jpayne@69: /*  GRAPHITE2 LICENSING
jpayne@69: 
jpayne@69:     Copyright 2010, SIL International
jpayne@69:     All rights reserved.
jpayne@69: 
jpayne@69:     This library is free software; you can redistribute it and/or modify
jpayne@69:     it under the terms of the GNU Lesser General Public License as published
jpayne@69:     by the Free Software Foundation; either version 2.1 of License, or
jpayne@69:     (at your option) any later version.
jpayne@69: 
jpayne@69:     This program is distributed in the hope that it will be useful,
jpayne@69:     but WITHOUT ANY WARRANTY; without even the implied warranty of
jpayne@69:     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
jpayne@69:     Lesser General Public License for more details.
jpayne@69: 
jpayne@69:     You should also have received a copy of the GNU Lesser General Public
jpayne@69:     License along with this library in the file named "LICENSE".
jpayne@69:     If not, write to the Free Software Foundation, 51 Franklin Street,
jpayne@69:     Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
jpayne@69:     internet at http://www.fsf.org/licenses/lgpl.html.
jpayne@69: 
jpayne@69:     Alternatively, the contents of this file may be used under the terms
jpayne@69:     of the Mozilla Public License (http://mozilla.org/MPL) or the GNU
jpayne@69:     General Public License, as published by the Free Software Foundation,
jpayne@69:     either version 2 of the License or (at your option) any later version.
jpayne@69: */
jpayne@69: #pragma once
jpayne@69: 
jpayne@69: #include "graphite2/Types.h"
jpayne@69: #include "graphite2/Font.h"
jpayne@69: 
jpayne@69: #ifdef __cplusplus
jpayne@69: extern "C"
jpayne@69: {
jpayne@69: #endif
jpayne@69: 
jpayne@69: enum gr_break_weight {
jpayne@69:     gr_breakNone = 0,
jpayne@69:     /* after break weights */
jpayne@69:     gr_breakWhitespace = 10,
jpayne@69:     gr_breakWord = 15,
jpayne@69:     gr_breakIntra = 20,
jpayne@69:     gr_breakLetter = 30,
jpayne@69:     gr_breakClip = 40,
jpayne@69:     /* before break weights */
jpayne@69:     gr_breakBeforeWhitespace = -10,
jpayne@69:     gr_breakBeforeWord = -15,
jpayne@69:     gr_breakBeforeIntra = -20,
jpayne@69:     gr_breakBeforeLetter = -30,
jpayne@69:     gr_breakBeforeClip = -40
jpayne@69: };
jpayne@69: 
jpayne@69: enum gr_justFlags {
jpayne@69:     /// Indicates that this segment is a complete line
jpayne@69:     gr_justCompleteLine = 0,
jpayne@69:     /// Indicates that the start of the slot list is not at the start of a line
jpayne@69:     gr_justStartInline = 1,
jpayne@69:     /// Indicates that the end of the slot list is not at the end of a line
jpayne@69:     gr_justEndInline = 2
jpayne@69: };
jpayne@69: 
jpayne@69: /** Used for looking up slot attributes. Most are already available in other functions **/
jpayne@69: enum gr_attrCode {
jpayne@69:     /// adjusted glyph advance in x direction in design units
jpayne@69:     gr_slatAdvX = 0,
jpayne@69:     /// adjusted glyph advance in y direction (usually 0) in design units
jpayne@69:     gr_slatAdvY,
jpayne@69:     /// returns 0. Deprecated.
jpayne@69:     gr_slatAttTo,
jpayne@69:     /// This slot attaches to its parent at the given design units in the x direction
jpayne@69:     gr_slatAttX,
jpayne@69:     /// This slot attaches to its parent at the given design units in the y direction
jpayne@69:     gr_slatAttY,
jpayne@69:     /// This slot attaches to its parent at the given glyph point (not implemented)
jpayne@69:     gr_slatAttGpt,
jpayne@69:     /// x-direction adjustment from the given glyph point (not implemented)
jpayne@69:     gr_slatAttXOff,
jpayne@69:     /// y-direction adjustment from the given glyph point (not implemented)
jpayne@69:     gr_slatAttYOff,
jpayne@69:     /// Where on this glyph should align with the attachment point on the parent glyph in the x-direction.
