1018 Commits

Author	SHA1	Message	Date
Thomas Harte	65bb31d55b	With around about a thousand issues, not the least of which being sometimes unsafe memory accesses, I've at last got pixels on screen.	2015-07-26 23:50:43 -04:00
Thomas Harte	cd0a62d21e	With a slight tweak to the informal protocol used for 6502 memory access cycles, ensured the wait strobe actually halts the CPU, to give a more accurate linking of machine time to real time.	2015-07-26 15:55:19 -04:00
Thomas Harte	8efd449834	Switched to a down counter and a reset test that remains unconditional but doesn't depend on % (which seems to turn into a big imul-powered deal). Probably pointless mulling around the edges at this point.	2015-07-26 15:45:19 -04:00
Thomas Harte	6252f6030f	Switched to idiomatic source name, ensured latest project name is in all appropriate header places, threw texture coordinates slightly into the shader mix.	2015-07-26 15:25:11 -04:00
Thomas Harte	ecb2898bd5	The overall architecture of who has responsibility for what is now very askew but: the CRT now outputs a tightly packed short buffer, with the probable OpenGL destination in mind. So it's now all fixed arithmetic internally. CRTFrame is reduced to a plain C struct with the intention that the OpenGL view will take responsibility for it and stop doing the back-and-forth sprint on getting buffer data. The Atari 2600 now outputs explicit blanks rather than level blacks for its border, so that it's easier visually to debug the CRT in its form as far as it has currently progressed: to drawing lines where the cathode ray gun would run while outputting pixel. I note that I'm still not quite getting vertical sync right yet — I'm just accepting it anywhere in teh frame — but that should be an easy fix.	2015-07-24 23:29:45 -04:00
Thomas Harte	d72287a776	Looked up normal retrace time (it's a lot less than 16µs and 26 scanlines — more like 7 and 10) and that the visible portion of a line is defined to start about 12 µs after the start of hsync, put the first two numbers into my CRT to make that more accurate, then derived a newer guess about what the Atari 2600 does for each of its 228 cycles. The text version of a frame is now looking pretty good. So it's probably time to hit OpenGL and the OS X side of things. Though I'll have a quick look to find out whether I can learn the exact real Atari 2600 timings before moving on.	2015-07-23 19:24:25 -04:00
Thomas Harte	529f61caa1	Removed a stray newline.	2015-07-22 20:45:21 -04:00
Thomas Harte	065050115f	Made an attempt to switch to a triple-buffering scheme for CRT outputs, with an eye towards asynchronicity.	2015-07-22 20:33:20 -04:00
Thomas Harte	963cb2f6fb	Attempted to switch to slightly more meaningful names within the CRT and implemented a delegate to investigate output. Working on it.	2015-07-22 18:15:18 -04:00
Thomas Harte	a1a1b15d18	Made a quick attempt to accumulate a list of detected output runs. Which means finally having to specify normal frame height. I'm already at too many magic formulae though, so this will need proper revision when I'm next awake. Definitely my horizontal position advancement is way off.	2015-07-20 23:18:56 -04:00
Thomas Harte	4e4c082a05	Made some minor attempt at proper sync response. I think I've gone way off piste and overcomplicated it.	2015-07-19 23:43:22 -04:00
Thomas Harte	4a1e9fe2a8	Rephrased the CRT as owning an arbitrary number of buffers and vending storage space for pixel output. That much better maps to potential implementations of this thing in GLSL, with ES 2.0's limitations kept in mind.	2015-07-19 21:21:34 -04:00
Thomas Harte	4d1e410150	Fix 1: _horizontalTimer should be treated as read only out here.	2015-07-19 16:51:11 -04:00
Thomas Harte	6f78ecdc9c	Made first genuine attempt at outputting a meaningful CRT stream. Which shows some significant errors. So work to do.	2015-07-19 16:48:14 -04:00
Thomas Harte	2d0f861474	Incoming: a 'CRT' class, to receive information intended for a cathode ray tube. To decode sync, etc.	2015-07-19 13:36:27 -04:00
Thomas Harte	03a25c8ff2	Fixed playfield pixel logic.	2015-07-19 10:56:04 -04:00
Thomas Harte	3e0679235a	This now goes just far enough to create an instance of Atari2600::Machine and push a ROM to it. Next jobs are to get a basic CRT emulation wired up, outputting to the window.	2015-07-16 20:40:46 -04:00
Thomas Harte	6558ae1425	Imported what little I have so far in the way of a memory-access cycle complete 6502 and just enough of a pretend Atari 2600 on top to be able to see some playfields in ASCII art.	2015-07-16 19:56:02 -04:00