playout.h File Reference

C API for paragraph layout. More...

#include "unicode/ubidi.h"
#include "layout/LETypes.h"
#include "plruns.h"

Go to the source code of this file.

Typedefs
typedef void	pl_paragraph
	The opaque type for a paragraph layout.
typedef void	pl_line
	The opaque type for a line in a paragraph layout.
typedef void	pl_visualRun
	The opaque type for a visual run in a line.

Functions
U_CAPI pl_paragraph *	pl_create (const LEUnicode chars[], le_int32 count, const pl_fontRuns *fontRuns, const pl_valueRuns *levelRuns, const pl_valueRuns *scriptRuns, const pl_localeRuns *localeRuns, UBiDiLevel paragraphLevel, le_bool vertical, LEErrorCode *status)
	Construct a ParagraphLayout object for a styled paragraph.
U_CAPI void	pl_close (pl_paragraph *paragraph)
	Close the given paragraph layout object.
U_CAPI le_bool	pl_isComplex (const LEUnicode chars[], le_int32 count)
	Examine the given text and determine if it contains characters in any script which requires complex processing to be rendered correctly.
U_CAPI UBiDiLevel	pl_getParagraphLevel (pl_paragraph *paragraph)
	Return the resolved paragraph level.
U_CAPI UBiDiDirection	pl_getTextDirection (pl_paragraph *paragraph)
	Return the directionality of the text in the paragraph.
U_CAPI le_int32	pl_getAscent (const pl_paragraph *paragraph)
	Return the max ascent value for all the fonts in the paragraph.
U_CAPI le_int32	pl_getDescent (const pl_paragraph *paragraph)
	Return the max descent value for all the fonts in the paragraph.
U_CAPI le_int32	pl_getLeading (const pl_paragraph *paragraph)
	Return the max leading value for all the fonts in the paragraph.
U_CAPI void	pl_reflow (pl_paragraph *paragraph)
	Reset line breaking to start from the beginning of the paragraph.
U_CAPI pl_line *	pl_nextLine (pl_paragraph *paragraph, float width)
	Return a pl_line object which represents next line in the paragraph.
U_CAPI void	pl_closeLine (pl_line *line)
	Close the given line object.
U_CAPI le_int32	pl_countLineRuns (const pl_line *line)
	Count the number of visual runs in the line.
U_CAPI le_int32	pl_getLineAscent (const pl_line *line)
	Get the ascent of the line.
U_CAPI le_int32	pl_getLineDescent (const pl_line *line)
	Get the descent of the line.
U_CAPI le_int32	pl_getLineLeading (const pl_line *line)
	Get the leading of the line.
U_CAPI le_int32	pl_getLineWidth (const pl_line *line)
	Get the width of the line.
U_CAPI const pl_visualRun *	pl_getLineVisualRun (const pl_line *line, le_int32 runIndex)
	Get a ParagraphLayout::VisualRun object for a given visual run in the line.
U_CAPI const le_font *	pl_getVisualRunFont (const pl_visualRun *run)
	Get the le_font object which represents the font of the visual run.
U_CAPI UBiDiDirection	pl_getVisualRunDirection (const pl_visualRun *run)
	Get the direction of the visual run.
U_CAPI le_int32	pl_getVisualRunGlyphCount (const pl_visualRun *run)
	Get the number of glyphs in the visual run.
U_CAPI const LEGlyphID *	pl_getVisualRunGlyphs (const pl_visualRun *run)
	Get the glyphs in the visual run.
U_CAPI const float *	pl_getVisualRunPositions (const pl_visualRun *run)
	Get the (x, y) positions of the glyphs in the visual run.
U_CAPI const le_int32 *	pl_getVisualRunGlyphToCharMap (const pl_visualRun *run)
	Get the glyph-to-character map for this visual run.
U_CAPI le_int32	pl_getVisualRunAscent (const pl_visualRun *run)
	A convenience method which returns the ascent value for the font associated with this run.
U_CAPI le_int32	pl_getVisualRunDescent (const pl_visualRun *run)
	A convenience method which returns the descent value for the font associated with this run.
U_CAPI le_int32	pl_getVisualRunLeading (const pl_visualRun *run)
	A convenience method which returns the leading value for the font associated with this run.

