Re: Drawing a single pixel
Re: Drawing a single pixel
- Subject: Re: Drawing a single pixel
- From: Bob Savage <email@hidden>
- Date: Mon, 28 May 2001 20:07:03 -0700
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Seems like a lot of overhead just to draw a pixel, though.
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I have a neural network I'm working on and will need to plot error points as
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a network learns. Obviously, I'll want any screen draws to be as quick as
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possible, but I'd also like them real-time. IOW, I don't want to have to
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wait until the whole map is drawn (off screen) to look at it.
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> Yes, he needs to use NSBitmapImageRep. However, I believe the reason he
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> wants to be able to change a single pixel is because he wants to build a
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> fractal picture up pixel by pixel and then display it. In that case, he
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> should just set all of the pixels in NSBitmapImageRep's bitmap to the proper
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> values and then display that.
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>
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> - Dennis D.
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Hey, Scott,
Maybe it shouldn't be thought of as a single pixel. I mean if you were going
to draw a single pixel only you would be drawing a window with a view that
is only one pixel large, right? If you are drawing into a 1 pixel by 1 pixel
window, then go ahead and draw the entire image each cycle :)
I think what you are saying, though, is that you want to draw a whole bunch
of pixels, maybe a million (maybe more?) to the screen, but you just want to
change one pixel in your million pixel image from white to black (or
whatever).
Consider how blazing fast a G4 is. What if "real time" means a pixel changes
every hundred thousandth of a second? Now you are wanting to draw a MILLION
or more pixels 100,000 times per second!
It seems like you should be able to find a way to refresh the screen often
enough that you are always getting a fairly current representation, but that
you are not taxing the graphics card by trying to have it keep up with a
computation rate far faster than human eyes can perceive :)
Best of luck,
Bob