Wich one of these two Prince of Persia you prefer?

[Eagle]

You have to do a special mask for each animation.

If you make them bigger by one pixel then you will get black outline.

 

 

 

But it will cost a lot of memory.

 

Eagle

[Jacques]

Memory shouldn't be a problem? It's working on 512 KB cart on C64 after all

[Rybags]

C64 doesn't do softsprites so the masking is saved there.

 

Masks for softsprites = same memory again as the softsprites themselves use.

 

But if there's sufficient RAM free, those masks can be constructed from the softsprite data although cutouts (eyes) would need extra data and processing. Although all that's going to do is save ROM space. With a 1 Meg cart, ROM space probably won't be an issue.

[José Pereira]

PMs don't have "background colour", the "0" data is always transparent.

 

You get "forced background colour" in softsprites by having it defined in the mask data.

 

That was my way of explaining...

But you can say that you still have it.

 

For example:

GFX byte 01,10,11,01

SPRITE byte: 00,(01,00,10) inside '()' are the sprite shape where I'll have the PM overlay

SPRITE Mask: 11,(00,00,00)

And I want SPRITE over GFX

 

GFX. byte: 01,10,11,01

<AND>

SPR MASK: 11,00,00,00

_____________________

Resulting in: 01,00,00,00

<OR>

SPRITE byte:00,01,00,10

_____________________

Final result: 01,01,00,10

 

Exactly the soft sprite over GFX and with the (00) on it's shape that would have the PM colour overlay.

 

 

EDIT: This is that MASK on Eagle guy's picture, I think...

Edited November 9, 2011 by José Pereira

[Eagle]

Yeeeee, but they don't need preshifted soft sprites and masks.

 

Approx: 110 animation * 200 bytes each * 4 preshifted * 2 (masks) =176k

And this is just the beginning.

[Rybags]

And add the PM parts to the mix.

 

Even though it's a fair bit less data, there's still masking requirements (piers) that are different to how PF is done, although a table lookup could suffice but will be slower.

 

PMs, less data but each animation will probably need offset/length information.

[José Pereira]

Yeeeee, but they don't need preshifted soft sprites and masks.

 

Approx: 110 animation * 200 bytes each * 4 preshifted * 2 (masks) =176k

And this is just the beginning.

 

 

Can I understand 'preshift' like 'pre-done' with all possible soft sprite bytes interaction/combination with screen gfxs?

 

If it's this it would be thousands of shapes/impossible, I think?

Edited November 9, 2011 by José Pereira

[Eagle]

Yeeeee, but they don't need preshifted soft sprites and masks.

 

Approx: 110 animation * 200 bytes each * 4 preshifted * 2 (masks) =176k

And this is just the beginning.

I forgot to mention that these are the calculations for only one direction.

This means that it will take twice as much memory for character animation.

176k*2= 352k !!!! :D

Edited November 9, 2011 by Eagle

[José Pereira]

Yeeeee, but they don't need preshifted soft sprites and masks.

 

Approx: 110 animation * 200 bytes each * 4 preshifted * 2 (masks) =176k

And this is just the beginning.

 

 

Can I understand 'preshift' like 'pre-done' with all possible soft sprite bytes interaction/combination with screen gfxs?

 

If it's this it would be thousands of shapes/impossible, I think?

 

 

Stupid I was, of course that if shifting is the outside Area of a soft sprite untill it's again on the next byte boundary then it would need to be this:

http://wordpress.ani...hifting-sprites

Edited November 9, 2011 by José Pereira

[Jacques]

Stupid I was (...)

 

Yoda?

[José Pereira]

Stupid I was (...)

 

Yoda?

 

Can't find the translation for what you are calling me in any language...

It sure isn't a good thing

[Eagle]

Yoda => Star Wars

[José Pereira]

Yoda => Star Wars

 

I would never think in that guy... but what he is related with me?

Oh, forget...

At least I went to Yoda character explanation in Wikipedia and discouver there's a Dark side, A Darth one called 'Sid...'.

No war, it's not me but probably the Author was 'Anti C64/SID'...

 

"In Star Wars Episode III: Revenge of the Sith, set three years after Attack of the Clones, Yoda leads the Jedi Council in pursuing the mysterious Sith Lord Darth Sidious"

 

Yoda vs Dart Sid...:

Edited November 9, 2011 by José Pereira

[emkay]

Yoda => Star Wars

 

I would never think in that guy... but what he is related with me?

