NEWS: Add notes for 1.3.4 snapshot

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+Snapshot 1.3.4 (2006-11-22 Carl Worth <cworth@cworth.org>)
+==========================================================
+This is the second development snapshot in the 1.3 series. It comes
+one week after the 1.3.2 snapshot.
+
+This snapshot has a couple of significant performance improvements,
+and also adds new support for producing multi-page SVG output, (when
+targeting SVG 1.2)---thanks to Emmanuel Pacaud. The details of the
+performance improvements are as follows:
+
+1. The long-awaited "new tessellator".
+
+   The credit for this being an improvement goes to Joonas Pihlaja. He
+   took my really slow code and really put it through its paces to get
+   the dramatic performance improvement seen below (up to 38x faster
+   on realistic cases, and more than 10x faster for the zrusin_another
+   test).
+
+   His own writeup of the work he did is quite thorough, but more than
+   can be quoted here. Please see his post for the interesting details:
+
+   http://lists.freedesktop.org/archives/cairo/2006-November/008483.html
+
+   (Though note that this snapshot also includes some additional,
+   significant improvements that were only sketched out in that
+   email---see "Generating fewer trapezoids").
+
+2. More floating-point improvements
+
+   Daniel Amelang continues to work the magic he began in the 1.3.2
+   snapshot. This time he short-circuits floating-point
+   transformations by identity matrices and applies the earlier
+   floating-to-fixed-point technique to the problem of rounding.
+
+   The improvements here will primarily benefit text performance, and
+   will benefit platforms without hardware floating-point more than
+   those that have it, (some text tests show 20% improvement on an x86
+   machine and closer to 80% improvement on arm).
+
+The performance chart comparing 1.3.2 to 1.3.4 really speaks for
+itself, (this is on an x86 laptop). This is quite a lot of progress
+for one week:
+
+ xlib-rgb    stroke_similar_rgba_over-256   74.99 1.45% ->   2.03 68.38%: 36.86x speedup
+███████████████████████████████████▉
+ xlib-rgb  stroke_similar_rgba_source-256   78.23 1.43% ->   3.30 67.05%: 23.71x speedup
+██████████████████████▊
+ xlib-rgba             tessellate-256-100  820.42 0.15% ->  35.06 2.84%: 23.40x speedup
+██████████████████████▍
+image-rgba             tessellate-256-100  819.55 0.32% ->  35.04 3.56%: 23.39x speedup
+██████████████████████▍
+ xlib-rgb      stroke_image_rgba_over-256   78.10 1.43% ->   4.33 65.56%: 18.04x speedup
+█████████████████
+ xlib-rgb    stroke_image_rgba_source-256   80.11 1.63% ->   5.75 63.99%: 13.94x speedup
+█████████████
+ xlib-rgba  zrusin_another_tessellate-415   89.22 0.35% ->   8.38 5.23%: 10.65x speedup
+█████████▋
+image-rgba  zrusin_another_tessellate-415   87.38 0.89% ->   8.37 5.22%: 10.44x speedup
+█████████▍
+image-rgba        zrusin_another_fill-415  117.67 1.34% ->  12.88 2.77%:  9.14x speedup
+████████▏
+ xlib-rgba        zrusin_another_fill-415  140.52 1.57% ->  15.79 2.88%:  8.90x speedup
+███████▉
+image-rgba              tessellate-64-100    9.68 3.42% ->   1.42 0.60%:  6.82x speedup
+█████▉
+ xlib-rgba              tessellate-64-100    9.78 4.35% ->   1.45 0.83%:  6.72x speedup
+█████▊
+ xlib-rgb     stroke_linear_rgba_over-256   46.01 2.44% ->   7.74 54.51%:  5.94x speedup
+█████
+ xlib-rgb   stroke_linear_rgba_source-256   48.09 2.15% ->   9.14 53.00%:  5.26x speedup
+████▎
+ xlib-rgb     stroke_radial_rgba_over-256   50.96 2.34% ->  12.46 47.99%:  4.09x speedup
+███▏
+ xlib-rgb   stroke_radial_rgba_source-256   53.06 1.57% ->  13.96 46.57%:  3.80x speedup
