Requested: Chunky Copper Tutorial

[sandruzzo]

Is there any c2p via copper tutorial available to properly set-up copper for chunky? I would like to do some test on OCS/ECS and Aga too.

[britelite]

Originally Posted by sandruzzo

Is there any c2p via copper tutorial available to properly set-up copper for chunky? I would like to do some test on OCS/ECS and Aga too.

Copperchunky isn't really a c2p as nothing is converted to planar

Basically, change one palette entry 40 times during a scanline and then repeat that for as many scanlines as you wish and you have a copperchunky screen. You can even use copper loops to get the chunky pixels to be larger than one scanline.Then you just write your pixels directly to the copperlist.

I usually set up a 1 bitplane screen and just change the COLOR01 entry, so that the palette changes won't bleed into the borders.

Here's the copperlist for a 200 scanline high screen

line    set   $4c3d
        rept  200
        dc.w  line,$fffe
        rept  40
        dc.w  COLOR01,$0000
        endr
line    set   line+$100
        endr

[sandruzzo]

@britelite

Thanks! Won't be better to use more planes in order to have less copper moves?

[britelite]

Originally Posted by sandruzzo

@britelite

Thanks! Won't be better to use more planes in order to have less copper moves?

You will always need one copper move per pixel (how else would you change the color of the pixel).

EDIT: You can use more planes to achieve smaller pixels than 8 pixel wide ones, but this will have some other restrictions instead. But I'll leave that exercise for you to figure out

[sandruzzo]

How the were able to get 2x2??? This is kind 8 pixels...

[britelite]

Originally Posted by sandruzzo

How the were able to get 2x2??? This is kind 8 pixels...

Not sure about 2x2, but 3x3 can easily be achieved on AGA with copperchunky. On AGA 2x2 resolutions are usually HAM c2p modes.

[sandruzzo]

Here about using more planes to have more colors...


http://ada.untergrund.net/?p=boardthread&id=442

[britelite]

Originally Posted by sandruzzo

Here about using more planes to have more colors...

http://ada.untergrund.net/?p=boardthread&id=442

And did you actually understand what you read?

[sandruzzo]

@britelite

More or less they use per load coppers' colors register to get full 57 move per scanline. Not so difficult to understand

[britelite]

Originally Posted by sandruzzo

@britelite

More or less they use per load coppers' colors register to get full 57 move per scanline. Not so difficult to understand

Okay, so then you understand that you won't reduce the number of moves required per chunky pixel by using more bitplanes, but that you can rather achieve better resolutions by incorporating bitplanes into the equation.

So, with all this information you should easily be able to get your own copperchunky running.

[chb]

On AGA you can have pretty much every pixel size you want, but you cannot get past the 57 or so CMOVEs per scanline. So a 200pix wide 2x2 copper chunky is possible, but not a 256 or 320pix wide one.

On OCS it's more complicated, as you do not have a lot of color registers to buffer the color changes. AFAIK 4x1 is possible with some trickery (and a narrow screen). There was a thread on ADA about that AFAIR.

[Antiriad_UK]

Anyone got a link to a demo to demonstrate what copperchunky looks like? I’m not sure I know what it is. Is it just spamming colour changes for a lores picture?

[ross]

Originally Posted by Antiriad_UK

Anyone got a link to a demo to demonstrate what copperchunky looks like? I’m not sure I know what it is. Is it just spamming colour changes for a lores picture?

https://eab.abime.net/showpost.php?p...9&postcount=11

A simple image rotation. I have the code somewhere .. maybe ..

[DanScott]

Originally Posted by Antiriad_UK

Anyone got a link to a demo to demonstrate what copperchunky looks like? I’m not sure I know what it is. Is it just spamming colour changes for a lores picture?

Essentially, in it's simplest form, yes... so you can easily do 8x1 pixel size in 12bit RGB...

For example in my Colombia 64k intro, the tunnels are using a method that gives a perceived 4x4 pixel size, although this is just a trick

[sandruzzo]

I'm thinking if its possible with scrollregister close the "gap" between pixels, by shifting bitmap after each chunky pixel, and get 1x1. AT LEAST on Aga

[britelite]

Originally Posted by sandruzzo

I'm thinking if its possible with scrollregister close the "gap" between pixels, by shifting bitmap after each chunky pixel, and get 1x1. AT LEAST on Aga

You don't need to scroll anything, you can just have a bitmap with 1 pixel wide stripes. Doesn't change the fact that you can only change 57 colors (pixels) per scanline, so that will leave you with a 57 pixel wide screen if you want to have 1x1 copperchunky pixels.

[sandruzzo]

I Can see it

[hooverphonique]

Originally Posted by Antiriad_UK

Anyone got a link to a demo to demonstrate what copperchunky looks like? I’m not sure I know what it is. Is it just spamming colour changes for a lores picture?

The final part of this is a coppper-chunky rotozoomer (shameless plug) : [ Show youtube player ]


Basically, all your classic copper plasma effects are a form of copper-chunky too

[britelite]

Well, maybe I should post one of my copper-chunky demos too

[ Show youtube player ]

[mr.spiv]

Riihimäki! wtf?!