Geometry Guides

A guide within a shape is essentially an equation with a set number of inputs and a single output. A guide is used to calculate construction values for a shape and thus can be manipulated to govern the shape's overall geometry.

An example of this can be seen in the following DrawingML.

<gdLst>
  <gd name=”y1” fmla=”*/ h adj1 100”/>
</gdLst>

This guide will calculate it’s output based on 3 input parameters and assign this output to a guide named <y1>. The formula that will be used in the calculation here is the multiply divide formula. The result for this guide will be calculated in the following manner: <y1 = ((h * adj1) / 100)>. After the result here is calculated, the guide <y1> can be used later within the <<gdlst>> or <<path>> to calculate further values. That is it can be used as an input for calculating another guide value. These guides then allow for a path to be based off of series of equations rather than static path coordinate values. To use a guide in the defining of a path we would simply specify the following within the path list.

<a:lnTo>
  <a:pt x="2" y="y1"/>
</a:lnTo>

This would draw a line to the point (2,y1) where <y1> is the calculated result of the guide equation shown above. The drawing of this line will then change based on the input parameters of <h> and <adj1> which are previously calculated guides as well.

Note that while <h> is a previously calculated guide. It is not calculated for each shape, rather it is a built-in guide that the generating application makes available to the shape.