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APPLE II DEVELOPMENT FORUM CONFERENCE LOG
October 17, 1989 10:00 pm eastern time
Topic: Special Guest: TML Systems
Discussion following the conference on how
to do decimal arithmatic in assembly language for
use in 3-D animation routines.
Forum Leader: Dave Sugar (AFL Dyfet)
TML Vince Looks like we may be missing our west coast regulars tonight..
AFA Gary J Yup.
A2GS or at least our SF regulars.
AFL Dyfet And others, Vince...I have heard from Dave Lyons and Matt, though,
and they are
TML Vince San Jose is a real mess from what I'm hearing on TV..
AFL Dyfet okay, just without power.
TML Vince Darn, was hoping Matt and Dave would be here.
TML Vince Hello Tom
A2GS where are they from?
TML Vince Cupertino.. just south of San Jose
TML Vince right in the middle of the whole mess
TML Tom Greetings.
AFL Dyfet Appearently some of the buildings were cracked, and they had to
evacuate
AFL Dyfet Apple.
AFA Gary J Hi Tom
AFL Dyfet But nobody there was hurt.
TML Vince glad to hear that..
AFL Dyfet Though Dave lost a monitor, and Matt gained a light fixture in his
cubical...
TML Vince :)
A2GS :)
AFA Gary J Hope everyone had backups :)
TML Vince Oh well, there goes my tech support... :))
AFL Dyfet Well, for those who might have missed the intro's we skipped, we
do have two
AFL Dyfet guests here from TML Systems, Vince Cooper, and Bob Leanord :).
Most of you
TML Vince Err, Tom's here, not Bob... :)
TML Tom Sorry, its Tom
AFL Dyfet are probably more familiar with Vince as 'AFL Vince' :), (Yes, you
are right,
AFL Dyfet Vince, I did confuse that :), but if Tom would like to take this
oppertunity to
AFL Dyfet introduce himself, this would be a good time :).
TML Tom Hi, I'm the president of TML Systems and the author of the
recently released TML Pascal II compiler
TML Tom for the Apple IIGS.
TML Tom I've also written the TML BASIC compiler and TML Pascal for the
Mac.
TML Tom I'm here tonight to answer whatever questions you might have about
TML Pascal II.
TML Tom ga
AFL Dyfet Thank you Tom :). Now, who would like to ask the first
question?
TML Vince I would, I'd like to know how many people here have actually seen
the new compiler?
Doctor Why I have.
AE PhilM Not I.
AFA Gary J Not I.
BRENTON Nor I.
AFL Dyfet I have, for one :)
John moyln not I(just spent the upgrade money on the Mac version...:)
Windrider5 Not I
Terry Cox Not I
TML Vince Ok, maybe we should tell you a bit about it, then you can ask
questions...
JDavies1 what are we commenting on?
AE PhilM Sounds like a good chance for 8 sales :))
Windrider5 ?
AFA Gary J :)
AFL Dyfet How many here are familiar with the older version of TML Pascal?
John moyln I am...
BRENTON Sorry.
John moyln ($@&^^($@* 32k editor...;)
AE PhilM Sort of..
Doctor Why I am.
Terry Cox Nope.
JDavies1 I am
A2GS A little
TML Tom I'll give a brief intro to TML Pascal II.
AFL Dyfet Okay, perhaps a good start, Vince, would be to explain some of the
differences
AFL Dyfet and then explain about TML Pascal in general for the new folks :).
GA Tom, I
AFL Dyfet did not see your comment fly in :)
TML Tom TML Pascal II is a new version of the original TML Pascal compiler
for the IIGS.
TML Tom It is a stand-alone application which operates in the IIGS 640
mode graphics screen.
TML Tom The product has an editor, compiler, linker and a resource
editor.
TML Tom The compiler and linker are mostly the same as the original
version with bug fixes and general
TML Tom improvements. The major new features include a new text editor
based on the new TextEdit toolset,
TML Tom interfaces to System Software v5.0, and most importantly the
resource editor.
TML Tom System Software 5.0 implements a Resource Mgr like the Mac and the
other toolsets have been extended
TML Tom to support resouces. This allows you to implements windows,
menus, dialogs, etc. separate from the
TML Tom code in your program. And further, these user interface elements
are now created "graphically"
TML Tom with the TML Pascal II resource editor.
