How to set the Color for a single Char ?

[paule32]

Hello,
I tried to "writeChar" a character with a TColorAttr Color, but I fail.

TColorAttr Color = { 0xffff00, 0x000000 };
writeChar(cursor.x, cursor.y, 'A', Color, 1);

The Color will be white on red - and this is not what I expect.
The Baseclass is a TDialog, but with cpBlue.

[magiblot]

Hi Jens! Sorry for not replying earlier.

If you look at the writeChar function:

tvision/source/tvision/tvwrite.cpp

Lines 354 to 359 in 0917f04

	void TView::writeChar( short x, short y, char c, uchar color, short count ) noexcept
	{
	if (count > 0)
	{
	TScreenCell cell;
	::setCell(cell, c, mapColor(color));

You will see that the color parameter is a uchar (instead of a TColorAttr) and that it is passed as an argument to mapColor. This means the color parameter of writeChar is meant to be a color palette index instead of a literal color, which is why you don't get the result you expected.

The "white on red" color you see is the color shown for invalid palette adresses (originating from TView::errorAttr).

In this case, in order to get the behaviour you desire, you should either use a TDrawBuffer, whose writeChar method does take a TColorAttr argument, or use a TScreenCell and call writeView, passing the address of the TScreenCell and count = 1.