TTCache unit

An object class is a structure layout that encapsulate one given type of data used by the FreeType engine. Each object class is completely described by:

A 'root' or 'leading' structure containing the first important fields of the class. The root structure is always of fixed size. It is implemented as a simple C structure, and may contain several pointers to sub-tables that can be sized and allocated dynamically.

Examples: TFace, TInstance, TGlyph and TExecution_Context (defined in TTObjs).

There is a difference between 'child' pointers and 'peer' pointers. A 'child' pointer points to a sub-table that is owned by the object, while a 'peer' pointer points to any other kind of data the object isn't responsible for. An object class is thus usually a 'tree' of 'child' tables.

Each object class needs a constructor and a destructor. A constructor is a function which receives the address of freshly allocated and zeroed object root structure and 'builds' all the valid child data that must be associated to the object before it becomes 'valid'.

A destructor does the inverse job : given the address of a valid object, it must discards all its child data and zero its main fields (essentially the pointers and array sizes found in the root fields).

Copyright 1996, 1997 by David Turner, Robert Wilhelm, and Werner Lemberg.

Classes and records

TCache	record
TCache_Class	record
TList_Element	record

Procedures and functions

Cache_Create	function
Cache_Destroy	function
Cache_Done	function
Cache_New	function
Element_Done	procedure
Element_New	function
TTCache_Done	function
TTCache_Init	function

Types

PCache	type
PCache_Class	type
PList_Element	type
TConstructor	procedure type
TDestructor	procedure type
TSingle_List	type

Uses

• TTTypes