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Ppu.cs
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Ppu.cs
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
namespace Emu6502
{
// TODO: "Faster" palette management
// TODO: "Faster" sprite management
public class Ppu
{
public const int ScreenWidth = 256;
public const int ScreenHeight = 240;
public const int Scanlines = 262;
public const int VsyncScanlines = 20;
public const int ClocksPerScanline = 341;
public int[] Framebuffer = new int[ScreenWidth * ScreenHeight];
private Nes nes;
//public byte[] PatternTables;
public byte[][] PatternTables;
public byte[][] NameAttributeTables;
public byte[] Palette;
public byte[] SpriteMem; // OAM stuff
private bool paletteDirty;
private int[] PaletteCache = new int[32];
public bool VsyncFlag;
public byte PpuCtrl;
public byte PpuMask;
public byte OAMAddr; // TODO: Do DMA from here...
public byte ScrollX;
public byte ScrollY;
/*public int ScrollLatch;
public int VramAddrLatch;*/
public bool PpuLatch;
public ushort VramAddr;
public byte DelayedVramRead;
public bool VsyncSignalToMainLoop = false;
public bool SpriteHitFlag;
public int WaitCycles = 0;
public int FrameCycle = 0;
public int ScanlineIndex = 0; // Essentially "Y" counter
//public int ScanlineCycle = 0; // Essentially "X" counter
//private StreamWriter fs = new StreamWriter("nmi.csv");
private byte[] Nametable1;
private byte[] Nametable2;
private byte[] Nametable3;
private byte[] Nametable4;
public MirrorType Mirroring { get; private set; }
// NEW STUFF
private bool latch;
private int loopyT;
private int loopyV;
private int fineX;
private bool cycleSkipToggle;
private bool justReadVBL;
private bool[] SpritePriorityBuffer = new bool[ScreenWidth];
private int[] SpriteBuffer = new int[ScreenWidth];
private int[] BGBuffer = new int[ScreenWidth];
private const int Cycle_Start = 0;
private const int Cycle_RaiseNMI = 3;
private const int Cycle_ClearVSync = 2270 * 3;
//private const int Cycle_SkipFrame = (19 * 341) + 328;
private const int Cycle_FirstVisibleScanline = (20 * 341);
public Ppu(Nes nes)
{
this.nes = nes;
}
public void Reset()
{
PpuLatch = false;
Framebuffer = new int[ScreenWidth * ScreenHeight];
VsyncFlag = false;
PpuCtrl = 0x0;
PpuMask = 0x0;
OAMAddr = 0x0;
//ScrollLatch = 0;
ScrollX = 0;
ScrollY = 0;
//VramAddrLatch = 0;
VramAddr = 0;
DelayedVramRead = 0;
VsyncSignalToMainLoop = false;
FrameCycle = 0;
ScanlineIndex = 0;
//ScanlineCycle = 0;
SpriteHitFlag = false;
cycleSkipToggle = false;
latch = false;
loopyT = loopyV = 0;
fineX = 0;
justReadVBL = false;
// TODO: This is mapper's job
//PatternTables = (nes.Rom.ChrRomBanks.Length == 0) ? new byte[8*1024] : nes.Rom.ChrRomBanks[0];
//NameAttributeTables = new byte[4096];
Nametable1 = new byte[1024];
Nametable2 = new byte[1024];
Nametable3 = new byte[1024];
Nametable4 = new byte[1024];