Detailed Description

C API for paragraph layout.

This is a technology preview. The API may change significantly.

Definition in file playout.h.

Typedef Documentation

pl_line

typedef void pl_line

The opaque type for a line in a paragraph layout.

Internal:

Do not use. This API is for internal use only.

Definition at line 44 of file playout.h.

pl_paragraph

typedef void pl_paragraph

The opaque type for a paragraph layout.

Internal:

Do not use. This API is for internal use only.

Definition at line 37 of file playout.h.

pl_visualRun

typedef void pl_visualRun

The opaque type for a visual run in a line.

Internal:

Do not use. This API is for internal use only.

Definition at line 51 of file playout.h.

Function Documentation

pl_close()

U_CAPI void pl_close

(

pl_paragraph *

paragraph

)

Close the given paragraph layout object.

Parameters

paragraph

the pl_paragraph object to be closed. Once this routine returns the object can no longer be referenced

Internal:

Do not use. This API is for internal use only.

pl_closeLine()

U_CAPI void pl_closeLine

(

pl_line *

line

)

Close the given line object.

Line objects are created by pl_nextLine but it is the client's responsibility to close them by calling this routine.

Parameters

line	the pl_line object to close.

Internal:

Do not use. This API is for internal use only.

pl_countLineRuns()

U_CAPI le_int32 pl_countLineRuns

(

const pl_line *

line

)

Count the number of visual runs in the line.

Parameters

line	the pl_line object.

Returns

the number of visual runs.

Internal:

Do not use. This API is for internal use only.

pl_create()

U_CAPI pl_paragraph * pl_create	(	const LEUnicode	chars[],
		le_int32	count,
		const pl_fontRuns *	fontRuns,
		const pl_valueRuns *	levelRuns,
		const pl_valueRuns *	scriptRuns,
		const pl_localeRuns *	localeRuns,
		UBiDiLevel	paragraphLevel,
		le_bool	vertical,
		LEErrorCode *	status
	)

Construct a ParagraphLayout object for a styled paragraph.

The paragraph is specified as runs of text all in the same font. An LEFontInstance object and a limit offset are specified for each font run. The limit offset is the offset of the character immediately after the font run.

Clients can optionally specify directional runs and / or script runs. If these aren't specified they will be computed.

If any errors are encountered during construction, status will be set, and the object will be set to be empty.

Parameters

chars	is an array of the characters in the paragraph
count	is the number of characters in the paragraph.
fontRuns	a pointer to a pl_fontRuns object representing the font runs.
levelRuns	is a pointer to a pl_valueRuns object representing the directional levels. If this pointer in NULL the levels will be determined by running the Unicode Bidi algorithm.
scriptRuns	is a pointer to a pl_valueRuns object representing script runs. If this pointer in NULL the script runs will be determined using the Unicode code points.
localeRuns	is a pointer to a pl_localeRuns object representing locale runs. The Locale objects are used to determine the language of the text. If this pointer is NULL the default locale will be used for all of the text.
paragraphLevel	is the directionality of the paragraph, as in the UBiDi object.
vertical	is true if the paragraph should be set vertically.
status	will be set to any error code encountered during construction.

Returns

a pointer to the newly created pl_paragraph object. The object will remain valid until pl_close is called.

See also

ubidi.h

longine.h

plruns.h

Internal:

Do not use. This API is for internal use only.

pl_getAscent()

U_CAPI le_int32 pl_getAscent

(

const pl_paragraph *

paragraph

)

Return the max ascent value for all the fonts in the paragraph.

Parameters

paragraph

the pl_paragraph

Returns

the ascent value.

