Using an attribute dependency listing from Francis Cave, I suggest the following as a starting point for discussion:
Amending the svg:viewBox entry as follows:
The svg:viewBox attribute specifies a rectangle in a local coordinate system of a shape. The syntax for using this attribute is the same as the [SVG] syntax. The value of the attribute are four numbers separated by white spaces, which define the left, top, width, and height of the rectangle. Such local coordinate system is used by the draw:points 19.206 and svg:d 19.530 attributes, as well as by the attributes of <draw:enhanced-geometry> 10.6.2 element and its child elements which specify coordinates.
The rectangle specified be the svg:viewBox attribute is mapped to the rectangle in the outer coordinate system, specified by the position and size attributes of the shape.
To:
The svg:viewBox attribute specifies a rectangle in a local coordinate system of a shape. The syntax for using this attribute is the same as the [SVG] syntax. The value of the attribute are four numbers separated by white spaces, which define the left, top, width, and height of the rectangle.
The rectangle specified be the svg:viewBox attribute is mapped to the rectangle in the outer coordinate system, specified by the position and size attributes of the shape.
The svg:viewBox attribute and its value shall be present in the following cases:
- draw:formula (on <draw:equation>), if the value contains any of the following identifiers: 'bottom', 'height', 'left', 'right', 'top', 'width', 'xstretch', 'ystretch'. The final two in this list are as a result of the dependency upon draw:path-stretchpoint-x and draw:path-stretchpoint-y.
- draw:handle-position (on <draw:handle>), if the value contains any of the following handle position constants: 'bottom', 'height', 'left', 'right', 'top', 'width', 'xstretch', 'ystretch'.
- draw:path-stretchpoint-x (on <draw:enhanced-geometry>).
- draw:path-stretchpoint-y (on <draw:enhanced-geometry>).
- draw:points (on <draw:area-polygon>, <draw:contour-polygon>, <draw:polygon> and <draw:polyline>).
Reviewed on 2013-04-15.
Possibly make viewBox non-optimal in ODF 1.3.