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[NTVDM:SVGA]

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Fix the refresh rate calculation.


svn path=/trunk/; revision=72480
This commit is contained in:
Aleksandar Andrejevic 2016-08-28 01:53:52 +00:00
parent 3ecb5aa01a
commit fd7db0e65b
1 changed files with 18 additions and 3 deletions
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21
reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c
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@ -1628,10 +1628,14 @@ static VOID FASTCALL VgaHorizontalRetrace(ULONGLONG ElapsedTime)
ULONG ElapsedCycles = CurrentCycleCount - HorizontalRetraceCycle;
ULONG Dots = (VgaSeqRegisters[VGA_SEQ_CLOCK_REG] & 1) ? 9 : 8;
ULONG HorizTotalDots = ((ULONG)VgaCrtcRegisters[VGA_CRTC_HORZ_TOTAL_REG] + 5) * Dots;
ULONG HSyncsPerSecond = VgaGetClockFrequency() / HorizTotalDots;
ULONG HSyncs = (ElapsedCycles * HSyncsPerSecond + (CurrentIps >> 1)) / CurrentIps;
BYTE MaximumScanLine = 1 + (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & 0x1F);
ULONG HSyncsPerSecond, HSyncs;
UNREFERENCED_PARAMETER(ElapsedTime);
if (VgaAcRegisters[VGA_AC_CONTROL_REG] & VGA_AC_CONTROL_8BIT) HorizTotalDots >>= 1;
HSyncsPerSecond = VgaGetClockFrequency() / HorizTotalDots;
HSyncs = (ElapsedCycles * HSyncsPerSecond + (CurrentIps >> 1)) / CurrentIps;
if (HSyncs == 0) HSyncs = 1;
VerticalTotal |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] & VGA_CRTC_OVERFLOW_VT8) << 8;
@ -1640,6 +1644,17 @@ static VOID FASTCALL VgaHorizontalRetrace(ULONGLONG ElapsedTime)
VerticalRetraceStart |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] & VGA_CRTC_OVERFLOW_VRS8) << 6;
VerticalRetraceStart |= (VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] & VGA_CRTC_OVERFLOW_VRS9) << 2;
if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & VGA_CRTC_MAXSCANLINE_DOUBLE)
{
VerticalRetraceStart <<= 1;
VerticalTotal <<= 1;
}
else
{
VerticalRetraceStart *= MaximumScanLine;
VerticalTotal *= MaximumScanLine;
}
/* Set the cycle */
HorizontalRetraceCycle = CurrentCycleCount;