Internal:

Do not use. This API is for internal use only.

pl_getDescent()

U_CAPI le_int32 pl_getDescent

(

const pl_paragraph *

paragraph

)

Return the max descent value for all the fonts in the paragraph.

Parameters

paragraph

the pl_paragraph

Returns

the decent value.

Internal:

Do not use. This API is for internal use only.

pl_getLeading()

U_CAPI le_int32 pl_getLeading

(

const pl_paragraph *

paragraph

)

Return the max leading value for all the fonts in the paragraph.

Parameters

paragraph

the pl_paragraph

Returns

the leading value.

Internal:

Do not use. This API is for internal use only.

pl_getLineAscent()

U_CAPI le_int32 pl_getLineAscent

(

const pl_line *

line

)

Get the ascent of the line.

This is the maximum ascent of all the fonts on the line.

Parameters

line	the pl_line object.

Returns

the ascent of the line.

Internal:

Do not use. This API is for internal use only.

pl_getLineDescent()

U_CAPI le_int32 pl_getLineDescent

(

const pl_line *

line

)

Get the descent of the line.

This is the maximum descent of all the fonts on the line.

Parameters

line	the pl_line object.

Returns

the descent of the line.

Internal:

Do not use. This API is for internal use only.

pl_getLineLeading()

U_CAPI le_int32 pl_getLineLeading

(

const pl_line *

line

)

Get the leading of the line.

This is the maximum leading of all the fonts on the line.

Parameters

line	the pl_line object.

Returns

the leading of the line.

Internal:

Do not use. This API is for internal use only.

pl_getLineVisualRun()

U_CAPI const pl_visualRun * pl_getLineVisualRun	(	const pl_line *	line,
		le_int32	runIndex
	)

Get a ParagraphLayout::VisualRun object for a given visual run in the line.

Parameters

line	the pl_line object.
runIndex	is the index of the run, in visual order.

Returns

the pl_visualRun object representing the visual run. This object is owned by the pl_line object which created it, and will remain valid for as long as the pl_line object is valid.

See also

pl_visualRun

Internal:

Do not use. This API is for internal use only.

pl_getLineWidth()

U_CAPI le_int32 pl_getLineWidth

(

const pl_line *

line

)

Get the width of the line.

This is a convenience method which returns the last X position of the last visual run in the line.

Parameters

line	the pl_line object.

Returns

the width of the line.

Internal:

Do not use. This API is for internal use only.

pl_getParagraphLevel()

U_CAPI UBiDiLevel pl_getParagraphLevel

(

pl_paragraph *

paragraph

)

Return the resolved paragraph level.

This is useful for those cases where the bidi analysis has determined the level based on the first strong character in the paragraph.

Parameters

paragraph

the pl_paragraph

Returns

the resolved paragraph level.

Internal:

Do not use. This API is for internal use only.

pl_getTextDirection()

U_CAPI UBiDiDirection pl_getTextDirection

(

pl_paragraph *

paragraph

)

Return the directionality of the text in the paragraph.

Parameters

paragraph

the pl_paragraph

Returns

UBIDI_LTR if the text is all left to right, UBIDI_RTL if the text is all right to left, or UBIDI_MIXED if the text has mixed direction.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunAscent()

U_CAPI le_int32 pl_getVisualRunAscent

(

const pl_visualRun *

run

)

A convenience method which returns the ascent value for the font associated with this run.

Parameters

run	the pl_visualRun object.

Returns

the ascent value of this run's font.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunDescent()

U_CAPI le_int32 pl_getVisualRunDescent

(

const pl_visualRun *

run

)

A convenience method which returns the descent value for the font associated with this run.

Parameters

run	the pl_visualRun object.

Returns

the descent value of this run's font.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunDirection()

U_CAPI UBiDiDirection pl_getVisualRunDirection

(

const pl_visualRun *

run

)

Get the direction of the visual run.

Parameters

run	the pl_visualRun object.