TML Tom That sounds like enough.
TML Tom ga
AFL Dyfet Thank you Tom :)...Okay, I believe that Windrider has the next
question, GA.
Windrider5 I have a very general question.
Windrider5 Why did you choose the pascal language over other languages such
as C
TML Tom TML Systems shipped its first product in December 1985. It was a
Pascal compiler (the first one!)
TML Tom for the Mac. When the IIGS was released, we decided to port that
compiler to the IIGS.
TML Tom So it was mostly a business decision since that was (and is) the
technology that we have. TML Systems
TML Tom has never programmed and projects in C, although we use assembly
quite routinely.
TML Tom ga
AFL Dyfet Okay, I believe Phil has the next question and the floor now. GA
Phil.
AE PhilM Can you link APW OMF files with the TML Linker? If you can that's
great, if
AE PhilM not how do you incorporate Assembly language routines in a TML
Pascal program?
AE PhilM ga
TML Tom No, the TML Pascal II linker can not link APW OMF files.
TML Tom Now that we have completed the features we thought were most
important for TML Pascal II (the resource
TML Tom editor and System 5.0 interfaces) I think that Vince has pretty
well communicated that this
TML Tom feature is really needed. I would look for it in
TML Tom furture versions.
TML Tom ga
TML Vince As for now, we do have the Inline statement.. :)
AE PhilM Thanks :)
AFL Dyfet I would like that feature, too :)...I believe that A2GS has the
next question,
AFL Dyfet GA A2 :)
A2GS Has TML thought about an assembly language assembler (made up
completely of
A2GS custom routines if the Desktop is the interface you would go with,
except for
A2GS such things like interfacing with the Resource Manager, etc) GA
TML Tom No, I don't think that you will see TML Systems release an
assembler. There are already two
TML Tom very fine assemblers for the machine.
A2GS Agreed...What do you consider them to be?
AFA Gary J :)
AFL Dyfet :)
TML Tom However, we will in the future provide a mechanism to link in at
least OMF files.
TML Tom Oh, I think I take a no comment on that one. But I will say that
I use the MPW IIGS assembler for
TML Tom whatever that is worth.
TML Tom ga
A2GS O.K. Thanx :)
AFL Dyfet A good answer, Tom :), actually, we all probably have strong
prejudices on that
AFL Dyfet one :). Okay, do we have any more questions from the audiance
tonight?
AFA Gary J Q = <empty>
AFL Dyfet Okay, Doctor Why, GA, you have the floor now.
Doctor Why Reading some of the folders here, there have been a number of
problems with
Doctor Why the current version of TML PASCAL II, (not all your fault)
Doctor Why You mentioned that there will be an update soon?
TML Tom You are absolutely right.
A2GS Never mind my Q, Gary.
TML Tom We have had numerous problem completing the software. Some
because of System Software v5.0
TML Tom and some because we just tried to do too much in the time frame
allocated.
TML Tom We have now been shipping v1.1 of the compiler together with
System Software v5.0.2 from Apple for
TML Tom about 2 weeks and this configuration has proved to be VERY solid.
We have also shipped free update
TML Tom disks to all customers who received v1.0 earlier this week.
TML Tom Vince, do you know what day that was?
TML Vince The last of the update disks went out yesterday. Some folks
should begin receiving them by tomorrow
Doctor Why You shipped to all registered owners?
TML Vince The only problem the update didnt take care of was the TE cut and
delete problem which will fix itself
TML Vince with a future system software update from Apple.. :)
TML Vince GA
Doctor Why Thanks.
AFL Dyfet Thank you, Vince and Bob :), does anyone else have any questions
for tonight?
TML Tom Any good meaty techical question?
A2GS Can TML Pascal II compile and link during a major Earthquake?
A2GS :)
TML Tom Even if you lose power!!! Its that good!
John moyln what sort of enhancements were made to the editor?
TML Tom The editor was replaced entirely. It is now based on the Text
edit toolset provided with
TML Tom System Software v5.0.x
TML Tom The major new features in the editor include: much impoved
find/replace, any font/font size, no 32K
TML Tom limit on file size, Undo, ...
