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c64- restructured VIC interrupt and vblank handling (will break a couple graphics modes for now)

This commit is contained in:
saxxonpike 2012-11-06 21:11:30 +00:00
parent 75ef0cc20d
commit 6be1c071f9
1 changed files with 146 additions and 97 deletions
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243
BizHawk.Emulation/Computers/Commodore64/VicII.cs
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@ -475,13 +475,14 @@ namespace BizHawk.Emulation.Computers.Commodore64
public byte bitmapDataMask;
public int borderBottom;
public int borderLeft;
public bool borderOnHorizontal;
public bool borderOnMain;
public bool borderOnVertical;
public int borderRight;
public int borderTop;
public int characterColumn;
public int characterIndex;
public byte[] characterMemory;
public int characterRow;
public bool charactersEnabled;
public byte[] colorMemory;
public int cycle;
public int cycleLeft;
@ -515,7 +516,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
public VicIIRegs regs;
public ChipSignals signal;
private delegate int PlotterDelegate(int offset);
private delegate int PlotterDelegate();
private PlotterDelegate Plotter;
public VicII(ChipSignals newSignal, VicIIMode videoMode)
@ -530,14 +531,14 @@ namespace BizHawk.Emulation.Computers.Commodore64
rasterLineLeft = 0x19C;
cycleLeft = 0;
spriteFetchCycle = 58;
visibleLeft = 0x19C; //0x1E9;
visibleRight = 0x19C;
visibleTop = 0x000; //0x041;
visibleBottom = 0x000; //0x013;
visibleLeft = 0x008;
visibleRight = 0x168;
visibleTop = 0x023; //0x041;
visibleBottom = 0x004; //0x013;
visibleRenderX = false;
visibleRenderY = false;
visibleWidth = 0x208; //418;
visibleHeight = 263; //235;
visibleRenderY = true;
visibleWidth = 352;
visibleHeight = 232;
renderOffset = 0;
break;
case VicIIMode.PAL:
@ -549,7 +550,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
// initialize raster
rasterWidth = totalCycles * 8;
rasterOffsetX = rasterLineLeft;
borderOnHorizontal = true;
borderOnMain = true;
borderOnVertical = true;
// initialize buffer
@ -563,6 +564,8 @@ namespace BizHawk.Emulation.Computers.Commodore64
// initialize screen buffer
characterMemory = new byte[41];
colorMemory = new byte[41];
characterIndex = -1;
charactersEnabled = false;
// initialize registers
HardReset();
@ -570,11 +573,16 @@ namespace BizHawk.Emulation.Computers.Commodore64
private void GetBitmapData()
{
int cMemIndex = characterMemory[characterIndex];
if (regs.ECM)
cMemIndex &= 0x3F;
ushort offset = (ushort)((regs.CB << 11) + (cMemIndex * 8) + characterRow);
bitmapData = mem.VicRead(offset);
if (characterIndex < 0 || characterIndex >= 40)
bitmapData = 0;
else
{
int cMemIndex = characterMemory[characterIndex];
if (regs.ECM)
cMemIndex &= 0x3F;
ushort offset = (ushort)((regs.CB << 11) + (cMemIndex * 8) + regs.RC);
bitmapData = mem.VicRead(offset);
}
}
private void GetScreenData(int index)
@ -603,9 +611,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
public void PerformCycle()
{
characterIndex = regs.VMLI;
characterRow = regs.RC;
// reset VC and VCBASE if on scan 0
if (regs.RASTER == 0x00)
{
@ -621,12 +626,36 @@ namespace BizHawk.Emulation.Computers.Commodore64
// badline calculation (for when the VIC must pause the CPU to get character data)
if (regs.RASTER >= 0x030 && regs.RASTER < 0x0F8)
badLine = (regs.YSCROLL == (regs.RASTER & 0x07) && displayEnabled);
badLine = ((regs.YSCROLL == (regs.RASTER & 0x07)) && displayEnabled);
else
badLine = false;
if (badLine)
idle = false;
// decide what to do this cycle
if (cycle >= 0 && cycle < 10)
if (cycle == 0)
{
// if vblank, reset the raster position
regs.RASTER++;
if (regs.RASTER == rasterTotalLines)
{
rasterOffset = 0;
regs.RASTER = 0;
renderOffset = 0;
displayEnabled = false;
refreshAddress = 0x3FFF;
}
// check to see if we are within viewing area Y
if (regs.RASTER == visibleBottom)
visibleRenderY = false;
if (regs.RASTER == visibleTop)
visibleRenderY = true;
// check for raster IRQ
if (regs.RASTER == rasterInterruptLine)
regs.IRST = true;
}
else if (cycle >= 1 && cycle < 10)
{
// fetch sprite data 3-7
int index = (cycle >> 1) + 3;
@ -655,7 +684,12 @@ namespace BizHawk.Emulation.Computers.Commodore64
{
regs.VC = regs.VCBASE;
regs.VMLI = 0;
characterIndex = 0;
characterIndex = -4;
characterColumn = 0;
if (badLine)
{
regs.RC = 0;
}
}
}
else if (cycle >= 15 && cycle < 55)
@ -670,7 +704,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
{
signal.VicAEC = true;
}
GetBitmapData();
regs.VC++;
regs.VMLI++;
}
@ -679,14 +712,12 @@ namespace BizHawk.Emulation.Computers.Commodore64
// increment VIC row counter
if (regs.RC == 7)
{
if (!borderOnHorizontal)
regs.VCBASE = regs.VC;
idle = true;
regs.VCBASE = regs.VC;
}
regs.RC = (regs.RC + 1) & 0x07;
if (badLine)
else
{
regs.RC = 0;
