schoch
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ExtTextOut to a Bitmap on Widows NT
I have the following code fragment:
hDC = CreateCompatibleDC(NULL);
hBitmap = CreateCompatibleBitmap(hDC
(void)SelectObject(hDC, hBitmap);
(void)SelectObject(hDC, myFont);
SelectPalette(hDC, myPalette, FALSE);
RealizePalette(hDC);
SetTextColor(hDC, PALETTEINDEX(1)); /* Usually yellow, but all colors fail */
ret = ExtTextOut(hDC, x, y, 0, NULL, chars, nchars, spacing); /* all valid */
if (ret == 0)
error = GetLastError();
At this point ret is 0 and error is 0. Why? Here is some more information:
This fails on Windows NT 4.0 with lastest patch. It works on Windows 95.
TextOut works. Only ExtTextOut fails.
It works if hDC is a window DC.
In summary, the ExtTextOut to a Bitmap fails on Windows NT 4.0. GetLastError returns 0.
Is this a known bug? Is there a workaround?
hDC = CreateCompatibleDC(NULL);
hBitmap = CreateCompatibleBitmap(hDC
(void)SelectObject(hDC, hBitmap);
(void)SelectObject(hDC, myFont);
SelectPalette(hDC, myPalette, FALSE);
RealizePalette(hDC);
SetTextColor(hDC, PALETTEINDEX(1)); /* Usually yellow, but all colors fail */
ret = ExtTextOut(hDC, x, y, 0, NULL, chars, nchars, spacing); /* all valid */
if (ret == 0)
error = GetLastError();
At this point ret is 0 and error is 0. Why? Here is some more information:
This fails on Windows NT 4.0 with lastest patch. It works on Windows 95.
TextOut works. Only ExtTextOut fails.
It works if hDC is a window DC.
In summary, the ExtTextOut to a Bitmap fails on Windows NT 4.0. GetLastError returns 0.
Is this a known bug? Is there a workaround?
ASKER
Edited text of question
ASKER
Adjusted points to 100
ASKER
Adjusted points to 150
ASKER
Adjusted points to 200
Are you sure you are using a palette based
screen mode?
screen mode?
ASKER
Yes, in this example, the VGA card (an S3 compatible) is set to 256 colors. If the card is set to more than 256 colors, I use RGB(255,255,0) instead of PALETTEINDEX(1). The result is the same in both cases.
I was also able to get it to fail on Windows 95 with some display drivers.
I was also able to get it to fail on Windows 95 with some display drivers.
ASKER
If ETO_OPAQUE and a RECT are passed, the background is painted, but the characters are not.
If spacing is NULL, it works (the characters are drawn with the default spacing). Of course, the reason I'm using ExtTextOut is to get the spacing I want without drawing each character with a separate GDI call.
If spacing is NULL, it works (the characters are drawn with the default spacing). Of course, the reason I'm using ExtTextOut is to get the spacing I want without drawing each character with a separate GDI call.
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You selected the palette into the DC, but didn't realized it (RealizePalette()).