TML Tom ga
AFL Dyfet I think people will most appreciate the breaking of the 32K
boundry :). Okay,
AFL Dyfet I see that AFL Scott is next, GA Scott.
AFL Scott How does the compiled look and run (speed wise) with respect to
code generated
John moyln (yep, into the present, our of the dark ages...;)
AFL Scott under the full optimization of compilers like ORCA/Pascal? It is
my under-
AFL Scott standing that TML II is an optimizing compiler, is it?
AFL Scott GA
TML Tom Well, I think that our compiler makes some very good decisions
about the code it generates, but
TML Tom I would not really call it a "optimizing" compiler. Such a
compiler would make at least two passes
TML Tom during code generation to make sophisticated code generation
decisions. The MPW IIGS compiler does
TML Tom this, I don't know what the ORCA compiler does.
TML Tom We have tried to emphasize speed, ease of use and now the resource
editor capability.
AFL Dyfet I think TML has done pretty well in the ease of use part,
certainly :)...Okay,
AFL Dyfet I see that A2GS has the next question, GA A2GS.
A2GS This is way off the subject, but I was wondering if maybe one of
the TML guys
A2GS or anyone else for that matter, has any idea where I might be able
to find code
A2GS or an algorithm for writing floating point routines in assembly
language? GA
TML Tom Not me.
TML Vince Hmm.. not I... I use the tools that are provided.. Ie SANE :)
A2GS Thanx anyways :) :(
TML Vince Since I'm not a masochist, I avoid Assembly when at all possible..
:)
AFL Dyfet Way back in a few very old issues of Byte, there were some pretty
good articals
A2GS need them for 3-d routines :)
AFL Dyfet on implimenting floating point math, and perhaps in other places
as well :).
A2GS how far back?
AFA Gary J There's a 3-d package in our library :)
A2GS when/where?
AFL Dyfet As to 3-d routines, I think, for speed, you would do best with
table driven
AFL Dyfet lookup routines for cos/sine :).
A2GS Working on my own....have all the routines/algorithms except for
the FP ones!
AFL Dyfet That is what Sublogic's 3-d toolkit did :)...I see Scott wishes to
comment, GA
AFL Dyfet Scott :)
AFA Gary J A friend of mine wrote the one in our library, I'm not sure what
he did for
AFA Gary J his algorithms.
AFL Scott Is there any support planned for the Innovative Systems Floating
Point Engine?
A2GS Will still need FP routines even with Cos/Sin Table (already had
it in mind :)
TML Vince Scott?
AFL Dyfet I believe Scott's question was directed twords TML :)
AFL Scott I do to!:)
AFL Scott too!:)
TML Vince err, I missed it :)
AFL Dyfet Um, Scott?
ProDude (scroll up)
TML Vince Oh, Floating Point Engine... we've discussed it, and I'm really
wondering how much saturation this
TML Vince product has really made... In other words, is full support really
needed? you tell me :)
AFL Scott I think so.
AFL Scott Anything is better than SANE.
TML Vince ah, a single voice raises from the masses.. :)
TML Vince I dont know, Tom, comments? FPE support, or the AE math card for
that matter..
AFL Dyfet I think it would be good, too, for those who have need of high
powered math
AFL Dyfet support :).
AFA Gary J I don't think Scott's opinion of SANE is singular.
AFA Gary J :)
AFL Dyfet That is also true, Gary :)
AFL Scott Either built in support or optional support (user purchase--extra)
would be
AFL Scott so nice!:)
TML Tom Unfortunately, I don't think we have the resources right now to
recode the code generation for these
TML Tom alternative FP mechanisms. I believe each of these, however,
patches SANE and dispatches the calls
TML Tom to their respective boards? GA
TML Vince I know FPE does this guys, not sure about FastMath
TML Vince GA
AFL Scott It does, but it's several orders of magnitude faster to call the
card directly
AFL Scott than to use the init.
TML Vince understood, and noted... :)
A2GS Prefer homemade FP routines for a Compiler.
A2GS NOT SANE!!!
Doctor Why ?
A2GS inSANE
TML Vince anyone else have a question relating to TML Pascal II?
AFL Dyfet I see that Doctor Why has a question :). GA Doctor :)
Doctor Why Are there any plans to add support for resources for icons and
cursors?
