Thomas Harte
80cf3d9301
Formally gave the 2600 responsibility for providing the code that decodes one of the things it has put into a buffer into a composite sample.
2015-09-03 12:28:16 -04:00
Thomas Harte
ac8fc9a1a0
Experimenting with pre-encoding luminance and chrominance separation over on the
...
CPU as otherwise the GPU does them repetitively and more awkwardly (as it's working purely in floats). It means uploading twice as much data though, so I don't
know. Still only half as much as the RGBA path of a few days ago. Will experiment.
Also slightly adjusted division of responsibility in the fragment shader per the
desire to have the `sample` function owned externally.
2015-09-03 11:15:23 -04:00
Thomas Harte
cb6e6e8acb
It's the worst fragment shader you'll ever see. The worst. But this attempts NTSC composite video emulation, artefacts included.
2015-09-01 22:36:45 -04:00
Thomas Harte
043d2f9896
It sounds like the two sync signals are exclusive ORd.
2015-08-19 21:36:33 -04:00
Thomas Harte
c5e480cfae
Threw in missile repeats.
2015-08-19 09:46:57 -04:00
Thomas Harte
ca6b54536e
Added fire and reset inputs.
2015-08-18 20:58:05 -04:00
Thomas Harte
bc805a90fe
Wired up joystick directions, at least, and fire button presses get as far as the C++. But there's some latching to figure out before they'll work.
2015-08-18 20:33:24 -04:00
Thomas Harte
d21ccddeef
Fixed: _vBlankExtend is now cleared at the correct moment.
2015-08-17 17:54:36 -04:00
Thomas Harte
a33d31d02a
Fixed to allow loading of ROMs less than 1kb in size.
2015-08-17 00:34:01 -04:00
Thomas Harte
df68aeff5a
Fixed: made sure that _vBlankExtend resets itself even on non-pixel lines.
2015-08-17 00:09:28 -04:00
Thomas Harte
414849f166
Confirmed: pixel counters are not paused by programmatic vertical blank.
2015-08-16 17:34:20 -04:00
Thomas Harte
a693c081f8
Switched on the appropriate compiler warnings re: signed comparisons and implicit conversions. Fixed all less-than-explicit calls.
2015-08-16 16:08:29 -04:00
Thomas Harte
410c09cb35
Made attempt not to touch the _collisions registers (which are instance variables) unless the local variables imply it's potentially necessary. So that's a broad phase on collisions, I guess.
2015-08-16 15:39:40 -04:00
Thomas Harte
40cb1cf60d
... and the ball graphic.
2015-08-16 11:24:33 -04:00
Thomas Harte
afaa86a649
Minor thing: skip the internal counter stuff if we're definitely going to end up with a transparent pixel anyway for the player and missile graphics.
2015-08-16 11:23:46 -04:00
Thomas Harte
4b5aabdd54
Attempted to take even more out of the inner pixel loop.
2015-08-13 23:23:04 +01:00
Thomas Harte
92c7d56cc3
Tiny little speed improvement. Every little helps.
2015-08-13 21:50:24 +01:00
Thomas Harte
17bbe27c9a
As an experiment, performed some very basic moving of playfield composition outside of the pixel loop.
2015-08-13 21:32:22 +01:00
Thomas Harte
033655835a
My understanding now is that object position counting will begin the cycle after the call is made, not that cycle, and that the timer loops just once, with the logic for counter pumping being whether the relevant flag is still set, irregardless of whether the counter is still going.
2015-08-13 18:59:23 +01:00
Thomas Harte
323aa27e13
Fixed: paging is based directly on the access, independent of the read/write line (since it isn't actually exposed to catridges).
2015-08-13 15:04:30 +01:00
Thomas Harte
9838e01cc1
Made a first attempt at paging.
2015-08-13 13:24:02 +01:00
Thomas Harte
9ca57b80a7
Minor steps to help with diagnostics; all commented out or merely to benefit with breakpoint placement.
2015-08-13 08:43:10 +01:00
Thomas Harte
6616265d93
Fixed collision tests, added a few more timing tests.
2015-08-13 03:33:45 +01:00
Thomas Harte
d19f8ed507
Removed the implicit reset upon 6502 startup, adding a reset line. Hence all tests now pass again. Added an empty shell for timing tests, the all-RAM 6502 now counting bus cycles.
2015-08-13 00:51:06 +01:00
Thomas Harte
687816d470
Made some attempted simplifications, implemented collisions.
2015-08-13 00:31:57 +01:00
Thomas Harte
aebf636528
Ensured the PIA timer resumes its normal tick rate after being read; fixed those spaces that had crept in where tabs should be.
2015-08-10 16:55:16 +01:00
Thomas Harte
42677f5f83
Fixed association of motion registers and actual registers.
2015-08-10 16:43:45 +01:00
Thomas Harte
2dde2efff0
Attempted to standardise object counters.
2015-08-10 15:09:40 +01:00
Thomas Harte
a228969655
This should happen every fourth cycle.
2015-08-10 08:16:17 +01:00
Thomas Harte
3c27306a8e
My counter was going the wrong way.
2015-08-10 00:33:37 +01:00
Thomas Harte
a4e52cc4db
Made an attempt to switch to a hardware-accurate object timer model. Without yet perfect success.
2015-08-10 00:20:18 +01:00
Thomas Harte
cd67e31e64
Made a first attempt at switching a little closer to TIA's real internal counter setup.
2015-08-09 22:47:11 +01:00
Thomas Harte
987be65a59
Made a quick attempt at reimplementing skip-to-the-end logic for ready waits.
