Layout and Writing Direction

Overview

A layout direction specifies how characters progress within a line and how successive lines progress through the layout. The character direction determines the layout orientation: horizontal characters form a horizontal layout, while top-to-bottom characters form a vertical layout.

Use orientationGSLayoutOrientationFromLayoutDirectionGSLayoutOrientationFromLayoutDirection to determine whether the horizontal direction applies to characters or lines. For a horizontal layout, horizontalDirectionGSHorizontalLayoutDirectionFromLayoutDirectionGSHorizontalLayoutDirectionFromLayoutDirection is the character direction. For a vertical layout, it is the line direction.

Writing Directions

GSWritingDirection is an option-set encoding used by APIs that can carry an unresolved or special direction. Convert it to GSLayoutDirection before using it for resolved layout.