ShuriZma
/
BizHawk
mirror of https://github.com/TASEmulators/BizHawk.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

commodore64: separate VIC memory fetches into separate functions per display mode

This commit is contained in:
saxxonpike 2012-11-07 18:53:55 +00:00
parent f682734c39
commit 483ef0d7e0
1 changed files with 175 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

221
BizHawk.Emulation/Computers/Commodore64/VicII.cs
View File

@ -481,7 +481,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
public int borderTop;
public int characterColumn;
public byte characterData;
public int characterIndex;
public byte[] characterMemory;
public bool charactersEnabled;
public byte colorData;
@ -520,6 +519,8 @@ namespace BizHawk.Emulation.Computers.Commodore64
public VicIIRegs regs;
public ChipSignals signal;
private Action FetchC;
private Action FetchG;
private Func<int> Plotter;
public VicII(ChipSignals newSignal, VicIIMode videoMode)
@ -572,6 +573,107 @@ namespace BizHawk.Emulation.Computers.Commodore64
HardReset();
}
// standard text mode
public void Fetch000C()
{
int cAddress = (regs.VM << 10) | regs.VC;
characterData = mem.VicRead((ushort)cAddress);
colorData = mem.colorRam[regs.VC];
}
public void Fetch000G()
{
int gAddress = (regs.CB << 11) | (characterData << 3) | regs.RC;
bitmapData = mem.VicRead((ushort)gAddress);
}
// multicolor text mode (same as standard text mode)
public void Fetch001C()
{
Fetch000C();
}
public void Fetch001G()
{
Fetch000G();
}
// standard bitmap mode
public void Fetch010C()
{
Fetch000C();
}
public void Fetch010G()
{
int gAddress = ((regs.CB & 0x4) << 11) | (regs.VC << 3) | regs.RC;
bitmapData = mem.VicRead((ushort)gAddress);
}
// multicolor bitmap mode (same as standard bitmap mode)
public void Fetch011C()
{
Fetch000C();
}
public void Fetch011G()
{
Fetch010G();
}
// extra color text mode
public void Fetch100C()
{
Fetch000C();
}
public void Fetch100G()
{
int gAddress = (regs.CB << 11) | ((characterData & 0x3F) << 3) | regs.RC;
bitmapData = mem.VicRead((ushort)gAddress);
}
// invalid text mode 101
public void Fetch101C()
{
Fetch000C();
}
public void Fetch101G()
{
Fetch100G();
}
// invalid bitmap mode 110
public void Fetch110C()
{
Fetch000C();
}
public void Fetch110G()
{
int gAddress = ((regs.CB & 0x4) << 11) | ((regs.VC & 0x33F) << 3) | regs.RC;
bitmapData = mem.VicRead((ushort)gAddress);
}
// invalid bitmap mode 111
public void Fetch111C()
{
Fetch000C();
}
public void Fetch111G()
{
Fetch110G();
}
// idle fetch
public void FetchIdleC()
{
characterData = 0;
colorData = 0;
}
public void FetchIdleG()
{
if (regs.ECM)
mem.VicRead(0x39FF);
else
mem.VicRead(0x3FFF);
}
public void HardReset()
{
idle = true;
@ -617,7 +719,11 @@ namespace BizHawk.Emulation.Computers.Commodore64
{
// screen memory c-access
if (badLine)
PerformCycleScreenFetch();
{
FetchC();
characterMemory[regs.VMLI] = characterData;
colorMemory[regs.VMLI] = colorData;
}
}
else if (cycle == 55)
{
@ -711,37 +817,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
visibleRenderY = true;
}
private void PerformCycleGraphicFetch()
{
if (idle)
{
if (regs.ECM)
