| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 2817.1 | That's a LOT of colors ... | ALLVAX::APPEL | Panic now ... avoid the rush ... | Fri May 25 1990 08:41 | 4 |
| Why does your customer want/need more than 16 million colors? (On a 1K
by 1K screen, he can't even display all the ones he has now!)
Neal
|
| 2817.2 | Which? | TKTVFS::KATSUMATA | Moto Katsumata WSST/CS/JAPAN | Sun May 27 1990 21:26 | 13 |
|
The only thing that I want to know is which DS5000 uses
TrueColor or DirectColor.
re.1
You're right. But I don't know why a customer wants more
than 16 million colors.
I didn't talk with a customer directly,a salesman told me
"Does DS5000 use TrueColor or DirectColor?".
Moto
|
| 2817.3 | | KONING::KONING | NI1D @FN42eq | Wed May 30 1990 14:03 | 8 |
| I'm puzzled.
With 24 bits, you can only have 2^24, i.e., 16 million, colors. Whether
you have truecolor or anything else makes no difference. (Ditto for
mapped color, where you have a 4 or 8 bit map index and a 24-bit entry:
that too allows 16 meg colors, just not all of them at the same time.)
paul
|
| 2817.4 | We want to change colormap dynamically | TKOV50::KANNO | Atsushi Kanno, EIS/SE/SPSG/WS | Wed May 30 1990 21:50 | 9 |
| Have you ever seen color wheel program on DECstation or VAXstation? The
demonstration program shows us that we can change colormap dynamically. It is
possible because it uses PseudoColor in DECwindows(X window). But PseudoColor
only supports less than 256 colors(I think). If you want to use 500 colors and
want to change your colormap dynamically, you have to use DirectColor. That is
why that we want to know what kind of visual types will DECstation 5000/200PXG
be able to support.
kan
|
| 2817.5 | | DECWIN::FISHER | Prune Juice: A Warrior's Drink! | Thu May 31 1990 18:22 | 24 |
| We are picking at nits, and I apologize for that, but I just want to make sure
you realize that there is no architectural reason that a Pseudo-color device
can't have more than 256 colormap entries. It's just that DEC does not.
Also, and this is NOT a nit, you have to be aware that with an 8/8/8 direct color scheme, you still
only have 256 INDEPENDENT colors. For example, let's say that you have color
index
FF0012
In direct color, this says "Get the red value from the red colormap at index
FF, the green value from the green colormap at entry 00, and the blue entry
from the blue colormap at entry 12.
Now suppose you have another index
12A512
Notice that this is a different color from the other index, it does share
the same blue colormap index (12) and thus must have the same blue component.
If you change the blue value of one index, you change the blue value of the
other index as well.
Burns
|
| 2817.6 | While it says true color, it looks like direct color.... | CVG::PETTENGILL | mulp | Fri Jun 01 1990 21:09 | 6 |
| According to the sales literature, the DECstation 5000/200PXG is true color
with 24 plane option and the 200PXGTurbo is true color. However, the
description mentions the use of a color LUT for both 8 and 24 plane, which
would imply direct color.
I'll forward this to the real authority, Jim Gettys.
|
| 2817.7 | Thank you for all your help! | TKOV50::KANNO | Atsushi Kanno, EIS/SE/SPSG/WS | Mon Jun 04 1990 02:59 | 10 |
| Re .5)
Thank you for your help. Your explanation is so excellent that beginnners of X
window system could understand DirectColor mechanism.
Re .6)
Thank you for answer. That is the answer that I have been looking for.
kanno
|
| 2817.8 | | DECWIN::FISHER | Prune Juice: A Warrior's Drink! | Mon Jun 04 1990 14:04 | 12 |
| re .6: I don't know anything about the various 5000 models. However, the
3520/3540 might have been advertised similarly. The reason is that the
HARDWARE is actually direct color. However, the default visual is TrueColor.
This is simulated by loading the direct color LUTS with ramps. You can still
use the direct color model by using a non-default visual type.
In otherwords, direct color is available, but not defaul.
Remember this is the VAXstation 3520/40 (Firefox). The DECstation 5k may
be similar, but I don't know for sure.
Burns
|