NameAttributeTables = new byte[4][];
// TODO: Only call this from the mapper's init
PatternTables = new byte[2][];
PatternTables[0] = new byte[0x1000];
PatternTables[1] = new byte[0x1000];
SetMirroring(nes.Rom.MirrorType);
// Matches blargg's startup palette
Palette = new byte[32] {
0x09, 0x01, 0x00, 0x01, 0x00, 0x02, 0x02, 0x0d, 0x08, 0x10, 0x08, 0x24, 0x00, 0x00, 0x04, 0x2c,
0x09, 0x01, 0x34, 0x03, 0x00, 0x04, 0x00, 0x14, 0x08, 0x3a, 0x00, 0x02, 0x00, 0x20, 0x2c, 0x08,
};
SpriteMem = new byte[256];
}
public void SetMirroring(MirrorType type)
{
Mirroring = type;
if (type == MirrorType.Horizontal)
{
NameAttributeTables[0] = NameAttributeTables[1] = Nametable1;
NameAttributeTables[2] = NameAttributeTables[3] = Nametable2;
}
else if (type == MirrorType.Vertical)
{
NameAttributeTables[0] = NameAttributeTables[2] = Nametable1;
NameAttributeTables[1] = NameAttributeTables[3] = Nametable2;
}
else if (type == MirrorType.FourScreen)
{
NameAttributeTables[0] = Nametable1;
NameAttributeTables[1] = Nametable2;
NameAttributeTables[2] = Nametable3;
NameAttributeTables[3] = Nametable4;
}
else if (type == MirrorType.SingleScreenLower)
{
NameAttributeTables[0] =
NameAttributeTables[1] =
NameAttributeTables[2] =
NameAttributeTables[3] = Nametable1;
}
else if (type == MirrorType.SingleScreenUpper)
{
NameAttributeTables[0] =
NameAttributeTables[1] =
NameAttributeTables[2] =
NameAttributeTables[3] = Nametable2;
}
Console.WriteLine("Mirroring={0} ({1})", type, IdentifyBanks());
}
// $2000 PPUCTRL (W)
public void WritePpuCtrl(byte val)
{
//Console.WriteLine("PPUCTRL = ${0:X2} PC = ${1:X4}", val, nes.Cpu.PC);
PpuCtrl = val;
if ((PpuCtrl & 0x80) != 0)
nes.RecordEvent("Ppu.Vbl.NmiDisabled");
else
nes.RecordEvent("Ppu.Vbl.NmiEnabled");
/*if ((PpuCtrl & 0x80) != 0)
fs.WriteLine("{0},{1},VBL NMI Enabled", nes.TotalCpuCycles, VsyncFlag?1:0);
else
fs.WriteLine("{0},{1},VBL NMI Enabled", nes.TotalCpuCycles, VsyncFlag ? 1 : 0);*/
// Set V&H in T
loopyT &= ~0xC00;
loopyT |= (val & 0x3) << 10;
}
// $2001 PPUMASK (W)
public void WritePpuMask(byte val)
{
//Console.WriteLine("PPUMASK = ${0:X2} PC = ${1:X4}", val, nes.Cpu.PC);
PpuMask = val;
}
// $2002 PPUSTATUS (R)
public byte ReadPpuStatus()
{
// TODO: Sprite overflow
// TODO: Sprite 0 hit
byte status = 0;
if (VsyncFlag)
{
//fs.WriteLine("{0},{1},VBL flag read", nes.TotalCpuCycles, VsyncFlag?1:0);
Console.WriteLine("PPUSTATUS read returned VSync flag PC=${0:X4} @ {1} cy", nes.Cpu.PC, nes.TotalCpuCycles);
status |= 0x80;
nes.RecordEvent("Ppu.Vbl.FlagRead");
//fs.WriteLine("{0},{1}", nes.TotalCpuCycles, VsyncFlag ? 1 : 0);
VsyncFlag = false;
//fs.WriteLine("{0},{1}", nes.TotalCpuCycles, VsyncFlag ? 1 : 0);
}
/*else
fs.WriteLine("{0},{1},VBL flag read", nes.TotalCpuCycles, VsyncFlag ? 1 : 0);*/
if (SpriteHitFlag)
status |= 0x40;
/*if (ScrollLatch != 0)
;// Console.WriteLine("Resetting SCROLL latch");
ScrollLatch = 0;
