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Theory on graphics


emkay

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rainbow_islands_01.gif

 

You see the C64 original picture...It's only for demonstration purpose...

 

Doesn't it look awesome colorful?

Does it? Hum.. It's 16 colors only...The ATARI has 128 colors available in that resolution. So after creating this picture on the A8 you should be able to do some gamma correction ;)

It is convertable onto the A8... maybe not pixelexact but you can enhance it with 128 colors... but i am really to lazy for it.

 

So this time I'd like to analyze the image.

 

 

The first step ist to make clear that those pictures always having 16 colors at max. and average 8 colors per line.

So all you have to do is to manage 16 colors on the A8, that is able to show up more than 16 colors per scanline.

 

"But the colors" are only changable in ranges" You say?

When analyzing the picture above, you see only changed colors in ranges, because there ARE always only 16 colors available.

 

Another point is, that even the C64 has a real of 160 dots in color-resolution horizontally.

 

To think around....

after setting one of the 160 dots, you have one less to set...

And there are always redoable logics to rebuild the color ranges by cycle counting, that G2F is already doing.

 

Shortly:

To convert such "colorful" pictures a softwarefilter may be very helpful

 

It could do a colorcheck every scanline and to set the raw color ranges by raster dividing.

This may be overlayed by PMg and finalized by the available playfield colors.

 

 

[later more...]

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I've extracted two lines out of the picture and spreaded it to view the actual linecontent

 

Rainbow-Bee is one line of the upper picture where the bees are besides the rainbow.

It has 10 colors

 

 

Belly is one line of the "Hero's" belly with a knob of his trouser...

It has 11 colors

 

 

 

The next step is how to rebuild this "Bit-combinations" with G2F...

Very important by doing so, is to keep in mind that you cannot change every register in every scanline.

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Hi Emkay, that'a an interesting approach. The Rainbow Islands picture is certainly one of the C64 pictures that stands out. Definately one of the best C64 pictures. Normally I would examine the pictures and break them down into elements, if this could be done by a software filter I would be way impressed.

 

Here's another conversion I was working on a while back. It's Hunters Moon from the C64. I still have some thinking to do to complete this but I thought I'd post a WIP. The only thing I can't fix yet is on the Thalamus logo on the right there is a light blue raster showing. It's nearly a pixel exact conversion although the planet things on the left of the big planet should be in red. Without a midscanline change of 3 PF cols I wouldn't be able to achive this though.

 

Very interested in your ideas Emkay, hope that someone can find a way to make this idea into a new "bit-combinations" technique

post-4724-1082198771_thumb.png

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Hi Emkay, that'a an interesting approach. The Rainbow Islands picture is certainly one of the C64 pictures that stands out. Definately one of the best C64 pictures. Normally I would examine the pictures and break them down into elements, if this could be done by a software filter I would be way impressed.

 

 

That's mainly the overall cause for this thread

 

 

 

Very interested in your ideas Emkay, hope that someone can find a way to make this idea into a new "bit-combinations" technique

 

This "bit-combinations-technique" is a reliable solution when the image is relieable.

On the other hand ... the better the image the less is a pixel- error recognizable...

The Picture has multiple errors in it when you try to look at it on a big screen, but the overall image is "very nice"....

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In another thread we discussed C64 to ATARI conversions...

 

 

download.php?id=12169

 

 

The lower image shows TMR's Reaxion on the C64

The upper image is a "Hand built" screen with charmode and Gprior resulting colors.

As you might see by the pink colored players... if only one player more was available you could do a 1 to 1 conversion from the C64.

Only the registers of 710 and 711 are filtered and enhanced by PM 1 and 2.

PM 3 and 4 (grey) are always behind 710 & 711 but in front of 708 & 709.

At the end Multiplexing PM1 and 2 over Antic 4 (or 5) will give the most flexibility in color enhancing.

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The result misses two colors that are used only once or didn't enhance the image...

To be fair... G2F does not support PM multiplexing

 

Really? :roll: I remeber I asked TeBe about enhancing amount of sprites, and he said it is possible but it's nearly useless as well.

You can use certain assembler command for making more sprites in raster

but usually it takes too much time to be effective (or something like that). :|

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The result misses two colors that are used only once or didn't enhance the image...

To be fair... G2F does not support PM multiplexing

 

Really? :roll: I remeber I asked TeBe about enhancing amount of sprites, and he said it is possible but it's nearly useless as well.

You can use certain assembler command for making more sprites in raster

but usually it takes too much time to be effective (or something like that). :|

 

 

This must have been at a time before raster changing in G2F was done....

 

Because to set a block of 8 chars like

 

#.#.#.#.

 

with Raster dividing is simply not possible.

Setting the player to a new position and/or the shape .... will make it possible....

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One way to get fantastic photos on an atari is to do video blending.

For this you have a brightly lit picture, or better yet a rear projection screen, and a slide projector.

You position a sheet of glass in front of your monitor at a 45 degree angle, so you see the monitor through the glass, but the glass reflects the photo or projected slide.

 

You build it all into a cabinet. Think they did something sort of like this on some arcade machines.

 

If the reflected image is about the same brightness as the monitor screen, it will seem like both are the same screen to your eye.

 

The glass can reflect from the right or left, but you might also fix it so it reflects what is just below the monitor or above the monitor, so you can make your cabinet smaller.

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