StdTxMeas

The default Quickdraw text-measuring routine

#include <Quickdraw.h> Quickdraw

short StdTxMeas(byteCnt, textAddr, numer, denom, fInfo );

short byteCnt ; number of characters in text buffer

Ptr textAddr ; address of buffer containing text to measure

Point *numerPt ; not really " points"; these specify the . . .

Point *denomPt ; . . . character scaling factor

FontInfo *fInfo ; address of 8-byte FontInfo structure

This is Quickdraw's default low-level routine for measuring text, as used in

CharWidth, StringWidth, and TextWidth. Using the txFont, txSize, and

spExtra fields of the current GrafPort, it returns the width, in pixels, of the

specified text.

byteCnt specifies the number of characters to measure.

textAddr is the address of a buffer containing the characters to be measured.

The buffer should contain at least byteCnt characters.

numerPt and . . .

denomPt are addresses of 4-byte Point structures. They specify the

horizontal and vertical scaling factors to be applied to each character,

as described under StdText. Note that the addresses are passed; thus

the function may modify these scaling factors.

fInfo is the address of an 8-byte FontInfo structure describing various

facts about the font character spacing.

Returns: a short declaring how wide the text would be if drawn in the current

font, style, and size, including the information passed in fInfo .

Notes: Use StdTxMeas only if your application intercepts the Quickdraw

bottleneck routines (see SetStdProcs).

This is a bottleneck routine that is often intercepted by application

programs. For instance, if the application supports only one or two sizes of

text, it may be possible to write an optimized version of StdTxMeas.

Another possibility is to make a smarter version that is able to interpret

embedded codes indicating changes in font size, etc.

Referenced by (7):