- Fixed non-interlaced display modes from not drawing every other frame
- Changed OAM halve to skip every other scanline in 224-height modes
- Updated renderer to properly support games that switch resolutions mid-frame
- Fixed VRAM address remapping modes, fixes DQ3R, FF: MQ
- Fixed a bug in main color window clipping affecting BGs
- Added video color curve option, thanks to Overload for the idea + color table
- Added vblank, FPS counter, and DDraw surface memory options to settings menu
- Added fullscreen modes 640x480 and 1024x768 to video modes
- Added option to toggle the menubar on and off by pressing the escape key
- Mode3 was not rendering sprites
- Priorities were wrong for modes 2-4, thanks to anomie for info
- Fixed a serious bug in IRQ interrupts. May not be perfect, but helps many games
moving the window + main color window clipping into the bg/oam/mode7 rendering routines themselves, I was able to greatly simplify the most complicated part of rendering: the final pass where color add/sub effects are applied. As a result, the new PPU core is not only ~35% faster (on graphics intensive screens, even faster on simpler screens), but more accurate as well. Awesome.
In celebration, I´m releasing bsnes v0.008. I can actually run all games I have at >60fps on my Athlon 1.67ghz PC. Probably not something to brag about, though ...
Oh, and I also updated the keyboard polling code to only capture keypresses if the main window has focus. I´ve been meaning to do this for the better part of a year now, but never got around to it.
If, for some reason, you still want to use the old renderer, you can uncomment the first line in src/ppu/bppu/bppu.h and recompile the emulator yourself. Or you can use v0.007a, I´ll leave it up for a bit.
I have done quite a bit, so I´ll try my best to recap most of the fixes since the last release...
- HDMA was not running during DMA transfers
- Emulator did not recognize any filetype other than .smc
- Added configuration file support and imported my vector/string/config libraries into bsnes
- Added option to use system RAM instead of video RAM for display, this can greatly increase speed on certain video cards
- Increased speed by ~15% by adding 256x224 renderer (still very buggy when the SNES mixes video modes mid-frame)
- mvn/mvp opcodes were not setting the DB register
- Fixed joypad input in many games (Super Mario: All Stars, Dragon Quest III, etc.)
- Major speedup with frakeskip option
- Fixed default aspect ratio when emulator is first started
There´s probably a lot more, but that´s all I remember offhand... this release should be a lot closer to the quality of v0.005a, but still needs a bit more polishing.
The rewrite is now complete. I finished adding frameskip, and fixed some crashing issues with loading multiple ROMs. I wrapped all malloc/free calls with memalloc/memfree, which are custom functions that log each call, and let you pass sprintf-style arguments to them to debug memory leaks. Don´t see any, nor have I noticed any in bsnes; but it makes a nice test tool anyway.
I found out today that the mvn/mvp instructions actually set the DB register to the destination bank. Weird. This fixed Final Fantasy V, Chrono Trigger, and Dragon Quest III (which now runs as a result) graphics. Not all of them, but quite a few. I had also previously been setting the M/X flags of the P register when xce was executed. I never anticipated a game using xce while in native mode to switch to... native mode... but apparently, Chrono Trigger does. And my code was incorrect. So now Chrono Trigger gets past the name select screen, but dies a few screens after still.
The only really major flaw I am aware of that bsnes v0.005 did not have is with the battle screens in Squaresoft games. I get horrible flickering and "crushed scanlines" every other frame on them, for some reason. I´ll try and track that down for the next release, but I didn´t want to hold up a new release any longer. As a result, I´ll leave up v0.005a for the time being until I get this problem fixed.
Released a new version of bsnes today. Version 0.0.005 is up on the main page now.
The changes since .004 wip10 include: DRAM timing fix (now occurs mid-opcode), memory address speed fix, added CPU cycle condition 4 to all opcodes that use it, and fixed a bug where DRAM refresh was not changing start positions every other scanline.
With the new version, Chrono Trigger should get a little further, and Final Fantasy 5 should get in-game now. The only problem FF5 seems to have is sprite corrution in the menus. I´m too busy with the CPU timing to mess around with the PPU right now, though. Also, the APU is not bridged to the CPU in this release, so compatibility is (still) really low.
After I get the APU working fairly well, I´ll (try and) start keeping a what´s new file so that people can know what all changed between public releases of the emulator without having to follow this page. Sorry for the inconvenience in the mean time.
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Doubled the width of sprites when the width of the screen is 512. The SNES Test Program now runs through all of the character test correctly. The windows are off-by-one though.
Added the very bizarre 00:4300-00:437f memory region that is unique from 7e:4300-7e:437f. Then I added read support from $2180. This allowed the SNES Test Program to not crash after failing the electronics test, and it also fixed the horrible graphics corruption in Der Langrisser.
