No eye candy today but some progress; rockets, fuel tanks and so-called 'mystery' objects are rendered as they appear and then deleted as they scroll off the screen. Interesting to note that they simply disappear as soon as they hit the edge of the visible area of the display, as confirmed in MAME. There is also a maximum of 8 ground-based objects on the screen at any one time.
I've also implemented the routine that switches landscape meta-data as you reach the end of the level. As a result, the demo now scrolls through the entire game, looping endlessly on the BASE level. I've currently only implemented the routine to decode (and render) the floor, so next task is to implement the routine to decode the ceiling.
I was thinking once that's done, I should put together some code that renders all 6 levels into a bitmap.
Generally arcade games have a bezel that hides the edges of the screen so aggressive clipping it not normally noticeable. Practically every emulation we do ends up needing some kind of edge clipping.
ReplyDeleteThe limit of 8 ground objects at once surprised me as it always felt like more. But, sure enough, watching a youtube video brings it home. I guess it helps that Scramble has the slightly odd combination of vertical display but horizontal scrolling.
I second the motion for a full map render.
Even more surprising for me was to learn that there are only 4 so-called "in-flight" enemies on screen at any one time. Fair enough for rockets and ufos, but only 4 fireballs??? Surely not?!? But yep, watching a video confirms it. Seems like there were a dozen!!!
ReplyDeleteI guess since there's been an overwhelming request for the map I'll have to do it now... only question is how I choose to colour each section as the landscape palette changes are immediate for the entire visible area.