if (VramAddrLatch != 0)
;// Console.WriteLine("Resetting VRAM latch");
VramAddrLatch = 0;*/
PpuLatch = false;
latch = false;
/*ScrollX = 0;
VramAddr = 0;*/
return status;
}
// $2003 OAMADDR (W)
public void WriteOAMAddr(byte val)
{
//Console.WriteLine("OAMADDR = ${0:X2}", val);
OAMAddr = val;
}
// $2004 OAMDATA (R/W)
public byte ReadOAMData() { return SpriteMem[OAMAddr]; }
public void WriteOAMData(byte val) { SpriteMem[OAMAddr++] = val; }
private void DumpPpuReg(int reg)
{
int coarseX = reg & 0x1f;
int coarseY = (reg >> 5) & 0x1f;
int fineY = (reg >> 12) & 0x7;
int H = (reg >> 10) & 0x1;
int V = (reg >> 11) & 0x1;
int scrlX = (byte)((coarseX) << 3 | fineX);
int scrlY = (byte)((coarseY) << 3 | fineY);
/*Console.WriteLine("REG=${7:X4}: fineY={0} H={1} V={2} coarseY={3} coarseX={4} ScrollX={5} ScrollY={6}",
fineY,
H,
V,
coarseY,
coarseX,
scrlX,
scrlY,
reg);*/
}
// $2005 PPUSCROLL (W)
public void WritePpuScroll(byte val)
{
// 1st write: SCROLLX
if (!latch)
{
//Console.WriteLine("$2005/1 = ${0:X2}", val);
loopyT &= ~0x1F;
loopyT |= (val >> 3);
fineX = val & 0x7;
/*Console.WriteLine("T:");
DumpPpuReg(loopyT);*/
}
// 2nd write: SCROLLY
else
{
//Console.WriteLine("$2005/2 = ${0:X2}", val);
loopyT &= ~0x73E0;
loopyT |= (val >> 3) << 5; // todo: simplify?
loopyT |= (val & 0x7) << 12;
/*Console.WriteLine("T:");
DumpPpuReg(loopyT);*/
}
latch = !latch;
/*
PpuCtrl &= 0xFC;
if (!PpuLatch)
{
ScrollX = val;
//Console.WriteLine("SCROLLX = ${0:X2}", val);
}
else// if (ScrollLatch == 1)
{
ScrollY = val;
//Console.WriteLine("SCROLLY = ${0:X2}", val);
}
//ScrollLatch++;
PpuLatch = !PpuLatch;
//ScrollLatch = (ScrollLatch + 1) % 2;
* */
}
// $2006 PPUADDR (W)
public void WritePpuAddr(byte val)
{
if (!latch)
{
//Console.WriteLine("$2006/1 = ${0:X2}", val);
/*loopyT &= ~0xFF00;
loopyT |= (val & 0x3F) << 8;*/
loopyT &= ~0xFF00;
loopyT |= (val & 0xFF) << 8;
DumpPpuReg(loopyT);
}
else
{
//Console.WriteLine("$2006/2 = ${0:X2}", val);
loopyT &= ~0xFF;
loopyT |= val;
loopyV = loopyT;
DumpPpuReg(loopyT);
}
latch = !latch;
#if false
/*VramAddr <<= 8;
VramAddr |= val;*/
if (!PpuLatch)
{
VramAddr = val;// (ushort)((VramAddr & 0xFF00) | val);
}
else
{
//VramAddr = (ushort)((VramAddr & 0x00FF) | (val<<8));
VramAddr <<= 8;
VramAddr |= val;
}
//Console.WriteLine("Latched PPU address: ${0:X4}", VramAddr);
/*if (VramAddrLatch == 0)
{
VramAddr = val;
Console.WriteLine("Latched PPU address low: ${0:X4}", VramAddr);
}
else if (VramAddrLatch == 1)
{
VramAddr <<= 8;
VramAddr |= 8;
Console.WriteLine("Latched PPU address hi: ${0:X4}", VramAddr);
}
else
Console.WriteLine("Excess PPU address latch: ${0:X2}", val);*/
PpuLatch = !PpuLatch;
#endif
}
// $2007 PPUDATA (R/W)
public byte ReadPpuData()
{
int vramAddr = loopyV & 0x3FFF;
byte result;
// Palette read
if (vramAddr >= 0x3f00)
{
DelayedVramRead = Read(0x2f00 | (vramAddr & 0xFF));
result = Read(vramAddr);