jpayne@69:     gr_slatAttWithX,
jpayne@69:     /// Where on this glyph should align with the attachment point on the parent glyph in the y-direction
jpayne@69:     gr_slatAttWithY,
jpayne@69:     /// Which glyph point on this glyph should align with the attachment point on the parent glyph (not implemented).
jpayne@69:     gr_slatWithGpt,
jpayne@69:     /// Adjustment to gr_slatWithGpt in x-direction (not implemented)
jpayne@69:     gr_slatAttWithXOff,
jpayne@69:     /// Adjustment to gr_slatWithGpt in y-direction (not implemented)
jpayne@69:     gr_slatAttWithYOff,
jpayne@69:     /// Attach at given nesting level (not implemented)
jpayne@69:     gr_slatAttLevel,
jpayne@69:     /// Line break breakweight for this glyph
jpayne@69:     gr_slatBreak,
jpayne@69:     /// Ligature component reference (not implemented)
jpayne@69:     gr_slatCompRef,
jpayne@69:     /// bidi directionality of this glyph (not implemented)
jpayne@69:     gr_slatDir,
jpayne@69:     /// Whether insertion is allowed before this glyph
jpayne@69:     gr_slatInsert,
jpayne@69:     /// Final positioned position of this glyph relative to its parent in x-direction in pixels
jpayne@69:     gr_slatPosX,
jpayne@69:     /// Final positioned position of this glyph relative to its parent in y-direction in pixels
jpayne@69:     gr_slatPosY,
jpayne@69:     /// Amount to shift glyph by in x-direction design units
jpayne@69:     gr_slatShiftX,
jpayne@69:     /// Amount to shift glyph by in y-direction design units
jpayne@69:     gr_slatShiftY,
jpayne@69:     /// attribute user1
jpayne@69:     gr_slatUserDefnV1,
jpayne@69:     /// not implemented
jpayne@69:     gr_slatMeasureSol,
jpayne@69:     /// not implemented
jpayne@69:     gr_slatMeasureEol,
jpayne@69:     /// Amount this slot can stretch (not implemented)
jpayne@69:     gr_slatJStretch,
jpayne@69:     /// Amount this slot can shrink (not implemented)
jpayne@69:     gr_slatJShrink,
jpayne@69:     /// Granularity by which this slot can stretch or shrink (not implemented)
jpayne@69:     gr_slatJStep,
jpayne@69:     /// Justification weight for this glyph (not implemented)
jpayne@69:     gr_slatJWeight,
jpayne@69:     /// Amount this slot mush shrink or stretch in design units
jpayne@69:     gr_slatJWidth = 29,
jpayne@69:     /// SubSegment split point
jpayne@69:     gr_slatSegSplit = gr_slatJStretch + 29,
jpayne@69:     /// User defined attribute, see subattr for user attr number
jpayne@69:     gr_slatUserDefn,
jpayne@69:     /// Bidi level
jpayne@69:     gr_slatBidiLevel = 56,
jpayne@69:     /// Collision flags
jpayne@69:     gr_slatColFlags,
jpayne@69:     /// Collision constraint rectangle left (bl.x)
jpayne@69:     gr_slatColLimitblx,
jpayne@69:     /// Collision constraint rectangle lower (bl.y)
jpayne@69:     gr_slatColLimitbly,
jpayne@69:     /// Collision constraint rectangle right (tr.x)
jpayne@69:     gr_slatColLimittrx,
jpayne@69:     /// Collision constraint rectangle upper (tr.y)
jpayne@69:     gr_slatColLimittry,
jpayne@69:     /// Collision shift x
jpayne@69:     gr_slatColShiftx,
jpayne@69:     /// Collision shift y
jpayne@69:     gr_slatColShifty,
jpayne@69:     /// Collision margin
jpayne@69:     gr_slatColMargin,
jpayne@69:     /// Margin cost weight
jpayne@69:     gr_slatColMarginWt,
jpayne@69:     // Additional glyph that excludes movement near this one:
jpayne@69:     gr_slatColExclGlyph,
jpayne@69:     gr_slatColExclOffx,
jpayne@69:     gr_slatColExclOffy,
jpayne@69:     // Collision sequence enforcing attributes:
jpayne@69:     gr_slatSeqClass,
jpayne@69:     gr_slatSeqProxClass,
jpayne@69:     gr_slatSeqOrder,
jpayne@69:     gr_slatSeqAboveXoff,
jpayne@69:     gr_slatSeqAboveWt,
jpayne@69:     gr_slatSeqBelowXlim,
jpayne@69:     gr_slatSeqBelowWt,
jpayne@69:     gr_slatSeqValignHt,
jpayne@69:     gr_slatSeqValignWt,
jpayne@69: 
jpayne@69:     /// not implemented
jpayne@69:     gr_slatMax,
jpayne@69:     /// not implemented
jpayne@69:     gr_slatNoEffect = gr_slatMax + 1
jpayne@69: };
jpayne@69: 
jpayne@69: enum gr_bidirtl {
jpayne@69:     /// Underlying paragraph direction is RTL
jpayne@69:     gr_rtl = 1,
jpayne@69:     /// Set this to not run the bidi pass internally, even if the font asks for it.
