Review: W-Ring: The Double Rings - A Very Good but Obscure Shmup

[Sadler]

Sprites + scanline is my guess. I think people underestimate what you can do with sprites.

[Black Tiger]

All you need is sliding strips of tiles and sprites in the right places, including "behind" the tiles. Sprites can float around on the base color of the tile palettes like a third layer. Since they don't penetrate the rest of the tile art, all kinds of neat effects can be achieved.

[NightWolve]

*ahem* I genuinely think this looks as good or better than anything on the Genesis or SNES (slight spoiler, this is the last area of Legend of Xanadu):

Final Stage

~1:20-2:00 is just amazing. Many layers of complex overlapping parallax.

All the side scrolling areas in that game that I've seen look great. See here for the first area.

Agreed, gonna be great to see this fan-translated one day which might just be some time next year!

[Sadler]

*ahem* I genuinely think this looks as good or better than anything on the Genesis or SNES (slight spoiler, this is the last area of Legend of Xanadu):

Final Stage

~1:20-2:00 is just amazing. Many layers of complex overlapping parallax.

All the side scrolling areas in that game that I've seen look great. See here for the first area.

Agreed, gonna be great to see this fan-translated one day which might just be some time next year!

I am very much looking forward to translated Xanadus!

[Punch]

 Parallax takes cpu resource on all three systems. It's not free. I'd say the PCE cpu is more than up for the task.

 That 'black spot' problem in Ninja Spirit and ShapeShifter can be avoid or 'fixed', with or without sprites. The linescroll issue you bring up, is also an issue with the Genesis and SNES when used in the far BG layer. You need solid color transition areas to hide the seam when straight edges aren't an option, when two BG layers can't be used in composition. Whether is looks 'cheap' or not, doesn't effect the gameplay though. Unless you consider it a distraction.

 
 Edit: Scroll speed isn't limited by parallax effects.
 

I really wasn't comparing the PCE to any of its competitors. With all that text I just wanted to say that parallax doesn't come for free and the design of the game is significantly influenced by how the BGs are designed to behave and look. Perhaps I'm too influenced by the NES but I always see these effects as "oh shit this is going to be 90% of my processing time isn't it", specially when it depends of a lot of Video RAM updates.

The line scroll technique looks great in Samurai Ghost but it does look cheap when the solid color of the edge clashes with the background that's supposed to be behind it isn't of a solid color as well. Well at least for me. My opinions suck, so what.
edit: an example that's the opposite of Samurai Ghost: Atlantean. Now that's a damn great looking game, because sprites are used to hide the linescroll and the BG is designed to be a set of rectangular walls one in front of the other. That's what I meant, it is a cheap technique processing time wise (specially with the built in line interrupt!) but it does show unless you go the extra mile, inducing flicker with too many sprites on screen.

You sure it doesn't? I don't see myself making a game update the virtual BG with new tile indexes as fast as a game like Sanic or Bio Force Ape while it uses part of vblank to also update the tile sets. Doesn't sound viable to me. I'm not challenging your opinion or anything, I just want to hear a detailed explanation of your statement.

[Gentlegamer]

*ahem* I genuinely think this looks as good or better than anything on the Genesis or SNES (slight spoiler, this is the last area of Legend of Xanadu):

Final Stage

~1:20-2:00 is just amazing. Many layers of complex overlapping parallax.

All the side scrolling areas in that game that I've seen look great. See here for the first area.

Agreed, gonna be great to see this fan-translated one day which might just be some time next year!

Be sure to make a special Tobias edition that infects his systems with malware.

[Black Tiger]

 Parallax takes cpu resource on all three systems. It's not free. I'd say the PCE cpu is more than up for the task.

 That 'black spot' problem in Ninja Spirit and ShapeShifter can be avoid or 'fixed', with or without sprites. The linescroll issue you bring up, is also an issue with the Genesis and SNES when used in the far BG layer. You need solid color transition areas to hide the seam when straight edges aren't an option, when two BG layers can't be used in composition. Whether is looks 'cheap' or not, doesn't effect the gameplay though. Unless you consider it a distraction.

