############################################################ Richard said:
Basically with texture mapping support in the graphics card, rotation and shear of the fractal zoom box are trivial operations and higher-quality than what you get with fractint right now.
Richard, How would the rotation and shear of the zoom box be higher quality using texture mapping support in the graphics card than the way Fractint does this now? With Fractint's current rotation and shear algorithms, don't the locations of the points in the complex plane that get calculated correspond one-to-one with each pixel on the display? With texture mapping support in the graphics card a number of texels (texture pixels) contribute to a final rendered rotated/sheared pixel. It seems to me that having to calculate these additional texels for the texture map -- to insure adequate coverage of the rotated/sheared output pixels it maps to -- could be very burdensome for slow-calculating fractals and/or older computers. Also, if the person computing the fractal does not have texture mapping hardware in their graphics card the implementation in software could be prohibitively slow on top of the fractal and texture application calculations. [Brief overviews of texture mapping and texture filtering are here: http://en.wikipedia.org/wiki/Texture_mapping and here: http://en.wikipedia.org/wiki/Texture_filtering ]
I have an idea for a sampling algorithm that maximizes the amount of reuse for each redraw...
You may be making some assumptions about how people use Fractint that need to be carefully validated. While some people may in fact use Fractint in a way that your algorithm would help the efficiency of their use of Fractint, others might serially calculate different fractals -- say, from different formulas or using the same formula with different parameters -- or calculate zooms into a fractal at very different locations for each zoom.
It would also be possible to store the iterations on your hard drive through this method so that you could browse your favorite fractal type and store as much iteration data as you wanted on your hard drive, up to the capacity of the drive.
While your disk storage method may be of benefit to a subset of Fractint user's it probably would not be useful to those with older machines with smaller hard drives -- unless your disk algorithm could be turned off and/or have its cache flushed. Similarly, going to texture mapping might be effective for those with texture mapping hardware in their graphics cards, but not for those without this hardware. Another item adding to the age-old problem of insufficient computational power may be that today's processors might be faster, but it appears to me that people's desire to fill higher resolution screens with ever more detailed fractals has seriously taken the edge off these CPU speed gains. (My claim here needs to be validated by Fractint users.) So, for example, changing from calculating an 800 x 600 fractal to calculating a 1600 x 1200 current screen resolution fractal requires four times as many pixels -- making a 2 GHz CPU appear four times 'slower' -- like a 500 MHz CPU calculating the 800 x 600 pixel fractal. But people regularly use 200 MHz CPUs to run Fractint on. And it looks like the last decade's CPU speed gains are not going to be happening in the future -- witness Intel's falling back to providing two CPU's on a chip instead of a single faster CPU as its last offering. Your proposed methods appear to be of potential value to those with current hardware, but do we want to leave the that portion of the Fractint user base behind that has not or cannot update their computers to include texture mapping hardware and large hard drives? Or would two versions of Fractint be needed -- one for computers with modern hardware features and another one for older computers? One of the premises of Fractint is that of getting the most function out of limited capacity hardware. Do we want to abandon this philosophy? - Hal Lane ######################### # hallane@earthlink.net <mailto:hallane@earthlink.net> # ######################### ############################################################ No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.6.6/795 - Release Date: 5/9/07 3:07 PM