//Console.WriteLine("R VRAM (pal) ${0:X4}=${1:X2}", VramAddr, result);
}
else
{
result = DelayedVramRead;
DelayedVramRead = Read(vramAddr);
//Console.WriteLine("R VRAM ${0:X4}=${1:X2}", VramAddr, result);
}
if ((PpuCtrl & 0x04) != 0)
vramAddr += 0x20;
else
vramAddr++;
loopyV &= ~0x3FFF;
loopyV |= (vramAddr & 0x3FFF);
return result;
}
public void WritePpuData(byte data)
{
int vramAddr = loopyV & 0x3FFF;
//nes.Cpu.Paused = true;
Write(vramAddr, data);
/*if(data != 0x00 && data != 0x24)
Console.WriteLine("W VRAM ${0:X4}=${1:X2}", VramAddr, data);*/
//Console.WriteLine("W VRAM ${0:X4}=${1:X2}", VramAddr, data);
if ((PpuCtrl & 0x04) != 0)
vramAddr += 0x20;
else
vramAddr++;
loopyV &= ~0x3FFF;
loopyV |= (vramAddr & 0x3FFF);
}
public string IdentifyBank(int addr)
{
int high = MirrorHigh(addr);
byte[] bank = NameAttributeTables[high];
if (bank == Nametable1)
return "A";
else if (bank == Nametable2)
return "B";
else if (bank == Nametable3)
return "C";
else
return "D";
}
public string IdentifyBanks()
{
return IdentifyBank(0x2000) +
IdentifyBank(0x2400) +
IdentifyBank(0x2800) +
IdentifyBank(0x2C00);
}
public static int MirrorHigh(int addr)
{
return (addr & 0xC00) >> 10;
}
public static int MirrorLow(int addr)
{
return (addr & 0x3FF);
}
public static int PatternHigh(int addr)
{
return (addr & 0x1000) >> 12;
}
public static int PatternLow(int addr)
{
return (addr & 0x0FFF);
}
public byte Read(int addr)
{
addr = addr & 0x3FFF;
//Console.WriteLine("R VRAM ${0:X4}", addr);
if(addr >= 0 && addr < 0x2000)
{
return PatternTables[PatternHigh(addr)][PatternLow(addr)];
}
else if(addr >= 0x2000 && addr < 0x3F00)
{
//int nameAttrAddr = addr & 0x0FFF;
byte data= NameAttributeTables[MirrorHigh(addr)][MirrorLow(addr)];
if ((addr & 0x3FF) <= 1)
Console.WriteLine("R VRAM ${0:X4}=${1:X2} Mirroring={2} Bank={3} of {4}", addr, data, Mirroring, IdentifyBank(addr), IdentifyBanks());
return data;
}
else// if(addr >= 0x3F00 && addr < 0x4000)
{
int paletteAddr = addr & 0x1F;
return Palette[paletteAddr];
}
}
public void Write(int addr, byte val)
{
addr = addr & 0x3FFF;
//Console.WriteLine("W VRAM ${0:X4}=${1:X2}", addr, val);
if(addr >= 0 && addr < 0x2000)
{
// Assume this is ROM for now
//Console.WriteLine("Writing to ROM! O_O");
// Temp. -- allow writing to ROM, overtest.nes does this -- should be mapper specific
//PatternTables[addr] = val;
// TODO: Check if this is ROM or RAM... depends on mapper
PatternTables[PatternHigh(addr)][PatternLow(addr)] = val;
}
else if(addr >= 0x2000 && addr < 0x3F00)
{
// TODO: Proper mirroring here
/*int nameAttrAddr = addr & 0xFFF;
NameAttributeTables[nameAttrAddr] = val;*/
//if ((addr & 0xFF) == 0)
if ((addr & 0x3FF) <= 1)
Console.WriteLine("R VRAM ${0:X4}=${1:X2} Mirroring={2} Bank={3} of {4}", addr, val, Mirroring, IdentifyBank(addr), IdentifyBanks());
NameAttributeTables[MirrorHigh(addr)][MirrorLow(addr)] = val;
