DrawOpenTypeText

Text, fonts, OpenType shaping

Description

Shapes and draws Unicode text from the in-memory font program associated with an existing font handle

Syntax

Delphi

Function TPDFlib.DrawOpenTypeText(XPos, YPos: Double; FontID: Integer; Size: Double; Const Text: WideString; Options: Integer): Integer;

Parameters

XPos, YPos	The text origin in page units
FontID	A TrueType or OpenType font handle whose source font program is available
Size	The text size in points
Text	The Unicode text to shape and draw
Options	Bit 0 selects right-to-left direction; bit 1 forces the bounded Pascal fallback instead of the native OpenType engine

Return values

Returns 1 when the shaped text is accepted and 0 for an invalid font, empty text, non-positive size, missing font program or shaping failure

Remarks

The portable native engine applies OpenType script shaping, GSUB substitutions, GPOS positioning and visual glyph ordering directly from the font bytes without requiring an installed system face

The bounded Pascal fallback supports cmap mapping, Arabic joining, default GSUB substitutions and common GPOS single, pair, cursive and mark attachment lookups when the native module is unavailable

The output uses a reusable Identity-H companion font, subsets the embedded program by glyph closure, retains required variable and colour-font tables, and writes source clusters to ToUnicode for extraction

Deploy PDFlibOpenType32.dll or PDFlibOpenType64.dll beside the executable on Windows; use libPDFlibOpenType.so on Linux or libPDFlibOpenType.dylib on macOS

PDFLIB_OPENTYPE_ENGINE may name an explicit native module path