PfExtentText()

Calculate the extent rectangle of a text string

Synopsis:

#include <photon/Pf.h>

PhRect_t *PfExtentText( PhRect_t *extent,
                        PhPoint_t const *pos,
                        const char *font,
                        const char *str,
                        int len);

Arguments:

extent

A pointer to a PhRect_t structure where the function stores the string's extent. For the interpretation of the members of this structure, see below.

pos

NULL, or a pointer to a PhPoint_t structure that defines an offset that you want to apply to the extent.

font

The base font to use when calculating the extent. You should create this argument by calling PfGenerateFontName().

str

The UTF-8 multibyte string whose extent you want to determine.

len

The number of bytes in the string. If len is 0, PfExtentText() assumes that it's strlen(str).

Library:

ph

Description:

This function calculates the extent rectangle of a text string. The base font determines the ascender and descender values of the extent. The width is dependent on the string — the actual font used by characters within the string may be different than this base font (as specified in the fontext and fontmap files).

PfExtentText() stores the text extent in the PhRect_t that extent points to. The members are used as follows:

ul.x

The left bearing.

lr.x

The maximum x distance.

ul.y

The ascender.

lr.y

The descender.

The baseline of the font is at position y=0; the width of the string is lr.x - min(ul.x, 0) + 1. The height of the string is lr.y - ul.y + 1.

The resulting extent is offset by the point passed in the PhPoint_t structure pointed to by pos. If pos is NULL, no offset is applied.

If metrics for the base font have been loaded locally (see PfLoadMetrics()) then this extent may be calculated internally; otherwise a request is sent to the font server.

Returns:

A pointer to the extent rectangle (extent) if successful, NULL otherwise.

Classification:

Photon

See also:

PfExtent(), PfExtentCx(), PfExtentTextToRect(), PfExtentWideText(), PfFractionalExtentText(), PfGenerateFontName(), PfLoadMetrics(), PgExtentText(), PhPoint_t, PhRect_t

Fonts chapter of the Photon Programmer's Guide