32 color shmup demo

[Master484]

Also maybe consider capping your framerate at the lowest acceptable setting to avoid slowdown, I'd rather play at 17fps with no slowdowns than 25 fps if it missed even the occasional frame.

Yes, for an action game a steady frame rate is a must. Right now the frame rate is capped to 25 FPS I think. But I noticed that actually the demo speed starts at 17 FPS on an A500, and not 25 FPS as I thought. So when it now runs the fastest, with just a few enemies on screen, that's actually 17 FPS. But the 16 color prototype starts at 25 FPS. And A1200 too can run the 32 color version at 25 FPS.

And drawing the bigger boss enemies with "Block" is indeed a good way to speed things up. And if Block isn't possible, then the other option is to drop the frame rate during the boss fight, that is still better than slowdown.

---

Although I think that a real "bullet hell" would need 50 FPS, or at least a very steady 25 FPS in order to look legitimate. And sprite multiplexing is the only way to achieve that on Amiga, and only one game has really done it at 50 FPS (Mega Typhoon).

But of course many of the best arcade shmups are not bullet hells; games like Varth, Grid Seeker and 1941 don't have that many bullets on screen, and with an engine like this, I would imagine that they could run at a steady 17 FPS at least, and surely so on an A1200, if not on an A500.

---

And also for other game types this drawing system could work very well. For example in a Red Alert style RTS, where hundreds of tanks need to be drawn every frame; something like this is surely the right way to do it, and slowdowns wouldn't matter so much.

And also 2D based pseudo 3D shooters, like Space Gun, Death Mask and Backlash, for these kind of games too it would make sense to draw the whole display every frame. If fact I have speculated that this would be the right way to make a fast first person shooter on the A500; do things like in Death Mask, but on full screen, faster, and with better animation and controls. And in a 1st person shooter even 17 FPS looks smooth.

[Master484]

The 16 color version is now ready, and the ADF has been added to the attachments of the first post in this thread.

In the beginning you can choose between 16 or 32 color mode, and the program then loads either 16 color or 32 color gfx.

Other changes include explosions for the enemies, turning animations for the player ship, and a lot faster collision detection system.

Performance is as follows:

---
---

A500 -- 16 color mode

FPS starts at 25 FPS

Enemies on screen without slowdown: 14
Bullets on screen without slowdown: 25

A500 -- 32 color mode

FPS starts at 17 FPS = constant slowdown

Enemies on screen without further slowdown: 11
Bullets on screen without further slowdown: 24

---
---

A1200 -- 16 color mode

FPS starts at 25 FPS

Enemies on screen without slowdown: 19
Bullets on screen without slowdown: 42

A1200 -- 32 color mode

FPS starts at 25 FPS

Enemies on screen without slowdown: 14
Bullets on screen without slowdown: 22

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So, not surprisingly, A1200 in 16 color mode runs the fastest.

It could actually achieve 50 FPS I think, but the FPS is limited to 25 FPS.

Especially the bullet amount is good in A1200 16 color mode, and interestingly it can handle a lot more bullets than enemies, but only in 16 colors.

The bullets are 8*8 and the enemies are 32*32. When moving from 32 colors to 16 colors, we can draw 5 more enemies, but bullets we can draw 20 more.

So on A1200 when colors are reduced, we gain a 35 % increase in the enemy amount, but a 100 % increase in the bullet amount.

I don't completely understand why this happens, maybe the time taken by the "blitter start" operation is much less in 16 colors than in 32 colors? And so the numerous smaller blitting operations would gain relatively more benefit when the color amount of the blits is reduced? This is just a guess though.

---

But anyways, a reasonably action filled shmup is possible at 25 FPS, on A1200. But to be safe, the frame rate should indeed be locked to 17 FPS, because this is the speed that the A1200 can firmly hold at almost all times.

I counted that 40 enemies are needed to make the 16 color version to drop from 17 FPS to 14 FPS, on A1200.

