Plotter / Dot Flag

[Codetapper]

PMC: Say goodbye to your free Amiga time from now on! My daughter is 4 weeks today and I've hardly had time to do anything the last month!

[Lonewolf10]

Originally Posted by pmc

I will do Brett, as soon as we're finished at the hospital - just waiting to leave - our little son was born yesterday! \o/

Congratulations.


Regards,
Lonewolf10

[StingRay]

Originally Posted by pmc

I will do Brett, as soon as we're finished at the hospital - just waiting to leave - our little son was born yesterday! \o/

Congratulations from me too!

[Siggy999]

Congrats!

I found I had very little free time all last year while my wife was pregnant (being lucky enough to work from home) and when the kids were born in May (twins - boy and girl) everything but work/sleep/kids/housework went out the window.

The good news was that after setting up the A2000 and monitor in the nursery (mainly so I could play dvds on the monitor for them) I've found that tooling around on it while they nap is not only really relaxing and gets my head back into my 'calm place', but I've made far more progress on projects than I have in the last 2 years (when I managed to finish getting the machine working).

All the best with your new arrival, they're a handful, but by far the most rewarding thing that's ever happened in my life.

[TheDarkCoder]

My warmest congratulations!

My daughter's birthday is the 23 of october. Is it the same day?

My daughter is now 3 years old. In these 3 years I was able to code almost nothing. Moreover, I was unable to find the time and the proper calm to mount a 68882 on my Blizzard 1230 and a Cybervision on my A4000

I also have many difficulties in updating software for my Amigas (still with old versions of many MUI classes) and in doing regular backups.
Gaming? I don't dare, I'll wait when she's a little olderso we can play together.

But despite all this, I am very happy as a father !!!

[pmc]

@ TCD & Lonewolf10 - thank you guys, much appreciated.

@ Codetapper - LOL - yeah, I think I might be taking a small break for a while but I won't stop coding when (if...!? ) I ever do get the time. All the best to you and your little one.

@ StingRay - thanks man, I'll be telling the little guy all about his uncle StingRay as he grows up.

@ Siggy999 - thanks man - everyone I speak to says that it's the best experience ever and I'm already finding it quite overwhelming. But twins! Well, what can I say? You *really* have your work cut out! Congratulations to you and your wife.

@ TheDarkCoder - yes! 23rd October is my son's birthday too. All the best to you and your little one.

Thanks for all your kind words guys!

[victim]

Originally Posted by pmc

I will do Brett, as soon as we're finished at the hospital - just waiting to leave - our little son was born yesterday! \o/

Hi PMC

and i Congratulations to you and wish them all the best !

so long..
victim

[korruptor]

Congrats PMC!

The 23rd is my Birthday as well.

[Leffmann]

Congratulations to you and Codetapper on becoming fathers

About the dot effects, in 15 years from now when you have time for coding again, you can look into using precomputed blocks of code.

The simplest method is generating code that plots fixed patterns which can be offset anywhere on the screen by adjusting the registers before you jump into the code.

Provide a coordinate value in D0/D1 and
calculate its offset into the bitplane

muls.w  #40, d1
moveq   #7, d2
and.b   d0, d2
asr.w   #3, d0
add.w   d0, d1

D1 holds the offset and D2 is the X coordinate modulo 7 which
we need in order to pick the right OP-code and write the
complete instruction to memory

lsl.w   #2, d2
move.w  opcodes(pc, d2.w), (a0)+
move.w  d1, (a0)+

... repeat for all dots in this pattern

Finish the code block by writing an absolute jmp instruction
that returns us to the end of our work loop

move.w  #$4EF9, (a0)+
move.l  #ReturnPoint, (a0)+

... go do next pattern

opcodes:

or.b    D0, 1(A0)
or.b    D1, 1(A1)
or.b    D2, 1(A2)
or.b    D3, 1(A3)
or.b    D4, 1(A4)
or.b    D5, 1(A5)
or.b    D6, 1(A6)
or.b    D7, 1(A7)

To f.ex draw a blanket of dots you would precompute f.ex a few hundred animated horizontal strings of 32 dots each, and then run 32 of these blocks of code and plot vertically down the screen.