TML Tom We will certainly enhance the resource editor based on demand. I
think that cursors and icons are
TML Tom right at the very TOP of the list!
AFL Dyfet Okay, I believe that A2GS has the next question. Ga A2, you have
the floor
AFL Dyfet now :)
A2GS How would you compare TML Pascal II with your competitors ver. of
Pascal? GA
TML Tom I think that our major advantages are speed, ease of use, System
Software 5.0 support which is fully
TML Tom conformant to the new Apple interfaces for Pascal, and most
especially the resource editor.
TML Tom Their product's major advantages are the debugger and
multi-language integration.
TML Tom ga
TML Vince I'll add that Ease of Use covers many angles!
A2GS Can you compare yours speedwise? (compiling time)
A2GS and what comes with the TML PASCAL II package? GA
TML Tom Honestly, I haven't compared their latest version with TML Pascal
II so I don't think it would be fair
TML Tom to say exactly.
TML Vince Speed wise, we're considerably quicker... I think you'll find our
competitor himself is willing to
TML Vince conceed the speed issue to us.
TML Vince GA
TML Tom The TML Pascal II product comes with two disks and a manual. The
disks include System Disk v5.0.2,
TML Tom the second disk contains the compiler, examples, toolbox
interfaces and source code to the interfaces.
A2GS Manual?
TML Tom The manual is pretty standard stuff. I think the nicest feature
is a complete listing of the toolbox
TML Tom interfaces with a full index of every toolbox procedure, function
and typename!
A2GS Clear list/explanation of commands available and usage? GA
AFL Dyfet Have you considered making that kind of information available
online in a live
AFL Dyfet help system?
AFL Dyfet (online, as in, while using the product, not as in on AO :)
TML Tom Yes, but so little time... Anyone want to do it?
TML Vince We also have a nice Source Code Library available as a companion
product... :)
AFL Dyfet It would certainly make an interesting companion DA for TML Pascal
:)
Rohit What does
Rohit How much does TML Pascal II cost?
TML Tom $125 retail and $49.95 for the SCL
Rohit Whats SCL?
AFA Gary J Source Code Library
AFL Dyfet Source Code Library, sample Pascal II source code, Rohit. Okay, I
believe we
AFL Dyfet can move to Doctor Why's question now. GA Doc.
Doctor Why In your first flyer on TML Pascal II, there was a contest
mentioned. Can you
Doctor Why give us some more details?
Rohit Doyou know of any good programs that were made with TML Pascal?
TML Vince I'll take this one... :)
TML Vince I'm in the process of working out the final details of the
Programming Challenge right now. You'll
TML Vince receive information on this when you return the registration card
from Pascal II. I think you'll
TML Vince like what we're lining up for you!
A2GS What's the prize?
TML Vince As for good programs written with Pascal II, if you've looked at
Britanica Software's new
TML Vince Revolution 76 game, it was written totally with TML Pascal..
Rohit Thanks
Rohit Bye
TML Vince And I can't tell you the prize... it would ruin all the fun... :)
kind of like christmas.. :)
A2GS prize?
TML Vince GA
AFL Dyfet Okay, I see that Doctor Why has a new question, GA Doc :)
Doctor Why Does the update just sent out have any changes to interfaces?
TML Vince Yes, we changed a couple of things in the Print and Desk
interfaces.
TML Vince I'm sure other things will eventually be found.. Apple is still
in the process of setting those
TML Vince things in stone.. :)
Doctor Why :)
TML Vince GA
Doctor Why the cement is still wet. :)
TML Vince Anyone else got anything about Pascal II you want to ask?
AFA Gary J What's the status of TML BASIC?
TML Vince Gary, its fine... :)
TML Vince Gee, and I thought we were going to make it all night without that
one... :)
TML Tom Bye.
Doctor Why Night Tom.
TML Vince Night, Tom
TML Vince Actually, I havent made any decisions about Basic, and it looks
like that decision is going to be
A2GS oops missed.
TML Vince my problem to make..
AFA Gary J What kind of decision?
TML Vince I want to look at a few things market wise before I do or say much
about Basic..