 

Grammar irrelevant is!

[Eagle]

No. I see that you were not a fan of Star Wars.

Yoda spoke in this way. "Stupid I was" instead of "I was stupid."

[popmilo]

You do not have to explain what it does?

No, not really

 

It all comes down to amount of data that needs to be processed...

Not really many shortcuts that we can take...

 

Zero page and self modifying code can save few cycles if used appropriately.

 

I noticed one thing though:

Simple LDA sprite , ORA screen, STA screen doesn't look that bad with Prince's background graphics.

As most of Prince's color is white, we could choose colors for bitpair 11 to be white so that even when prince walks over large piece of colored background it would still be white.

 

Turns out that maybe masking for prince is not needed - what do you think ?

 

ps. Masking for PMs would be needed for certain colors off course.

But as that is special case already (1 bit per color pixel -> 1 byte of PM = 2 bytes of screen) we can work at it separetly.

 

pps. Masks for soft sprite parts could also be made with lookup tables - no need for 2x data...

For every pixel that is 00 mask would be 11 and for any other it would be 00.

Black color can be achieved with masks for PM parts ...

 

Now, this is all coming from perspective of my wish to fit something like this into my unexpanded 800Xl.

If there is no need to save memspace - unroll everything !

 

ppps. Or something like that - I'm just brainstorming and throwing ideas here

[José Pereira]

Yoda => Star Wars

 

I would never think in that guy... but what he is related with me?

 

Grammar irrelevant is!

 

Exactly that 'Grammar irrelevant is'

And I was thinking 'calling a name to me someone was'

[José Pereira]

As most of Prince's color is white, we could choose colors for bitpair 11 to be white so that even when prince walks over large piece of colored background it would still be white.

 

 

Psst... Don't do that that as it would turn the Enemy get a skin colour impossible

See if the White can be one of the other bit-pairs...

[popmilo]

Psst... Don't do that that as it would turn the Enemy get a skin colour impossible

See if the White can be one of the other bit-pairs...

I'm just thinking - maybe we don't need to mask whole 100% of large sprite ?

Only the parts with 'special' colors need masking.

 

ps. "Front" of background is another topic - pillars and grid are "other" kind of soft sprite. They need to mask everything behind them - even PM.... That should be interesting to code

[José Pereira]

Psst... Don't do that that as it would turn the Enemy get a skin colour impossible

See if the White can be one of the other bit-pairs...

I'm just thinking - maybe we don't need to mask whole 100% of large sprite ?

Only the parts with 'special' colors need masking.

 

ps. "Front" of background is another topic - pillars and grid are "other" kind of soft sprite. They need to mask everything behind them - even PM.... That should be interesting to code

 

 

Be free to think.

But White would not be (11) right?

That would be the great trouble that I can't think how to...

[José Pereira]

Don't know if this helps (or probably would even get things hard, but it's the reality we have now):

 

The guys soft sprite in their 'real shape and where's also could be or not PM(s) overlay(s)' use:

PRINCE: 00,01,10

ENEMY: 00,11,10

If having White as (10) but white can be also (01)...

 

This way PRINCE never use (11) and ENEMY never use (01)

[popmilo]

But White would not be (11) right?

That would be the great trouble that I can't think how to...

You are right Jose. I forgot about combinations needed for prior0 to work...

Have to think about it... Till than I'll implement masking and see how it works...

[pseudografx]

Finally, Mr.Sid has released the disassembled Apple II sources of PoP: http://www.twinbirds.com/prince_of_persia/prince_of_persia_apple2_disasm.zip

[STE'86]

You shouldn't need any masks for the sprites. the transparent separators for the legs etc will work perfectly adequately without masks, as they do on the c64 version, because, predominantly the sprite is drawn over colours darker than itself (black usually). The eye can be got around in the same manner that Andreas did it, presumably. by making the hair and the eye dark brown instead of yellow.

 

Steve

[Rybags]

They'll most likely be softsprites, so masks needed for all of them in that case.

 

The OR method just won't work with this game - there's the possibility of the kid moving over any possible playfield colour. The only way it'd work is if only the clothes colour is Playfield and PMGs are used for all other aspects of the kid.