This avoids having to do separate getTextWidth calls in several places.
More getTextWidth calls could be saved by splitting the rendering of
the font to an off-screen buffer from the final composition onto the
destination surface: the routines that draw text inside a box have to
compute the width before they can draw the box and currently the box
has to be drawn before the text.
This implementation is based on the implementation in TextDialog::preProcess,
with one major difference: it works on the entire input string, copies it much
less as part of its function, and tries to quickly establish a small search
space for the length of the beginning split of each line.
With most standard fonts and sizes, this means up to 9 computations of metrics
per output line.
Multi-line message boxes had the incorrect height.
I also took the opportunity to make named constants out of magic numbers
making up the various message box dimensions.
This reverts commit 0908aa7bb7.
It turns out there are multi-line text messages in use: Nebuleon found
one in the confirmation message when deleting a section.
When trying to test the previous commit, I couldn't find any place in
the application where strings containing newlines are drawn. So I'm
assuming this is an unnecessary feature, until someone comes up with
a test case proving otherwise.
Yeah, I'm too lazy to review all the code that draws text...
In well-described fonts, this enables multi-line text (e.g. in manuals) to be
more readable.
The term "height" is also replaced with "line spacing" in Font's code.
Replaced Font constructor with factory method, so that if the TTF
cannot be loaded, the Font object is not constructed. The normal C++
way of handling this is with exceptions, but we're compiling with
-fno-exceptions.
Originally the font implementation was based on SFont, but it was
recently replaced by an SDL_ttf based implementation, so the name
no longer made sense.
