From 97a689ab55eebe8dec752ebcbec1c703febaeb97 Mon Sep 17 00:00:00 2001 From: Rekai Musuka Date: Wed, 20 Apr 2022 09:39:12 -0300 Subject: [PATCH] chore: broken impl of ch1 --- src/apu.zig | 403 ++++++++++++++++++++++++++++++++++++++++++++-- src/scheduler.zig | 9 ++ 2 files changed, 401 insertions(+), 11 deletions(-) diff --git a/src/apu.zig b/src/apu.zig index 5800061..7bc8d4b 100644 --- a/src/apu.zig +++ b/src/apu.zig @@ -32,9 +32,11 @@ pub const Apu = struct { stream: *SDL.SDL_AudioStream, sched: *Scheduler, + fs: FrameSequencer, + pub fn init(sched: *Scheduler) Self { const apu: Self = .{ - .ch1 = ToneSweep.init(), + .ch1 = ToneSweep.init(sched), .ch2 = Tone.init(), .ch3 = Wave.init(), .ch4 = Noise.init(), @@ -49,9 +51,13 @@ pub const Apu = struct { .sampling_cycle = 0b00, .stream = SDL.SDL_NewAudioStream(SDL.AUDIO_F32, 2, 1 << 15, SDL.AUDIO_F32, 2, host_sample_rate) orelse unreachable, .sched = sched, + + .fs = FrameSequencer.init(), }; sched.push(.SampleAudio, sched.now() + apu.sampleTicks()); + sched.push(.{ .ApuChannel = 0 }, sched.now() + SquareWave.ticks); + sched.push(.FrameSequencer, sched.now() + ((1 << 24) / 1 << 15)); return apu; } @@ -67,14 +73,39 @@ pub const Apu = struct { self.dma_cnt = new; } + /// NR52 pub fn setSoundCntX(self: *Self, value: bool) void { self.cnt.apu_enable.write(value); + + if (value) { + self.fs.step = 0; // Reset Frame Sequencer + + // TODO: Reset Duty position for Square channels + + // TODO: Reset Channel 3 offset ptr + } else { + // TODO: Reset APU + } } + /// NR52 + pub fn soundCntX(self: *const Self) u32 { + const apu_enable = @boolToInt(self.cnt.apu_enable.read()); + + const ch1_enable = @boolToInt(self.ch1.enabled); + const ch2_enable = @boolToInt(self.ch2.enabled); + const ch3_enable = @boolToInt(self.ch3.enabled); + const ch4_enable = @boolToInt(self.ch4.enabled); + + return apu_enable << 7 | ch4_enable << 3 | ch3_enable << 2 | ch2_enable << 1 | ch1_enable; + } + + /// NR50 pub fn setSoundCntLLow(self: *Self, byte: u8) void { self.ch_vol_cnt.raw = (self.ch_vol_cnt.raw & 0xFF00) | byte; } + /// NR51 pub fn setSoundCntLHigh(self: *Self, byte: u8) void { self.ch_vol_cnt.raw = @as(u16, byte) << 8 | (self.ch_vol_cnt.raw & 0xFF); } @@ -84,16 +115,26 @@ pub const Apu = struct { } pub fn sampleAudio(self: *Self, late: u64) void { - const chA = if (self.dma_cnt.chA_vol.read()) self.chA.amplitude() else self.chA.amplitude() / 2; - const chA_left = if (self.dma_cnt.chA_left.read()) chA else 0; - const chA_right = if (self.dma_cnt.chA_right.read()) chA else 0; - const chB = if (self.dma_cnt.chB_vol.read()) self.chB.amplitude() else self.chB.amplitude() / 2; - const chB_left = if (self.dma_cnt.chB_left.read()) chB else 0; - const chB_right = if (self.dma_cnt.chB_right.read()) chB else 0; + // Sample Channel 1 + const ch1_sample = self.ch1.amplitude(); + const ch1_left = if (self.ch_vol_cnt.ch1_left.read()) ch1_sample else 0; + const ch1_right = if (self.ch_vol_cnt.ch1_right.read()) ch1_sample else 0; - const left = (chA_left + chB_left) / 2; - const right = (chA_right + chB_right) / 2; + // Sample Dma Channels + // const chA = if (self.dma_cnt.chA_vol.read()) self.chA.amplitude() else self.chA.amplitude() / 2; + // const chA_left = if (self.dma_cnt.chA_left.read()) chA else 0; + // const chA_right = if (self.dma_cnt.chA_right.read()) chA else 0; + + // const chB = if (self.dma_cnt.chB_vol.read()) self.chB.amplitude() else self.chB.amplitude() / 2; + // const chB_left = if (self.dma_cnt.chB_left.read()) chB else 0; + // const chB_right = if (self.dma_cnt.chB_right.read()) chB else 0; + + // Mix all Channels + // const left = (chA_left + chB_left + ch1_left) / 3; + // const right = (chA_right + chB_right + ch1_right) / 3 + const left = ch1_left; + const right = ch1_right; if (self.sampling_cycle != self.bias.sampling_cycle.read()) { log.warn("Sampling Cycle changed from {} to {}", .