The fonts were still failing, so I went in with my tracer and found out what was causing it. The following code:
gx816->regs.pc += (signed char)(arg + 2);
This is the code used to increment the pc counter after relative branches. The problem is that I had parinthesis around the + 2 as well as arg. Therefore, if arg was 0x7e, 0x7f, 0xfe, or 0xff, it would change the sign. This would in turn make the program counter off by 256 bytes. Very bad. Fixing this fixed the font in Der Langrisser, and also fixed Super Mario World, when Yoshi spits a turtle out, the game will no longer crash.
Next, via the Der Langrisser world map, I realized that anomie´s description of the BG/mode7 register latches was reversed: the BG registers (may) share a common latch between all of them, but the mode7 registers do not. I removed the common latches from the mode7 regs, but I haven´t added the latch to the BG registers yet.
I also realized that clearing the entire screen on a BG mode change would probably not be a good thing for games that change video modes mid-frame. So I tried working on getting the weird single-frame garble that pops up every minute or so to go away, but to no avail. I´m having a difficult time tracking down the exact cause of the error, but I believe it to be a buffer overflow, or something along those lines.
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The bug in the Bahamut Lagoon mode7 screens turned out to be that I never added the dividend result to $4216/$4217. It always returned the multiplication of $4202/$4203. This also fixed the sprites in battles for Dai Kaijuu Monogatari. I added a bunch of window stuff, including a double size windowed mode, and a fullscreen mode. Lots of fixes to the interface, as well as code cleanup. It's still pretty buggy, there's a lot of variables to keep up with in the GUI at present...
I also added better tile caching, I just cache all tiles when they are rendered, for all 3 color depths (4, 16, 256). Seems to help a little. A portion of the speed gain was lost by fixing the dividend result, though. Very strange, since I wouldn't think much work would go into a simple line of code that's called 20 times a frame probably at best... oh well.
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First, I fixed some issues with the mode7 / scroll regs thanks to info from anomie. Qwertie's mode7 demo runs without modification now. Next, I fixed a small glitch with tiles getting cut off on the right edge of the screen, fixes some flickering on the edges in Zelda 3. Finally, I added tile caching to all 4 BG layers. It didn't really increase speed by much (~10%), and upped the RAM requirements by 1.2mb... I left the old code in case I need to fall back on it. My only guess (hope) is that the bottleneck lies somewhere else...
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Had a small glitch in the OAM $2102/$2103 register settings, fixed that and now both Zelda 3 and Super Mario World always show sprites perfectly. The only error to my knowledge in the below screenshots is that the large version of the mario sprite in the third pic is not shown at the top left of the screen. Which could be because I have no mosaic support. But at any rate, both games should be completely playable now, albeit very slowly. I tried to speed up things by caching some stuff in the PPU, but I couldn't find a nice way to implement it that would result in a significant speed increase. Oh yeah, Zelda won't follow you in Zelda 3, but you can just go to the throne room and push the picture to the right yourself, and she'll appear when you reach the sanctuary.
I also updated the debugger, it uses a smaller font, which is a bit harder to read, but saves a lot of screen space. This will definately be needed when I add in more of the debugging windows in the future, so it's better to get used to it now than later.
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Added SRAM support. It's compatible with other emulators. It maps both the LoROM SRAM between $700000-$7dffff, and HiROM SRAM between $3n6000-$3n7fff (where n = 0 - f).
Modified the screen to redraw at scanline 224, instead of 0. Fixes some flickering between screens in some games.
Moved the lighting adjustment code ($2100 bits 0-3) directly into the PPU, rather than outside in the platform-specific code. This is because games have the ability to adjust this value per scanline. Also allowed the games to control the background enable ($2100 bit 7) flag per scanline now. This allowed Bahamut Lagoon's dragon intro to work.
I then added mode2 support, so now all that's missing is modes 5 and 6 (interlaced).
I also created an easy #define to select between the public domain mode7 code I wrote, and the snes9x mode7 code. I'll go through one of these days and rewrite the snes9x code in a clean environment (e.g. without using the current mode7 file as a reference) to avoid the issue altogether, but for now... the snes9x code is twice as fast, and that's good enough for me.
Lastly, I also added in a trace checkbox to enable tracing. As such, the zip file of my work up now has debug mode enabled by default. I really need an overhaul of the gui implementation, and a configuration file. I have a very nice string library system (that I wrote myself) that I would love to take advantage of in this project.
Here's some screenshots of the dragon intro. Lots of HDMA here, showing that I pretty much have HDMA down, now. I remember zsnes used to have a problem with these screens, and had to do something with an HDMA hack to get around it. They figured out what the problem was, eventually. I was actually quite surprised my emulator does not suffer from this same problem. Lucky for me, as they never did mention what the problem was to begin with. The HDMA is technically drawing too soon (at the start of the scanline instead of the end) which probably messes things up a bit, and I'm guessing the scroll registers are screwing up in one or two of the below pics. No mosaic support either.
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byuu