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WizHarDx

Pixel plotting

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Hi I have to use pixel plotting ( don''t ask why). I was just wondering when I lock the surface & covert ddsd.lpSurface to a word*, is it slower than me making a WORD* varible initlizeing it then using memcpy to copy to surface ? if so why , is because of the bus or something ? thanx in advance WizHarD

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I have been using ye old pixel averaging algorithm for a fire simulation. It of course uses pixel plotting.

I found that when I create an off screen surface in system memory, I don''t have to keep locking/unlocking the surface. I do it once upon initialization to get a pointer to the surface. Then I just calculate offsets for the surface.

I have used memcpy for copying to surfaces, though I did not use it in this case. I would think it would be quite fast. My fire simulator uses something like this.

for ( ptr = surf_start ; ptr < surf_end ; ptr++ )
*ptr = some_colour;

I have found to be quite quick as well.
You could use something like that for source destination copies, but I would use memcpy in case like that.

Guy

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