bsnes/higan/md/apu/apu.cpp

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Update to v100r02 release. byuu says: Sigh ... I'm really not a good person. I'm inherently selfish. My responsibility and obligation right now is to work on loki, and then on the Tengai Makyou Zero translation, and then on improving the Famicom emulation. And yet ... it's not what I really want to do. That shouldn't matter; I should work on my responsibilities first. Instead, I'm going to be a greedy, self-centered asshole, and work on what I really want to instead. I'm really sorry, guys. I'm sure this will make a few people happy, and probably upset even more people. I'm also making zero guarantees that this ever gets finished. As always, I wish I could keep these things secret, so if I fail / give up, I could just drop it with no shame. But I would have to cut everyone out of the WIP process completely to make it happen. So, here goes ... This WIP adds the initial skeleton for Sega Mega Drive / Genesis emulation. God help us. (minor note: apparently the new extension for Mega Drive games is .md, neat. That's what I chose for the folders too. I thought it was .smd, so that'll be fixed in icarus for the next WIP.) (aside: this is why I wanted to get v100 out. I didn't want this code in a skeleton state in v100's source. Nor did I want really broken emulation, which the first release is sure to be, tarring said release.) ... So, basically, I've been ruminating on the legacy I want to leave behind with higan. 3D systems are just plain out. I'm never going to support them. They're too complex for my abilities, and they would run too slowly with my design style. I'm not willing to compromise my design ideals. And I would never want to play a 3D game system at native 240p/480i resolution ... but 1080p+ upscaling is not accurate, so that's a conflict I want to avoid entirely. It's also never going to emulate computer systems (X68K, PC-98, FM-Towns, etc) because holy shit that would completely destroy me. It's also never going emulate arcade machines. So I think of higan as a collection of 2D emulators for consoles and handhelds. I've gone over every major 2D gaming system there is, looking for ones with games I actually care about and enjoy. And I basically have five of those systems supported already. Looking at the remaining list, I see only three systems left that I have any interest in whatsoever: PC-Engine, Master System, Mega Drive. Again, I'm not in any way committing to emulating any of these, but ... if I had all of those in higan, I think I'd be content to really, truly, finally stop writing more emulators for the rest of my life. And so I decided to tackle the most difficult system first. If I'm successful, the Z80 core should cover a lot of the work on the SMS. And the HuC6280 should land somewhere between the NES and SNES in terms of difficulty ... closer to the NES. The systems that just don't appeal to me at all, which I will never touch, include, but are not limited to: * Atari 2600/5200/7800 * Lynx * Jaguar * Vectrex * Colecovision * Commodore 64 * Neo-Geo * Neo-Geo Pocket / Color * Virtual Boy * Super A'can * 32X * CD-i * etc, etc, etc. And really, even if something were mildly interesting in there ... we have to stop. I can't scale infinitely. I'm already way past my limit, but I'm doing this anyway. Too many cores bloats everything and kills quality on everything. I don't want higan to become MESS v2. I don't know what I'll do about the Famicom Disk System, PC-Engine CD, and Mega CD. I don't think I'll be able to achieve 60fps emulating the Mega CD, even if I tried to. I don't know what's going to happen here with even the Mega Drive. Maybe I'll get driven crazy with the documentation and quit. Maybe it'll end up being too complicated and I'll quit. Maybe the emulation will end up way too slow and I'll give up. Maybe it'll take me seven years to get any games playable at all. Maybe Steve Snake, AamirM and Mike Pavone will pool money to hire a hitman to come after me. Who knows. But this is what I want to do, so ... here goes nothing.
2016-07-09 04:21:37 +00:00
#include <md/md.hpp>
namespace MegaDrive {
APU apu;
auto APU::Enter() -> void {
while(true) scheduler.synchronize(), apu.main();
}
auto APU::main() -> void {
Update to v101r04 release. byuu says: Changelog: - pulled the (u)intN type aliases into higan instead of leaving them in nall - added 68K LINEA, LINEF hooks for illegal instructions - filled the rest of the 68K lambda table with generic instance of ILLEGAL - completed the 68K disassembler effective addressing modes - still unsure whether I should use An to decode absolute addresses or not - pro: way easier to read where accesses are taking place - con: requires An to be valid; so as a disassembler it does a poor job - making it optional: too much work; ick - added I/O decoding for the VDP command-port registers - added skeleton timing to all five processor cores - output at 1280x480 (needed for mixed 256/320 widths; and to handle interlace modes) The VDP, PSG, Z80, YM2612 are all stepping one clock at a time and syncing; which is the pathological worst case for libco. But they also have no logic inside of them. With all the above, I'm averaging around 250fps with just the 68K core actually functional, and the VDP doing a dumb "draw white pixels" loop. Still way too early to tell how this emulator is going to perform. Also, the 320x240 mode of the Genesis means that we don't need an aspect correction ratio. But we do need to ensure the output window is a multiple 320x240 so that the scale values work correctly. I was hard-coding aspect correction to stretch the window an additional \*8/7. But that won't work anymore so ... the main higan window is now 640x480, 960x720, or 1280x960. Toggling aspect correction only changes the video width inside the window. It's a bit jarring ... the window is a lot wider, more black space now for most modes. But for now, it is what it is.
