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[NES] speaking of music being a worthy thing...

This commit is contained in:
zeromus 2011-03-13 00:34:24 +00:00
parent 1de366349e
commit 2c62271fc7
4 changed files with 335 additions and 3 deletions
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1
BizHawk.Emulation/BizHawk.Emulation.csproj
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@ -55,6 +55,7 @@
</ItemGroup>
<ItemGroup>
<Compile Include="Consoles\Calculator\TI83.cs" />
<Compile Include="Consoles\Nintendo\NES\APU.cs" />
<Compile Include="Consoles\Nintendo\NES\BoardSystem.cs" />
<Compile Include="Consoles\Nintendo\NES\Boards\AxROM.cs">
<SubType>Code</SubType>

308
BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs Normal file
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@ -0,0 +1,308 @@
using System;
using System.Collections.Generic;
//http://wiki.nesdev.com/w/index.php/APU_Mixer_Emulation
//http://wiki.nesdev.com/w/index.php/APU
//http://wiki.nesdev.com/w/index.php/APU_Pulse
//sequencer ref: http://wiki.nesdev.com/w/index.php/APU_Frame_Counter
namespace BizHawk.Emulation.Consoles.Nintendo
{
partial class NES
{
public class APU : ISoundProvider
{
NES nes;
public APU(NES nes)
{
this.nes = nes;
}
static int[] LENGTH_TABLE = { 10, 254, 20, 2, 40, 4, 80, 6, 160, 8, 60, 10, 14, 12, 26, 14, 12, 16, 24, 18, 48, 20, 96, 22, 192, 24, 72, 26, 16, 28, 32, 30 };
static byte[,] PULSE_DUTY = {
{0,1,0,0,0,0,0,0}, //(12.5%)
{0,1,1,0,0,0,0,0}, //(25%)
{0,1,1,1,1,0,0,0}, //(50%)
{1,0,0,1,1,1,1,1}, //(25% negated (75%))
};
class PulseUnit
{
public PulseUnit(int unit) { this.unit = unit; }
public int unit;
//reg0
int duty, length_halt, envelope_constant, envelope_cnt_value;
//reg1
int sweep_en, timer_period, negate, shiftcount;
//reg2/3
int len_cnt;
int timer_raw_reload_value, timer_reload_value;
//from other apu regs
public int lenctr_en;
public void WriteReg(int addr, byte val)
{
//Console.WriteLine("write pulse {0:X} {1:X}", addr, val);
switch(addr)
{
case 0:
envelope_cnt_value = val & 0xF;
envelope_constant = (val >> 4) & 1;
length_halt = (val >> 5) & 1;
duty = (val >> 6) & 3;
break;
case 1:
shiftcount = val & 7;
negate = (val >> 3) & 1;
timer_period = (val >> 4) & 7;
sweep_en = (val >> 7) & 1;
break;
case 2:
timer_reload_value = (timer_reload_value & ~0xFF) | val;
timer_raw_reload_value = timer_reload_value;
calc_sweep_unit();
break;
case 3:
len_cnt = LENGTH_TABLE[(val >> 3) & 0x1F];
timer_reload_value = (timer_reload_value & 0xFF) | ((val & 0x07) << 8);
timer_raw_reload_value = timer_reload_value;
sq_seq = 0;
calc_sweep_unit();
//serves as a useful note-on diagnostic
Console.WriteLine("{0} timer_reload_value: {1}", unit, timer_reload_value);
break;
}
}
int swp_val_result;
bool swp_silence;
int sq_seq;
public int sample;
int envelope_value;
void calc_sweep_unit()
{
//1's complement for chan 0, 2's complement if chan 1
if (negate == 1) //check to see if negate is on
swp_val_result = ~swp_val_result + unit;
//add with the shifter chan
swp_val_result += timer_reload_value;
if ((timer_reload_value < 8) ||
((swp_val_result > 0x7FF) && (negate==0)))
swp_silence = true; //silence
else
swp_silence = false; //don't silence
}
public void clock_sweep()
{
//(as well as length counter)
if(sweep_en==1)
timer_raw_reload_value = swp_val_result & 0x7FF;
}
public void clock_env()
{
}
public void Run()
{
envelope_value = 15; //HAX
//sweep units are figured out during memory writes to the regs
//that set the timer, length counter are figured out in the
//writes and frame counter, and envelope is set through the memory
//regs also, so we just need to deal with the timer and sequencer here
if (--timer_period==0)
{
sq_seq = (sq_seq + 1) & 7;
//reload timer
timer_period = timer_raw_reload_value + 2;
}
if (PULSE_DUTY[duty,sq_seq] == 1) //we are outputting something
{
if (envelope_constant==1)
sample = envelope_cnt_value;
else
sample = envelope_value;
if (swp_silence)
sample = 0;
if (len_cnt==0) //length counter is 0
sample = 0; //silenced
}
else
sample = 0; //duty cycle is 0, silenced.