+██▊
+image-rgba  paint_similar_rgba_source-256    0.12 1.57% ->   0.08 9.92%:  1.42x speedup
+▍
+image-rgba    paint_image_rgba_source-256    0.12 2.49% ->   0.08 10.70%:  1.41x speedup
+▍
+image-rgba                  world_map-800  356.28 0.46% -> 275.72 1.15%:  1.29x speedup
+▎
+ xlib-rgba                  world_map-800  456.81 0.39% -> 357.95 1.39%:  1.28x speedup
+▎
+image-rgb               tessellate-16-100    0.09 0.57% ->   0.07 3.43%:  1.23x speedup
+▎
+image-rgba              tessellate-16-100    0.09 0.06% ->   0.07 2.46%:  1.23x speedup
+▎
+image-rgba        text_solid_rgb_over-256    5.39 4.01% ->   4.47 0.70%:  1.21x speedup
+▎
+image-rgba       text_solid_rgba_over-256    5.37 0.82% ->   4.45 0.75%:  1.21x speedup
+▎
+image-rgba        text_image_rgb_over-64     0.78 0.10% ->   0.65 0.74%:  1.20x speedup
+▎
+image-rgba       text_image_rgba_over-64     0.78 0.29% ->   0.65 0.68%:  1.19x speedup
+▎
+image-rgb         text_solid_rgb_over-64     0.76 2.45% ->   0.63 0.81%:  1.19x speedup
+▎
+image-rgba       text_solid_rgba_over-64     0.76 0.33% ->   0.64 0.66%:  1.19x speedup
+▎
+image-rgba     text_similar_rgba_over-256    5.99 4.72% ->   5.04 1.09%:  1.19x speedup
+▎
+
+We should point out that there is some potential for slowdown in this
+snapshot. The following are the worst slowdowns reported by the cairo
+performance suite when comparing 1.3.2 to 1.3.4:
+
+image-rgba              subimage_copy-256    0.01 0.87% ->   0.01 3.61%:  1.45x slowdown
+▌
+ xlib-rgb        paint_solid_rgb_over-256    0.31 10.23% ->   0.38 0.33%:  1.26x slowdown
+▎
+image-rgba           box-outline-fill-100    0.01 0.30% ->   0.01 2.52%:  1.21x slowdown
+▎
+image-rgba        fill_solid_rgb_over-64     0.20 1.22% ->   0.22 1.59%:  1.12x slowdown
+▏
+image-rgb       fill_similar_rgb_over-64     0.21 1.04% ->   0.24 1.06%:  1.11x slowdown
+▏
+image-rgba        fill_image_rgb_over-64     0.21 1.19% ->   0.24 0.72%:  1.11x slowdown
+▏
+image-rgba      fill_similar_rgb_over-64     0.21 0.18% ->   0.24 0.30%:  1.11x slowdown
+▏
+image-rgb        fill_solid_rgba_over-64     0.22 1.66% ->   0.24 1.15%:  1.11x slowdown
+▏
+image-rgb         fill_image_rgb_over-64     0.21 0.14% ->   0.24 0.80%:  1.11x slowdown
+▏
+image-rgba       fill_image_rgba_over-64     0.22 1.34% ->   0.25 0.20%:  1.11x slowdown
+▏
+image-rgba       fill_solid_rgba_over-64     0.22 1.48% ->   0.24 0.95%:  1.11x slowdown
+▏
+image-rgb      fill_similar_rgba_over-64     0.22 1.13% ->   0.25 1.25%:  1.10x slowdown
+▏
+
+The 45% slowdown for subimage_copy is an extreme case. It's unlikely
+to hit many applications unless they often use cairo_rectangle;
+cairo_fill to copy a single pixel at a time. In any case, it shows a
+worst-case impact of the overhead of the new tessellator. The other
+slowdowns (~ 10%) are probably more realistic, and still very
+concerning.
+
+We will work to ensure that performance regressions like these are not
+present from one major release of cairo to the next, (for example,
+from 1.2 to 1.4).
+
+But we're putting this 1.3.4 snapshot out there now, even with this
+potential slowdown so that people can experiment with it. If you've
+got complex geometry, we hope you will see some benefit from the new
+tessellator. If you've got primarily simple geometry, we hope things
+won't slowdown too much, but please let us know what slowdown you see,
+if any, so we can calibrate our performance suite against real-world
+impacts.
+
+Thanks, and have fun with cairo!
+
 Snapshot 1.3.2 (2006-11-14 Carl Worth <cworth@cworth.org>)
 ==========================================================
 This is the first development snapshot since the 1.2 stable series