FreeType Fonts and Rendering

FreeType Fonts and Rendering — Functions for shape engines to manipulate FreeType fonts

Types and Values

Object Hierarchy

    GObject
    ╰── PangoFontMap
        ╰── PangoFcFontMap
            ╰── PangoFT2FontMap

Description

The macros and functions in this section are used to access fonts and render text to bitmaps using the FreeType 2 library.

Functions

pango_ft2_font_map_new ()

PangoFontMap *
pango_ft2_font_map_new (void);

Create a new PangoFT2FontMap object; a fontmap is used to cache information about available fonts, and holds certain global parameters such as the resolution and the default substitute function (see pango_ft2_font_map_set_default_substitute()).

Returns

the newly created fontmap object. Unref with g_object_unref() when you are finished with it.

Since: 1.2


pango_ft2_font_map_set_resolution ()

void
pango_ft2_font_map_set_resolution (PangoFT2FontMap *fontmap,
                                   double dpi_x,
                                   double dpi_y);

Sets the horizontal and vertical resolutions for the fontmap.

Parameters

fontmap

a PangoFT2FontMap

 

dpi_x

dots per inch in the X direction

 

dpi_y

dots per inch in the Y direction

 

Since: 1.2


pango_ft2_font_map_create_context ()

PangoContext *
pango_ft2_font_map_create_context (PangoFT2FontMap *fontmap);

pango_ft2_font_map_create_context has been deprecated since version 1.22 and should not be used in newly-written code.

Use pango_font_map_create_context() instead.

Create a PangoContext for the given fontmap.

[skip]

Parameters

fontmap

a PangoFT2FontMap

 

Returns

the newly created context; free with g_object_unref().

Since: 1.2


PangoFT2SubstituteFunc ()

void
(*PangoFT2SubstituteFunc) (FcPattern *pattern,
                           gpointer data);

Function type for doing final config tweaking on prepared FcPatterns.

Parameters

pattern

the FcPattern to tweak.

 

data

user data.

 

pango_ft2_font_map_set_default_substitute ()

void
pango_ft2_font_map_set_default_substitute
                               (PangoFT2FontMap *fontmap,
                                PangoFT2SubstituteFunc func,
                                gpointer data,
                                GDestroyNotify notify);

Sets a function that will be called to do final configuration substitution on a FcPattern before it is used to load the font. This function can be used to do things like set hinting and antialiasing options.

Parameters

fontmap

a PangoFT2FontMap

 

func

function to call to to do final config tweaking on FcPattern objects.

 

data

data to pass to func

 

notify

function to call when data is no longer used.

 

Since: 1.2


pango_ft2_font_map_substitute_changed ()

void
pango_ft2_font_map_substitute_changed (PangoFT2FontMap *fontmap);

Call this function any time the results of the default substitution function set with pango_ft2_font_map_set_default_substitute() change. That is, if your substitution function will return different results for the same input pattern, you must call this function.

Parameters

fontmap

a PangoFT2FontMap

 

Since: 1.2


pango_ft2_get_context ()

PangoContext *
pango_ft2_get_context (double dpi_x,
                       double dpi_y);

pango_ft2_get_context has been deprecated since version 1.22 and should not be used in newly-written code.

Use pango_font_map_create_context() instead.

Retrieves a PangoContext for the default PangoFT2 fontmap (see pango_ft2_font_map_for_display()) and sets the resolution for the default fontmap to dpi_x by dpi_y .

[skip]

Parameters

dpi_x

the horizontal DPI of the target device

 

dpi_y

the vertical DPI of the target device

 

Returns

the new PangoContext


pango_ft2_render ()

void
pango_ft2_render (FT_Bitmap *bitmap,
                  PangoFont *font,
                  PangoGlyphString *glyphs,
                  gint x,
                  gint y);

Renders a PangoGlyphString onto a FreeType2 bitmap.

Parameters

bitmap

the FreeType2 bitmap onto which to draw the string

 

font

the font in which to draw the string

 

glyphs

the glyph string to draw

 

x

the x position of the start of the string (in pixels)

 

y

the y position of the baseline (in pixels)

 

pango_ft2_render_transformed ()

void
pango_ft2_render_transformed (FT_Bitmap *bitmap,
                              const PangoMatrix *matrix,
                              PangoFont *font,
                              PangoGlyphString *glyphs,
                              int x,
                              int y);

Renders a PangoGlyphString onto a FreeType2 bitmap, possibly transforming the layed-out coordinates through a transformation matrix. Note that the transformation matrix for font is not changed, so to produce correct rendering results, the font must have been loaded using a PangoContext with an identical transformation matrix to that passed in to this function.

Parameters

bitmap

the FreeType2 bitmap onto which to draw the string

 

font

the font in which to draw the string

 

matrix

a PangoMatrix, or NULL to use an identity transformation.

[nullable]

glyphs

the glyph string to draw

 

x

the x position of the start of the string (in Pango units in user space coordinates)

 

y

the y position of the baseline (in Pango units in user space coordinates)

 

Since: 1.6


pango_ft2_render_layout_line ()

void
pango_ft2_render_layout_line (FT_Bitmap *bitmap,
                              PangoLayoutLine *line,
                              int x,
                              int y);

Render a PangoLayoutLine onto a FreeType2 bitmap

Parameters

bitmap

a FT_Bitmap to render the line onto

 

line

a PangoLayoutLine

 

x

the x position of start of string (in pixels)

 

y

the y position of baseline (in pixels)

 

pango_ft2_render_layout_line_subpixel ()

void
pango_ft2_render_layout_line_subpixel (FT_Bitmap *bitmap,
                                       PangoLayoutLine *line,
                                       int x,
                                       int y);

Render a PangoLayoutLine onto a FreeType2 bitmap, with he location specified in fixed-point Pango units rather than pixels. (Using this will avoid extra inaccuracies from rounding to integer pixels multiple times, even if the final glyph positions are integers.)

