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Standard Macros

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commonly-used macros.

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<para>
These macros provide a few commonly-used features.
</para>

<!-- ##### MACRO TRUE ##### -->
<para>
Defines the TRUE value for the #gboolean type.
</para>


<!-- ##### MACRO FALSE ##### -->
<para>
Defines the FALSE value for the #gboolean type.
</para>


<!-- ##### MACRO NULL ##### -->
<para>
Defines the standard NULL pointer.
</para>


<!-- ##### MACRO MIN ##### -->
<para>
Calculates the minimum of @a and @b.
</para>

@a: a numeric value.
@b: a numeric value.
@Returns: the minimum of @a and @b.

<!-- ##### MACRO MAX ##### -->
<para>
Calculates the maximum of @a and @b.
</para>

@a: a numeric value.
@b: a numeric value.
@Returns: the maximum of @a and @b.

<!-- ##### MACRO ABS ##### -->
<para>
Calculates the absolute value of @a.
The absolute value is simply the number with any negative sign taken away.
</para>
<para>
For example,
<itemizedlist>
<listitem><para>
ABS(-10) is 10.
</para></listitem>
<listitem><para>
ABS(10) is also 10.
</para></listitem>
</itemizedlist>
</para>

@a: a numeric value.
@Returns: the absolute value of @a.

<!-- ##### MACRO CLAMP ##### -->
<para>
Ensures that @x is between the limits set by @low and @high.
</para>
<para>
For example,
<itemizedlist>
<listitem><para>
CLAMP(5, 10, 15) is 10.
</para></listitem>
<listitem><para>
CLAMP(15, 5, 10) is 10.
</para></listitem>
<listitem><para>
CLAMP(20, 15, 25) is 20.
</para></listitem>
</itemizedlist>
</para>

@x: the value to clamp.
@low: the minimum value allowed.
@high: the maximum value allowed.
@Returns: the value of @x clamped to the range between @low and @high.

