Content for  TS 23.040  Word version:  18.0.0

Polyline is a set of straight lines connecting a sequence of points. When there is only one point, it is defined as a dot.

Circular Polyline is a line that contains at least one circular curve segment. The curve segment connects two adjacent points by a circular arc. The curve segment is determined by the two adjacent points and a curve offset (the perpendicular distance from the center of the line connecting the adjacent points to the circular arc).

Curve offset values are within the range - 0,5 to 0,5, inclusive. A value of 0,5 or - 0,5 identifies that the curve offset equals half of length of the connecting line. The value indicates that the curve is close to a half circle. A positive value indicates that the curve is at the left side of the base line viewed from the curve direction. A negative value indicates that the curve is at the right side of the base line viewed from the curve direction.

A Bezier Polyline contains one or more off curve control points in between on curve points. Bezier curves can be filled to create curved shapes and are common in generalized font representations. All line elements have direction from the start point to the end point. Color fill may apply to a line. Refer to clause G.2.1.4.

When a line is specified with the fill attribute, the line is considered as a closed line, which connects the start point and the end point using a straight line. The enclosed area of a closed line can be used for color fill. The enclosed area is based on nonzero fill rule. Following are two examples in which the light color indicates the enclosed area.

Ellipses are defined by their major axis, minor axis, center and angle of rotation. Circles are considered a special case of ellipse in which the major and minor axis are the same length.

Rectangles are represented by their center, width, height, and rotation angle. Squares are considered special rectangles in which the width and height are identical. When the "round corner" indicator is set, the corner of the rectangle should be rounded. There is no specific radius of the round corner is defined. The recommended radius of the rounded corner should be 20% of the length of the shorter edge of the rectangle or the square.

A simple shape element has its reference point at its center.

Simple animation is defined for WVG. All animation timing is based on an "Animation Cycle". WVG animation is repetitive. After completion of playing one cycle, a subsequent cycle play commences immediately. There are two types of animation cycles defined, short cycle and long cycle. The time length of animation cycles are not defined. The time length of a long cycle should be twice the length of a short cycle. Recommended short cycle should collapses for 1 second and long cycle pay for 2 seconds. There are two types of animations. Visibility: an element can be visible or invisible during a specific cycle segments. A short cycle is divided into 4 time segments equally and a long cycle is divided into 8 time segments equally. In the following example, a visibility for short cycle animation is defined. The element to be animated will blink following the pattern defined in the Visibility field below. Bit 1 indicates the element should be displayed during the time segment. Bit 0 indicates it should not be displayed during the time segment. In the following example, a visibility for long cycle animation is defined. The element to be animated will blink following the pattern defined in the visibility field below. Round Rotation: an element can be rotated at clockwise or counter-clockwise directions. Transform: a start and an end transform can be applied to an element to describe the start and end position of a rotate, a scale, a translate animation or any combination of these action. When a transform element is omitted, it defaults to use the element's original position. An animation element must include at least one transform element. The animated element can also be a group to allow the animation action applied to a group of elements. In simple animation, a transform from start position to end position should be completed in one cycle. A bounced flag can be turned on to allow "bouncing" animation. A bounced transform transforms the element from start position to end position in one cycle. Transform in a short cycle: Bounced Transform in a short cycle: Transform in a long cycle: Bounced Transform in a long cycle: Visibility and transform animation can be applied to the same element.

A Standard Animation Element contains animation information such as begin transform position, end transform position, begin color, end color, begin time, end time, etc. This allows one animation element to represent a series of related images, which results in significant compression of the data stream. The WVG player interpolates between the beginning state and end state to achieve animation. Animation elements are not allowed inside groups. Animation rotation ranges from 0 to 360 degrees in both clockwise and counter-clockwise directions.