diff options
Diffstat (limited to 'src/apu.rs')
| -rw-r--r-- | src/apu.rs | 175 |
1 files changed, 118 insertions, 57 deletions
@@ -1,7 +1,11 @@ #![allow(dead_code)] use mos6502::CPU_FREQ; use memory::CPUBus; +use utils::Sampler; +use core::mem::size_of; +use utils::{Read, Write, load_prefix, save_prefix}; +#[repr(C)] struct LPFilter { prev_out: i16 } @@ -25,6 +29,14 @@ impl LPFilter { LPFilter { prev_out: 0 } } + fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, 0, reader) + } + + fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, 0, writer) + } + fn output(&mut self, input: i16) -> i16 { let out = cutoff(self.prev_out as i32 + (input as i32 - self.prev_out as i32) @@ -34,6 +46,7 @@ impl LPFilter { } } +#[repr(C)] struct HPFilter { prev_in: i16, prev_out: i16, @@ -49,6 +62,14 @@ impl HPFilter { } } + fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, 0, reader) + } + + fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, 0, writer) + } + fn output(&mut self, input: i16) -> i16 { let out = cutoff( self.prev_out as i32 * self.hp_factor / AUDIO_LEVEL_MAX + @@ -137,52 +158,7 @@ const TND_TABLE: [u16; 203] = [ 0xbbfe, 0xbc84, 0xbd09, 0xbd8d, 0xbe11 ]; -pub struct Sampler { - freq2: u32, - q0: u32, - r0: u32, - ddl: (u32, u32), - cnt: u32, - sec_cnt: u32 -} - -impl Sampler { - pub fn new(freq1: u32, freq2: u32) -> Self { - let q0 = freq1 / freq2; - let r0 = freq1 - q0 * freq2; - Sampler { - freq2, - q0, - r0, - ddl: (q0, r0), - cnt: 0, - sec_cnt: 0 - } - } - - pub fn tick(&mut self) -> (bool, bool) { - let (q, r) = self.ddl; - if self.cnt == q { - let nr = r + self.r0; - self.ddl = if nr > self.freq2 { - (self.q0, nr - self.freq2) - } else { - (self.q0 - 1, nr) - }; - self.cnt = 0; - self.sec_cnt += 1; - let sec = self.sec_cnt == self.freq2; - if sec { - self.sec_cnt = 0 - } - (true, sec) - } else { - self.cnt += 1; - (false, false) - } - } -} - +#[repr(C)] pub struct Pulse { /* envelope */ env_period: u8, @@ -223,6 +199,14 @@ impl Pulse { seq_wave: 0, seq_cnt: 0, enabled: false, comple} } + fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, 0, reader) + } + + fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, 0, writer) + } + pub fn write_reg1(&mut self, data: u8) { self.seq_wave = DUTY_TABLE[(data >> 6) as usize]; self.env_loop = data & 0x20 == 0x20; @@ -351,6 +335,7 @@ impl Pulse { } } +#[repr(C)] pub struct Triangle { /* linear counter */ cnt_rld: bool, @@ -377,6 +362,14 @@ impl Triangle { } } + fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, 0, reader) + } + + fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, 0, writer) + } + pub fn write_reg1(&mut self, data: u8) { self.cnt_rld_val = data & 0x7f; self.ctrl = data >> 7 == 1; @@ -452,6 +445,7 @@ impl Triangle { } +#[repr(C)] pub struct Noise { /* envelope */ env_period: u8, @@ -482,6 +476,14 @@ impl Noise { enabled: false} } + fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, 0, reader) + } + + fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, 0, writer) + } + pub fn write_reg1(&mut self, data: u8) { self.env_loop = data & 0x20 == 0x20; self.env_const = data & 0x10 == 0x10; @@ -564,6 +566,7 @@ impl Noise { } } +#[repr(C)] pub struct DMC { dmc_loop: bool, dmc_cnt: u8, @@ -591,6 +594,14 @@ impl DMC { } } + fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, 0, reader) + } + + fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, 0, writer) + } + pub fn write_reg1(&mut self, data: u8) { self.irq_enabled = (data >> 7) == 1; self.dmc_loop = data & 0x40 == 0x40; @@ -681,27 +692,49 @@ impl DMC { fn output(&self) -> u8 { self.level } } +#[repr(C)] pub struct APU<'a> { + /*-- begin state --*/ + frame_lvl: u8, + frame_mode: bool, /* true for 5-step mode */ + frame_inh: bool, + frame_int: bool, + cycle_even: bool, + /*-- end state --*/ + + /*-- begin sub-state --*/ pub pulse1: Pulse, pub pulse2: Pulse, pub triangle: Triangle, pub noise: Noise, pub dmc: DMC, - frame_lvl: u8, - frame_mode: bool, /* true for 5-step mode */ - frame_inh: bool, - frame_int: bool, + + lp_filter: LPFilter, + hp_filter1: HPFilter, + hp_filter2: HPFilter, + frame_sampler: Sampler, audio_sampler: Sampler, - cycle_even: bool, + /*-- end sub-state --*/ + spkr: &'a mut Speaker, - lp_filter: LPFilter, - hp_filter1: HPFilter, - hp_filter2: HPFilter } +const APU_IGNORED_SIZE: usize = + size_of::<Pulse>() + + size_of::<Pulse>() + + size_of::<Triangle>() + + size_of::<Noise>() + + size_of::<DMC>() + + size_of::<LPFilter>() + + size_of::<HPFilter>() + + size_of::<HPFilter>() + + size_of::<Sampler>() + + size_of::<Sampler>() + + size_of::<&Speaker>(); + impl<'a> APU<'a> { - pub fn new(spkr: &'a mut Speaker/*, bus: &'a CPUBus<'a>*/) -> Self { + pub fn new(spkr: &'a mut Speaker) -> Self { APU { pulse1: Pulse::new(false), pulse2: Pulse::new(true), triangle: Triangle::new(), @@ -718,12 +751,40 @@ impl<'a> APU<'a> { } } + pub fn load(&mut self, reader: &mut Read) -> bool { + load_prefix(self, APU_IGNORED_SIZE, reader) && + self.pulse1.load(reader) && + self.pulse2.load(reader) && + self.triangle.load(reader) && + self.noise.load(reader) && + self.dmc.load(reader) && + self.lp_filter.load(reader) && + self.hp_filter1.load(reader) && + self.hp_filter2.load(reader) && + self.frame_sampler.load(reader) && + self.audio_sampler.load(reader) + } + + pub fn save(&self, writer: &mut Write) -> bool { + save_prefix(self, APU_IGNORED_SIZE, writer) && + self.pulse1.save(writer) && + self.pulse2.save(writer) && + self.triangle.save(writer) && + self.noise.save(writer) && + self.dmc.save(writer) && + self.lp_filter.save(writer) && + self.hp_filter1.save(writer) && + self.hp_filter2.save(writer) && + self.frame_sampler.save(writer) && + self.audio_sampler.save(writer) + } + pub fn tick(&mut self, bus: &CPUBus) -> bool { let mut irq = false; - if let (true, _) = self.frame_sampler.tick() { + if self.frame_sampler.tick() { irq = self.tick_frame_counter(); } - if let (true, _) = self.audio_sampler.tick() { + if self.audio_sampler.tick() { let sample = self.output(); self.spkr.queue(sample); } |