And when slowdown does happen on a game the runs at 17 FPS, we only get a small drop from 17 FPS to 14 FPS. And this is hardly noticeable, only 3 frames per second are lost, compared to the 8 frame loss that happens when 25 FPS drops to 17 FPS, or the massive 25 frames that are lost when 50 FPS takes a dive to 25 FPS. This is why games like Xenon 2 seem to be maintaining a "steady frame rate" despite the screen being full of stuff.

[Anakirob]

Looking quite promising so far. I do hope you take my suggestion of taking a SWIV style approach to level design and use QAmiga to load data on the fly without braking the display. If you're skipping 3 frames anyway that should give you enough time to load a reasonable amount of data between display refreshes, even from floppy. And I'm not sure, but you may possibly be able to multitask data loading with game logic routines if you're in QAmiga mode

[Master484]

Looking quite promising so far. I do hope you take my suggestion of taking a SWIV style approach to level design and use QAmiga to load data on the fly without braking the display. If you're skipping 3 frames anyway that should give you enough time to load a reasonable amount of data between display refreshes, even from floppy. And I'm not sure, but you may possibly be able to multitask data loading with game logic routines if you're in QAmiga mode

I have used QAmiga mode before in my other projects, and it's a good way to load more stuff into the program, but I think there would be some problems if we wanted to use it for real time dynamic SWIV style level loading.

One problem is that sprites at least only work in Blitz mode, and I think some other commands too were Blitz mode only. And jumping back and forth between Blitz and QAmiga modes in the middle of gameplay is not recommended because of the 5 second "safety wait" that has to be made when entering Blitz mode after file loading. Blitz manual strongly recommends this 5 seconds wait, so I have always used it, despite the fact that even the demo examples in the Biltz disk simply seem to ignore this safety time, and jump straight to Blitz after loading their stuff.

But even if all gfx, sound and joystick read commands would work fine in QAmiga mode, so that the whole game could run in QAmiga, I think everything else still stops during file loading. Level data could maybe be loaded in a few frames, but big graphics files would be too slow. And in a game like this each level needs to have different graphics. So all gfx files would need to be broken into smaller parts and maybe be compressed too, and then loaded and uncompressed in the background before the next level part starts.

This all might be possible somehow, but it would be complex and hard to make.

So I think I'll load stuff in the traditional way. And I think it's good to give the player a rest between levels, so that he can relax a little bit and listen to the sounds of the disk drive.

[idrougge]

Safety wait is for the drive motor to stop. SWIV doesn't stop the drive motor.

[Master484]

Safety wait is for the drive motor to stop. SWIV doesn't stop the drive motor.

Ok good to know.

I think in Final Fight too the drive motor stays on during the game, and it too dynamically loads new level data from the disk, just like SWIV.

[Master484]

Made an updated version again. ADF has been added to attachments of the first post of this thread.

New stuff in this version:

1.
Bigger 256*208 game area + 256*16 status panel at the bottom.

2.
Speed locked to 17 FPS, and color mode is now 16 colors and can't be changed anymore.

3.
Enemies and background share the same 16 colors, but Player is a sprite so it has it's own 16 color sprite palette.

4.
Two new enemy types added, press 4 and 5 to generate them. The second one is a "boss" enemy and fills most of the screen.

5.
Added music to the background, it's the "two channel" mod made by LordsOfChaos that was also used in the Megaman X demo.

6.
Also greatly improved engine speed and fixed some animation issues.

---

Approximate object amounts on screen at 17 FPS without slowdown:

A500

Small bullets : 64
Normal Enemies : 34
Big Enemies : 15
Huge Boss Enemies : 4

A1200

Small bullets : 110
Normal Enemies : 48
Big Enemies : 20
Huge Boss Enemies : 6

---

The music plays from the same VBlank interrupt that handles the sprites, so it never slows down. However, due to the slowness of the PlayMed command, this delayed the "Show" command that happens after the VWait, and this caused graphics flashing.

So, as a solution I made a system where the PlayMed is only executed from the interrupt during frames 1 and 2. And when frame 3 ( 17 FPS "Showtime" ) arrives and it's time to switch Bitmaps with "Show", at this frame the interrupt doesn't execute the Playmed, but instead it's executed in the main loop after the Show command.

