Re: [Traverso-devel] Accuracy of waveform drawing, and performance

[Jonatan Liljedahl]

Ok, I see. If it's gonna be much faster, and no precision is lost when
zooming in, then I think it's all well. =)
Perhaps there could be an option to use each pixel or only each even
pixel? Also, when using only each even, do you take the max() of the two
or simply ignoring the odd ones?

Remon wrote:
>> Ok, my thought was that the linedrawing was more detailed and showed
>> short transients and peaks better? the polygons looked a little smoothed
>> out... But speed is also important.
> 
> The painting of 0.40.0 looks much different due the brush has a little 
> different color, the part that forms the eyecandy (one line of code... 
> couldn't resist ;-P )
> 
> This one gives a better comparison:
> 
> http://traverso-daw.org/screenies/screen14.png
> 
> 
> The more you zoom in, the less chance of differences in the polygon based 
> drawing with 1 pixel or 2 pixels per polygon point.
> 
> The order is the same as before, top one with polygon based painting, one 
> polygon point per pixel, mid 2 pixels per point.
> 
> Depending on your graphicscard, the speedup can be 5 x to perhaps couple of 
> 100's :-)
> The benefit is that there is no need to cache the painting, which makes 
> sense, 
> for example, Gain Curves are merged into the painting real time, so caching 
> doesn't help there, and so the painting _needs_ to be fast.
> 
> The problem: OpenGL acceleration only paints the waveform correctly when 2 
> pixels per polygon point are used, so the drawing is a tiny bit less 
> accurate, mostly when zoomed out.
> 
> Note though that if you need very precise editing, you're most likely zoomed 
> in a lot, and at that point, the audio data is read directly from harddisk, 
> painted as a line, and is as precise as possible!
> 
> So that's the dilemma I'm facing right now....
> 
> Regards,
> 
> Remon
> 
> P.S.
> The waveform just shows the highest peak values anyways, it's not an 
> indication for the loudness .....!

-- 
/Jonatan         [ http://kymatica.com ]