Technical viability of this game design

Discuss technical or other issues relating to programming the Nintendo Entertainment System, Famicom, or compatible systems. See the NESdev wiki for more information.

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Bananmos
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Re: Technical viability of this game design

Post by Bananmos »

Oh, looks like there's an playable web version of the original arcade game here

Pretty cool technology... these pre-microprocessor arcade games have always fascinated me, as the effort to create the game logic makes any retro-development of even the early CPUs look like child's play in comparison. And I still find it incredible that the 1974 Wild Gunman was probably the first FMV arcade game.

Anyway, looks like the original arcade game has a very distinct split between sky and water, so I'd say go with the colour emphasis bits solution for splitting...
lidnariq
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Re: Technical viability of this game design

Post by lidnariq »

tokumaru wrote:IIRC, the NES has a black that isn't affected by the emphasis bits, so at least the border can remain consistent.
(tangent) Colors $xE and $xF are blacks that are unaffected by emphasis. All eight are the same black as color $1D if emphasis is off, but $1D is affected by emphasis.
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FrankenGraphics
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Re: Technical viability of this game design

Post by FrankenGraphics »

Bananmos wrote:Oh, looks like there's an playable web version of the original arcade game here
That's the museum where i took notes. :) The web version is pretty faithful, apart from from the scope being too fast-moving and less precise via mouse (and some other minor details like sound and light) That's something to concider when trying to translate the feeling of rotating manually to d-pad.

AFAIK the title "Morskoj Boj" was used for a number of games, including "battleship" and a board game. A 2 player "co-op or compete" version of the arcade game was named "Torpednaja Ataka" (pretty self-explanatory title).
Anyway, looks like the original arcade game has a very distinct split between sky and water, so I'd say go with the colour emphasis bits solution for splitting...
That's my reasoning too, after reading the discussion. I'm still on the fence if i want to keep that aspect true or add a little variation, like they did in Radar Mission. I suppose it could look good enough as long as no ship is intersecting the sky/water line, or as long as the intersecting colour is black.
Pretty cool technology... these pre-microprocessor arcade games have always fascinated me
They had plenty of that in their collection, for historical reasons. Mixed parts of mechanical, discrete, and just sometimes microprocessor topologies. I could upload a photo report in the general section if anyone's interested.
tokumaru wrote:I thought of that too. If the OP doesn't need complete control over the colors
A distinct feature of the arcade version is that the sky quickly fades to dark-red for about a second when something is hit. But emphasis may help with that, too, either by damping non-reds in the sky or changing bg0 to red-ish and damp reds in the water (which should be a little more dynamic, animation-wise and atari 2600 style). It's worth trying out at least!
IIRC, the NES has a black that isn't affected by the emphasis bits, so at least the border can remain consistent.
+
lidnariq wrote:(tangent) Colors $xE and $xF are blacks that are unaffected by emphasis. All eight are the same black as color $1D if emphasis is off, but $1D is affected by emphasis.
My understanding is that NES "empasis" is subtractive rather than true additive emphasis. If that's the case, is there enough colour value to subtract from $1D for the eye to detect a difference? Not that it matters if $xE and $xF are excluded, but for the sake of knowing.
Dwedit wrote:I'd say NOPE to any kind of mid-screen palette changing.
Yeah, that's super-far beyond my confidence level, to begin with. :shock:
Also, i only have two PAL units to do hardware tests on.
rainwarrior wrote:and you could even raise and lower the water level, which would be very cool for a submarine game.
I had this in mind and had hoped to find an easy way to do this! Besides diving/surfacing, a sinusoid function with varying amplitude applied to sprites and emphasis timing would yield a good sense of weather conditions (and bleed slightly into the domain of perception based game/difficulty mechanics) as the submarine should bob along rough waves when @ periscope depth.
rahsennor wrote:Can you widen the viewport so that the four "important" rows have no visible mask, like in the first image you posted? You could scroll just them and leave everything else stationary. That's 2 sprites per line for the sights, and only on those four rows.
That seems to be the only viable option for using sprites as masks. However, after reading this very helpful discussion, it seems i can get closer to what i want with BG masking sprites.
lidnariq
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Re: Technical viability of this game design

Post by lidnariq »

WheelInventor wrote:My understanding is that NES "empasis" is subtractive rather than true additive emphasis.
From an RGB point of view, that's mostly accurate. Each emphasis bit will shift the full set of colors in the YUV/YCbCr colorspace towards its own specific coordinate. Combinations of bits are not purely linear.

If that's the case, is there enough colour value to subtract from $1D for the eye to detect a difference?
This is where the analog-ness of CVBS (composite) makes everything a big fat hairy mess.

On many CRT TVs, $0E black isn't "no light". But it is the darkest that the signal is ever supposed to be.

Using $1D as the background color and turning on emphasis will either be "blacker than black", causing the blacks to look "richer", or it might will tickle the dynamic range compression and make every other color brighter, or both. Plus it might also tickle the same problem as using color $0D, causing a loss of hsync in some TVs.
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rainwarrior
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Re: Technical viability of this game design

Post by rainwarrior »

Bananmos wrote:Yep... emphasis bits to darken the background comes to mind - although the color change quite subtle, and affects everything rendered (may not be a problem depending on the game's design)
That's a good idea!
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Dwedit
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Re: Technical viability of this game design

Post by Dwedit »

My TV can even display 0D (blacker than black) with emphasis bits set as a shade distinct from the other blacks.
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