Even 100 boss enemies on screen won't slow the interrupt; sprites and music still run at 50 FPS.

[Frog]

this project really sound interesting !
The Graphics are nice too, I appreciate these colors saturated.

[Anakirob]

Is 17 FPS the pace that Xenon 2 moved at? Or was that as low as 12.5? And how much time do you have left on your third frame? Enough to blit arial objects to a single EHB bitplane? Shadows would really make this game pop and was something that the Amiga did really well. I like the boss, I have yet to see it moving though. A youtube clip might be nice now there's sound.

And have you considered making it NTSC compatible? The slightly smaller screen could give some small improvement and slightly faster refresh makes all the difference when dropping more than one frame. In one demo I did with DisasterArea with Blitz we checked the screen mode and adjusted the height of the copperlist accordingly so it was near the top if NTSC was detected and in the middle for a widescreen effect when PAL.

Also, copper gradients have like no overhead once set up and can really spice up something like a status panel.

And finally, as well as bullets, I imagine that those small bobs could be small enemies too.

[Amigajay]

Love these side projects of yours! Though i hope one of them does become a game one time!

[Master484]

Is 17 FPS the pace that Xenon 2 moved at?

Yes, 17 FPS is the standard update rate in Xenon 2, and it keeps it up quite well, although slowdown can happen in some points if I remember right.

Lethal Xcess is another shooter example that runs in 17 FPS mode, and it has lots of bobs and bullets all the time, especially on later levels.

Right now this engine can handle about the same amount of BOBs as Lethal Xcess, which is enough for a decent shmup.

And how much time do you have left on your third frame?

At low to average BOB amounts there is lots of steam left...about one entire frame in fact. So making the game run at 25 FPS would also be possible, although then it could display less BOBs.

Maybe I'll actually try to make it 25 FPS with a frame skipper that would activate when the action gets too hot...it would look a lot smoother that way.

I don't know about the shadow effects though, it sounds like advanced stuff that I can't code. And also I think this will be a PAL game, I'll worry about NTSC compatibility once/if this ever becomes a full game.

Also, copper gradients have like no overhead once set up and can really spice up something like a status panel.

And finally, as well as bullets, I imagine that those small bobs could be small enemies too.

Yes, Copper will be surely used. I also have some cool ideas about mid-game palette swapping to give enemies and backgrounds more varied colors, for example the greens of the forest are no longer needed once the forest ends, and so they can be changed to something else and so on.

And about the small enemies, they would indeed be as fast as the bullets now are, and the engine should be able to handle large 16*16 enemy attack waves with ease.

Love these side projects of yours! Though i hope one of them does become a game one time!

There is always hope lol.

[Anakirob]

Originally Posted by Master484

I don't know about the shadow effects though, it sounds like advanced stuff that I can't code.

BitplanesBitmap is the command to handle an individual bitplane as a separate bitmap object if I recall correctly, from there it's pretty simple

[Anakirob]

Xenon 2's main draw card was its licensed music. And being at least as good as Xenon 2 seems to be what you're going for then how about some licensed music of your own.

Find attached an example of what might be possible in MOD format inside the attached ZIP.

The first half of Worlds on Fire by The Prodigy in two MOD's
(I would do all the resampling again from scratch once I have got the structure down

Now I am a reasonable man, and I figure that The Prodigy (or at least their label, as that's who you'd be dealing with) probably won't be interested at all. but hey, if you're going to dream, then why not dream big?

Anyway the point of this is I believe that I have demonstrated how it can be quite easy to get 1:15-1:30 worth of reasonable quality audio recording onto a floppy in a format that the Amiga can easily play. But of course this method would only really be any good for Amiga HD or CD32 as loading the next 1:20 worth of music would simply take too long on floppy. But you could potentially have a little cutscene graphic or big explosion pause the display and load the next section similar to how demo Jesus on E's managed to have around 20 minutes of uninterrupted music.

And as you cannot see, as you don't have the full conversion in front of you as I do The whole song would easily fit inside 8MB of fast-ram which many A1200 ownere have. And that's without taking the optimisations I could potentially make by using smaller samples into account. But MED would be better as it allows for twice as many.

