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[NTVDM:SVGA]

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Fix read mode 1.


svn path=/trunk/; revision=72479
This commit is contained in:
Aleksandar Andrejevic 2016-08-27 23:40:44 +00:00
parent b4743181f7
commit 3ecb5aa01a
1 changed files with 12 additions and 12 deletions
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24
reactos/subsystems/mvdm/ntvdm/hardware/video/svga.c
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@ -1814,33 +1814,33 @@ VOID FASTCALL VgaReadMemory(ULONG Address, PVOID Buffer, ULONG Size)
}
else
{
const ULONG BitExpandTable[] =
const ULONG BitExpandInvertTable[] =
{
0x00000000, 0x000000FF, 0x0000FF00, 0x0000FFFF,
0x00FF0000, 0x00FF00FF, 0x00FFFF00, 0x00FFFFFF,
0xFF000000, 0xFF0000FF, 0xFF00FF00, 0xFF00FFFF,
0xFFFF0000, 0xFFFF00FF, 0xFFFFFF00, 0xFFFFFFFF
0xFFFFFFFF, 0xFFFFFF00, 0xFFFF00FF, 0xFFFF0000,
0xFF00FFFF, 0xFF00FF00, 0xFF0000FF, 0xFF000000,
0x00FFFFFF, 0x00FFFF00, 0x00FF00FF, 0x00FF0000,
0x0000FFFF, 0x0000FF00, 0x000000FF, 0x00000000
};
ULONG ColorCompareBytes = BitExpandTable[VgaGcRegisters[VGA_GC_COLOR_COMPARE_REG] & 0x0F];
ULONG ColorIgnoreBytes = BitExpandTable[VgaGcRegisters[VGA_GC_COLOR_IGNORE_REG] & 0x0F];
ULONG ColorCompareBytes = BitExpandInvertTable[VgaGcRegisters[VGA_GC_COLOR_COMPARE_REG] & 0x0F];
ULONG ColorIgnoreBytes = BitExpandInvertTable[VgaGcRegisters[VGA_GC_COLOR_IGNORE_REG] & 0x0F];
/*
* These values can also be computed in the following way, but using the table seems to be faster:
*
* ColorCompareBytes = VgaGcRegisters[VGA_GC_COLOR_COMPARE_REG] * 0x000204081;
* ColorCompareBytes &= 0x01010101;
* ColorCompareBytes = (ColorCompareBytes << 8) - ColorCompareBytes;
* ColorCompareBytes = ~((ColorCompareBytes << 8) - ColorCompareBytes);
*
* ColorIgnoreBytes = VgaGcRegisters[VGA_GC_COLOR_IGNORE_REG] * 0x000204081;
* ColorIgnoreBytes &= 0x01010101;
* ColorIgnoreBytes = (ColorIgnoreBytes << 8) - ColorIgnoreBytes;
* ColorIgnoreBytes = ~((ColorIgnoreBytes << 8) - ColorIgnoreBytes);
*/
/* Loop through each byte */
for (i = 0; i < Size; i++)
{
ULONG PlaneData;
ULONG PlaneData = 0;
/* This should always return a plane 0 address */
VideoAddress = VgaTranslateAddress(Address + i);
@ -1849,13 +1849,13 @@ VOID FASTCALL VgaReadMemory(ULONG Address, PVOID Buffer, ULONG Size)
PlaneData = *(PULONG)&VgaMemory[VideoAddress * VGA_NUM_BANKS];
/* Reverse the bytes for which the color compare register is zero */
PlaneData ^= ~ColorCompareBytes;
PlaneData ^= ColorCompareBytes;
/* Apply the color ignore register */
PlaneData |= ColorIgnoreBytes;
/* Store the value in the buffer */
BufPtr[i] = (PlaneData | (PlaneData >> 8) | (PlaneData >> 16) | (PlaneData >> 24)) & 0xFF;
BufPtr[i] = (PlaneData & (PlaneData >> 8) & (PlaneData >> 16) & (PlaneData >> 24)) & 0xFF;
}
}