Fast scrolling game howto, anyone?
Posted: Tue Feb 19, 2013 8:00 pm
Hi all.
Now that Twi is about to release a fantastic tool for designing tile-based games, I remembered I had something in my hard disk for months now. It is a quite disappointing test trying to find out a possible technique for fast scrolling games in the Oric.
I managed to produce masked sprites over a quite rich scrolling background even with some kind of paralax effect!, though my stars (those balls on the background which should be more spread) are just a first and not successful attempt, they are still on the background, while the rest of the world moves. Everything is done with double buffering and moves quite fast.
Of course still no animations for the ship, no other enemies (which would move as fast as your ship or lasers)...
Have a look at this video:
http://youtu.be/zS1SJmFYc20
You surely imagined it is using TEXT mode. This has many inconvenients I cannot figure out how to solve:
1. The scroll is bumpy. Yes, sub-character scrolling is not possible, so it is not smooth.
2. For the same reason it is not possible to scroll slowly (for the ships up and down moves it is indeed possible), so playability may suffer.
3. As there is no way to sync with the screen refresh, you sometimes "see" the drawing and the borders of the enemy "big ship" appear jagged as it scrolls. Anybody found a way to minimize this without the VSYNC cable hack?
4. TEXT mode means NO AIC mode, so very very little color. I am not sure I am ready to step back that much.
5. Tiles are used up very quickly, and there are not many of them. I am using currently 54+59 for the big ship, and several are needed for the sprites (the player's ship is 2x2, as well as the shadow, and 3x2 will be needed for sub-character up/down movement). Yes I am using both ALT and STD charsets. Ship animation does not take up extra tiles, however, as it is drawn from the image data in memory over the same tiles (this is mandatory anyway, as we want masked drawing).
The upper portion of the screen (in white) is HIRES mode, so a nice panel can be drawn there. The lower part is TEXT mode, so no use. But I don't see why I wouldn't extend the play area to the bottom of the screen. It shouldn't affect performance too much.
I am sure that some of you have explored this field. Any ideas?
Has anybody found an alternative way to do this? It takes ages to perform a scroll in HIRES!
Now that Twi is about to release a fantastic tool for designing tile-based games, I remembered I had something in my hard disk for months now. It is a quite disappointing test trying to find out a possible technique for fast scrolling games in the Oric.
I managed to produce masked sprites over a quite rich scrolling background even with some kind of paralax effect!, though my stars (those balls on the background which should be more spread) are just a first and not successful attempt, they are still on the background, while the rest of the world moves. Everything is done with double buffering and moves quite fast.
Of course still no animations for the ship, no other enemies (which would move as fast as your ship or lasers)...
Have a look at this video:
http://youtu.be/zS1SJmFYc20
You surely imagined it is using TEXT mode. This has many inconvenients I cannot figure out how to solve:
1. The scroll is bumpy. Yes, sub-character scrolling is not possible, so it is not smooth.
2. For the same reason it is not possible to scroll slowly (for the ships up and down moves it is indeed possible), so playability may suffer.
3. As there is no way to sync with the screen refresh, you sometimes "see" the drawing and the borders of the enemy "big ship" appear jagged as it scrolls. Anybody found a way to minimize this without the VSYNC cable hack?
4. TEXT mode means NO AIC mode, so very very little color. I am not sure I am ready to step back that much.
5. Tiles are used up very quickly, and there are not many of them. I am using currently 54+59 for the big ship, and several are needed for the sprites (the player's ship is 2x2, as well as the shadow, and 3x2 will be needed for sub-character up/down movement). Yes I am using both ALT and STD charsets. Ship animation does not take up extra tiles, however, as it is drawn from the image data in memory over the same tiles (this is mandatory anyway, as we want masked drawing).
The upper portion of the screen (in white) is HIRES mode, so a nice panel can be drawn there. The lower part is TEXT mode, so no use. But I don't see why I wouldn't extend the play area to the bottom of the screen. It shouldn't affect performance too much.
I am sure that some of you have explored this field. Any ideas?
Has anybody found an alternative way to do this? It takes ages to perform a scroll in HIRES!