I am trying to come up with a solution, but I have a hard time imagining how it can be reliable. I have music tracks that are ~2 minutes long full PCM, and I want to play these during the title screen, intermission, and gameplay. I believe this adds presentation value that is far above the sum of parts if one only considers how impressive an implementation is on paper. This would not use Streaming Music, it would be an attempt at Streaming PCM or a compressed variant.
It seems a lot harder that I initially imagined. Vram data will get filled from level data in the SPI Ram, which takes some complexities to implement, but there is nothing inherently stopping that part. 128K is not enough to store the level, and also a "real" full length music track, so that runs to the nasty beast of intermittent SD card access(something I am checking into on Artcfox's SD scrolling implementation, non-blocking stuff). I feel no qualms about having some test at boot, which tells the user if their card is not fast enough and stops there, after which I can make some necessary assumptions about read latency.
I see some workarounds to make these things cooperate. Some frames, it will not be required to add new values into vram on the '644 so I could use the SPI bus for other purposes. If I am to randomly stream PCM from SPI ram for sound effects, that is not going to work because it will create horrible sound drops if I access the SD card which must be done to the sum of at least 15,700 bytes per second on average(averaged over say, 8 seconds where 96K of SPI Ram is a buffer for PCM music). I think I have to choose: PCM music or PCM sound effects from the SPI Ram, and not both. Because this game only requires a few short sound effects, I might try to squeeze them in flash as PCM(where you can use ~8khz PCM, and play it back double speed like Columns sounding well enough), where I can fall back to wave based sounds if I run out of space. If I do that, I believe it is possible on fast cards, to keep up with music and scrolling..maybe.
Graphics are coming along pretty close to done for the tracks. I suck at isometric art, I give up on that, oh well it is straight top down..what can I do
I am trying for some spiffy menus, title screen, race intros, conclusion, intermission where you can buy parts at the RC shop, etc. That is pretty hard, I struggle to find a good way to make some semi-photo-realistic RC parts with the ridiculously small resolution I have to use. Upgrades will be different types of tires(need to fit in a ram tile frame of ~6x6/48x48 pixels), different motors(brushless, higher RPMs, etc.), different batteries(NiMh, Li-ion, LiPo, and Lithium-Air as a mythical top end). Every individual item has to fit in ram tiles, as it has to come from SD/SPI Ram. I will post some graphics for that once I get somewhere, right now I have to increase my art ability just to make something presentable for this...looks terrible
Random update there, I am having some Uzebox fun today!