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Recently when building a GIS display system I ran into the problem of displaying characters at many different sizes, rotations (escapments), and in several typefaces all in the same view. Unfortunately the redraw performance I was able to obtain using Windows' font routines was not very good. Reaching back to my past (and definitely showing my age) I decided to use the venerable "Hershey" vector fonts.
All of the font management and display is wrapped up the class
the use of which it illustrated in the FontDemo
program included. The only method of any real consequence is:
void SMFontUtil::DrawString( CDC * pDC, //device context to draw to CPoint pStart, //starting point double pRotation, //rotation angle clockwise in radians (0 = 12:00) double pCharWidth, //width of each character double pCharHeight, //height of each character FONT_TYPE pFontType, //the font to use CString pString) //the string
NOTE: For this article I hard-coded the path so that the font definition data
(found in FontData.zip) must reside in
C:\HersheyFonts. In the real system this is
stored on a server with the GIS data.
The original Hershey font character codes do not match well ASCII.
I have built a translation table that maps ASCII character and font to
a Hershey character. The included fonts are:
I have also included a crude font editor that lets you edit the vertices and the translation table. To edit a character right click on it in any view. To assign a hershey font to a ASCII font family pairing select the character in the numeric view and select "index save" from the menu. Switch to Xlated view and select the target cell, then select "Assign Index".
The font data resides in two files. The vector data, and the translation table
I have supplied both the runtime version, and a human readable version in CSV
format for those who wish to use them. The
SMFontUtils class provides a method
to convert from the CSV to the runtime. Again, please note that for
the purposes of this article the font definition data (FontData.zip) must be