But splitting the recording into MOD's while convinient to handle is not the most efficient, as there are a number of samples which get reused across different sections, and of course the huge pattern data overhead of the standard MOD format. So I have ideas for custom music format based around this format which could potentially see the whole 4:55 song fit on a floppy at over 16KHz without any compromises to the composition.

And none of this is considering the possibility of lowering the sample rate a bit more. But as a musician and composer I might be a little insulted if someone represented such a low-fidelity recording of one of my compositions so i wouldn't do it to them in a public forum, but I'd say you could safely halve the samplerate again.

[Master484]

Interesting.

I tested the mods, but the standard Blitz MOD module player commands are broken so the mods didn't sound as they should have.

But the Octamed MED module commands in Blitz seem to work OK, they always play without any problems. So all musics should be in MED format, because that's the only format that Blitz can play without resorting to 3rd party libraries. And if the MED format is also better than MOD, then great.

The idea itself could work, but as you said, the game would need to be HD only, or alternatively the music track should play directly from the CD. And simply playing the song from the CD would be better option, because then it wouldn't need to use any Chip RAM, which even the A1200 only has 2 MB. I'm not sure how Fast Ram works, but I believe that in order to play a mod, it has to be in Chip Ram. And of course if the game itself would come in a CD, then playing the music from CD would be a natural option.

Although even on floppy disks, by having two disk drives, with the game disk in DF0 and the music disk in DF1, this could work. Although I would imagine that it would be one song per disk, and so if all levels would have different music (as they should have in good game), then the disk amount could be well over 10.

---

And using some real band's music would of course mean copyright problems, and negotiating a deal with a big band could be almost impossible. And even if we were succesful, then they would want royalties because we play their songs. And when the song's licence time expires, then our game would be removed from Steam lol.

But of course having "real" music doesn't mean that it has to be licenced from a mainstream band. There are many indie musicians out there who would probably love to see their songs in a retro game, and it wouldn't cost us anything.

Electric guitars and rock'n roll would indeed work well in a shmup, and if a good song (or even just a 1 minute loop from a good song) can be squeezed into a reasonably sized MED module, or arranged so that it would fit into a 100 KB or 150 KB or something like that, then why not, we could use it.

And I also have a plan that there should be a level music + boss music, and boss music should start instantly when a boss appears. So something like two MEDs, with each being 100 KB or sightly more, is something that would fit into the 2MB of Chip RAM that we have on ECS/AGA, and this could work.

[Anakirob]

Originally Posted by Master484

...And simply playing the song from the CD would be better option, because then it wouldn't need to use any Chip RAM, which even the A1200 only has 2 MB. I'm not sure how Fast Ram works, but I believe that in order to play a mod, it has to be in Chip Ram.

Playing music from CD means that you have to stop the music to load data, which is not the point of this method. I would be wanting the music to play constantly from the moment the game initialises.

Also with such compression as I've used then one could fit a LOT more music than 60 minutes worth on a CD.

And finally it is indeed possible to play from fast-ram, using only a small chip-buffer. I seem to recall that there's even a Blitz library for this purpose. one of the XB ones I think, but I'm a bit hazy.

But I have got the whole song into a 1.3 MB XM so it could play fine on an unexpanded A1200 or CD32 even if the whole thing were loaded into chip anyway. And I still have not optimised it properly.

But of course having "real" music doesn't mean that it has to be licenced from a mainstream band. There are many indie musicians out there who would probably love to see their songs in a retro game, and it wouldn't cost us anything.

Electric guitars and rock'n roll would indeed work well in a shmup, and if a good song (or even just a 1 minute loop from a good song) can be squeezed into a reasonably sized MED module, or arranged so that it would fit into a 100 KB or 150 KB or something like that, then why not, we could use it.

There would have to be at least half a dozen musicians in my friends list that would jump at the chance. Not the least of whom being cTrix, but first things first.

I think if I had the source material for the prodigy track then 150KB would be doable. And that's possibly with 22KHz drums and 16KHz vocals. So a track with similar, loop based structure from another artist should work as well.