AFL Dyfet I think it would be a very good time to put out a decent basic for
the gs
AFL Dyfet myself...:)
Doctor Why How about making TMLBASIC capable of doing custom controls?
TML Vince About how much we're going to do with it Gary, it needs more than
a simple update.
AFA Gary J :)
TML Vince in all honesty, it needs HELP
TML Vince :)
TML Vince how many of you actually write serious programming projects in
Basic?
A2GS Ampersand revisited.
AFA Gary J I picked up an unopened copy at a garage sale, but have never
cracked the
A2GS LOL Vince.
AFA Gary J wrapper.
AFA Gary J I don't write serious programs in BASIC because I don't have a
serious BASIC.
AFL Dyfet Well put Gary!!
Doctor Why Sometimes you just don't want to write a serious program! :)
TML Vince The problem with Basic is that the toolbox is not designed for it.
Pascal and C are stack based
TML Vince languages, Basic isnt. The toolbox is designed to interact with a
stack based language... It CAN
TML Vince be done, but not done well.
AFL Dyfet One can mold the internal architecure of Basic in any way one
wishes,
AFL Dyfet actually :)...One only needs to see what MicroSloth did with
QuickBasic to see
AFL Dyfet what Basic can be :)
AFA Gary J Right!
AFA Gary J (I DO have QuickBasic on the IBM clone at work :)
TML Vince I'm looking seriously at QuickBasic, Dave.. It is a good
implementation, but it still leaves a lot
A2GS You can have it!
TML Vince to be desired for serious programming projects.
TML Vince I'm looking at QB for the Mac.. :)
AFL Dyfet The Mac implimentation, from what I have seen, is a very poor
cousin of the
AFL Dyfet PC ones, and lacks most of the features found there.
TML Vince It's a nice attempt, as is Zbasic on the Mac.. Like I said, our
basic can be made better... I just
TML Vince need to do some study before I'm willing to commit to anything.
Doctor Why Vince, can I ask a dumb question on Pascal II?
AFA Gary J No such thing as a dumb question :)
TML Vince GA, Doctor
Doctor Why Just wait... :)
A2GS :)
Doctor Why When printing out samples and selecting page numbers, I only got
it on the
Doctor Why 1st page.
TML Vince only got what? a listing?
Doctor Why yes, printing out the sample programs.
TML Vince I didnt know it even asked you how many pages to print...
TML Vince am I misunderstanding the problem?
Doctor Why No, I only got one page number, many pages.
Doctor Why and no page breaks.
TML Vince Oh, ok, set if for cut sheets instead of continous forms..
TML Vince if = it
TML Vince there are two buttons there, you DONT want the default.. :)
TML Vince GA
Doctor Why Oh , really? I thought that was asking if you were using
continuous forms or
Doctor Why single sheets.
TML Vince It is, but its confused.. :)
Doctor Why :) So am I. :)
Doctor Why I'll give it a try.
AFA Gary J :)
TML Vince it'll work, I promise.. :)
Doctor Why If that's the case, is the number of lines per page
Doctor Why the number of lines you WANT printed per page?
TML Vince you do what the default (60) on the lines per page..
TML Vince a page has 66 lines, 60 lines of printing leaves 3 lines each at
the top and bottom for a margin.
TML Vince you should also position the form so that you already have a small
margin at the top of the
TML Vince page before you start to print.. it makes a nice listing if you
do.
Doctor Why One other comment on printing.
TML Vince GA
Doctor Why It would be nice for you to provide a left margin for those of us
who would
AFL Dyfet Okay, did we have any more questions for tonight? :)
Doctor Why like to put these in binders.
TML Vince you can do that yourself by sending a printer command. we do
provide a box for you to do that. :)
TML Vince I forget the command though, look in your imagewriter manual to
find it.
Doctor Why Oh, that didn't occur to me. I'll give that a try also.
A2GS Man, these guys think of everything :)
Doctor Why hehe
TML Vince Great! well folks, its about time for me to cut out! It's been a
real pleasure to talk to you
TML Vince tonight!
Doctor Why Thanks for the help Vince.
<log file resumed after a brief laps>
Question on doing floating point arithmatic for 3-D animation routines, and
a discussion on doing decimal arithmatic in assembly language:
AFA Gary J There's the Perspective View 3-D program in the library that my
AFA Gary J friend wrote. You could take a look at that and see if it would
AFA Gary J do what you want, or maybe take a look at some of the code. I'm
AFA Gary J not sure exactly where in the program you would have to look for
the calc routines..
