Jonathan Osuch <osuchj@avalon.net> wrote:
On Thursday 18 November 2004 12:58 am, Hiram Berry wrote:
[snipped]
When we zoom in, though, the domain pixels (the parameter values used for the orbits) will be accordingly changed, right? What I want to do is to possibly get the domain values from a different area than what the screen is showing for the display range, without having to change parameters on the z-screen if a zoom is done.
Ah, the light comes on! Would using the default coordinates for each fractal type be acceptable? Yes; for user written FRMs further translation can be done by hand, though my experience of the last few days trying to implement that by translating from the scrnpix coordinates is that it is tedious. The real need is for Fractint built-in types where this is not even possible for the user. If the domain remained constant at the default coords, the image should at least be invariant with zooming, though a whole lot of points are going to be offscreen. Alternatively, I am planning to add a <cntl-p> screen with passes options on it and default coordinates could be on it. Possibly just an X and Y value, and then show -X to +X and -Y to +Y on the screen.
From a user's standpoint I like that a little better; it gives a lot of leeway for choosing the domain for the orbit image.
The first option is preferable from an impementation standpoint since it wouldn't involve adding additional parameters to PARs and GIFs. I've already done it in my version, and it does prevent rotating the image, as was done with the Demonic_Moose image.
Well that's certainly understandable.
Yes, but that mapping is fixed to the screen rectangle. I'm suggesting the possibility, of say mapping scrnpix to the inside of the cardioid r=(1-cos(theta))/2 for example if we only want to see the orbits from the points originating on the period=1 cardioid of the M-set.
So, instead of plotting: for (row=0, row<ydots, row++) for (col=0, col<xdots, col++)
we could plot: for (theta=0, theta<360, theta++)
Or something similar.
Yes, for the circle its trivial, and not much harder for the cardioid, BUT what's hard is distributing the points with even density within those areas without incurring a whole lot of computational overhead, at least that's how it looks from where I'm sitting. I had wanted to see what the orbit image of the subset of the Mandelbrot set lying only on the rim of the main cardioid looked like by this point in time, but I haven't been able to distribute the points on the curve evenly yet. Still, for purposes of development, don't forget that many subobjects of the M-set are more or less circular, so having an option to choose a disk shaped area is reasonable. ---Hiram