{ self.sampling_cycle, self.bias.sampling_cycle.read() }); @@ -121,6 +162,36 @@ pub const Apu = struct { return @as(u64, 1) << (15 + @as(u6, self.bias.sampling_cycle.read())); } + pub fn tickFrameSequencer(self: *Self, late: u64) void { + self.fs.tick(); + + switch (self.fs.step) { + 7 => self.tickEnvelopes(), // Clock Envelope + 0, 4 => self.tickLengths(), // Clock Length + 2, 6 => { + // Clock Length and Sweep + self.tickLengths(); + self.ch1.tickSweep(); + }, + 1, 3, 5 => {}, + } + + self.sched.push(.FrameSequencer, self.sched.now() + ((1 << 24) / 1 << 15) - late); + } + + fn tickLengths(self: *Self) void { + self.ch1.tickLength(); + self.ch2.tickLength(); + self.ch3.tickLength(); + self.ch4.tickLength(); + } + + fn tickEnvelopes(self: *Self) void { + self.ch1.tickEnvelope(); + self.ch2.tickEnvelope(); + self.ch4.tickEnvelope(); + } + pub fn handleTimerOverflow(self: *Self, cpu: *Arm7tdmi, tim_id: u3) void { if (!self.cnt.apu_enable.read()) return; @@ -148,21 +219,159 @@ const ToneSweep = struct { /// NR13, NR14 freq: io.Frequency, - fn init() Self { + /// Length Functionality + len_dev: Length, + + /// Sweep Functionality + sweep_dev: Sweep, + + /// Envelope Functionality + env_dev: Envelope, + + square: SquareWave, + + enabled: bool, + + sample: u8, + + const Sweep = struct { + const This = @This(); + + timer: u8, + enabled: bool, + shadow: u11, + + pub fn init() This { + return .{ + .timer = 0, + .enabled = false, + .shadow = 0, + }; + } + + pub fn tick(this: *This, ch1: *Self) void { + if (this.timer != 0) this.timer -= 1; + + if (this.timer == 0) { + const period = ch1.sweep.period.read(); + this.timer = if (period == 0) 8 else period; + + if (this.enabled and period != 0) { + const new_freq: u11 = this.calcFrequency(ch1); + + if (new_freq <= 0x7FF and ch1.sweep.shift.read() != 0) { + ch1.freq.frequency.write(new_freq); + this.shadow = new_freq; + + _ = this.calcFrequency(ch1); + } + } + } + } + + fn calcFrequency(this: *This, ch1: *Self) u11 { + const shadow_shifted = this.shadow >> ch1.sweep.shift.read(); + const decrease = ch1.sweep.direction.read(); + const freq = if (decrease) this.shadow - shadow_shifted else this.shadow + shadow_shifted; + + if (freq > 0x7FF) ch1.enabled = false; + + return freq; + } + }; + + fn init(sched: *Scheduler) Self { return .{ .sweep = .{ .raw = 0 }, .duty = .{ .raw = 0 }, .envelope = .{ .raw = 0 }, .freq = .{ .raw = 0 }, + .sample = 0, + .enabled = false, + + .square = SquareWave.init(sched), + .len_dev = Length.init(), + .sweep_dev = Sweep.init(), + .env_dev = Envelope.init(), }; } + fn tickSweep(self: *Self) void { + self.sweep_dev.tick(self); + } + + pub fn tickLength(self: *Self) void { + self.len_dev.tick(self.freq, &self.enabled); + } + + pub fn tickEnvelope(self: *Self) void { + self.env_dev.tick(self.envelope); + } + + pub fn channelTimerOverflow(self: *Self, late: u64) void { + self.square.handleTimerOverflow(self.freq, late); + + self.sample = 0; + if (!self.isDacEnabled()) return; + self.sample = if (self.enabled) self.square.getSample(self.duty) * self.env_dev.vol else 0; + } + + fn amplitude(self: *const Self) f32 { + return (@intToFloat(f32, self.sample) / 7.5) - 1.0; + } + + /// NR11 + pub fn setDuty(self: *Self, value: u8) void { + self.duty.raw = value; + self.len_dev.timer = 64 - self.duty.length.read(); + } + + /// NR12 + pub fn setEnvelope(self: *Self, value: u8) void { + self.envelope.raw = value; + if (!self.isDacEnabled()) self.enabled = false; + } + + /// NR13 pub fn setFreqLow(self: *Self, byte: u8) void { self.freq.raw = (self.freq.raw & 0xFF00) | byte; } + /// NR14 pub fn setFreqHigh(self: *Self, byte: u8) void { - self.freq.raw = (@as(u16, byte) << 8) | (self.freq.raw & 0xFF); + var new: io.Frequency = .{ .raw = (@as(u16, byte) << 8) | (self.freq.raw & 0xFF) }; + + if (new.trigger.read()) { + if (self.len_dev.timer == 0) { + self.len_dev.timer = 64; + + // FIXME: This conflicts with my GB emulator + new.length_enable.write(false); + } + + // TODO: Reload Frequency Timer (last two bits unmodified) + self.square.reloadTimer(self.freq.frequency.read()); + // Reload Envelope period and timer + self.env_dev.timer = self.envelope.period.read(); + self.env_dev.vol = self.envelope.init_vol.read(); + + // Sweep Trigger Behaviour + const sw_period = self.sweep.period.read(); + const sw_shift = self.sweep.shift.read(); + + self.sweep_dev.shadow = self.freq.frequency.read(); + self.sweep_dev.timer = if (sw_period == 0) 8 else sw_period; + self.sweep_dev.enabled = sw_period != 0 or sw_shift != 0; + if (sw_shift != 0) _ = self.sweep_dev.calcFrequency(self); + + self.enabled = self.isDacEnabled(); + } + + self.freq = new; + } + + fn isDacEnabled(self: *const Self) bool { + return self.envelope.raw & 0xF8 != 0; } }; @@ -176,14 +385,34 @@ const Tone = struct { /// NR23, NR24 freq: io.Frequency, + /// Length Functionarlity + len_dev: Length, + + /// Envelope Functionality + env_dev: Envelope, + + enabled: bool, + fn init() Self { return .{ .duty = .{ .raw = 0 }, .envelope = .{ .raw = 0 }, .freq = .{ .raw = 0 }, + .enabled = false, + + .len_dev = Length.init(), + .env_dev = Envelope.init(), }; } + pub fn tickLength(self: *Self) void { + self.len_dev.tick(self.freq, &self.enabled); + } + + pub fn tickEnvelope(self: *Self) void { + self.env_dev.tick(self.envelope); + } + pub fn setFreqLow(self: *Self, byte: u8) void { self.freq.raw = (self.freq.raw & 0xFF00) | byte; } @@ -206,15 +435,27 @@ const Wave = struct { /// NR33, NR34 freq: io.Frequency, + /// Length Functionarlity + len_dev: Length, + + enabled: bool, + fn init() Self { return .{ .select = .{ .raw = 0 }, .vol = .{ .raw = 0 }, .freq = .{ .raw = 0 }, .length = 0, + + .len_dev = Length.init(), + .enabled = false, }; } + pub fn tickLength(self: *Self) void { + self.len_dev.tick(self.freq, &self.enabled); + } + pub fn setFreqLow(self: *Self, byte: u8) void { self.freq.raw = (self.freq.raw & 0xFF00) | byte; } @@ -237,14 +478,34 @@ const Noise = struct { /// NR44 cnt: io.NoiseControl, + /// Length Functionarlity + len_dev: Length, + + /// Envelope Functionality + env_dev: Envelope, + + enabled: bool, + fn init() Self { return .{ .len = 0, .envelope = .{ .raw = 0 }, .poly = .{ .raw = 0 }, .cnt = .