jpayne@69:     /// This presumes that the segment is in a single direction. Most of the time
jpayne@69:     /// this bit should be set unless you know you are passing full paragraphs of text.
jpayne@69:     gr_nobidi = 2,
jpayne@69:     /// Disable auto mirroring for rtl text
jpayne@69:     gr_nomirror = 4
jpayne@69: };
jpayne@69: 
jpayne@69: typedef struct gr_char_info     gr_char_info;
jpayne@69: typedef struct gr_segment       gr_segment;
jpayne@69: typedef struct gr_slot          gr_slot;
jpayne@69: 
jpayne@69: /** Returns Unicode character for a charinfo.
jpayne@69:   *
jpayne@69:   * @param p Pointer to charinfo to return information on.
jpayne@69:   */
jpayne@69: GR2_API unsigned int gr_cinfo_unicode_char(const gr_char_info* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns breakweight for a charinfo.
jpayne@69:   *
jpayne@69:   * @return Breakweight is a number between -50 and 50 indicating the cost of a
jpayne@69:   * break before or after this character. If the value < 0, the absolute value
jpayne@69:   * is this character's contribution to the overall breakweight before it. If the value
jpayne@69:   * > 0, then the value is this character's contribution to the overall breakweight after it.
jpayne@69:   * The overall breakweight between two characters is the maximum of the breakweight
jpayne@69:   * contributions from the characters either side of it. If a character makes no
jpayne@69:   * contribution to the breakweight on one side of it, the contribution is considered
jpayne@69:   * to be 0.
jpayne@69:   * @param p Pointer to charinfo to return information on.
jpayne@69:   */
jpayne@69: GR2_API int gr_cinfo_break_weight(const gr_char_info* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the slot index that after this character is after in the slot stream
jpayne@69:   *
jpayne@69:   * In effect each character is associated with a set of slots and this returns
jpayne@69:   * the index of the last slot in the segment this character is associated with.
jpayne@69:   *
jpayne@69:   * @return after slot index between 0 and gr_seg_n_slots()
jpayne@69:   * @param p Pointer to charinfo to return information on.
jpayne@69:   */
jpayne@69: GR2_API int gr_cinfo_after(const gr_char_info* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the slot index that before this character is before in the slot stream
jpayne@69:   *
jpayne@69:   * In effect each character is associated with a set of slots and this returns
jpayne@69:   * the index of the first slot in the segment this character is associated with.
jpayne@69:   *
jpayne@69:   * @return before slot index between 0 and gr_seg_n_slots()
jpayne@69:   * @param p Pointer to charinfo to return information on.
jpayne@69:   */
jpayne@69: GR2_API int gr_cinfo_before(const gr_char_info* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the code unit index of this character in the input string
jpayne@69:   *
jpayne@69:   * @return code unit index between 0 and the end of the string
jpayne@69:   * @param p Pointer to charinfo to return information on.
jpayne@69:   */
jpayne@69: GR2_API size_t gr_cinfo_base(const gr_char_info* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the number of unicode characters in a string.
jpayne@69:   *
jpayne@69:   * @return number of characters in the string
jpayne@69:   * @param enc Specifies the type of data in the string: utf8, utf16, utf32
jpayne@69:   * @param buffer_begin The start of the string
jpayne@69:   * @param buffer_end Measure up to the first nul or when end is reached, whichever is earliest.
jpayne@69:   *            This parameter may be NULL.
jpayne@69:   * @param pError If there is a structural fault in the string, the location is returned
jpayne@69:   *               in this variable. If no error occurs, pError will contain NULL. NULL
jpayne@69:   *               may be passed for pError if no such information is required.
