Good explanation why half-brite is too slow for game engines?

[alain.treesong]

Originally Posted by Galahad/FLT

Pinball Dreams is EHB, but for that game, its not particularly stressed out.

Uses hardware sprites for the ball, the table is complete in memory, and the scrolling up and down is done by changing bitplane pointers.

Lots of the animations are simply colour changes, so this is an area where EHB really shines.

No wonder then it wasn't converted to Megadrive, whilst that machine can display 64 colours, its only has a palette of 512 versus the 4096 of the Amiga, so it wouldn't have been as well shaded on Megadrive.

So I looked with Winuae. Pinball dreams is effectively in EHB. The sprites are used for the balls and only for that as I can see. The both "flippers" are managed by the blitter.

Of course all of the table is in memory but I suppose there are many objects managed by the blitter to handle the display priorities between the ball and some elements like the bumpers. Moreover without speaking of the problem of the physic of the ball, there is well animated score panel (yet better in pinball fantasies). So it is not probably so easy to keep the 50 fps and probably required a good coding skill at the time.

[jotd]

upper score panel may not use EHB but only 8 or 16 colors.

[Galahad/FLT]

Originally Posted by alain.treesong

So I looked with Winuae. Pinball dreams is effectively in EHB. The sprites are used for the balls and only for that as I can see. The both "flippers" are managed by the blitter.

Of course all of the table is in memory but I suppose there are many objects managed by the blitter to handle the display priorities between the ball and some elements like the bumpers. Moreover without speaking of the problem of the physic of the ball, there is well animated score panel (yet better in pinball fantasies). So it is not probably so easy to keep the 50 fps and probably required a good coding skill at the time.

Sorry, but Pinball Dreams is easily keeping within 50fps, hence why there is never any slowdowns.

The score panel is not EHB its changed by the copper, it's a simple display that isnt stressing the Amiga one bit, other than flippers and masking the ball when it gets obscured by parts of the table, the blitter really isnt doing a whole lot, there are not a lot of things it needs to blit.

It's why it can be EHB, because technically, as in workload, the hardware is easily able to keep up.

Even the ball physics cant be stressing the CPU out that much (though admittedly it's the most complex part of the game), the lowly CPU in the SNES was able to cope without problems in that area.

Pinball Dreams is a perfect example of EHB being used to great effect because it isnt so demanding

[alain.treesong]

Originally Posted by Galahad/FLT

Sorry, but Pinball Dreams is easily keeping within 50fps, hence why there is never any slowdowns.

The score panel is not EHB its changed by the copper, it's a simple display that isnt stressing the Amiga one bit, other than flippers and masking the ball when it gets obscured by parts of the table, the blitter really isnt doing a whole lot, there are not a lot of things it needs to blit.

It's why it can be EHB, because technically, as in workload, the hardware is easily able to keep up.

Even the ball physics cant be stressing the CPU out that much (though admittedly it's the most complex part of the game), the lowly CPU in the SNES was able to cope without problems in that area.

Pinball Dreams is a perfect example of EHB being used to great effect because it isnt so demanding

Obviously the scoreboard is not in 64 colors. There is a redefinition of the registers by the copper of course. What I wanted to say is that there's a lot of management of things in the game and so it's not just a sprite running around in a screen of about 500 pixels high.
Generally speaking, even if it's not "Shadow of the Beast 3" or "Stardust", many of the Amiga's particularities have been well exploited in this game. So in the end for the Amiga it is indeed a textbook case of the use of the EHB mode.But it's still well done and probably not that trivial.
Of course the Amiga can do more extraordinary as a global technical rendering (but rarely as a global result)

[lionagony]

Originally Posted by roondar

Dynamically switching bitplanes on and off is such a neat and Amiga specific trick. I should really look at Powder to see what the end result looks like. Makes me wonder if more games did that?

Thinking about it some more, if you don't need the 6th bitplane for anything but shadows/transparencies you would be able to save a big part of the cost (i.e. you could get away with blitting only 5 planes for your objects). You'd still lose out compared to doing straight 5 bitplanes, but not by as much as full EHB.

The downside would be that you'd have to have a pretty static 6th bitplane for that to work well. Interesting idea though. Might also work for 5 bitplane screens.

Do you think this scenario could work? A static 6th bitplane that is prevented to scroll by the blitter but acts as a non moving parallax layer and then the objects are only blitted in 5 bitplanes. Would that be a way to get parallax without dual playfield, would it be fast enough?

[ross]

Originally Posted by lionagony

Do you think this scenario could work? A static 6th bitplane that is prevented to scroll by the blitter but acts as a non moving parallax layer and then the objects are only blitted in 5 bitplanes. Would that be a way to get parallax without dual playfield, would it be fast enough?

No, this can't work.
EHB mode is special, it has no color registers, so even if you created a 'blitter static bitplane' all you would have is a 'shadow' on all the other bitplanes, based on the 'texture' of the sixth bitplane; basically a mask.

Sure you can create interesting effects, but that's not what you want to do, which can only be done for <=5 bitplanes enabled.

[lionagony]

Originally Posted by ross

No, this can't work.
EHB mode is special, it has no color registers, so even if you created a 'blitter static bitplane' all you would have is a 'shadow' on all the other bitplanes, based on the 'texture' of the sixth bitplane; basically a mask.

Sure you can create interesting effects, but that's not what you want to do, which can only be done for <=5 bitplanes enabled.

Okay, so even if one of the colors in the 32 color palette was black and then the EHB gave you a grey from that you couldn't use that to draw say a 1 color static grey mountain range in the background?

[ross]

Originally Posted by lionagony

Okay, so even if one of the colors in the 32 color palette was black and then the EHB gave you a grey from that you couldn't use that to draw say a 1 color static grey mountain range in the background?

EHB works the other way around.

A 1 bit in the sixth biptlane lowers the RGB value in the color register (technically every 4bit of the components has a >>1).
A 0 bit leaves the color unchanged.

[saimon69]

EHB is so reminescent of my ZX spectrum days that i felt back home

[Estrayk]

simon the sorcerer (OCS) I think he was also in EHB, can anyone confirm this?

[malko]

Originally Posted by Daedalus

[...] I'm working on a game at the moment that originally used EHB, but was simply too slow for what I needed to do. With a very minimal impact on the artwork, reducing it to 32 colours and constructing a palette with strategically-placed half-brightness shades, I was able to achieve the very same effect with 5 bitplanes - blitting to the 5th bitplane created a shadow effect, and the difference in speed was enough to get what I needed out of the game. 4 bitplanes would be even better speed-wise of course, but then the significantly reduced colours would impact the artwork more than I would like.

What is the name of your game ? Is there any thread, video or demo we can put our eyes or hands on ?

[dlfrsilver]

Originally Posted by Estrayk

simon the sorcerer (OCS) I think he was also in EHB, can anyone confirm this?

Simon is indeed EHB 64 colors on A500.