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[NTVDM]

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Implement VGA horizontal splitting.


svn path=/trunk/; revision=69725
This commit is contained in:
Aleksandar Andrejevic 2015-10-27 22:16:53 +00:00
parent 0a11c6ee0e
commit 325318311d
1 changed files with 36 additions and 3 deletions
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39
reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c
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@ -1185,10 +1185,14 @@ static VOID VgaUpdateFramebuffer(VOID)
DWORD AddressSize = VgaGetAddressSize();
DWORD ScanlineSize = (DWORD)VgaCrtcRegisters[VGA_CRTC_OFFSET_REG] * 2;
BYTE PresetRowScan = VgaCrtcRegisters[VGA_CRTC_PRESET_ROW_SCAN_REG] & 0x1F;
BYTE BytePanning = (VgaCrtcRegisters[VGA_CRTC_PRESET_ROW_SCAN_REG] >> 5) & 3;
DWORD Address = MAKEWORD(VgaCrtcRegisters[VGA_CRTC_START_ADDR_LOW_REG],
VgaCrtcRegisters[VGA_CRTC_START_ADDR_HIGH_REG])
+ PresetRowScan * ScanlineSize
+ ((VgaCrtcRegisters[VGA_CRTC_PRESET_ROW_SCAN_REG] >> 5) & 3);
+ BytePanning;
WORD LineCompare = VgaCrtcRegisters[VGA_CRTC_LINE_COMPARE_REG]
| ((VgaCrtcRegisters[VGA_CRTC_OVERFLOW_REG] & VGA_CRTC_OVERFLOW_LC8) << 4);
BYTE PixelShift = VgaAcRegisters[VGA_AC_HORZ_PANNING_REG] & 0x0F;
/*
* If the console framebuffer is NULL, that means something
@ -1216,9 +1220,38 @@ static VOID VgaUpdateFramebuffer(VOID)
InterlaceHighBit >>= 1;
}
if (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & VGA_CRTC_MAXSCANLINE_DOUBLE)
{
/* Halve the line compare value */
LineCompare >>= 1;
}
else
{
/* Divide the line compare value by the maximum scan line */
LineCompare /= 1 + (VgaCrtcRegisters[VGA_CRTC_MAX_SCAN_LINE_REG] & 0x1F);
}
/* Loop through the scanlines */
for (i = 0; i < CurrResolution.Y; i++)
{
if (i == LineCompare)
{
if (VgaAcRegisters[VGA_AC_CONTROL_REG] & VGA_AC_CONTROL_PPM)
{
/*
* Disable the pixel shift count and byte panning
* for the rest of the display cycle
*/
PixelShift = 0;
BytePanning = 0;
}
/* Reset the address, but assume the preset row scan is 0 */
Address = MAKEWORD(VgaCrtcRegisters[VGA_CRTC_START_ADDR_LOW_REG],
VgaCrtcRegisters[VGA_CRTC_START_ADDR_HIGH_REG])
+ BytePanning;
}
if ((VgaGcRegisters[VGA_GC_MISC_REG] & VGA_GC_MISC_OE) && (i & 1))
{
/* Odd-numbered line in interlaced mode - set the high bit */
@ -1233,11 +1266,11 @@ static VOID VgaUpdateFramebuffer(VOID)
/* Apply horizontal pixel panning */
if (VgaAcRegisters[VGA_AC_CONTROL_REG] & VGA_AC_CONTROL_8BIT)
{
X = j + ((VgaAcRegisters[VGA_AC_HORZ_PANNING_REG] & 0x0F) >> 1);
X = j + (PixelShift >> 1);
}
else
{
X = j + (VgaAcRegisters[VGA_AC_HORZ_PANNING_REG] & 0x0F);
X = j + PixelShift;
}
/* Check the shifting mode */