jpayne@69:   */
jpayne@69: GR2_API size_t gr_count_unicode_characters(enum gr_encform enc, const void* buffer_begin, const void* buffer_end, const void** pError);
jpayne@69: 
jpayne@69: /** Creates and returns a segment.
jpayne@69:   *
jpayne@69:   * @return a segment that needs seg_destroy called on it. May return NULL if bad problems
jpayne@69:   *     in segment processing.
jpayne@69:   * @param font Gives the size of the font in pixels per em for final positioning. If
jpayne@69:   *             NULL, positions are returned in design units, i.e. at a ppm of the upem
jpayne@69:   *             of the face.
jpayne@69:   * @param face The face containing all the non-size dependent information.
jpayne@69:   * @param script This is a tag containing a script identifier that is used to choose
jpayne@69:   *               which graphite table within the font to use. Maybe 0. Tag may be 4 chars
jpayne@69:   *               NULL padded in LSBs or space padded in LSBs.
jpayne@69:   * @param pFeats Pointer to a feature values to be used for the segment. Only one
jpayne@69:   *               feature values may be used for a segment. If NULL the default features
jpayne@69:   *               for the font will be used.
jpayne@69:   * @param enc Specifies what encoding form the string is in (utf8, utf16, utf32)
jpayne@69:   * @param pStart Start of the string
jpayne@69:   * @param nChars Number of unicode characters to process in the string. The string will
jpayne@69:   *               be processed either up to the first NULL or until nChars have been
jpayne@69:   *               processed. nChars is also used to initialise the internal memory
jpayne@69:   *               allocations of the segment. So it is wise not to make nChars too much
jpayne@69:   *               greater than the actual number of characters being processed.
jpayne@69:   * @param dir Specifies whether the segment is processed right to left (1) or left to
jpayne@69:   *            right (0) and whether to run the internal bidi pass, if a font requests it.
jpayne@69:   *            See enum gr_bidirtl for details.
jpayne@69:   */
jpayne@69: GR2_API gr_segment* gr_make_seg(const gr_font* font, const gr_face* face, gr_uint32 script, const gr_feature_val* pFeats, enum gr_encform enc, const void* pStart, size_t nChars, int dir);
jpayne@69: 
jpayne@69: /** Destroys a segment, freeing the memory.
jpayne@69:   *
jpayne@69:   * @param p The segment to destroy
jpayne@69:   */
jpayne@69: GR2_API void gr_seg_destroy(gr_segment* p);
jpayne@69: 
jpayne@69: /** Returns the advance for the whole segment.
jpayne@69:   *
jpayne@69:   * Returns the width of the segment up to the next glyph origin after the segment
jpayne@69:   */
jpayne@69: GR2_API float gr_seg_advance_X(const gr_segment* pSeg/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the height advance for the segment. **/
jpayne@69: GR2_API float gr_seg_advance_Y(const gr_segment* pSeg/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the number of gr_char_infos in the segment. **/
jpayne@69: GR2_API unsigned int gr_seg_n_cinfo(const gr_segment* pSeg/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns a gr_char_info at a given index in the segment. **/
jpayne@69: GR2_API const gr_char_info* gr_seg_cinfo(const gr_segment* pSeg/*not NULL*/, unsigned int index/*must be <number_of_CharInfo*/);
jpayne@69: 
jpayne@69: /** Returns the number of glyph gr_slots in the segment. **/
jpayne@69: GR2_API unsigned int gr_seg_n_slots(const gr_segment* pSeg/*not NULL*/);      //one slot per glyph
jpayne@69: 
jpayne@69: /** Returns the first gr_slot in the segment.
jpayne@69:   *
jpayne@69:   * The first slot in a segment has a gr_slot_prev_in_segment() of NULL. Slots are owned
jpayne@69:   * by their segment and are destroyed along with the segment.
