gp_text_metric.h File Reference

A text metric. More...

#include <core/gp_types.h>
#include <text/gp_text_style.h>

Go to the source code of this file.

Functions
gp_size	gp_glyph_advance_x (const gp_text_style *style, uint32_t ch)
	Returns a letter advance in horizontal direction.
gp_ssize	gp_glyph_bearing_x (const gp_text_style *style, uint32_t ch)
	Returns horizontal bearing.
gp_size	gp_text_width_len (const gp_text_style *style, enum gp_text_len_type type, const char *str, size_t len)
	Calculates the width of the string drawn in the given style.
static gp_size	gp_text_wbbox_len (const gp_text_style *style, const char *str, size_t len)
	Calculates bounding box width of the string drawn in the given style.
gp_size	gp_text_width (const gp_text_style *style, enum gp_text_len_type type, const char *str)
	Calculates the width of the string drawn in the given style.
static gp_size	gp_text_wbbox (const gp_text_style *style, const char *str)
	Calculates bounding box width of the string drawn in the given style.
gp_size	gp_text_max_width (const gp_text_style *style, unsigned int len)
	Counts maximal width for len characters.
gp_size	gp_text_avg_width (const gp_text_style *style, unsigned int len)
	Counts average width for len characters.
gp_size	gp_text_max_width_chars (const gp_text_style *style, const char *chars, unsigned int len)
	Returns maximal width for text written with len characters from str.
gp_size	gp_text_height (const gp_text_style *style)
	Returns maximal text height.
gp_size	gp_text_ascent (const gp_text_style *style)
	Returns an ascent.
gp_size	gp_text_descent (const gp_text_style *style)
	Returns a descent.
size_t	gp_text_fit_width (const gp_text_style *style, const char *str, gp_size width)
	Counts how many characters will fit into a width pixels.
gp_size	gp_text_cur_pos (const gp_text_style *style, const char *str, gp_coord x_off)
	Returns position between string characters given an x pixel coordinate from the start of the rendered string. The return value is between [0, strlen(str)], where 0 means cursor before string and strlen(str) cursor after string.

Detailed Description

A text metric.

Definition in file gp_text_metric.h.

Function Documentation

gp_glyph_advance_x()

gp_size gp_glyph_advance_x	(	const gp_text_style *	style,
		uint32_t	ch
	)

Returns a letter advance in horizontal direction.

Parameters

style	A text style + font formatting
ch	An unicode glyph.

Returns

Horizontal advance in pixels.

gp_glyph_bearing_x()

gp_ssize gp_glyph_bearing_x	(	const gp_text_style *	style,
		uint32_t	ch
	)

Returns horizontal bearing.

Bearing is a distance to be added to the x coordinate before we start drawing a glyph bitmap. Bearing may be negative in some cases, typically for letter 'J' and 'j'.

Parameters

style	A text style + font formatting
ch	An unicode glyph.

Returns

Horizontal bearing in pixels.

gp_text_ascent()

gp_size gp_text_ascent

(

const gp_text_style *

style

)

Returns an ascent.

Returns an ascent, the height from the baseline to the top of characters, for the given text style.

Parameters

style

A text style + font formatting.

Returns

An ascent in pixels.

Referenced by gp_widget_size_units_get().

gp_text_avg_width()

gp_size gp_text_avg_width	(	const gp_text_style *	style,
		unsigned int	len
	)

Counts average width for len characters.

Parameters

style	A text style + font formatting.
len	A number of glyphs to draw.

Returns

Width in pixels.

gp_text_cur_pos()

gp_size gp_text_cur_pos	(	const gp_text_style *	style,
		const char *	str,
		gp_coord	x_off
	)

Returns position between string characters given an x pixel coordinate from the start of the rendered string. The return value is between [0, strlen(str)], where 0 means cursor before string and strlen(str) cursor after string.

Parameters

style	A text style.
str	An UTF8 string.
x_off	Horizontal offset in the rendered string in pixel.

Returns

A cursor position in the string.

gp_text_descent()

gp_size gp_text_descent

(

const gp_text_style *

style

)

Returns a descent.

Returns a descend, the height from the baseline to the bottom of characters, for the given text style.

Parameters

style

A text style + font formatting.

Returns

A descent in pixels.

gp_text_fit_width()

size_t gp_text_fit_width	(	const gp_text_style *	style,
		const char *	str,
		gp_size	width
	)

Counts how many characters will fit into a width pixels.

Parameters

style	A text style.
str	An UTF-8 string.
width	Width in pixels.

Returns

How many characters from the string will fit the space.

gp_text_height()

gp_size gp_text_height

(

const gp_text_style *

style

)

Returns maximal text height.

Parameters

style

A text style + font formatting.

Returns

Height in pixels.

gp_text_max_width()

gp_size gp_text_max_width	(	const gp_text_style *	style,
		unsigned int	len
	)

Counts maximal width for len characters.

Parameters

style	A text style + font formatting.
len	A number of glyphs to draw.

Returns

Width in pixels.

gp_text_max_width_chars()

gp_size gp_text_max_width_chars	(	const gp_text_style *	style,
		const char *	chars,
		unsigned int	len
	)

Returns maximal width for text written with len characters from str.

First we find maximal width of an character from the given string, then we use that to compute maximal width. Note that first and last character needs special handling due to bearing and advance.

Parameters

style	A text style + font formatting.
chars	An UTF8 string.
len	A number of glyphs to draw.

Returns

Width in pixels.

gp_text_wbbox()

static gp_size gp_text_wbbox ( const gp_text_style *  style, const char *  str  )

inlinestatic

Calculates bounding box width of the string drawn in the given style.

Parameters

style	A text style + font formatting.
str	A string.

Returns

Width in pixels.

Definition at line 106 of file gp_text_metric.h.

References gp_text_width().

gp_text_wbbox_len()

static gp_size gp_text_wbbox_len ( const gp_text_style *  style, const char *  str, size_t  len  )

inlinestatic

Calculates bounding box width of the string drawn in the given style.

Parameters

style	A text style + font formatting.
str	A string.
len	Maximal lenght of the string.

Returns

Width in pixels.

Definition at line 82 of file gp_text_metric.h.

References gp_text_width_len().

gp_text_width()

gp_size gp_text_width	(	const gp_text_style *	style,
		enum gp_text_len_type	type,
		const char *	str
	)

Calculates the width of the string drawn in the given style.

Parameters

style	A text style + font formatting.
type	Select if we want a bounding box or advance.
str	A string.

Returns

Width in pixels.

Referenced by gp_text_wbbox().

gp_text_width_len()

gp_size gp_text_width_len	(	const gp_text_style *	style,
		enum gp_text_len_type	type,
		const char *	str,
		size_t	len
	)

Calculates the width of the string drawn in the given style.

Parameters

style	A text style + font formatting.
type	Select if we want a bounding box or advance.
str	A string.
len	Maximal lenght of the string.

Returns

Width in pixels.

Referenced by gp_text_wbbox_len().