2015-08-09 02:42:01 -04:00
Thomas Harte
eb23a493e5
Switched back to one texel per colour clock, at least for now. Attempted to break _RGBA assumption within the cathode ray view.
2015-08-05 23:36:04 -04:00
Thomas Harte
fd36f13baf
The cathode ray view no longer hard codes the frame size. So that's one less coupling. Doubled pixel output size to give sufficient sampling detail to capture the NTSC colour clock (ummm, hopefully).
2015-08-05 21:45:47 -04:00
Thomas Harte
5644b3a1cc
Fixed scanline sizing and fill issues, as well as shortening vsync to the correct Atari length.
2015-08-05 20:55:27 -04:00
Thomas Harte
5313b48ebd
I'm ashamed to admit, I: played with numbers until enough things looked stable such that I can investigate other things. Discovery: my PAL autodetection was way off. Fixed, hopefully.
2015-08-02 20:32:18 -04:00
Thomas Harte
5f1d76e855
Can't seem to find any documentation: assumed horizontal sync is generated during vertical.
2015-07-31 18:49:02 -04:00
Thomas Harte
9c91f1a2eb
Added an attempt at NTSC/PAL autodetection, based on number of missed vertical syncs.
2015-07-31 18:04:33 -04:00
Thomas Harte
a5d66e9dd6
Factored out a few more constants, started trying to ensure there's enough slack and the mechanisms in place for the CathodeRayView to hold onto two frames if it desires, for potential phosphor simulation, switched once again to additive blending — much more like a real CRT — and added a sine function across the width of spans per my understanding of how an electron gun actually fires.
...
Why do all this when overall timing is still so far off? It helps me more easily see how overall timing is so far off.
2015-07-31 17:47:10 -04:00
Thomas Harte
c1d1fb65cb
Made an attempt properly to emulate the RDY line and the Atari's use of it.
2015-07-31 16:54:20 -04:00
Thomas Harte
53dd5c8f16
Trying to fix my RDY line emulation. Switched to PAL timings, at least temporarily, since it's starting to make a difference.
2015-07-31 16:44:53 -04:00
Thomas Harte
39bfbf1000
Attempted ball graphics enable delay.
2015-07-30 23:01:28 -04:00
Thomas Harte
78e66d2577
Added an attempt at ball rendering.
2015-07-30 21:30:00 -04:00
Thomas Harte
a95b36a53d
Made first attempt at missile display. In Enduro, at least, one seems to work but the other seems to be absent.
2015-07-30 21:09:18 -04:00
Thomas Harte
1b7846f09b
Made a first attempt at the sprite latches. Hopefully this should make a few more Activision logos, etc, show up correctly.
2015-07-30 20:52:26 -04:00
Thomas Harte
1fa7a77793
Continuing in my attempts to figure out the complete absence of graphics from some games: there are 262 lines on an NTSC screen, not 256. Also ensured that the CRT has a little spare range at the edges so that its generated triangles don't wrap around just because of integer overflow.
2015-07-30 20:07:20 -04:00
Thomas Harte
98efae2536
Reintroduced emergency vertical sync — so that output occurs even when the emulation isn't catching syncs properly — and switched some spaces to tabs.
2015-07-30 17:16:49 -04:00
Thomas Harte
14adcd2096
Had a quick bash at timer overflow.
2015-07-30 16:09:32 -04:00
Thomas Harte
58908b60ac
So, provisionally: this looks like (i) the one cycle to write; plus (ii) the number of cycles to get to the end of the pixels (which is _horizontalTimer+1 for me because _horizontalTimer = 0 is a pixel); plus (iii) one cycle of latency to wake up. Am I making that up? Time will tell.
2015-07-30 15:49:38 -04:00
Thomas Harte
f5475369d6
Fixed foreshadowing of sprites yet to come. Put flipMask back the other way around.
2015-07-30 12:07:28 -04:00
Thomas Harte
f653b5dff3
Made a first tentative attempt at supporting all eight sprite modes.
2015-07-30 11:52:28 -04:00
Thomas Harte
151c6b4421
Quick fix: add one cycle to get to the genuine end of the line (i.e. after cycle 0, not on it). Not 3, with the video then becoming desynchronised from the CPU clock.
2015-07-30 00:00:35 -04:00
Thomas Harte
d1ae2caf91
Did the absolute minimum necessary to get some sprites showing in some capacity.
2015-07-29 23:48:52 -04:00
Thomas Harte
23df94d011
Got at least as far as putting a single dot at the player 0 and player 1 positions. Which may or may not be accurate.
2015-07-29 22:37:37 -04:00
Thomas Harte
164866d613
Collapsed two methods into one, to avoid redundant pixel copying.
2015-07-27 22:12:13 -04:00
Thomas Harte
3c25ead1f3
Started working out some of my retain cycles and general failures to release. Switched .mm filename so that Xcode will stop getting confused when I try to switch between implementation and interface files.
2015-07-27 21:15:10 -04:00
Thomas Harte
1f229ee6f7
More tweaks to provide a stable image, at least for the time being.
2015-07-27 20:18:25 -04:00
Thomas Harte
01109d441b
Made an attempt at NTSC colours. Hard coded in RGB, not composite. Short cuts, tsk.
2015-07-27 19:04:03 -04:00
Thomas Harte
caffe56a2d
Slightly expanded width of cathode ray gun, decided to figure out exactly how to deal with off-by-one lengths and precision at a later date, ensured that failure to catch vertical sync doesn't cause out-of-bounds buffer access on the hard-coded, assumed large enough, 512x512 data textures.
2015-07-27 00:28:47 -04:00
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
