THotPDF Shaping Subset and ToUnicode Mapping Methods

Αρχική Περιεχόμενα Επισκόπηση

THotPDF API reference

THotPDF Methods Auto Shaping GSUB

Τεκμηριώνει το glyph-subset και ToUnicode plumbing που κάνει τα shaped GIDs να αποδίδονται και να εξάγονται σωστά

Delphi syntax

procedure EnableShapingFeatureForSubset(const FeatureTag: AnsiString); overload;

procedure EnableShapingFeatureForSubset(Feature: THPDFShapingFeature); overload;

procedure MarkUnicodeGlyphUsed(GID: Word);

procedure RegisterToUnicodeReverseMapping(SubstCodepoint: Cardinal; const SourceCodepoints: array of Cardinal);

procedure ClearToUnicodeReverseMappings;

function ToUnicodeReverseMappingCount: Integer;

function AssignSyntheticCodepointForGID(GID: Word; out SyntheticCP: Word): Boolean;

function GetSyntheticCodepointForGID(GID: Word): Word;

procedure MarkSyntheticCpRTL(Cp: Word);

function IsRTLSyntheticCp(Cp: Word): Boolean;

function IsRTLSyntheticGID(GID: Word): Boolean;

Covered APIs

API	Usage notes
`EnableShapingFeatureForSubset`	Marks GSUB features whose output glyphs must be retained in the embedded subset
`MarkUnicodeGlyphUsed`	Adds a returned substitute GID to the embedded font subset closure
`RegisterToUnicodeReverseMapping`	Registers a substitute codepoint to source-codepoint mapping for extraction and accessibility
`ClearToUnicodeReverseMappings`	Clears all caller-registered reverse mappings for the current document
`ToUnicodeReverseMappingCount`	Returns the number of registered reverse mappings
`AssignSyntheticCodepointForGID`	Allocates a private-use synthetic codepoint that renders a glyph ID through CIDToGIDMap
`GetSyntheticCodepointForGID`	Returns the synthetic codepoint already assigned to a glyph ID
`MarkSyntheticCpRTL`	Marks a synthetic codepoint as right-to-left so emit ordering remains correct
`IsRTLSyntheticCp`	Reports whether a synthetic codepoint was marked for right-to-left emission
`IsRTLSyntheticGID`	Reports whether a glyph ID resolves to a synthetic codepoint marked for right-to-left emission

Usage notes

Χρησιμοποιήστε αυτά τα APIs όταν ένα shaping workflow εκπέμπει glyph IDs που δεν είναι προσβάσιμα μέσω κανονικής Unicode cmap entry. Τα synthetic codepoints δρομολογούν το rendering μέσω CIDToGIDMap, ενώ τα reverse mappings ανακτούν τα αρχικά source codepoints για text extraction