Problems in bitblt (in x11drv)

Ove Kaaven ovek at
Wed Jun 8 21:04:06 CDT 2005

tir, 07,.06.2005 kl. 23.00 -0700, skrev David Albrecht:
> VOID CreateLcdBitmap(VOID)
> {
> 	// create LCD bitmap
> 	_ASSERT(nLcdDoubled == 1 || nLcdDoubled == 2 || nLcdDoubled == 4);
> 	bmiLcd.Lcd_bmih.biWidth = LCD1_ROW * nLcdDoubled;
> 	bmiLcd.Lcd_bmih.biHeight = -64 * nLcdDoubled;
> 	hLcdDC = CreateCompatibleDC(hWindowDC);
> 	_ASSERT(hLcdDC != NULL);
> 	hLcdBitmap = CreateDIBSection(hLcdDC, 
> 	_ASSERT(hLcdBitmap != NULL);
> 	hOldLcdBitmap = SelectObject(hLcdDC, hLcdBitmap);
> 	_ASSERT(hPalette != NULL);
> 	SelectPalette(hLcdDC, hPalette, FALSE);	// set palette for LCD DC
> 	RealizePalette(hLcdDC);					// realize palette
> 	UpdateContrast(Chipset.contrast);
> }

When creating a memory DC for an 8-bit DIB section, it is normal to
create a palette matching the DIB color table, then just selecting it
into that DC. In such usage, RealizePalette is not used. Perhaps there's
an explanation to be found in that direction.

MSDN says, for example:

"The RealizePalette function modifies the palette for the device
associated with the specified device context. If the device context is a
memory DC, the color table for the bitmap selected into the DC is
modified. If the device context is a display DC, the physical palette
for that device is modified."

This suggests that RealizePalette should set the DIB color table from
the palette, something Wine might not do properly. Although this is the
opposite of your hack, it does make the palette and the DIB color table
identical again, so perhaps it would still work for you.

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