}
else// if(addr >= 0x3F00 && addr < 0x4000)
{
paletteDirty = true;
int paletteAddr = addr & 0x1F;
// Zeroth element of every palette entry is mirrored
if ((paletteAddr & 0xF) == 0)
{
//Console.WriteLine("Palette (Mirror) ${0:X2} = ${1:X2}", paletteAddr, val);
Palette[0x00] =
/*Palette[0x04] =
Palette[0x08] =
Palette[0x0c] =*/
Palette[0x10] =
/*Palette[0x14] =
Palette[0x18] =
Palette[0x1c] =*/ val;
}
else
{
//Console.WriteLine("Palette ${0:X2} = ${1:X2}", paletteAddr, val);
Palette[paletteAddr] = val;
}
}
}
private void FillBG(int row)
{
int bgcolor = PpuOutput.Palette[Palette[0] & 0x3f] | 0xFF << 24;
int pos = ScreenWidth * row;
for (int x = 0; x < ScreenWidth; x++)
Framebuffer[pos++] = bgcolor;
}
private static int[] tempPalette = new int[4];
private void UpdatePaletteCache()
{
paletteDirty = false;
for(int i=0; i<32; ++i)
PaletteCache[i] = PpuOutput.Palette[Palette[i] & 0x3f] | 0xFF << 24;
}
private void RenderBG(int srcRow, int ntX, int ntY, int screenX, int screenY)
{
int rowStart = screenY << 8; // Multiply by 256
int bgPatternStart = (PpuCtrl & 0x10) != 0 ? 0x1000 : 0x0000;
//int nametableStart = 0x2000;
if (paletteDirty)
UpdatePaletteCache();
//tempPalette[0] = 0;
int mirrorHigh = ntY << 1 | ntX;//MirrorHigh(nameTableOffset);
int tileY = srcRow / 8;
int subtileY = srcRow % 8;
int attrByteY = tileY >> 2;/// 4;
int attrByteSubY = tileY & 0x3;
int nibbleY = (attrByteSubY >> 1) & 0x1;
for (int tileX = 0; tileX < 32; ++tileX)
{
int attrByteX = tileX >> 2;/// 4;
int attrByteSubX = tileX & 0x3;
int attrAddr = 0x3c0 + attrByteX + (attrByteY <<3);
byte attrByte = NameAttributeTables[mirrorHigh][attrAddr];
int nibbleX = (attrByteSubX >> 1) & 0x1;
int shiftAmt = (nibbleY << 2 | nibbleX << 1);
int paletteAddr = ((attrByte >> shiftAmt) & 0x3) <<2;
//int palette0 = PpuOutput.Palette[Palette[0] & 0x3f] | 0xFF << 24;
/*int palette1 = PpuOutput.Palette[Palette[paletteAddr + 1] & 0x3f] | 0xFF << 24;
int palette2 = PpuOutput.Palette[Palette[paletteAddr + 2] & 0x3f] | 0xFF << 24;
int palette3 = PpuOutput.Palette[Palette[paletteAddr + 3] & 0x3f] | 0xFF << 24;*/
/*tempPalette[1] = PaletteCache[paletteAddr+1];//PpuOutput.Palette[Palette[paletteAddr + 1] & 0x3f] | 0xFF << 24;
tempPalette[2] = PaletteCache[paletteAddr+2];//PpuOutput.Palette[Palette[paletteAddr + 2] & 0x3f] | 0xFF << 24;
tempPalette[3] = PaletteCache[paletteAddr + 3];//PpuOutput.Palette[Palette[paletteAddr + 3] & 0x3f] | 0xFF << 24;
*/
int pattern = NameAttributeTables[mirrorHigh][(tileY << 5) + tileX];
int patternAddr = bgPatternStart + (pattern << 4);
int addr1 = patternAddr + subtileY;
int addr2 = patternAddr + subtileY + 8;
int hi = PatternHigh(addr1);
int lo = PatternLow(addr1);
byte[] pt = PatternTables[hi];
/*byte b1 = pt[lo];
byte b2 = pt[lo + 8];*/
ushort b1b2 = (ushort)(pt[lo] << 8 | pt[lo + 8]);
int targetX = screenX + 8;
if (targetX >= ScreenWidth)