-edit-
see attachment for two game music loops
-Second Edit-
Added another MOD, this time Smack My Bitch Up. I think that this one could be made to use less than 200KB chip ram if I were to put the effort in.

Also, I'm pretty sure that OctaMED also features fast-ram playback routines, but they're a bit slow.

[Master484]

Just loaded the new mods to Octamed 4, and they sound really good and high quality. And they seem to use just 2 channels, which leaves 2 channels free for sound effects, which is great.

And the size is now better. Using 350 KB for music is OK I think. And if the whole song is about 1 MB, then even that could be OK for a 2 MB Chip + 1 MB Fast configuration. Although I'm not sure how much RAM the graphics and other stuff are going to take in their final form. And all the bitmaps and display buffers have to fit into Chip RAM also.

But maybe if the game code would go to Fast RAM, then we could use 1 MB for graphics and the other 1 MB for music and sound effects. So maybe level music + a shorter boss music loop + sound effects could fit into 1 MB ? If so, then I believe the whole thing could fit into the 2 MB of chip RAM.

And of course one mid-level loading break is acceptable; the boss battle would be the best place for that and quite many games load before boss battles. So the boss music + boss graphics could be loaded separately, and this would mean 1 MB free for level music + sounds, and the other 1 MB for level graphics.

And the Smack My Bitch Up song sounds great, it's better than Worlds On Fire I think.

---

Also I noticed something about the default Blitz Mod commands; Blitz seems to play all MOD songs at maximum speed, and there is no way to change the speed. This is why all MOD files sound so strange in Blitz.

Because when I loaded the MODs in Octamed 4, and tried to change the song speed to maximum, it sounded exactly the same as when playing it from Blitz.

But luckily Blitz has the "MED module" commands too, which work fine, although they only work for Octamed MED modules. And then there are those external libraries too, although I've never used them.

---

Also about the song used in Xenon 2, the actual full song only plays in the title screen, and I believe it takes almost all space on disk 1, and most of the RAM too. Because when game starts you have to insert disk 2, and the song that plays during the game is a shortened and simplified "loop version" of the full song. That's the only way the song + all the graphics could fit into the 1 MB they had back then. And even then every level is actually divided into two parts, with a loading break between the parts, but this loading was "hidden" because they put the "weapons shop" between the two level parts.

[Anakirob]

Originally Posted by Master484

Just loaded the new mods to Octamed 4, and they sound really good and high quality. And they seem to use just 2 channels, which leaves 2 channels free for sound effects, which is great.

I'm glad you liked them, I'm pretty pleased with how they turned out. I think the high-fidelity sound at only 8Khz may be largely due to how they were originally produced and mastered. The Prodigy's music does not seem to suffer as much from the conversion from 44Khz 16-bit to 8KHz 8-bit as much as other compositions I've noticed.

Also, if you look closely at the pattern data you will notice that they actually use only one channel. I just doubled it so it would play in stereo, which is what you would want', but you could potentially have 3 channels of SFX with this music.

And the size is now better. Using 350 KB for music is OK I think. And if the whole song is about 1 MB, then even that could be OK for a 2 MB Chip + 1 MB Fast configuration. Although I'm not sure how much RAM the graphics and other stuff are going to take in their final form. And all the bitmaps and display buffers have to fit into Chip RAM also.

Yeah, <300Kb was what I was aiming for, I didn't quite get there, but then I didn't put as much care into the conversion as I did Worlds on Fire, so if I were to optimise this, then I would grab all my samples again.

There is an additional 100Kb of samples which could have very easily gone into Smack My Bitch Up to make it almost the complete song. But they are only used briefly and didn't really add much to a shoot-em-up atmosphere so I left them out as I was trying to prove what could be reasonably used in an Amiga game. I have made this into a separate MOD which you can find attached. I was possibly thinking of having different music when there is not much going on.

And as far as file size goes one thing to consider is all that redundant pattern data, simply storing the sequence in ascii+samples would be more efficient. All the samples trigger at regular intervals in these MODS.

