Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!vtserf!morpheus!frank From: frank@morpheus.UUCP (Frank McPherson) Newsgroups: comp.sys.amiga.graphics Subject: Re: So, does *anyone* make 1024x768 x256 for the A3000? Message-ID: Date: 26 Apr 91 11:38:53 GMT References: <15230@helios.TAMU.EDU> <1991Apr24.162452.22106@hubcap.clemson.edu> <15250@helios.TAMU.EDU> <1991Apr24.211729.19270@bronze.ucs.indiana.edu> <61934@masscomp.westford.ccur.com> Organization: Virginia Polytechnic Institute Lines: 49 In article <61934@masscomp.westford.ccur.com> mark@calvin..westford.ccur.com (Mark Thompson) writes: > >I think there is a little confusion here. In graphics systems, the frame >buffer is organized as either a packed pixel array, planar array, or some >hybrid of both (generally speaking). Regardless of the memory configuration, >a 24bit graphics system has storage for 3 bytes of data per pixel. I do >not understand why any distinction is being made between "24 planes" and >"24-bit plane" and it occurs to me to be more of a case of confusion in >terminology. I assume you are refering to the two different memory >organizations mentioned above. If so, 24 plane and 24bit require the same >amount of memory and produce the same output. The only difference is the >way the data is accessed, each having its own advantages. > >>"24 bit graphics" does not imply 24 bit planes. I'm sure someone will >>correct me if I'm wrong, but I think that with normal 24 bit graphics >>boards, they allow you to choose 256 colours (8 bitplanes) from a >>palatte of 16 million (approx. 2^24). > >"24 bit graphics" DOES imply 24bits per pixel of storage and not 8bits. >Anyone who calls their 8bit board (256 color out of 16M) 24bit graphics >is lying. However, with all the hype about 24bit graphics lately and all >the over-zealous marketing going on, its easy to get confused. -- It was pointed out to me that some (all, possibly?) of my numbers were off by eight. It seems that I temporarily forgot that there are these things called bytes, and these things called bits. I was freely intermixing them, which takes away any meaning the numbers I was posting could have had. So, now here I go with what I should have been doing in the first place: asking questions. (Side note: I divided my numbers by eight. The answers are now much more reasonable. A 640x400x24 picture takes 768,000 bytes. The numbers I was so amazed at getting before were in bits; I didn't realize that until someone pointed it out to me.) Do these things have 24 bits of information per pixel, or do they have 24 bitplanes? What's the difference? I thought that 24 bitplanes MEANT that something had 24 bits of colour information per pixel. If that's not what it means, then my understanding of bitplanes is way off, and someone should explain it to me. (Again, sorry for posting my numbers in bits yesterday, while calling them bytes. I should be less hasty about following up to something I don't really know anything about.) -- Frank McPherson INTERNET : emcphers@fox.cs.vt.edu -- -- AmigaUUCP : uunet!vtserf!morpheus!frank --