targetX = ScreenWidth;
while (screenX < targetX)
{
/*if (screenX >= ScreenWidth)
return;*/
if (screenX >= 0)
{
int result = (b1b2 >> 15) | ((b1b2 >> 6) & 0x2);
if (result != 0)
BGBuffer[screenX] = PaletteCache[paletteAddr + result];
}
++screenX;
b1b2 <<= 1;
}
}
}
private void RenderSpriteRow(int row, int spriteX, int spriteY, int patternAddr, int palette, bool flipH, bool flipV, bool priority, bool spriteZero)
{
int paletteAddr = 0x10 + palette * 4;
int palette1 = PpuOutput.Palette[Palette[paletteAddr + 1] & 0x3f] | 0xFF << 24;
int palette2 = PpuOutput.Palette[Palette[paletteAddr + 2] & 0x3f] | 0xFF << 24;
int palette3 = PpuOutput.Palette[Palette[paletteAddr + 3] & 0x3f] | 0xFF << 24;
int rowStart = ScreenWidth * row;
int cx = flipH ? 0 : 7;
int dir = flipH ? 1 : -1;
int cy = row - spriteY;
if (flipV)
cy = 7 - cy;
int addr1 = patternAddr + cy;
int addr2 = patternAddr + cy + 8;
byte b1 = PatternTables[PatternHigh(addr1)][PatternLow(addr1)];
byte b2 = PatternTables[PatternHigh(addr2)][PatternLow(addr2)];
for (int n = 0; n < 8; ++n)
{
// TODO: What do do if sprite 0 is already blocked by something?
if (spriteX + n >= 0 && spriteX + n < ScreenWidth && SpriteBuffer[spriteX+n] == 0)
{
byte bit1 = (byte)((b1 >> cx) & 0x1);
byte bit2 = (byte)((b2 >> cx) & 0x1);
byte result = (byte)(bit2 << 1 | bit1);
if (result != 0)
{
int color;
if (result == 1)
color = palette1;
else if (result == 2)
color = palette2;
else// if (result == 3)
color = palette3;
if (spriteZero && BGBuffer[spriteX + n] != 0)
{
nes.RecordEvent("Ppu.Sprite0Hit");
SpriteHitFlag = true; // TODO: Store which cycle it happened on
}
SpriteBuffer[spriteX + n] = color;
SpritePriorityBuffer[spriteX + n] = priority;
/*OpaqueBuffer[spriteX + n] = true;
SpritePriorityBuffer[spriteX + n] = priority;
ColorBuffer[spriteX + n] = color;*/
}
/*if (result == 1)
Framebuffer[rowStart + spriteX + n] = palette1;
else if (result == 2)
Framebuffer[rowStart + spriteX + n] = palette2;
else if (result == 3)
Framebuffer[rowStart + spriteX + n] = palette3;*/
}
cx += dir;
}
}
private void RenderSprites8x8(int row, bool priority)
{
// TODO: Sprite-BG tests...
int spritePatternTableAddr = (PpuCtrl & 0x08) != 0 ? 0x1000 : 0x0000;
// Render sprites
int offset = 0;
for (int i = 0; i < 64; ++i)
{
int y = SpriteMem[offset++];
byte B1 = SpriteMem[offset++];
byte B2 = SpriteMem[offset++];
int x = SpriteMem[offset++];
if (y >= 0xEE)
continue;
y += 1;
int cy = row - y;
if (cy < 0 || cy >= 8)
continue;
bool spritePriority = (B2 & 0x20) != 0;
/*if (spritePriority != priority)
continue;*/
int palette = (B2 & 0x3);
int patternAddr = spritePatternTableAddr + B1 * 16;
bool flipH = (B2 & 0x40) != 0;
bool flipV = (B2 & 0x80) != 0;
RenderSpriteRow(row, x, y, patternAddr, palette, flipH, flipV, spritePriority, i == 0);
}
}
private void RenderSprites8x16(int row, bool priority)
{
// TODO: Sprite-BG tests...
