6 Commits

Include renames

Author	SHA1	Message	Date
Se.Cherkasov	188444f987	feat(mmc5): implement MMC5 mapper with accurate scanline IRQ and CHR banking ... - Add ExRAM (modes 0-1) and fill-mode nametable routing via read_nametable_byte / write_nametable_byte mapper hooks - Separate sprite and BG CHR bank sets ($5120-$5127 vs $5128-$512B); BG banks are only active in 8x16 sprite mode - Use mapper.ppu_read_sprite() for sprite tile loads so they always use the sprite bank set regardless of PPU fetch phase - Replace CPU-cycle IRQ stub with scanline-based counter matching Mesen2 hardware behaviour: fire when counter == irq_scanline at dot 2 (start of scanline), irq_scanline=0 never fires - Add Mapper::notify_frame_start() called unconditionally at the PPU frame boundary; MMC5 uses it to hard-reset the scanline counter even when rendering is disabled (e.g. during room transitions), preventing stale counter values from shifting the CHR split by 8+ scanlines - Fix CHR bank calculation for modes 0-2: use << 3/2/1 shifts instead of & !7/3/1 masking to correctly convert bank numbers to 1KB indices - Correct $5204 read: bit 7 = IRQ pending (cleared on read), bit 6 = in-frame flag; IRQ line stays asserted until $5204 is read - Dispatch $4020-$5FFF CPU reads/writes to mapper cpu_read_low / cpu_write_low so MMC5 internal registers are accessible	2026-03-15 17:10:50 +03:00
Se.Cherkasov	d9666c23b4	feat: Hermite resampling, sprite shift registers, controller open bus ... #3 audio.rs: replace linear interpolation with Catmull-Rom Hermite cubic. Stores prev_sample as p0 control point; m1=(p2-p0)/2, m2=(p2-p1)/2 tangents give continuous first derivative across batch boundaries. #4 ppu: add per-slot sprite shift registers (spr_shift_lo/hi, spr_x_counter, spr_attr_latch). load_sprite_shifters fetches pattern bytes with h-flip at dot 1 of each visible scanline. sprite_pixel_from_shifters replaces the per-pixel OAM scan; sprite-0 hit detection integrated into the shifter path. #5 joypad.rs: format_controller_read now preserves bits 1-5,7 as open bus (!0x41 mask) instead of zeroing bits 1-4, matching NES hardware behaviour.	2026-03-15 11:30:14 +03:00
Se.Cherkasov	d8f41bc2c9	fix(apu): correct frame counter timing, add LP filter, mute aliased triangle ... - Fix frame counter running at 2× speed: clock_frame_counter now skips odd CPU cycles (APU cycle = CPU/2), so envelope, sweep, and length counters tick at the correct rate. Fixes sweep-driven whistle in Megaman II. - Switch audio sampling to per-CPU-cycle granularity in run_until_frame_complete_with_audio to eliminate square-wave harmonic aliasing caused by sampling only once per instruction. - Add IIR one-pole low-pass filter (~14 kHz) to AudioMixer to smooth abrupt level transitions (crackling) introduced by correct envelope timing. - Mute triangle channel when timer_period < 2 (≥27 kHz), which aliases into the audible range at 48 kHz. Real NES RC circuit removes these ultrasonics; emulator must suppress them explicitly. - Update all APU bus tests to use correct (doubled) CPU cycle counts.	2026-03-15 10:44:43 +03:00
Se.Cherkasov	d2be893cfe	fix: stabilize desktop audio playback	2026-03-13 19:20:33 +03:00
Se.Cherkasov	cd0a99a813	feat(apu): add timer/sequencer/LFSR fields for channel output tracking	2026-03-13 16:06:37 +03:00
Se.Cherkasov	bdf23de8db	Initial commit: NES emulator with GTK4 desktop frontend ... Full NES emulation: CPU, PPU, APU, 47 mappers, iNES/NES 2.0 parsing. GTK4 desktop client with HeaderBar, pixel-perfect Cairo rendering, drag-and-drop ROM loading, and keyboard shortcuts. 187 tests covering core emulation, mappers, and runtime.	2026-03-13 11:48:45 +03:00