To f.ex plot something at offset 0, 0 you would set up your registers like this:

D0 to D7: $80 $40 $20 $10 $08 $04 $02 $01
A0 to A7:   0   0   0   0   0   0   0   0

for offset 2, 3 with 40 bytes wide bitplanes you would do:

D0 to D7: $20 $10 $08 $04 $02 $01 $80 $40
A0 to A7: 120 120 120 120 120 120 121 121

etc.

[Asman]

Hi

Congrats for PMC and Codetapper.

I must agree with Codetapper, because ... my son have about 16 months and I can only find about 1h per week to launch amiga.

There is another easy trick with dots. You can use more bitplan then one to show more dots. Just set background color to black and rest of colors to white. And copy bitplane pointers from bpl0pth and bpl0ptl to bplxpth and bplxptl with some offsets.

Regards

[Plagueis/KRX]

Wow!!! Congrats to both of you dudez!

[pmc]

Hey fellas

Back at work now after my two weeks paternity leave I had some time to code again.

So, check out the attached .exe of a little intro I made for a glimpse of my new faster plot routine in action. I decided to avoid a standard dotflag and go for a formation that seemed a little more appropriate.

707 plots in one frame in this little intro, there's room for a few more but then it'd be right on the limit of fitting in a single frame so I think the routine can still do with being made quicker.

Enjoy.

no longer attached but optimised and fixed version of the Jacob plotter is available here: http://retro.untergrund.net/prods.html

[Leffmann]

Cool!

[StingRay]

Indeed, and cute! Really made me smile, nice one pmc!

[Herpes]

Originally Posted by pmc

...
Enjoy.

Respect!
... also a very nice tune

[pmc]

For a new thing I'm working on I want to make a dot ball to make use of my faster plotter. I want it to be as nice as the one in Phenomena's Enigma demo. That one is supposedly 800 points. Now rotating, plotting and hiding the hidden points is not possible in one frame without some serious cheating with shortcuts.

So, now I'm thinking about how to get it done. I've got an idea for reducing the number of points any calculations need to be done on and wondered what you guy's thoughts were...?

My basic idea is this:

Can't I generate the point locations for a whole 800 point dot ball by rotating only 100 points and then negating x and y values to get the locations of the rest...?

Check the pics of a dotball viewed face on. Stage one would be to negate only the x values of the first 100 points to get the second 100 points. Stage two would be to negate the y values of these 200 points to get the second 200 points giving me the visible points of the dotball.

What do you guys think - is this or something similar feasible...?

[pmc]

Done a bit more playing around.

I've worked out a set of 3d points now for an 800 point, radius 60 pixels, dotball.

As per something Leffmann said in another thread, when these are translated to 2d points and plotted they look OK as they are ie. no need for perspective transform. This will save time as only adds and subs are needed to convert 3d to 2d - no divides required.

So, now I need to work out some shortcuts with the rotations and get some kind of mirroring working and I should get a nice dotball going.

[korruptor]

Not sure what you're thinking, but mirroring the top left to the top right would mean the dots converge at the middle, wouldn't it?

[Lonewolf10]

Originally Posted by korruptor

Not sure what you're thinking, but mirroring the top left to the top right would mean the dots converge at the middle, wouldn't it?

I have not experience in this (yet), but I suspect you are correct. The way I would do it is to calculate the top half dots and then mirror that to create the bottom half (using a negative modulo with the bitplanes).


Regards,
Lonewolf10

[pmc]

Originally Posted by korruptor

Not sure what you're thinking, but mirroring the top left to the top right would mean the dots converge at the middle, wouldn't it?

I did some testing with this today - worked just fine as per my mirroring post.

Originally Posted by Lonewolf10

The way I would do it is to calculate the top half dots and then mirror that to create the bottom half (using a negative modulo with the bitplanes).

This might work for a static image (negative modulos to repeat rows of the displayed bitplane - a bit like copper "reflections") but I'm not sure how well this would work in this context. I need to be able to 3d rotate as few points as possible and mirror the rest to make it look like lots more points are rotated.

Using my method I should be able to rotate and bounce an 800 point dotball but only actually be rotating 100 points to do so. Even this may still need some short cutting to achieve in one frame when the other parts of the routine are added in...

I won't know for sure what all the short cuts needed are until I discover them and iron them out.

I'm working on it - reckon I'll have this one all done in the next few days.