A2GS I've been working on some of my own routines, and have
completed the
AFA Gary J ..It has been a while since I've used the program,
AFA Gary J and it is modulized. I'm not sure which is which.
A2GS Mult. routine...but it's buggy...still trying to work out all the
kinks.
A2GS Well I'll download it...can't really hurt...but I don't think
it'll help too
AFL Dyfet Again, most of that can be done much faster with table lookup
routines...
A2GS much. If you could GARY, please ask your friend what he
used....probably
A2GS the same routines used by Applesoft.
AFA Gary J Ok.. I'll ask him.
AFL Dyfet Especially since the resolution of the screen is typically much
lower than the
AFL Dyfet resolution of full FP math routines...
A2GS Yes Dyfet, you have to use a lookup table for the cos/sin values
but you still
A2GS need FP routines when dealing with the cos/sin values.
A2GS in calculating the x,y,z results.
AFL Dyfet You can treat them as fractional integers, and then do simple
integer multiply
AFL Dyfet and devides to apply them :)
A2GS Have to keep track of where decimal point is located....can't do
that in hex
A2GS form.
AFA Gary J Pixel locations are integer values.
AFL Dyfet You don't need to...You multiply values by cos/sin values in the
range 0-ffff
AFL Dyfet and throw away the low product, giving you the actual rounded
displacement.
A2GS multiply them by what?
AFL Dyfet Say you have $80 (128) as your value, and the cos is .45 (or
approximately
AFL Dyfet $6800), just multiply the $6800 fraction of $10000 by the $80, and
the high
AFL Dyfet part of your result will be about $35xxxx, or the scaled value.
AFL Dyfet Just drip the xxxx and you are done :)
AFA Gary J you can drop the xxxx too :)
AFL Dyfet (drop=drip :)
A2GS how do you get cos .45=$6800?
AFL Dyfet I guestimated...but take $10000 (655536) * .45 and you will find
the value to
AFL Dyfet actually use :)
A2GS 65536
AFL Dyfet I added an extra 5 :)
AFL Dyfet Oops :)
AFA Gary J Yes, you can drip the 5. :)
AFA Gary J :)
A2GS yes, but I need the COS of .45 not just .45!
AFL Dyfet Thanks a lot, Gary :)
AFA Gary J <sorry> :)
A2GS :)
A2GS which BTW is .9999
AFL Dyfet What you want, really, is the scaled 1 to -1 value of the cos/sin
of any angle,
AFL Dyfet and then to form that as a table :)
A2GS right
A2GS no problem doing that
A2GS But...
AFL Dyfet The .45 might be cos of 70 deg. for example :), and then you
multiply the
A2GS Once you've created the table of .xxxx decimal cos/sin
results....
AFL Dyfet appropriate axes by the scaled value :)
A2GS how do you multiply that by an integer value and then get rid of
the
A2GS insignificant value to the right of the decimal point which would
normally
A2GS be produced in base 10 math....you don't get simple # like that in
hex.
AFL Dyfet Don't think in terms of base 10 decimal arithmatic...think in
terms of base 2,
AFL Dyfet scale your table as base 2 fractions of $10000, and when you
multiply by the
A2GS Easier said then done :)
AFL Dyfet fraction, your high word (yyyyxxxxx) product (the yyyy part) would
be the
AFL Dyfet integer result of zzzz * cos[n]
AFL Dyfet If you have a line of 10 pixels long rotated by 30 degrees, the x
and y axes
A2GS But no matter how you look at it, you will come out with some
insignificant
AFL Dyfet for one of the end points simply becomes len * cos[10] for x and
len * sin[10]
AFL Dyfet for y.
A2GS hex # and the object is to try and figure the significant value
(integer) from
A2GS the insignificant (fraction leftover).
AFL Dyfet The significent portion is always the leftmost word if your table
is scaled in
A2GS while it's in it's hex form.
AFL Dyfet $1000 as 1 and $0000 as 0.
Guide NR is this still open questions?