Returns

the direction of the run. This will be UBIDI_LTR if the run is left-to-right and UBIDI_RTL if the line is right-to-left.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunFont()

U_CAPI const le_font * pl_getVisualRunFont

(

const pl_visualRun *

run

)

Get the le_font object which represents the font of the visual run.

This will always be a non-composite font.

Parameters

run	the pl_visualRun object.

Returns

the le_font object which represents the font of the visual run.

See also

le_font

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunGlyphCount()

U_CAPI le_int32 pl_getVisualRunGlyphCount

(

const pl_visualRun *

run

)

Get the number of glyphs in the visual run.

Parameters

run	the pl_visualRun object.

Returns

the number of glyphs.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunGlyphs()

U_CAPI const LEGlyphID * pl_getVisualRunGlyphs

(

const pl_visualRun *

run

)

Get the glyphs in the visual run.

Glyphs with the values 0xFFFE and 0xFFFF should be ignored.

Parameters

run	the pl_visualRun object.

Returns

the address of the array of glyphs for this visual run. The storage is owned by the pl_visualRun object and must not be deleted. It will remain valid as long as the pl_visualRun object is valid.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunGlyphToCharMap()

U_CAPI const le_int32 * pl_getVisualRunGlyphToCharMap

(

const pl_visualRun *

run

)

Get the glyph-to-character map for this visual run.

This maps the indices into the glyph array to indices into the character array used to create the paragraph.

Parameters

run	the pl_visualRun object.

Returns

the address of the character-to-glyph map for this visual run. The storage is owned by the pl_visualRun object and must not be deleted. It will remain valid as long as the pl_visualRun object is valid.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunLeading()

U_CAPI le_int32 pl_getVisualRunLeading

(

const pl_visualRun *

run

)

A convenience method which returns the leading value for the font associated with this run.

Parameters

run	the pl_visualRun object.

Returns

the leading value of this run's font.

Internal:

Do not use. This API is for internal use only.

pl_getVisualRunPositions()

U_CAPI const float * pl_getVisualRunPositions

(

const pl_visualRun *

run

)

Get the (x, y) positions of the glyphs in the visual run.

To simplify storage management, the x and y positions are stored in a single array with the x positions at even offsets in the array and the corresponding y position in the following odd offset. There is an extra (x, y) pair at the end of the array which represents the advance of the final glyph in the run.

Parameters

run	the pl_visualRun object.

Returns

the address of the array of glyph positions for this visual run. The storage is owned by the pl_visualRun object and must not be deleted. It will remain valid as long as the pl_visualRun object is valid.

Internal:

Do not use. This API is for internal use only.

pl_isComplex()

U_CAPI le_bool pl_isComplex	(	const LEUnicode	chars[],
		le_int32	count
	)

Examine the given text and determine if it contains characters in any script which requires complex processing to be rendered correctly.

Parameters

chars	is an array of the characters in the paragraph
count	is the number of characters in the paragraph.

Returns

true if any of the text requires complex processing.

Internal:

Do not use. This API is for internal use only.

pl_nextLine()

U_CAPI pl_line * pl_nextLine	(	pl_paragraph *	paragraph,
		float	width
	)

Return a pl_line object which represents next line in the paragraph.

The width of the line is specified each time so that it can be varied to support arbitrary paragraph shapes.

Parameters

paragraph	the pl_paragraph
width	is the width of the line. If width is less than or equal to zero, a ParagraphLayout::Line object representing the rest of the paragraph will be returned.

Returns

a ParagraphLayout::Line object which represents the line. The caller is responsible for deleting the object. Returns NULL if there are no more lines in the paragraph.

See also

pl_line

Internal:

Do not use. This API is for internal use only.

pl_reflow()

U_CAPI void pl_reflow

(

pl_paragraph *

paragraph

)

Reset line breaking to start from the beginning of the paragraph.

Parameters

paragraph

the pl_paragraph

Internal:

Do not use. This API is for internal use only.