}
}
PulseUnit[] pulse = { new PulseUnit(0), new PulseUnit(1) };
int sequencer_counter, sequencer_step, sequencer_mode, sequencer_irq_inhibit, sequencer_irq_flag;
void sequencer_reset()
{
sequencer_counter = 0;
sequencer_step = 0;
sequencer_check();
}
void sequencer_tick()
{
sequencer_counter++;
//this figure is not valid for PAL. it must be recalculated
if (sequencer_counter != 89490) return;
sequencer_counter = 0;
sequencer_step++;
sequencer_check();
}
void sequencer_check()
{
switch (sequencer_mode)
{
case 0: //4-step
pulse[0].clock_env();
pulse[1].clock_env();
if (sequencer_step == 1 || sequencer_step == 3)
{
pulse[0].clock_sweep();
pulse[1].clock_sweep();
}
if (sequencer_step == 3)
{
if (sequencer_irq_inhibit == 0)
{
sequencer_irq_flag = 1;
//TODO - actually fire IRQ
}
sequencer_step = 0;
}
break;
case 1: //5-step
if (sequencer_step != 4)
{
pulse[0].clock_env();
pulse[1].clock_env();
}
if (sequencer_step == 0 || sequencer_step == 2)
{
pulse[0].clock_sweep();
pulse[1].clock_sweep();
}
if (sequencer_step == 4)
sequencer_step = 0;
break;
}
}
public void WriteReg(int addr, byte val)
{
if (addr >= 0x4000 && addr <= 0x4003)
pulse[0].WriteReg(addr - 0x4000, val);
if (addr >= 0x4004 && addr <= 0x4007)
pulse[1].WriteReg(addr - 0x4004, val);
switch (addr)
{
case 0x4015:
pulse[0].lenctr_en = (val & 1);
pulse[1].lenctr_en = ((val>>1) & 1);
break;
case 0x4017:
sequencer_mode = (val>>7)&1;
if(((val>>6)&1)==1)
sequencer_irq_inhibit = 0;
sequencer_reset();
break;
}
}
public byte ReadReg(int addr)
{
switch (addr)
{
default:
return 0x00;
}
}
public void Run(int cycles)
{
for (int i = 0; i < cycles; i++)
RunOne();
}
void RunOne()
{
pulse[0].Run();
pulse[1].Run();
sequencer_tick();
int mix = pulse[0].sample;
mix += pulse[1].sample;
EmitSample(mix);
//since the units run concurrently, the APU frame sequencer
//is ran last because
//it can change the ouput values of the pulse/triangle channels,
//we want the
//changes to affect it on the *next* cycle.