]But maybe if the game code would go to Fast RAM, then we could use 1 MB for graphics and the other 1 MB for music and sound effects. So maybe level music + a shorter boss music loop + sound effects could fit into 1 MB ? If so, then I believe the whole thing could fit into the 2 MB of chip RAM.

And of course one mid-level loading break is acceptable; the boss battle would be the best place for that and quite many games load before boss battles. So the boss music + boss graphics could be loaded separately, and this would mean 1 MB free for level music + sounds, and the other 1 MB for level graphics.

And the Smack My Bitch Up song sounds great, it's better than Worlds On Fire I think.

Yeah, I sat down and listened to a few Prodigy tracks and carefully selected the one which would yield the best results. Even with the half-arsed job I did of converting it I do think it's a pretty reasonable reproduction/adaptation of the original.

You're right, when the boss's profile picture comes onto the screen and he says a few words there's lots of opportunity to load data while that is happening. And also a big explosion which makes the whole screen go white for a second is another point where you can pause the display to load data unnoticed.

[Master484]

There is an additional 100Kb of samples which could have very easily gone into Smack My Bitch Up to make it almost the complete song. But they are only used briefly and didn't really add much to a shoot-em-up atmosphere so I left them out as I was trying to prove what could be reasonably used in an Amiga game. I have made this into a separate MOD which you can find attached. I was possibly thinking of having different music when there is not much going on.

I agree, slow parts like that wouldn't fit well to a shmup, so it's better to leave it out.

And the Invaders song sounded good too, and surely a 300-350 KB mod is small enough to be used in a game in a 2 MB Chip Amiga.

---

All looks good then, only the game is missing.

I'll try to make some kind of level prototype in the coming months.

The vision that I have is something like Crisis Force on the NES; a forest section followed by a short sea section and then a city, and a good boss fight will take place in the city. And screen has to be filled with maximum destruction and mayhem, on a magnitude that has never been seen before in an Amiga game.

Here is video of Crisis Force, something like this is the aim, but with more action:
[ Show youtube player ]

And I have a crazy game plot idea ready too, but more of that later, first we need the prototype level ready and running.

[Anakirob]

I've got Smack My Bitch Up down to under 280KB and it loops around in a pleasing way. Had to cut 90% of the vocals out, but that's probably for the best. And I've also compressed the entire 2:56 track in to a single MOD pattern, as well as optimising a few of the samples and making it loop nicely. Be warned I made very heavy use of Protracker's Exy commands so many PC MOD players will fail. OctaMED itself should handle it fine, although you may find that the MED routines don't support MMD1.

Instead of LoadModule try LoadTrackerModule (I seem to recall that's the command, someone else will have to confirm). Also, no MED means no MED library.

Find attached the updated version, I promise this is the last one I spam to the forum. Email would be much better. Also a couple of greyscale images. But be warned, they have not really been prepared for the Amiga yet, although they are all 256 high.

Invaders Must Die is a funny one, this one would be much better if I actually covered it properly instead of using loops, as I know how to play all the different keyboard parts for that song. But I do think it would make a fitting soundtrack to some kind of Space Invaders clone.

[Master484]

I've got Smack My Bitch Up down to under 280KB and it loops around in a pleasing way. Had to cut 90% of the vocals out, but that's probably for the best. And I've also compressed the entire 2:56 track in to a single MOD pattern, as well as optimising a few of the samples and making it loop nicely. Be warned I made very heavy use of Protracker's Exy commands so many PC MOD players will fail.

Yesterday I just managed to install the Ultimate Blitz CD, and today I figured out how to add the extra commands to it such as LoadTrackerModule and LoadPTModule. The tracker commands didn't work at first, but then I realized they required an A1200 setup, and now they work fine.

However, there seems to be a problem with this latest version of the SmackMyBitchUp mod: It starts to play, but then gets stuck into an infinite loop, and just repeats positions 10,11 and 12 forever. It seems that it was meant to do a loop at this position, but it gets stuck and the song doesn't progress any further. This problem happened with both LoadTrackerModule, LoadPTModule, and also with Protracker 3.1.

I don't know what causes this. But all the other mods you have posted load and play fine in both Blitz and Protracker.