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_seg_first_slot(gr_segment* pSeg/*not NULL*/);    //may give a base slot or a slot which is attached to another
jpayne@69: 
jpayne@69: /** Returns the last gr_slot in the segment.
jpayne@69:   *
jpayne@69:   * The last slot in a segment has a gr_slot_next_in_segment() of NULL
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_seg_last_slot(gr_segment* pSeg/*not NULL*/);    //may give a base slot or a slot which is attached to another
jpayne@69: 
jpayne@69: /** Justifies a linked list of slots for a line to a given width
jpayne@69:   *
jpayne@69:   * Passed a pointer to the start of a linked list of slots corresponding to a line, as
jpayne@69:   * set up by gr_slot_linebreak_before, this function will position the glyphs in the line
jpayne@69:   * to take up the given width. It is possible to specify a subrange within the line to process.
jpayne@69:   * This allows skipping of line initial or final whitespace, for example. While this will ensure
jpayne@69:   * that the subrange fits width, the line will still be positioned with the first glyph of the
jpayne@69:   * line at 0. So the resulting positions may be beyond width.
jpayne@69:   *
jpayne@69:   * @return float   The resulting width of the range of slots justified.
jpayne@69:   * @param pSeg     Pointer to the segment
jpayne@69:   * @param pStart   Pointer to the start of the line linked list (including skipped characters)
jpayne@69:   * @param pFont    Font to use for positioning
jpayne@69:   * @param width    Width in pixels in which to fit the line. If < 0. don't adjust natural width, just run justification passes
jpayne@69:   *                 to handle line end contextuals, if there are any.
jpayne@69:   * @param flags    Indicates line ending types. Default is linked list is a full line
jpayne@69:   * @param pFirst   If not NULL, the first slot in the list to be considered part of the line (so can skip)
jpayne@69:   * @param pLast    If not NULL, the last slot to process in the line (allow say trailing whitespace to be skipped)
jpayne@69:   */
jpayne@69: GR2_API float gr_seg_justify(gr_segment* pSeg/*not NULL*/, const gr_slot* pStart/*not NULL*/, const gr_font *pFont, double width, enum gr_justFlags flags, const gr_slot* pFirst, const gr_slot* pLast);
jpayne@69: 
jpayne@69: /** Returns the next slot along in the segment.
jpayne@69:   *
jpayne@69:   * Slots are held in a linked list. This returns the next in the linked list. The slot
jpayne@69:   * may or may not be attached to another slot. Returns NULL at the end of the segment.
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_slot_next_in_segment(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns the previous slot along in the segment.
jpayne@69:   *
jpayne@69:   * Slots are held in a doubly linked list. This returns the previos slot in the linked
jpayne@69:   * list. This slot may or may not be attached to it. Returns NULL at the start of the
jpayne@69:   * segment.
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_slot_prev_in_segment(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns the attachment parent slot of this slot.
jpayne@69:   *
jpayne@69:   * Attached slots form a tree. This returns the parent of this slot in that tree. A
jpayne@69:   * base glyph which is not attached to another glyph, always returns NULL.
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_slot_attached_to(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns the first slot attached to this slot.
jpayne@69:   *
jpayne@69:   * Attached slots form a singly linked list from the parent. This returns the first
jpayne@69:   * slot in that list. Note that this is a reference to another slot that is also in
jpayne@69:   * the main segment doubly linked list.
jpayne@69:   *
jpayne@69:   * if gr_slot_first_attachment(p) != NULL then gr_slot_attached_to(gr_slot_first_attachment(p)) == p.
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_slot_first_attachment(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns the next slot attached to our attachment parent.
jpayne@69:   *
jpayne@69:   * This returns the next slot in the singly linked list of slots attached to this
jpayne@69:   * slot's parent. If there are no more such slots, NULL is returned. If there is
jpayne@69:   * no parent, i.e. the passed slot is a cluster base, then the next cluster base
jpayne@69:   * in graphical order (ltr, even for rtl text) is returned.
jpayne@69:   *
jpayne@69:   * if gr_slot_next_sibling_attachment(p) != NULL then gr_slot_attached_to(gr_slot_next_sibling_attachment(p)) == gr_slot_attached_to(p).
jpayne@69:   */
jpayne@69: GR2_API const gr_slot* gr_slot_next_sibling_attachment(const gr_slot* p);
jpayne@69: 
jpayne@69: 
jpayne@69: /** Returns glyph id of the slot
jpayne@69:   *
jpayne@69:   * Each slot has a glyphid which is rendered at the position given by the slot. This
jpayne@69:   * glyphid is the real glyph to be rendered and never a pseudo glyph.