Parameters

bitmap

a FT_Bitmap to render the line onto

 

line

a PangoLayoutLine

 

x

the x position of start of string (in Pango units)

 

y

the y position of baseline (in Pango units)

 

Since: 1.6


pango_ft2_render_layout ()

void
pango_ft2_render_layout (FT_Bitmap *bitmap,
                         PangoLayout *layout,
                         int x,
                         int y);

Render a PangoLayout onto a FreeType2 bitmap

Parameters

bitmap

a FT_Bitmap to render the layout onto

 

layout

a PangoLayout

 

x

the X position of the left of the layout (in pixels)

 

y

the Y position of the top of the layout (in pixels)

 

pango_ft2_render_layout_subpixel ()

void
pango_ft2_render_layout_subpixel (FT_Bitmap *bitmap,
                                  PangoLayout *layout,
                                  int x,
                                  int y);

Render a PangoLayout onto a FreeType2 bitmap, with he location specified in fixed-point Pango units rather than pixels. (Using this will avoid extra inaccuracies from rounding to integer pixels multiple times, even if the final glyph positions are integers.)

Parameters

bitmap

a FT_Bitmap to render the layout onto

 

layout

a PangoLayout

 

x

the X position of the left of the layout (in Pango units)

 

y

the Y position of the top of the layout (in Pango units)

 

Since: 1.6


pango_ft2_get_unknown_glyph ()

PangoGlyph
pango_ft2_get_unknown_glyph (PangoFont *font);

pango_ft2_get_unknown_glyph is deprecated and should not be used in newly-written code.

Return the index of a glyph suitable for drawing unknown characters with font , or PANGO_GLYPH_EMPTY if no suitable glyph found.

If you want to draw an unknown-box for a character that is not covered by the font, use PANGO_GET_UNKNOWN_GLYPH() instead.

Parameters

font

a PangoFont

 

Returns

a glyph index into font , or PANGO_GLYPH_EMPTY


pango_ft2_font_get_kerning ()

int
pango_ft2_font_get_kerning (PangoFont *font,
                            PangoGlyph left,
                            PangoGlyph right);

pango_ft2_font_get_kerning is deprecated and should not be used in newly-written code.

Retrieves kerning information for a combination of two glyphs.

Use pango_fc_font_kern_glyphs() instead.

Parameters

font

a PangoFont

 

left

the left PangoGlyph

 

right

the right PangoGlyph

 

Returns

The amount of kerning (in Pango units) to apply for the given combination of glyphs.


pango_ft2_font_get_face ()

FT_Face
pango_ft2_font_get_face (PangoFont *font);

pango_ft2_font_get_face is deprecated and should not be used in newly-written code.

Returns the native FreeType2 FT_Face structure used for this PangoFont. This may be useful if you want to use FreeType2 functions directly.

Use pango_fc_font_lock_face() instead; when you are done with a face from pango_fc_font_lock_face() you must call pango_fc_font_unlock_face().

Parameters

font

a PangoFont

 

Returns

a pointer to a FT_Face structure, with the size set correctly, or NULL if font is NULL.

[nullable]


pango_ft2_font_get_coverage ()

PangoCoverage *
pango_ft2_font_get_coverage (PangoFont *font,
                             PangoLanguage *language);

pango_ft2_font_get_coverage is deprecated and should not be used in newly-written code.

Gets the PangoCoverage for a PangoFT2Font. Use pango_font_get_coverage() instead.

Parameters

font

a PangoFT2Font.

 

language

a language tag.

 

Returns

a PangoCoverage.


pango_ft2_font_map_for_display ()

PangoFontMap *
pango_ft2_font_map_for_display (void);

pango_ft2_font_map_for_display is deprecated and should not be used in newly-written code.

Returns a PangoFT2FontMap. This font map is cached and should not be freed. If the font map is no longer needed, it can be released with pango_ft2_shutdown_display(). Use of the global PangoFT2 fontmap is deprecated; use pango_ft2_font_map_new() instead.

[skip]

Returns

a PangoFT2FontMap.


pango_ft2_shutdown_display ()

void
pango_ft2_shutdown_display (void);

pango_ft2_shutdown_display is deprecated and should not be used in newly-written code.

Free the global fontmap. (See pango_ft2_font_map_for_display()) Use of the global PangoFT2 fontmap is deprecated.

Types and Values

PangoFT2FontMap

typedef struct _PangoFT2FontMap PangoFT2FontMap;

The PangoFT2FontMap is the PangoFontMap implementation for FreeType fonts.


PANGO_RENDER_TYPE_FT2

#define PANGO_RENDER_TYPE_FT2 "PangoRenderFT2"

PANGO_RENDER_TYPE_FT2 is deprecated and should not be used in newly-written code.

A string constant that was used to identify shape engines that work with the FreeType backend. See PANGO_RENDER_TYPE_FC for the replacement.