------------------------------------------------------------------
+ xlib-rgba              subimage_copy-512   10.50 ->   : 53.97x speedup
+█████████████████████████████████████████████████████
+
+Thanks to Christopher (Monty) Montgomery for this big performance
+improvement. Any application which has a large image surface and is
+copying small pieces of it at a time to an xlib surface, (imagine an
+application that loads a single image containing all the "sprites" for
+that application), will benefit from this fix. The larger the ratio of
+the image surface to the portion being copied, the larger the benefit.
+
+Floating-point conversion (3x faster)
+-------------------------------------
+ xlib-rgba  pattern_create_radial-16    27.75 ->   3.93 :  2.94x speedup
+██
+image-rgb   pattern_create_radial-16    26.06 ->   3.74 :  2.90x speedup
+█▉
+
+Thanks to Daniel Amelang, (and others who had contributed the idea
+earlier), for this nice improvement in the speed of converting
+floating-point values to fixed-point.
+
+Text rendering (1.3 - 2x faster)
+------------------------------
+ xlib-rgba text_image_rgba_source-256  319.73 ->  62.40 :  2.13x speedup
+█▏
+image-rgb    text_solid_rgba_over-64     2.85 ->   0.88 :  1.35x speedup
+▍
+
+I don't think we've ever set out to improve text performance
+specifically, but we did it a bit anyway. I believe the extra
+improvement in the xlib backend is due to Monty's image copying fix
+above, and the rest is due to the floating-point conversion speedup.
+
+Thin stroke improvements (1.5x faster)
+---------------------------------------------
+image-rgb               world_map-800  1641.09 -> 414.77 :  1.65x speedup
+▋
+ xlib-rgba              world_map-800  1939.66 -> 529.94 :  1.52x speedup
+▌
+
+The most modest stuff to announce in this release is the 50%
+improvement I made in the world_map case. This is in improvement that
+should help basically anything that is doing strokes with many
+straight line segments, (and the thinner the better, since that makes
+tessellation dominate rasterization). The fixes here are to use a
+custom quadrilateral tessellator rather than the generic tessellator
+for straight line segments and the miter joins.
+
+Performance results from the Nokia 770
+--------------------------------------
+ xlib-rgba          subimage_copy-512     55.88 ->     2.04 : 27.34x speedup
+██████████████████████████▍
+ xlib-rgb     text_image_rgb_over-256   1487.58 ->   294.43 :  5.05x speedup
+████
+image-rgb   pattern_create_radial-16     187.13 ->    91.86 :  2.04x speedup
+█
+ xlib-rgba              world_map-800  21261.41 -> 15628.02 :  1.36x speedup
+▍
+
+Here we see that the subimage_copy improvement was only about half as
+large as the corresponding improvement on my laptop, (27x faster
+compared to 54x) and the floating-point conversion fix also was quite
+as significant, (2x compared to 3x). Oddly the improvement to text
+rendering performance was more than twice as good (5x compared to
+2x). I don't know what the reason for that is, but I don't think it's
+anything anybody should complain about.
+
 Release 1.2.6 (2006-11-02 Behdad Esfahbod <behdad@behdad.org>)
 ==============================================================
 This is the third bug fix release in the 1.2 series, coming less than