[Freetype] transformed text in Graphical context

[Klaas Holwerda]

Hi,

For some time i try to figure out how to do the following.

Can someone tell me the best approach?
And maybe where in some open source it is done?

I want to have a graphics context ( i call wxDrawer)  using freetype 
internal for text rendering ( c++ ).
The drawing context can have a transform matrix set for it, by which all 
drawing is transformed before
actually drawing it.
Something like the following should be possible, and as fast as possible.

wxDrawer MyDrawer;
MyDrawer->SetFont( "filename", face etc. );
MyDrawer->SetTransForm( MyAffineMatrix );
MyDrawer->DrawText( "blah blah", size1 );
MyDrawer->SetTransForm( MyNextAffineMatrix );
MyDrawer->DrawText( "other blah blah" );

MyDrawer->SetFont( "filename", face etc., size2 );
MyDrawer->SetTransForm( MyOtherAffineMatrix );
MyDrawer->DrawText( "other font blah blah", size3 );

Currently i store the glyphs inside the drawable objects itself, but 
this is not very smart, if the
same font/glyphs are used frequently. I looks like this:
http://wxart2d.sourceforge.net/screenshots/freetypetrans.png

Therefore  i want to use the wxDrawer drawing context to also be able to 
draw freetype strings.

The main problem i see is that the size of the text glyphs/font to draw 
will change depending on the transform
that is set for the drawing context. An object containing text can be 
placed by several transforms, which
mean a constant change in the font size, or at least its transform.
So how should i cache the font inside my drawing context, in such a 
manner that the size is not yet fixed,
and the transform of the drawing context can be applied on the cached 
glyphs?

I studied the Caching approach, but it seems to work with more or less 
fixed sizes.
Or should i use a fixed Normalized  font size inside the drawing 
context, and transform and scale
that font/glyhs, to have the transformed DrawText at a certain size?

( understand that my object are in Relative World coordinates, and the 
canvas is in worldcoordinates,
the text eventually is transformed to device coordinates directly from 
relativeworld to device.
So i have not a clear idea what font size needs to be set, since it is 
not defined in any units ( pixel or points ),
this becuase any rectangle in world coordinates can be mapped to the 
canvas  window. )

Any advice welcome, and thanks in advance,

Klaas