MSW:Script Layout

7. Script Layout
Sign languages are fundamentally different than spoken language, just as vision is fundamentally different that sound. SignWriting is an unusual script because the writer chooses symbols from a vast symbol set and the writer chooses the 2-dimensional position for each symbol.

The layout of the SignWriting script is based on clusters of symbols and individual punctuation. Each cluster represents a sign of a sign language or a visual performance of a sign gesture. Punctuation divides the clusters into sentences. Most commonly, the clusters are arranged vertically, from top to bottom aligned on their centers. Other times, the signs are arranged horizontally from left to right.

7.A. Symbol
Each symbol has a specific shape and size. The size of each symbol is static with an explicit width and height for each. The shape of each symbol is meaningful but informal.

7.B. SignBox
A SignBox is a 2 dimensional arrangement of writing symbols. The 2 dimensional nature of the SignBox does not have a normative string representation. Consider the following arrangement. |          |  B         C | ---+--          |               |    A

The previous arrangement is not ABC, ACB, BAC, BCA, CAB, or CBA. There is no definitive first, second, or third element. For an accurate representation, the following arrangement must specify the 2 dimensional position of each element: C (-2,-1), B (3,-2), A (5,2). The sequential order of the elements in not meaningful, except in cases of overlap.

7.B.1. SignBox Space
SignBox space is 2 dimensional with an X and Y axis. Each axis has a range from -250 to 249. The center of SignBox space is the coordinate (0,0).

Y Axis | -250            |             |   X Axis    | +    -250    |    +249             |             |             | +249

7.B.2. Bounding Box
A tight bounding box is defined as the smallest possible rectangle that encloses a set of symbols. The size of a sign is defined by a tight bounding box. Each bounding box has 3 points of interest: a minimum, a maximum, and a center. The minimum coordinate is explicitly defined by the position of the symbols. Since symbols are positioned by the top-left coordinate, the minimum coordinate is a combination of the minimum X coordinate and the minimum Y coordinate. These values can come from 2 different symbols.

The maximum coordinate is the bottom-right of the bounding box. The maximum coordinate is not explicitly defined by the position of the symbols. The maximum coordinate requires the respective width and height of each symbol. For each symbol, the width and height are added to the placement coordinate. The maximum X and Y from this new list is the maximum coordinate for the bounding box.

The maximum coordinate can be preprocessed, processable, or undefined. If the value is preprocessed, the maximum coordinate is explicitly defined for the SignBox. If the value is processable, the symbol list includes both the symbol placement and the symbol size. If the value is undefined, the size of the symbols must be looked up from some outside data source.

The center coordinate of a bounding box is some point within the bounding box, but no necessarily the midpoint. If a sign is centered, the center is the coordinate (0,0). This means that a centered sign will have a negative minimum coordinate and a positive maximum coordinate.

7.B.3. Center
The center of a sign is important for layout. The center of a sign is dependent upon the types of symbols used in the SignBox. If a SignBox does not contain any head or trunk symbols, then the center of a SignBox is the midpoint of the tight bounding box around all of the symbols.

If a SignBox contains head symbols, then the vertical center is the midpoint of the tight bounding box around the head symbols. If a SignBox contains head or trunk symbols, then the horizontal center is the midpoint of the tight bounding box around the head and trunk symbols.

A custom center would allow a user to specifically set the center of a sign and override any predetermined value.

7.C. Vertical Layout
When written vertically, SignWriting can use 3 different lanes: left, middle, and right. The middle lane is the default lane and punctuation is always used in the middle lane. No matter the lane, the center of a sign is aligned with the center of the lane.

For body weight shifts to one side or the other, the center of the cluster is aligned with a fixed horizontal offset from the middle lane into either the left or right lane.

The left and right lanes are used to represent body weight shifts and are represented by a horizontal offset from the middle lane. Body weight shifts are important to the grammar of sign languages, used for two different grammatical aspects: 1) role shifting during sign language storytelling, and 2) spatial comparisons of two items under discussion. One "role" or "item" is placed on the right side of the body (right lane), and the other on the left side of the body (left lane), and the weight shifts back and forth between the two, with the narrator in the middle (middle lane).

7.D. Horizontal Layout
When written horizontally, SignWriting uses 2 lanes: a middle lane and an upper head lane. Signs with head symbols are centered in the upper head lane. All other signs and punctuation are centered in the middle lane.