NeoGeo Metal Slug conversion to Amiga 500 - madman task ;-)

[robinsonb5]

Originally Posted by sandruzzo

Since I like made stuff, even very slow, I've started stuff.

Excellent - keep it up, and show us the progress as it happens - how long it takes doesn't matter. Just have fun with the project - it's guaranteed that you'll learn loads in the process, whatever the outcome.

[sandruzzo]

@robinsonb5

Words to live with! Unfortunatelly, I had to stop it, cos my limits with gfx...

Btw, even on Pc, I have it....

[DamienD]

Off topic posts removed sandruzzo and saimon69.

[sandruzzo]

My Idea, was to have 256*192 32 colors, and use sprites for parallax. I had difficult time since gfx. Now, I'm gonna set the whole project for good: drawers, directories(!?) and resources.

[sandruzzo]

I've set base project which is like this: I have main directory called Metal Slug with inside sub dir:

-MetalSlug
| - InGame
| - Menu


- InGame
|- Gfx
|- Sounds


- Gfx
| -Levels
| -Maps
|- Enemies
|- Player


- Sounds
| -Musics
| -Sfx


Menu directory is more ore less like Ingame, Into MetalSlug, I've sources and exe. It needs a little bit of polish, but more or less, is good.



upload photos

[sandruzzo]

Screen Area will be 256*192, but actual size is bigger: I need to add 32 pixel for scrolling, plus 32 for guard band clipping, and More size in Y direction to be able to move into y direction, not totally free like turrican, but with a good range of motion.

This will be for 2 buffer, third will be less big, since I don't need Guard band clipping.

[DanScott]

I think Metal Slug should definitely be achievable on Amiga, with that directory structure

[sandruzzo]

Speaking about code, I'll work around scrolling first, and I want try to drive blitter with copper in order to free cpu as much as possible. To optimize registers' setup, I can skip some of them by arranging tiles' sheet.

If I use one file for each tile, I can avoid, after first blitting, the others' source register setup, since blitter will point exactly a the start of the next tiles' bitplane.

Or, if I did the math well, keep all the tiles into one sheet and, first blit all the tiles plane by plane, since destination register, at the end of each blit, should point exactly , a the start of the next screen tiles' position.

I hope it's clear.

[DanScott]

Metal Slug will work at 25fps

[Retro-Nerd]

Yeah, in a 160x100 programmed image size.

[sandruzzo]

@DanScott Try to push 50hz, or mix between 50hz (scrolling) and 25hz (enemies out of focus).

@Retro-Nerd

[Tigerskunk]

Originally Posted by sandruzzo

My Idea, was to have 256*192 32 colors, and use sprites for parallax. I had difficult time since gfx. Now, I'm gonna set the whole project for good: drawers, directories(!?) and resources.

32 colors is imo a good idea, since that will make gfx conversion a very easy job.

Just did a quick conversion, and this is the game in 32 colours.

If you deduct the blended colors for the HUD, and do that with some copper shit, you'd even be more colourful than that.

I'd skip the sprite parallax, though. You'll slow the game down too much with that and almost certainly have to go 25 fps, if not lower.

[sandruzzo]

@Steril707

That's why I'm gonna do some test. So far, working on allmost "8 way limited" scrolling, with triple buffer. Each tile will be 16*24, in order to lower cpu and blitter usage. 16*32 would be even better, but we could lost a lor of memory to build tiles' map.

In the middle there is balance...

[sandruzzo]

Now, using this map: it's 640x240 pics that i'll use to pic up tiles and simulate scrolling.

[sandruzzo]

Like I said before, I can "only" set in place games' engine, since in order to do the whole game, we still need a good solid Game Design, Build Around Amiga.

Let's see were we can go..

[LongLifeA1200]

I thought you guys wanted the original, not the GBA version which is not even worthy of being the original's shadow.

Originally Posted by LongLifeA1200

8+7
I'm stuck with 7 foreground playfield colors for all moving objects. Very low for a conversion like this.

There was something I left out of that summary. 8 Hardware sprites that share 4 sets of 3 color palettes.

So it's more like 8+19 or 22 depending on whether you want to combine hardware sprites to make a 32 pixel wide sprite of 15 colors.

Originally Posted by LongLifeA1200

Yet, if the framerate stays steady at 50-60hz, I can "flicker" two colors in the same spot to give the illusion of a third color. The two colors have to come from the 7 available and they have to be of the same brightness. Is that right?

Moving objects have to be stationary (not move) for 2 frames for the "flicker"-cycle to complete.

For the background playfield, I can use a separate 8 color palette, however, these can be changed multiple times within a single frame of the screen. When and how often, though? What would the x(horizontal),y(vertical) coordinates look like? Starting at 0,0 when would the next palette change occur?

Originally Posted by sandruzzo

...
you change 8 colors every 8-16 lines
...

While 'Agony' gets referenced a lot as an example, I looked in earnest for opportunities to change the palette every 8 lines of the background, but unlike Agony, the problem was not only that the majority of the 8 colors were in demand the entire length down, but also that new colors were demanded on the same line when you scrolled the background. Besides removing objects in the background at various heights, less interesting backgrounds that act as filler giving the palette a chance to change in preparation for the next more-interesting background ahead, means more work and time needed.

[sandruzzo]

@LongLifeA1200

I think we need to do a Game Like MS but not a strick port. I've switched to 32 full colors so, we'll be easier to do a good Gfx.

[sandruzzo]

Vertial Blitting allmost done. Now in motion!

[sandruzzo]

Left and right scrolling on place. I have to polish some stuffs and then up and down scroll. Remember I'm working on game engine, no the actual Game..


image share

[Retro1234]

Why set yourself up to fail like this ?