Bitmap fonts sometimes clip first character on left edge about mpf-mc

[qcapen]

This occurs when the first character in the drawn text has a negative xoffset value in the font descriptor file. Because the drawing loop adds the xoffset to the current cursor position, a negative value in the first character is drawn outside of the label widget bounds. Positive xoffset values for the first character can also lead to clipping of the last character for the same reason.

The solution is to adjust the initial cursor/drawing position by the first character xoffset position so it is always drawn at position 0.

[qcapen]

Backported fix to version 0.54.1

[qcapen]

Now there are some conditions where the right edge of the last character is cut off. It appears the issue is in the BitmapFont.get_extents method. The algorithm used to calculate the extents does not properly take into account the width of the last character (only the xadvance character attribute which is sometimes less than the character width).

[qcapen]

The algorithm to calculate the font extents and do the drawing had some slight differences that in some conditions could cause clipping on either the right or left edge of the text widget. This is now fixed as both methods are now in sync.