// Render sprites
int offset = 0;
for (int i = 0; i < 64; ++i)
{
int y = SpriteMem[offset++];
byte B1 = SpriteMem[offset++];
byte B2 = SpriteMem[offset++];
int x = SpriteMem[offset++];
if (y >= 0xEE)
continue;
y += 1;
int cy = row - y;
if (cy < 0 || cy >= 16)
continue;
bool spritePriority = (B2 & 0x20) != 0;
/*if (spritePriority != priority)
continue;*/
int pattern1 = B1 & 0xFE;
int bank = (B1 & 0x1) != 0 ? 0x1000 : 0x0000;
int palette = (B2 & 0x3);
int patternAddr1 = bank + pattern1 * 16;
int patternAddr2 = bank + (pattern1 + 1) * 16;
bool flipH = (B2 & 0x40) != 0;
bool flipV = (B2 & 0x80) != 0;
if (flipV)
{
if (cy < 8)
RenderSpriteRow(row, x, y, patternAddr2, palette, flipH, flipV, spritePriority, i == 0);
else
RenderSpriteRow(row, x, y + 8, patternAddr1, palette, flipH, flipV, spritePriority, i == 0);
}
else
{
if (cy < 8)
RenderSpriteRow(row, x, y, patternAddr1, palette, flipH, flipV, spritePriority, i == 0);
else
RenderSpriteRow(row, x, y + 8, patternAddr2, palette, flipH, flipV, spritePriority, i == 0);
}
}
}
private void RenderRow(int row)
{
if ((PpuMask & 0x18) != 0)
{
loopyV &= ~0x41F;
loopyV |= (loopyT & 0x41F);
}
for (int x = 0; x < ScreenWidth; ++x)
{
SpriteBuffer[x] = 0;
BGBuffer[x] = 0;
//PriorityBuffer[x] = false;
//ColorBuffer[x] = 0;
}
bool enableBG = (PpuMask & 0x08) !=0;
bool enableSprites = (PpuMask & 0x10)!=0;
int baseNTX = (loopyV & (1 << 10)) != 0 ? 1 : 0;
int baseNTY = (loopyV & (1 << 11)) != 0 ? 1 : 0;
int uberScrollY = baseNTY << 8 | ScrollY;
//int baseNTX = PpuCtrl & 0x1;
//int baseNTY = (PpuCtrl >> 1) & 0x1;
bool _8x16 = (PpuCtrl & 0x20) != 0;
//baseNTY = uberScrollY >= 30 * 8 ? 1 : 0;
//int scrollY = uberScrollY % (30 * 8);
/*baseNTX = 0; baseNTY = 0; ScrollX = 0; ScrollY = 0;*/
//FillBG(row);
// Hrm, not exactly, but getting there.
// It looks like stuff should be a bit further down... (by 16px)
int scrollY = ScrollY;// % 100; ;// % (30 * 8);
int virtualRow = row + ScrollY + baseNTY*(30*8);
int rowModulo = virtualRow % (30 * 8);
if (enableBG)
{
/*if (virtualRow >= 0 && virtualRow < ScreenHeight)
{
RenderBG(rowModulo, baseNTX, 0, -ScrollX, row);
baseNTX ^= 1;
RenderBG(rowModulo, baseNTX, 0, -ScrollX + ScreenWidth, row);
}
else if (virtualRow >= ScreenHeight && virtualRow < ScreenHeight*2)
{
RenderBG(rowModulo, baseNTX, 1, -ScrollX, row);
baseNTX ^= 1;
RenderBG(rowModulo, baseNTX, 1, -ScrollX + ScreenWidth, row);
}
else if (virtualRow >= ScreenHeight*2 && virtualRow < ScreenHeight*3)
{
RenderBG(rowModulo, baseNTX, 0, -ScrollX, row);
baseNTX ^= 1;
RenderBG(rowModulo, baseNTX, 0, -ScrollX + ScreenWidth, row);
}
else
{
RenderBG(rowModulo, baseNTX, 1, -ScrollX, row);
baseNTX ^= 1;
RenderBG(rowModulo, baseNTX, 1, -ScrollX + ScreenWidth, row);
}*/
if (row >= ScreenHeight - scrollY)
{
baseNTY ^= 1;
RenderBG(row + scrollY - ScreenHeight, baseNTX, baseNTY, -ScrollX, row);
baseNTX ^= 1;
