On 27.02.2005, at 15:19, Sven Neumann wrote:
It is called once per tile. Your approach probably makes sense as long as don't use g_rand_new() but g_rand_new_with_seed(). g_rand_new() initializes the random number generator from /dev/urandom which is probably too expensive to be done once per tile.
Not too bad, here are the results (Patch in different mail):
Before:
Linear Gradient blend on a 3000x3000 pixel image (Dithering on) 1 processor: 7.2 s 2 processors: 8.9 s
Linear Gradient blend on a 3000x3000 pixel image (Dithering OFF) 1 processor: 2.5 s 2 processors: 1.5 s
After Linear Gradient blend on a 3000x3000 pixel image (Dithering on) 1 processor: 7.0 s 2 processors: 3.6 s
Linear Gradient blend on a 3000x3000 pixel image (Dithering OFF) 1 processor: 2.6 s 2 processors: 1.4 s
The degradation in the 1 processor setting without dithering seems to be a small measurement fluke in my last round since I consistently get better times in all other cases. Apologies for that.
I need to think about a larger test image since its starting to get too difficult to time this microbench...
Servus,
Daniel
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