FMMATRIX(3W)							  FMMATRIX(3W)

NAME    [Toc]    [Back]

     fminitpagematrix,	fmsetpagematrix, fmgetpagematrix, fmscalepagematrix,
     fmrotatepagematrix, fmconcatpagematrix - font manager page	matrix
     operations

SYNOPSIS    [Toc]    [Back]

     #include <fmclient.h>

     void fminitpagematrix()

     void fmsetpagematrix(m)
     double m[3][2];

     void fmgetpagematrix(m)
     double m[3][2];

     void fmscalepagematrix(x)
     double x;

     void fmrotatepagematrix(angle)
     double angle;

     void fmconcatpagematrix(m)
     double m[3][2];

DESCRIPTION    [Toc]    [Back]

     The argument m points to a	3x2 matrix of doubles, of which	you need fill
     in	only the first two rows	when loading values. (The third	row is
     reserved for future development and is currently ignored.)	 This matrix
     is	a two dimensional transformation matrix	that you can multiply against
     the page matrix.  (The page matrix	is independent of the hardware matrix
     stack.)  You can use this multiplication of the page matrix to scale and
     rotate text.  For more information	on two-dimensional transformation
     matrices, see Chapter 7, "Geometrical Transformations" in Fundamentals of
     Interactive Computer Graphics by J.D. Foley and A.	Van Dam, (AddisonWesley,
 1982).

     Changing the page matrix changes the page,	which you can visualize	as a
     transparent sheet that lies on top	of the window.	Distorting this	sheet
     changes the appearance of text rendered on	it.  If	you rotate the page,
     you rotate	the text in the	window.	 If you	stretch	or compress the	page
     (scale the	page) you stretch or compress the text on the page.

     If	you are	not familiar with using	transformation matrices, you should
     avoid the routines	that require the m matrix.  Fortunately, you can still
     perform scales or rotations on the	page matrix.  Use the
     fmscalepagematrix and fmrotatepagematrix routines.	Currently, the only
     way to render rotated text	is to alter the	page matrix. However, you do
     not always	need to	scale the page matrix (call fmscalepagematrix) to
     render text of a different	size.  In fact,	the preferred method for
     scaling text often	is to call fmscalefont.	This associates	a scaling
     factor to a given font, which, as in PostScript, begins as	a 1-point-high



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FMMATRIX(3W)							  FMMATRIX(3W)



     set of characters.

     But, getting back to the page matrix, use:	 fminitpagematrix to
     initialize	the page matrix	to an identity matrix.

     fmsetpagematrix to	load the page matrix with the floating point values
     supplied in matrix	m.

     fmgetpagematrix to	return the current page	matrix in the matrix supplied
     by	the client.

     fmscalepagematrix to uniformly scale the page matrix by x.

     fmrotatepagematrix	to rotate the page matrix by the specified angle,
     where the angle (measured in degrees) increases up	from the x axis.

     fmconcatpagematrix	to post	concatenate the	m matrix (supplied by the
     client) with the current page matrix.

SEE ALSO    [Toc]    [Back]

     fminit(3W), fmgetfontinfo(3W), fmprstr(3W), fmscalefont(3W),
     fmsetfont(3W).

NOTE    [Toc]    [Back]

     This routine is available only in immediate mode.


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