}
int accumulate;
double timer;
Queue<int> squeue = new Queue<int>();
void EmitSample(int samp)
{
const double kMixRate = 44100.0/1789772.0;
const double kInvMixRate = (1 / kMixRate);
timer += kMixRate;
for(;;)
{
if (timer <= 1)
{
accumulate += samp;
break;
}
else
{
timer -= 1;
int outsamp = (int)(accumulate / kInvMixRate);
squeue.Enqueue(outsamp);
accumulate -= (int)(outsamp*kInvMixRate);
}
}
}
void ISoundProvider.GetSamples(short[] samples)
{
//Console.WriteLine("a: {0} with todo: {1}",squeue.Count,samples.Length/2);
for (int i = 0; i < samples.Length/2; i++)
{
int samp = 0;
if (squeue.Count != 0)
samp = squeue.Dequeue();
//if(samp != 0) Console.WriteLine("samp: {0}", samp);
samples[i*2+0] = (short)(samp * 256);
samples[i*2+1] = (short)(samp * 256);
}
}
} //class APU
}
}

27
BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
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@ -14,6 +14,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
protected MOS6502 cpu;
int cpu_accumulate; //cpu timekeeper
public PPU ppu;
public APU apu;
byte[] ram;
protected byte[] CIRAM; //AKA nametables
string game_name; //friendly name exposed to user and used as filename base
@ -30,6 +31,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
cpu.ReadMemory = ReadMemory;
cpu.WriteMemory = WriteMemory;
ppu = new PPU(this);
apu = new APU(this);
ram = new byte[0x800];
CIRAM = new byte[0x800];
ports = new IPortDevice[2];
@ -54,8 +56,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
ppu.FrameAdvance();
}
protected void RunCpu(int cycles)
protected void RunCpu(int ppu_cycles)
{
int cycles = ppu_cycles;
if (ppu.PAL)
cycles *= 15;
else
@ -65,7 +68,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
int todo = cpu_accumulate / 48;
cpu_accumulate -= todo * 48;
if (todo > 0)
{
cpu.Execute(todo);
apu.Run(todo);
}
}
public byte ReadPPUReg(int addr)
@ -77,9 +83,17 @@ namespace BizHawk.Emulation.Consoles.Nintendo
{
switch (addr)
{
case 0x4000: case 0x4001: case 0x4002: case 0x4003:
case 0x4004: case 0x4005: case 0x4006: case 0x4007:
case 0x4008: case 0x4009: case 0x400A: case 0x400B:
case 0x400C: case 0x400D: case 0x400E: case 0x400F:
case 0x4010: case 0x4011: case 0x4012: case 0x4013:
return apu.ReadReg(addr);
case 0x4014: /*OAM DMA*/ break;
case 0x4015: return apu.ReadReg(addr); break;
case 0x4016:
case 0x4017:
return read_joyport(addr);
case 0x4017: return apu.ReadReg(addr); break;
default:
//Console.WriteLine("read register: {0:x4}", addr);
break;
@ -97,11 +111,20 @@ namespace BizHawk.Emulation.Consoles.Nintendo
{
switch (addr)
{
case 0x4000: case 0x4001: case 0x4002: case 0x4003:
case 0x4004: case 0x4005: case 0x4006: case 0x4007:
case 0x4008: case 0x4009: case 0x400A: case 0x400B:
case 0x400C: case 0x400D: case 0x400E: case 0x400F:
case 0x4010: case 0x4011: case 0x4012: case 0x4013:
apu.WriteReg(addr, val);
break;
case 0x4014: Exec_OAMDma(val); break;
case 0x4015: apu.WriteReg(addr, val); break;
case 0x4016:
ports[0].Write(val & 1);
ports[1].Write(val & 1);
break;
case 0x4017: apu.WriteReg(addr, val); break;
default:
//Console.WriteLine("wrote register: {0:x4} = {1:x2}", addr, val);
break;

2
BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
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@ -68,7 +68,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
public IVideoProvider VideoProvider { get { return new MyVideoProvider(this); } }
public ISoundProvider SoundProvider { get { return new NullEmulator(); } }
public ISoundProvider SoundProvider { get { return apu; } }
public static readonly ControllerDefinition NESController =
new ControllerDefinition