{ .raw = 0 }, + .enabled = false, + + .len_dev = Length.init(), + .env_dev = Envelope.init(), }; } + + pub fn tickLength(self: *Self) void { + self.len_dev.ch4Tick(self.cnt, &self.enabled); + } + + pub fn tickEnvelope(self: *Self) void { + self.env_dev.tick(self.envelope); + } }; pub fn DmaSound(comptime kind: DmaSoundKind) type { @@ -285,3 +546,123 @@ const DmaSoundKind = enum { A, B, }; + +const FrameSequencer = struct { + const Self = @This(); + + step: u3, + + pub fn init() Self { + return .{ .step = 0 }; + } + + pub fn tick(self: *Self) void { + self.step +%= 1; + } +}; + +const Length = struct { + const Self = @This(); + + timer: u16, + + pub fn init() Self { + return .{ .timer = 0 }; + } + + fn tick(self: *Self, freq: io.Frequency, ch_enabled: *bool) void { + const len_enable = freq.length_enable.read(); + + if (len_enable and self.timer > 0) { + self.timer -= 1; + + // if length timer is now 0 + if (self.timer == 0) ch_enabled.* = false; + } + } + + fn ch4Tick(self: *Self, cnt: io.NoiseControl, ch_enabled: *bool) void { + const len_enable = cnt.length_enable.read(); + + if (len_enable and self.timer > 0) { + self.timer -= 1; + + // if length timer is now 0 + if (self.timer == 0) ch_enabled.* = false; + } + } +}; + +const Envelope = struct { + const Self = @This(); + + /// Period Timer + timer: u3, + /// Current Volume + vol: u4, + + pub fn init() Self { + return .{ .timer = 0, .vol = 0 }; + } + + pub fn tick(self: *Self, cnt: io.Envelope) void { + if (cnt.period.read() != 0) { + if (self.timer != 0) self.timer -= 1; + + if (self.timer == 0) { + self.timer = cnt.period.read(); + + if (cnt.direction.read()) { + if (self.vol > 0x0) self.vol -= 1; + } else { + if (self.vol < 0xF) self.vol += 1; + } + } + } + } +}; + +const SquareWave = struct { + const Self = @This(); + const ticks: u64 = (1 << 24) / (1 << 18); + + pos: u3, + sched: *Scheduler, + + pub fn init(sched: *Scheduler) Self { + return .{ + .pos = 0, + .sched = sched, + }; + } + + fn handleTimerOverflow(self: *Self, cnt: io.Frequency, late: u64) void { + const when = (2048 - @as(u64, cnt.frequency.read())) * 4; + + self.pos = (self.pos +% 1) & 7; + self.sched.push(.{ .ApuChannel = 0 }, when * ticks - late); + } + + fn reloadTimer(self: *Self, value: u11) void { + self.sched.removeScheduledEvent(.{ .ApuChannel = 0 }); + + // TODO: Implement Obscure Behaviour + const when = (2048 - @as(u64, value)) * 4; + + self.sched.push(.{ .ApuChannel = 0 }, when * ticks); + } + + fn getSample(self: *const Self, cnt: io.Duty) u1 { + const pattern = cnt.pattern.read(); // 2^18 + + const i = self.pos ^ 7; // index of 0 should get highest bit + const result = switch (pattern) { + 0b00 => @as(u8, 0b00000001) >> i, // 1/8th + 0b01 => @as(u8, 0b10000001) >> i, // 1/4th + 0b10 => @as(u8, 0b10000111) >> i, // 1/2nd + 0b11 => @as(u8, 0b01111110) >> i, // 3/4th + }; + + return @truncate(u1, result); + } +}; diff --git a/src/scheduler.zig b/src/scheduler.zig index b4b1d4a..4e5368d 100644 --- a/src/scheduler.zig +++ b/src/scheduler.zig @@ -51,6 +51,13 @@ pub const Scheduler = struct { 3 => cpu.bus.tim._3.handleOverflow(cpu, late), } }, + .ApuChannel => |id| { + switch (id) { + 0 => cpu.bus.apu.ch1.channelTimerOverflow(late), + else => {}, + } + }, + .FrameSequencer => cpu.bus.apu.tickFrameSequencer(late), .SampleAudio => cpu.bus.apu.sampleAudio(late), .HBlank => cpu.bus.ppu.handleHBlankEnd(cpu, late), // The end of a HBlank .VBlank => cpu.bus.ppu.handleHDrawEnd(cpu, late), // The end of a VBlank @@ -104,4 +111,6 @@ pub const EventKind = union(enum) { Draw, TimerOverflow: u2, SampleAudio, + FrameSequencer, + ApuChannel: u2, };