A2GS so what does decimal 215 become
AFA Gary J We're talking about decimal arithmatic in hex, Neil.
A2GS Dyfet?
AFL Dyfet 215 is still $d3. That is then multiplied by the fraction, say
.50, which woul
A2GS $D3 what....$D300 or $00D3.
AFL Dyfet d be $8000 ($10000 * .50 is $8000), yielding an integer product of
$670000, and
Guide NR bye all
AFL Dyfet the $67 would be the part you want, dropping the lower 16 bits.
AFL Dyfet I need a hex calculator for this, to make sure my numbers are
right :), but
AFL Dyfet the principle is correct.
A2GS let's take a real example to test your theory. :)
A2GS me too.
A2GS hold on.
A2GS o.k.
A2GS say you have...
A2GS sin 5.683 * 42
A2GS put it in an easier form....btw sin 5.683=.0990
AFL Dyfet Okay, first you need a look up table element equal to $10000 *
.0990 :)
AFL Dyfet Let's call it .1 for simplicity, or 6553, rounding down.
AFL Dyfet Anyone know what 6553 in hex is???
A2GS in dec. = 6488.064, for practical reasons let's say 6488
AFA Gary J $1999
A2GS thanx
AFA Gary J 6553 = $1999
AFL Dyfet Okay, but Gary, was that $1999 for 6553 or 6488? :)
A2GS is that 6553 or 6488
A2GS :)
A2GS o.k.
A2GS we'll use 6553
A2GS 6553 * 42
AFL Dyfet Ah, okay...42 in hex is $2A...
AFA Gary J 6553 = $1999, 6488 = $1930
AFA Gary J (There's not enough light in here to power my solar calculator...
I have to
AFL Dyfet Theory: $2A * 6553 = 42 *.0990 * 65536 :)
AFA Gary J keep walking away from the computer to get the answers :)
A2GS right...go on
A2GS :)
AFL Dyfet Drop the 65536 by shifting left (as it's $1000), and the results
should be
AFL Dyfet the same (minus rounding error :)
AFL Dyfet What is 42 * 6553? Anyone with a calc.?
A2GS 275226
AFL Dyfet (or 42 * 6488, since we're now in decimal land)
A2GS dec.
AFL Dyfet Okay, and what is 275226 in hex?
A2GS 272496
A2GS in dec.
AFL Dyfet Or 272496 in hex :)
A2GS for 42 * 6488
A2GS lol
AFA Gary J $42870
A2GS Gary?
A2GS thanx
AFA Gary J 272496 = $42870
AFL Dyfet Okay, result $4, or 4!
AFA Gary J (getting out flashlight to power calculator :)
AFL Dyfet (dropping the $2870)
AFL Dyfet 42 *.0990 certainly is near 4 :)
A2GS what?????
A2GS oh.
AFL Dyfet The $2870 becomes the fractional part below $10000 :)
A2GS right!!!!
AFL Dyfet You could keep it around for further calculations and future
accuracy, and you
AFL Dyfet would then have fixed point fractional numbers, which are faster,
by the way,
A2GS Now things are clearing up.....I see the Light.....(if only Gary's
calculator
AFL Dyfet than using full floating point math :)
A2GS did :)
AFL Dyfet So the full result is $4 and $2870/$10000's :)
AFA Gary J This calculator is a real power hog. :)
A2GS Yeah...but how do you know how much of the result to drop off (in
our case the
AFL Dyfet If all your fractions are expressed as parts of $10000 then you
always drop off
A2GS $2780) from the way it seems to me you always drop off the lower
word....
A2GS right?
AFL Dyfet the last two bytes for the integer :)
AFL Dyfet And, for plotting, it's the integer xy position your interested in
:)
A2GS right
A2GS so briefly let's go through the steps...
A2GS Put sin # into .dec form and multiply by $10000
A2GS or cos #
A2GS drop the point BTW
AFL Dyfet Yes, or round it :)
A2GS Then multiply the integer which you already have (the x, y, or z,
value)
A2GS which should be in word form (easier for word * word = 32 bit
result routine)
AFL Dyfet Good so far! :)
A2GS then drop the relutant xxxx word in the result (result =
yyyyxxxx)
A2GS relutent=resultant
AFL Dyfet Or keep the xxxx as your fractional portion, since you could
always add it to
A2GS and you've got you integer (x,y, or z point)
AFL Dyfet another fractional number in the form yyyyxxxxx if you need to
:)
A2GS (probably won't)
AFL Dyfet But the yyyy part is the integer you are looking for :)
A2GS and that's it!