mem.VicRead(0x39FF);
else
mem.VicRead(0x3FFF);
}
else
{
characterIndex = regs.VMLI;
if (characterIndex < 0 || characterIndex >= 40)
{
bitmapData = 0;
colorData = 0;
characterData = 0;
}
else
{
characterData = characterMemory[characterIndex];
if (regs.ECM)
characterData &= 0x3F;
bitmapData = mem.VicRead((ushort)((regs.CB << 11) + (characterData * 8) + regs.RC));
colorData = colorMemory[characterIndex];
}
regs.VC++;
regs.VMLI++;
}
}
private void PerformCycleRender()
{
for (int i = 0; i < 8; i++)
@ -753,7 +828,11 @@ namespace BizHawk.Emulation.Computers.Commodore64
if (regs.XSCROLL == (rasterOffsetX & 0x7))
{
characterColumn = 0;
PerformCycleGraphicFetch();
characterData = characterMemory[regs.VMLI];
colorData = colorMemory[regs.VMLI];
FetchG();
regs.VC++;
regs.VMLI++;
}
}
@ -795,13 +874,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
}
private void PerformCycleScreenFetch()
{
ushort offset = (ushort)((regs.VM << 10) + regs.VC);
characterMemory[regs.VMLI] = mem.VicRead(offset);
colorMemory[regs.VMLI] = mem.colorRam[regs.VC];
}
private void PerformCycleSpriteFetch(int index, int fetchCycle)
{
ushort offset = (ushort)((regs.VM << 10) + 0x3F8 + index);
@ -838,11 +910,11 @@ namespace BizHawk.Emulation.Computers.Commodore64
charData >>= 6;
switch (charData)
{
case 0:
case 1:
return regs.BxC[1];
case 2:
return regs.BxC[charData];
default:
return regs.BxC[2];
case 3:
return colorData & 0x07;
}
}
@ -857,12 +929,37 @@ namespace BizHawk.Emulation.Computers.Commodore64
// standard bitmap mode
private int Plot010()
{
return regs.BxC[0];
if (characterColumn >= 0)
{
byte charData = bitmapData;
charData <<= characterColumn;
if ((charData & 0x80) != 0x00)
return characterData >> 4;
}
return characterData & 0xF;
}
// multicolor bitmap mode
private int Plot011()
{
if (characterColumn >= 0)
{
int offset = characterColumn;
byte charData = bitmapData;
offset |= 0x01;
offset ^= 0x01;
charData <<= offset;
charData >>= 6;
switch (charData)
{
case 1:
return characterData & 0xF;
case 2:
return characterData >> 4;
case 3:
return colorData & 0xF;
}
}
return regs.BxC[0];
}
@ -936,23 +1033,55 @@ namespace BizHawk.Emulation.Computers.Commodore64
private void UpdatePlotter()
{
// determine the plot mode
// determine the plot and fetch mode
if (!regs.ECM && !regs.BMM && !regs.MCM)
{
FetchC = Fetch000C;
FetchG = Fetch000G;
Plotter = Plot000;
}
else if (!regs.ECM && !regs.BMM && regs.MCM)
{
FetchC = Fetch001C;
FetchG = Fetch001G;
Plotter = Plot001;
}
else if (!regs.ECM && regs.BMM && !regs.MCM)
{
FetchC = Fetch010C;
FetchG = Fetch010G;
Plotter = Plot010;
}
else if (!regs.ECM && regs.BMM && regs.MCM)
{
FetchC = Fetch011C;
FetchG = Fetch011G;
Plotter = Plot011;
}
else if (regs.ECM && !regs.BMM && !regs.MCM)
{
FetchC = Fetch100C;
FetchG = Fetch100G;
Plotter = Plot100;
}
else if (regs.ECM && !regs.BMM && regs.MCM)
{
FetchC = Fetch101C;
FetchG = Fetch101G;
Plotter = Plot101;
}
else if (regs.ECM && regs.BMM && !regs.MCM)
{
FetchC = Fetch110C;
FetchG = Fetch110G;
Plotter = Plot110;
}
else
{
FetchC = Fetch111C;
FetchG = Fetch111G;
Plotter = Plot111;
}
}
public void Write(ushort addr, byte val)