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diff --git a/docs/TEXT/glossary b/docs/TEXT/glossary new file mode 100644 index 00000000..aa1d1f58 --- /dev/null +++ b/docs/TEXT/glossary @@ -0,0 +1,49 @@ +CFont: A font component. This is a rendering-specific entity + which is paired with a glyph index to uniquely indentify + a glyph. Each abstract Font maps to one or more CFonts; + the method for obtaining CFonts from Fonts is also + rendering system specific. + +Cluster: A cluster is a small portion of text that is rendered + as typographically intertwined glyphs. + + A number of properties are associated with clusters + and cluster boundaries. + + 1) Clusters are the smallest unit of text that is guaranteed to + progress in reading order. Within a cluster, reordering + of glyphs may occur. + + 2) At the boundaries of clusters, character boundaries + and glyph boundaries are guaranteed to coincide. + + 3) There will be a cursor position between every two clusters. + There may not be a cursor position at some positions + inside a cluster. + + 4) The cluster boundary is the only place where information + about the correspondence between character position + and screen position is conveyed from the shape-engine + to the layers above. + +Engine: A script-specific object that is responsible for + converting Unicode text into glyphs or resolving + the properties of the text. Engines may be + rendering-system specific or independent of rendering + system. + +Font: An abstract font. The method in which a font is + created is dependent on the rendering system. + +Item: An item is a portion of text in a single script, handled + by a single shaping engine, and with a single directional + level. g_script_itemize() returns a list of items. + +Module: A dynamically loaded shared object containing one + or more Engines. + +Range: A subportion of an item. You pass a range into + g_script_shape() by passing in the analysis structure + for the item and some subportion of the text. + + |