A2GS Thanx....
AFL Dyfet Yes, that is it...and it can be table driven, and use a simple
word * word
AFA Gary J easy as pi
AFL Dyfet multiply :)
A2GS makes life a lot easier!!!
A2GS Didn't think of this way...thoought about a million other ways of
converting
A2GS and reconverting from and too integer and hex form but always came
up with
A2GS something interfering in the simplicity of it.
AFL Dyfet Well, the rest should be easy :)
A2GS You make a great teacher!!!! Dyfet....BTW Thanx for the Hex help
GARY!
A2GS Dyfet have you considered working at NYU they could use a couple
of decent
A2GS professors!
A2GS :)
AFL Dyfet *blush*...Actually, I have never considered teaching before :)
AFA Gary J (Now the batteries are running down on my flashlight! What are
solar
AFA Gary J calculators good for, anyway! :)
A2GS Well you just ended my Month long search...kept getting wierd
results when
AFA Gary J I agree. I found your explanation to be very clear and
understandable, Dave :)
A2GS converting to hex...should have thought of multiplying by
65536!!!!!
A2GS Now things are clear as a bell....what I was doing wrong all this
time!
AFL Dyfet Once you understand how to look at numbers, the rest is easy :)
A2GS Yeah.....you better believe it
AFL Dyfet It's just that you have to stop thinking of base 10 and start
thinking about
AFL Dyfet what fractions are really about :)
A2GS somebody showed me a FAST way to always calculate an address on
the screen
A2GS if given the x,y coordinates.
AFA Gary J On the screen? A graphics screen memory address?
A2GS Have to admit....Never would have thought of it!
A2GS Yup!!!
AFL Dyfet There are a number of cute ways to do that trick (finding a line
address on the
AFA Gary J You can use lookup tables for that, too, which are the fastest
way.
AFL Dyfet hires screen :)
A2GS On the Super-Hires acreen.
Pamme M Rehi!
AFL Dyfet You only need a lookup for the 24 base screen lines, as it's a mod
24, with the
AFA Gary J Rehi, Pamme!
A2GS Too difficult........the table would have to be pretty big.
AFL Dyfet remainder an offset :)
A2GS I see....But I was shown a simpler/ still very fast way.
A2GS thought about lookup tables....like to avoid them if not
needed....prefer
A2GS general algorithms :)
AFA Gary J Depends if you want a faster program, or more memory :)
AFL Dyfet Okay...that would just be my way of doing it :)...everyone has
their own
AFL Dyfet preferences :)
A2GS True
A2GS The way I was shown....
AFL Dyfet I do think the best way is the LARGE table (all 192 base line
addresses), for
AFL Dyfet the fastest speed possible :)
AFA Gary J Yup. I've seen it used, too.
A2GS WhoW!!! I'm talking about the Super Hires screen!!!
AFL Dyfet Ohhh...the Super Res screen could also benifit from a 200 line
address table
AFA Gary J Super hi-res is linear, so it's not quite so much of a problem as
the other
AFA Gary J screens.
AFL Dyfet map, as the code is simpler and faster to use :)
A2GS true...but there's a more GRACEFUL way (trickier :)
AFA Gary J which is.... ?
A2GS Take the Y-value (line #) Do 5 ASL' to it...then add the X coord
and do 2 more
A2GS ASL' and you have the exact byte/pixels address.
AFL Dyfet Hmm...that sounds kinda neat :)...I will have to think about that
:)
A2GS Simple/Obvious/Tricky and still does the job quick!
A2GS Figures out the Y value and multiplies it by 160 (bytes per scan
line)
A2GS with all the ASL's....believe me it works....I wrote a line
drawing
AFL Dyfet Yes, that is cute and clever :)
AFA Gary J Yes.
A2GS algorithm using it and it beat's the pants off of any other line
drawing
A2GS routine I've seen to date on the GS!!
A2GS Got to go soon....listen in on the SF quake....work on 3-d
routines :)