From acc387c1eb5d93640fae45459b9f7c321d7f9eef Mon Sep 17 00:00:00 2001 From: Pierre Ossman Date: Wed, 9 Jul 2014 16:28:55 +0200 Subject: Test results comparing PixelTransformer and bufferFromBuffer() --- tests/results/notrans/README | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 tests/results/notrans/README (limited to 'tests/results/notrans/README') diff --git a/tests/results/notrans/README b/tests/results/notrans/README new file mode 100644 index 00000000..3723e67d --- /dev/null +++ b/tests/results/notrans/README @@ -0,0 +1,28 @@ +This directory contains the test results in preparation for the removal +of the PixelTransformer class. + +Tests were performed on Linux with these CPUs: + + - Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz + - ARM i.MX6 DualLite @ 1 GHz + +The tests show that the new bufferFromBuffer() has similar performance +as PixelTransformer in most cases. It gets beaten in two cases: + + - Input format is 16 BPP and PixelTransformer is in the + non-economical mode (the default mode). + + - Input format is 8 BPP, mode irrelevant. + +PixelTransformer is about twice as fast in both these cases (more if +converting between two low colour formats). + +Although this is significant, it is in cases that are already difficult +to deal with performance wise, and exceedingly rare with modern +hardware. As such it is difficult to motivate the extra complexity that +PixelTransformer requires. + +If it turns out that these cases are significant, than we can move +PixelTransformer's massive lookup tables into a shared cache in +PixelFormat. Implementation complexity would be similar, but at least +we would have a friendly API. -- cgit v1.2.3