RenderBG(row + scrollY - ScreenHeight, baseNTX, baseNTY, -ScrollX + ScreenWidth, row);
}
else
{
RenderBG(row + scrollY, baseNTX, baseNTY, -ScrollX, row);
baseNTX ^= 1;
RenderBG(row + scrollY, baseNTX, baseNTY, -ScrollX + ScreenWidth, row);
}
}
bool spriteFlagBefore = SpriteHitFlag;
if (enableSprites)
{
if (_8x16)
RenderSprites8x16(row, true);
else
RenderSprites8x8(row, true);
}
int defaultBgColor = PpuOutput.Palette[Palette[0] & 0x3f] | 0xFF << 24;
int fbPos = row*ScreenWidth;
for (int x = 0; x < ScreenWidth; ++x)
{
int color;// = PpuOutput.Palette[Palette[0] & 0x3f] | 0xFF << 24;
int spriteColor = SpriteBuffer[x];
int bgColor = BGBuffer[x];
if(bgColor == 0 && spriteColor == 0)
color = defaultBgColor;
else if (bgColor != 0 && spriteColor == 0)
color = bgColor;
else if (bgColor == 0 && spriteColor != 0)
color = spriteColor;
else // both BG & sprite set
color = SpritePriorityBuffer[x] ? bgColor : spriteColor;
Framebuffer[fbPos++] = color;
}
/*if (spriteFlagBefore != SpriteHitFlag)
{
fbPos = row * ScreenWidth;
for (int x = 0; x < ScreenWidth; ++x)
Framebuffer[fbPos++] = 0xFF << 24 | 0xFF0000;
}*/
/*if (enableSprites)
{
if (_8x16)
RenderSprites8x16(row, false);
else
RenderSprites8x8(row, false);
}*/
/*Framebuffer[ScreenWidth*row + ScrollX] = 0xFF << 24 | 0xFF0000;
Framebuffer[ScreenWidth * row + ScrollY] = 0xFF << 24 | 0x00FF00;*/
}
private void RaiseVsyncNmi()
{
if ((PpuCtrl & 0x80) != 0)
{
nes.RecordEvent("Ppu.Vbl.NmiRaised");
//fs.WriteLine("{0},1,NMI Triggered", nes.TotalCpuCycles);
nes.Cpu.NMI();
}
else
nes.RecordEvent("Ppu.Vbl.NmiNotRaised");
}
private void Vsync()
{
SpriteHitFlag = false;
VsyncFlag = true;
VsyncSignalToMainLoop = true;
/*if ((PpuCtrl & 0x80) != 0)
{
nes.RecordEvent("Ppu.Vbl.NmiRaised");
//fs.WriteLine("{0},1,NMI Triggered", nes.TotalCpuCycles);
nes.Cpu.NMI();
}
else
nes.RecordEvent("Ppu.Vbl.NmiNotRaised");*/
nes.RecordEvent("Ppu.Vbl.Total");
// Console.WriteLine("VSync NMI Ignored");
}
private void BeginScanline()
{
int row = ScanlineIndex;// -VsyncScanlines;
// If BG & sprites are enabled, V = T @ scanline 0
// TODO: Actually do this imemdiately at *CYCLE ZERO* not at cycle zero of visible row 0
if ((PpuMask & 0x18) != 0 && row == 0)
loopyV = loopyT;
int coarseX = loopyV & 0x1F;
int coarseY = (loopyV >> 5) & 0x1f;
int fineY = (loopyV >> 12) & 0x7;
ScrollX = (byte)((coarseX) << 3 | fineX);
ScrollY = (byte)((coarseY) << 3 | fineY);
if (row >= 0 && row < ScreenHeight)
RenderRow(row);
++ScanlineIndex;
}
#if false
private void FinishScanline()
{
++ScanlineIndex;
//ScanlineCycle = 0;
if (ScanlineIndex >= Scanlines)
{
//fs.WriteLine("{0},{1}", nes.TotalCpuCycles, VsyncFlag ? 1 : 0);
ScanlineCycle = 0;
ScanlineIndex = 0;
FrameCycle = 0;
Vsync();
//fs.WriteLine("{0},1,VBL set", nes.TotalCpuCycles);
//fs.WriteLine("{0},{1}", nes.TotalCpuCycles, VsyncFlag ? 1 : 0);
//Console.WriteLine("NMI @ {0} cycles", nes.TotalCpuCycles);