 
 Edit: Scroll speed isn't limited by parallax effects.
 

I really wasn't comparing the PCE to any of its competitors. With all that text I just wanted to say that parallax doesn't come for free and the design of the game is significantly influenced by how the BGs are designed to behave and look. Perhaps I'm too influenced by the NES but I always see these effects as "oh shit this is going to be 90% of my processing time isn't it", specially when it depends of a lot of Video RAM updates.

The line scroll technique looks great in Samurai Ghost but it does look cheap when the solid color of the edge clashes with the background that's supposed to be behind it isn't of a solid color as well. Well at least for me. My opinions suck, so what.
edit: an example that's the opposite of Samurai Ghost: Atlantean. Now that's a damn great looking game, because sprites are used to hide the linescroll and the BG is designed to be a set of rectangular walls one in front of the other. That's what I meant, it is a cheap technique processing time wise (specially with the built in line interrupt!) but it does show unless you go the extra mile, inducing flicker with too many sprites on screen.

You sure it doesn't? I don't see myself making a game update the virtual BG with new tile indexes as fast as a game like Sanic or Bio Force Ape while it uses part of vblank to also update the tile sets. Doesn't sound viable to me. I'm not challenging your opinion or anything, I just want to hear a detailed explanation of your statement.

Although 16-bit consoles could always be pushed further, anything already achieved is proof of what is possible at the very least. It doesn't matter how something might seem to be theoretically, like the resource impact of dynamic tiles, because we already have so many PCE games which already make liberal use of dynamic tiles for stuff like parallax, while at the same time still run an "intensive" game like a shooter.

[Bonknuts]

You sure it doesn't? I don't see myself making a game update the virtual BG with new tile indexes as fast as a game like Sanic or Bio Force Ape while it uses part of vblank to also update the tile sets. Doesn't sound viable to me. I'm not challenging your opinion or anything, I just want to hear a detailed explanation of your statement.

 Well, the tilemap itself would have more entries to update, but dynamic tiles are just the position number/frame to write to vram. Dynamic tiles and hsync scrolls aren't affected by scroll speed. They are a constant factor. That just leaves the tilemap update.

 How fast does Sonic scroll? Let's say it's 64 pixels per frame. That's 15 full frames scroll per second in PCE low res. That's pretty damn fast! A full screen has completely scrolled by in just 4 frames (there are 60 frames in a second for the video). That's 8x2x28= 448 bytes to update to vram. Just using a simple load/store loop (no block transfer), that's ~11 cpu cycles per byte. That's 4,928 cpu cycles (4.1% cpu resource per frame). There's 16,380 cpu cycles in vblank with a frame of 256x224. (262-224-2)* 455 cpu cycles. That still leaves 11,452 cpu cycles left over in vblank.

 But here's the thing; I wouldn't update the tilemap during vblank for scrolling. The PCE can write vram during active display. And the virtual map is large enough to write offscreen during this time. I would (and do) do this during active display. That frees up all of vblank. SATB doesn't need to be updated during vblank either. There are also ways to do dynamic tiles without having to resort to vblank as well. Vblank time is more of a NES, Genesis, SNES time of thing/limitation. That's why the Genesis and SNES have local to vram DMAs, because such a short amount of time - the cpu isn't fast enough to update vram. The NES only has a sprite DMA option.

 Vblank should be saved for critical things that can't be double buffered or done off screen during active display (like palette ram updates, etc).


Edit: Scrolling 64 pixels per frame is ridiculous and unrealistic, or a rare special case. Even 8 pixels per frame is pretty fast for scrolling (almost two screens per second).

*If you're using HuC and the default map libraries, well then maybe you'll run into some issues. Those map routines are slow and unoptimized. They're are meant for general flexibility.