jpayne@69:   */
jpayne@69: GR2_API unsigned short gr_slot_gid(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns X offset of glyph from start of segment **/
jpayne@69: GR2_API float gr_slot_origin_X(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns Y offset of glyph from start of segment **/
jpayne@69: GR2_API float gr_slot_origin_Y(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns the glyph advance for this glyph as adjusted for kerning
jpayne@69:   *
jpayne@69:   * @param p    Slot to give results for
jpayne@69:   * @param face gr_face of the glyphs. May be NULL if unhinted advances used
jpayne@69:   * @param font gr_font to scale for pixel results. If NULL returns design
jpayne@69:   *             units advance. If not NULL then returns pixel advance based
jpayne@69:   *             on hinted or scaled glyph advances in the font. face must be
jpayne@69:   *             passed for hinted advances to be used.
jpayne@69:   */
jpayne@69: GR2_API float gr_slot_advance_X(const gr_slot* p, const gr_face* face, const gr_font *font);
jpayne@69: 
jpayne@69: /** Returns the vertical advance for the glyph in the slot adjusted for kerning
jpayne@69:   *
jpayne@69:   * Returns design units unless font is not NULL in which case the pixel value
jpayne@69:   * is returned scaled for the given font
jpayne@69:   */
jpayne@69: GR2_API float gr_slot_advance_Y(const gr_slot* p, const gr_face* face, const gr_font *font);
jpayne@69: 
jpayne@69: /** Returns the gr_char_info index before us
jpayne@69:   *
jpayne@69:   * Returns the index of the gr_char_info that a cursor before this slot, would put
jpayne@69:   * an underlying cursor before. This may also be interpretted as each slot holding
jpayne@69:   * a set of char_infos that it is associated with and this function returning the
jpayne@69:   * index of the char_info with lowest index, from this set.
jpayne@69:   */
jpayne@69: GR2_API int gr_slot_before(const gr_slot* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the gr_char_info index after us
jpayne@69:   *
jpayne@69:   * Returns the index of the gr_char_info that a cursor after this slot would put an
jpayne@69:   * underlying cursor after. This may also be interpretted as each slot holding a set
jpayne@69:   * of char_infos that it is associated with and this function returning the index of
jpayne@69:   * the char_info with the highest index, from this set.
jpayne@69:   */
jpayne@69: GR2_API int gr_slot_after(const gr_slot* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Returns the index of this slot in the segment
jpayne@69:   *
jpayne@69:   * Returns the index given to this slot during final positioning. This corresponds
jpayne@69:   * to the value returned br gr_cinfo_before() and gr_cinfo_after()
jpayne@69:   */
jpayne@69: GR2_API unsigned int gr_slot_index(const gr_slot* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Return a slot attribute value
jpayne@69:   *
jpayne@69:   * Given a slot and an attribute along with a possible subattribute, return the
jpayne@69:   * corresponding value in the slot. See enum gr_attrCode for details of each attribute.
jpayne@69:   */
jpayne@69: GR2_API int gr_slot_attr(const gr_slot* p/*not NULL*/, const gr_segment* pSeg/*not NULL*/, enum gr_attrCode index, gr_uint8 subindex); //tbd - do we need to expose this?
jpayne@69: 
jpayne@69: /** Returns whether text may be inserted before this glyph.
jpayne@69:   *
jpayne@69:   * This indicates whether a cursor can be put before this slot. It applies to
jpayne@69:   * base glyphs that have no parent as well as attached glyphs that have the
jpayne@69:   * .insert attribute explicitly set to true. This is the primary mechanism
jpayne@69:   * for identifying contiguous sequences of base plus diacritics.
jpayne@69:   */
jpayne@69: GR2_API int gr_slot_can_insert_before(const gr_slot* p);
jpayne@69: 
jpayne@69: /** Returns the original gr_char_info index this slot refers to.
jpayne@69:   *
jpayne@69:   * Each Slot has a gr_char_info that it originates from. This is that gr_char_info.
jpayne@69:   * The index is passed to gr_seg_cinfo(). This information is useful for testing.
jpayne@69:   */
jpayne@69: GR2_API int gr_slot_original(const gr_slot* p/*not NULL*/);
jpayne@69: 
jpayne@69: /** Breaks a segment into lines.
jpayne@69:   *
jpayne@69:   * Breaks the slot linked list at the given point in the linked list. It is up
jpayne@69:   * to the application to keep track of the first slot on each line.
jpayne@69:   */
jpayne@69: GR2_API void gr_slot_linebreak_before(gr_slot *p/*not NULL*/);
jpayne@69: 
jpayne@69: #ifdef __cplusplus
jpayne@69: }
jpayne@69: #endif