2016-08-12 01:07:04 +00:00
step(1);
}
auto APU::step(uint clocks) -> void {
Update to v101r04 release. byuu says: Changelog: - pulled the (u)intN type aliases into higan instead of leaving them in nall - added 68K LINEA, LINEF hooks for illegal instructions - filled the rest of the 68K lambda table with generic instance of ILLEGAL - completed the 68K disassembler effective addressing modes - still unsure whether I should use An to decode absolute addresses or not - pro: way easier to read where accesses are taking place - con: requires An to be valid; so as a disassembler it does a poor job - making it optional: too much work; ick - added I/O decoding for the VDP command-port registers - added skeleton timing to all five processor cores - output at 1280x480 (needed for mixed 256/320 widths; and to handle interlace modes) The VDP, PSG, Z80, YM2612 are all stepping one clock at a time and syncing; which is the pathological worst case for libco. But they also have no logic inside of them. With all the above, I'm averaging around 250fps with just the 68K core actually functional, and the VDP doing a dumb "draw white pixels" loop. Still way too early to tell how this emulator is going to perform. Also, the 320x240 mode of the Genesis means that we don't need an aspect correction ratio. But we do need to ensure the output window is a multiple 320x240 so that the scale values work correctly. I was hard-coding aspect correction to stretch the window an additional \*8/7. But that won't work anymore so ... the main higan window is now 640x480, 960x720, or 1280x960. Toggling aspect correction only changes the video width inside the window. It's a bit jarring ... the window is a lot wider, more black space now for most modes. But for now, it is what it is.
2016-08-12 01:07:04 +00:00
Thread::step(clocks);
synchronize(cpu);
}
auto APU::wait() -> void {
step(1);
}
auto APU::read(uint16 addr) -> uint8 {
step(1);
return 0x00;
}
auto APU::write(uint16 addr, uint8 data) -> void {
step(1);
}
auto APU::power() -> void {
}
auto APU::reset() -> void {
create(APU::Enter, system.colorburst());
}
Update to v100r02 release. byuu says: Sigh ... I'm really not a good person. I'm inherently selfish. My responsibility and obligation right now is to work on loki, and then on the Tengai Makyou Zero translation, and then on improving the Famicom emulation. And yet ... it's not what I really want to do. That shouldn't matter; I should work on my responsibilities first. Instead, I'm going to be a greedy, self-centered asshole, and work on what I really want to instead. I'm really sorry, guys. I'm sure this will make a few people happy, and probably upset even more people. I'm also making zero guarantees that this ever gets finished. As always, I wish I could keep these things secret, so if I fail / give up, I could just drop it with no shame. But I would have to cut everyone out of the WIP process completely to make it happen. So, here goes ... This WIP adds the initial skeleton for Sega Mega Drive / Genesis emulation. God help us. (minor note: apparently the new extension for Mega Drive games is .md, neat. That's what I chose for the folders too. I thought it was .smd, so that'll be fixed in icarus for the next WIP.) (aside: this is why I wanted to get v100 out. I didn't want this code in a skeleton state in v100's source. Nor did I want really broken emulation, which the first release is sure to be, tarring said release.) ... So, basically, I've been ruminating on the legacy I want to leave behind with higan. 3D systems are just plain out. I'm never going to support them. They're too complex for my abilities, and they would run too slowly with my design style. I'm not willing to compromise my design ideals. And I would never want to play a 3D game system at native 240p/480i resolution ... but 1080p+ upscaling is not accurate, so that's a conflict I want to avoid entirely. It's also never going to emulate computer systems (X68K, PC-98, FM-Towns, etc) because holy shit that would completely destroy me. It's also never going emulate arcade machines. So I think of higan as a collection of 2D emulators for consoles and handhelds. I've gone over every major 2D gaming system there is, looking for ones with games I actually care about and enjoy. And I basically have five of those systems supported already. Looking at the remaining list, I see only three systems left that I have any interest in whatsoever: PC-Engine, Master System, Mega Drive. Again, I'm not in any way committing to emulating any of these, but ... if I had all of those in higan, I think I'd be content to really, truly, finally stop writing more emulators for the rest of my life. And so I decided to tackle the most difficult system first. If I'm successful, the Z80 core should cover a lot of the work on the SMS. And the HuC6280 should land somewhere between the NES and SNES in terms of difficulty ... closer to the NES. The systems that just don't appeal to me at all, which I will never touch, include, but are not limited to: * Atari 2600/5200/7800 * Lynx * Jaguar * Vectrex * Colecovision * Commodore 64 * Neo-Geo * Neo-Geo Pocket / Color * Virtual Boy * Super A'can * 32X * CD-i * etc, etc, etc. And really, even if something were mildly interesting in there ... we have to stop. I can't scale infinitely. I'm already way past my limit, but I'm doing this anyway. Too many cores bloats everything and kills quality on everything. I don't want higan to become MESS v2. I don't know what I'll do about the Famicom Disk System, PC-Engine CD, and Mega CD. I don't think I'll be able to achieve 60fps emulating the Mega CD, even if I tried to. I don't know what's going to happen here with even the Mega Drive. Maybe I'll get driven crazy with the documentation and quit. Maybe it'll end up being too complicated and I'll quit. Maybe the emulation will end up way too slow and I'll give up. Maybe it'll take me seven years to get any games playable at all. Maybe Steve Snake, AamirM and Mike Pavone will pool money to hire a hitman to come after me. Who knows. But this is what I want to do, so ... here goes nothing.
2016-07-09 04:21:37 +00:00
}