BizHawk/BizHawk.Emulation.Cores/Consoles/Atari/2600/Tia/Tia.PlayerData.cs

163 lines
3.4 KiB
C#

using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Atari.Atari2600
{
public partial class TIA
{
private struct PlayerData
{
public MissileData Missile;
public byte Grp;
public byte Dgrp;
public byte Color;
public byte HPosCnt;
public byte ScanCnt;
public byte ScanStrchCnt;
public byte HM;
public bool Reflect;
public bool Delay;
public byte Nusiz;
public bool Reset;
public byte ResetCnt;
public byte Collisions;
public bool Tick()
{
var result = false;
if (ScanCnt < 8)
{
// Make the mask to check the graphic
byte playerMask = (byte)(1 << (8 - 1 - ScanCnt));
// Reflect it if needed
if (Reflect)
{
playerMask = (byte)ReverseBits(playerMask, 8);
}
// Check the graphic (depending on delay)
if (!Delay)
{
if ((Grp & playerMask) != 0)
{
result = true;
}
}
else
{
if ((Dgrp & playerMask) != 0)
{
result = true;
}
}
// Reset missile, if desired
if (ScanCnt == 0x04 && HPosCnt <= 16 && Missile.ResetToPlayer)
{
Missile.HPosCnt = 0;
}
// Increment counter
// When this reaches 8, we've run out of pixel
// If we're drawing a stretched player, only incrememnt the
// counter every 2 or 4 clocks
// Double size player
if ((Nusiz & 0x07) == 0x05)
{
ScanStrchCnt++;
ScanStrchCnt %= 2;
}
// Quad size player
else if ((Nusiz & 0x07) == 0x07)
{
ScanStrchCnt++;
ScanStrchCnt %= 4;
}
// Single size player
else
{
ScanStrchCnt = 0;
}
if (ScanStrchCnt == 0)
{
ScanCnt++;
}
}
// At counter position 0 we should start drawing, a pixel late
// Set the scan counter at 0, and at the next pixel the graphic will start drawing
if (HPosCnt == 0 && !Reset)
{
ScanCnt = 0;
if ((Nusiz & 0x07) == 0x05 || (Nusiz & 0x07) == 0x07)
{
ScanStrchCnt = 0;
}
}
if (HPosCnt == 16 && ((Nusiz & 0x07) == 0x01 || ((Nusiz & 0x07) == 0x03)))
{
ScanCnt = 0;
}
if (HPosCnt == 32 && ((Nusiz & 0x07) == 0x02 || ((Nusiz & 0x07) == 0x03) || ((Nusiz & 0x07) == 0x06)))
{
ScanCnt = 0;
}
if (HPosCnt == 64 && ((Nusiz & 0x07) == 0x04 || ((Nusiz & 0x07) == 0x06)))
{
ScanCnt = 0;
}
// Reset is no longer in effect
Reset = false;
// Increment the counter
HPosCnt++;
// Counter loops at 160
HPosCnt %= 160;
if (ResetCnt < 4)
{
ResetCnt++;
}
if (ResetCnt == 4)
{
HPosCnt = 0;
Reset = true;
ResetCnt++;
}
return result;
}
public void SyncState(Serializer ser)
{
Missile.SyncState(ser);
ser.Sync("grp", ref Grp);
ser.Sync("dgrp", ref Dgrp);
ser.Sync("color", ref Color);
ser.Sync("hPosCnt", ref HPosCnt);
ser.Sync("scanCnt", ref ScanCnt);
ser.Sync("scanStrchCnt", ref ScanStrchCnt);
ser.Sync("HM", ref HM);
ser.Sync("reflect", ref Reflect);
ser.Sync("delay", ref Delay);
ser.Sync("nusiz", ref Nusiz);
ser.Sync("reset", ref Reset);
ser.Sync("resetCnt", ref ResetCnt);
ser.Sync("collisions", ref Collisions);
}
}
}
}