regs.RC = (regs.RC + 1) & 0x07;
}
}
else if (cycle >= spriteFetchCycle)
@ -712,6 +743,14 @@ namespace BizHawk.Emulation.Computers.Commodore64
}
if (cycle == 63)
{
if ((regs.RASTER == borderTop) && (regs.DEN))
borderOnVertical = false;
if (regs.RASTER == borderBottom)
borderOnVertical = true;
}
// determine the plot mode
if (!regs.ECM && !regs.BMM && !regs.MCM)
Plotter = Plot000;
@ -732,6 +771,13 @@ namespace BizHawk.Emulation.Computers.Commodore64
for (int i = 0; i < 8; i++)
{
if ((rasterOffsetX & 0x07) == regs.XSCROLL)
{
characterColumn = 0;
characterIndex++;
GetBitmapData();
}
// pixel clock is 8x the VIC clock
int pixel;
@ -740,31 +786,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
{
// reset to the left side
rasterOffsetX -= rasterWidth;
regs.RASTER++;
// if vblank, reset the raster position
if (regs.RASTER == rasterTotalLines)
{
rasterOffset = 0;
regs.RASTER = 0;
renderOffset = 0;
displayEnabled = false;
refreshAddress = 0x3FFF;
}
// check to see if we are within viewing area Y
if (regs.RASTER == visibleBottom)
visibleRenderY = false;
if (regs.RASTER == visibleTop)
visibleRenderY = true;
// check to see if we are on a horizontal border
if (displayEnabled && (regs.RASTER == borderTop || regs.RASTER == borderBottom))
borderOnHorizontal = !borderOnHorizontal;
// check for raster IRQ
if (regs.RASTER == rasterInterruptLine)
regs.IRST = true;
}
// check to see if we are within viewing area X
@ -773,31 +794,48 @@ namespace BizHawk.Emulation.Computers.Commodore64
if (rasterOffsetX == visibleLeft)
visibleRenderX = true;
// check to see if we are on a vertical border
if (rasterOffsetX == borderLeft)
borderOnVertical = false;
// check to see if we are at the border
if (rasterOffsetX == borderRight)
borderOnVertical = true;
borderOnMain = true;
if (rasterOffsetX == borderLeft)
{
if (regs.RASTER == borderBottom)
borderOnVertical = true;
if ((regs.RASTER == borderTop) && regs.DEN)
borderOnVertical = false;
if (!borderOnVertical)
borderOnMain = false;
}
// draw the border if it is on, otherwise draw the screen
if (borderOnHorizontal || borderOnVertical)
if (borderOnMain || borderOnVertical)
{
pixel = regs.EC;
}
else
{
pixel = Plotter(i);
if (characterIndex >= 0 && characterIndex < 40)
pixel = Plotter();
else
pixel = regs.BxC[0];
}
// plot the pixel if within visible range
if (visibleRenderX && visibleRenderY)
{
/*
if (regs.RC == 0x00)
pixel ^= 0x08;
if ((regs.RASTER & 0x07) == regs.YSCROLL)
pixel ^= 0x01;*/
WritePixel(pixel);
}
// increment raster position
rasterOffset++;
rasterOffsetX++;
characterColumn++;
}
UpdateInterrupts();
@ -813,79 +851,90 @@ namespace BizHawk.Emulation.Computers.Commodore64
}
// standard text mode
private int Plot000(int offset)
private int Plot000()
{
byte charData = bitmapData;
charData <<= offset;
if ((charData & 0x80) != 0x00)
return colorMemory[characterIndex];
else
return regs.BxC[0];
if (characterColumn >= 0)
{
byte charData = bitmapData;
charData <<= characterColumn;
if ((charData & 0x80) != 0x00)
return colorMemory[characterIndex];
}
return regs.BxC[0];
}
// multicolor text mode
private int Plot001(int offset)
private int Plot001()
{
if ((colorMemory[characterIndex] & 0x08) != 0x00)
if (characterColumn >= 0)
{
byte charData = bitmapData;
offset |= 0x01;
offset ^= 0x01;
charData <<= offset;
charData >>= 6;
switch (charData)
if ((colorMemory[characterIndex] & 0x08) != 0x00)
{
case 0:
case 1:
case 2:
return regs.BxC[charData];
default:
return colorMemory[characterIndex] & 0x07;
int offset = characterColumn;
byte charData = bitmapData;
offset |= 0x01;
offset ^= 0x01;
charData <<= offset;
charData >>= 6;
switch (charData)
{
case 0:
case 1:
case 2:
return regs.BxC[charData];
default:
return colorMemory[characterIndex] & 0x07;
}
}
else
{
return Plot000();
}
}
else
{
return Plot000(offset);
}
return regs.BxC[0];
}
// standard bitmap mode
private int Plot010(int offset)
private int Plot010()
{
return regs.BxC[0];
}
// multicolor bitmap mode
private int Plot011(int offset)
private int Plot011()
{
return regs.BxC[0];
}
// extra color text mode
private int Plot100(int offset)
private int Plot100()
{
byte charData = bitmapData;
charData <<= offset;
if ((charData & 0x80) != 0x00)
return colorMemory[characterIndex];
else
return regs.BxC[characterMemory[characterIndex] >> 6];
if (characterColumn >= 0)
{
byte charData = bitmapData;
charData <<= characterColumn;
if ((charData & 0x80) != 0x00)
return colorMemory[characterIndex];
else
return regs.BxC[characterMemory[characterIndex] >> 6];
}
return regs.BxC[0];
}
// invalid mode
private int Plot101(int offset)
private int Plot101()
{
return regs.BxC[0];
}
// invalid mode
private int Plot110(int offset)
private int Plot110()
{
return regs.BxC[0];
}
// invalid mode
private int Plot111(int offset)
private int Plot111()
{
return regs.BxC[0];
}