Define Drawing Scale

Purpose

The Define Drawing Scale function describes the real-world scale of the DWF's logical coordinates.

Syntax

ScaleX ASCII representation of a floating-point or a double-precision floating point number that indicates the real-world size (horizontally) of a single logical coordinate unit as measured in Units units

ScaleY ASCII representation of a floating-point or a double-precision floating-point number that indicates the real-world size (vertically) of a single logical coordinate unit as measured in Units units

Units ASCII string label that indicates the unit of measure that Scale represents when measuring a single logical coordinate

Details

By defining a scale the illustrations contained in a .dwf file can be related to real-world dimensions. This is useful, for example, when you print a drawing of a mechanical part that it appears in its actual size: For example, (Scale 0.001 0.001 meter) indicates that the following represents a five meter long line:

L 0,0 5000,0

 

Normally, the DWF reading application does not need to recognize the file units or scale. The units as applied to a graph can represent temperature, dollars, pressure, and so forth. However, if the user requests that a drawing be printed in actual size (assuming that the unit of measure is one of distance), then the DWF reading application must understand the Units argument. Most DWF readers recognize two units of distance measurement, inch and meter.

Notes

For increased precision of the Scale argument, an ASCII representation of a double-precision floating-point value should be used.

A .dwf file should contain at most one occurrence of the scale opcode, which by convention should be nested inside a Define Drawing Information Block opcode.

Default

By default, no drawing scale is defined, which is equivalent to

(Scale 1.0 1.0 undefined)

Implementation in WHIP! Versions

See Also

Define Drawing Information Block