326 lines
4.5 KiB
Plaintext
326 lines
4.5 KiB
Plaintext
<!-- ##### SECTION Title ##### -->
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clutter-fixed
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<!-- ##### SECTION Short_Description ##### -->
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Fixed point API
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<!-- ##### SECTION Long_Description ##### -->
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<para>
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Clutter has a fixed point API targeted at platforms without a floating
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point unit, such as embedded devices. This API should be preferred to
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the floating point one as it does not trigger the slow path of software
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emulation, relying on integer math for fixed-to-floating and
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floating-to-fixed conversion.
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</para>
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<section>
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<title>Basic Rules of Fixed Point Arithmetic</title>
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<itemizedlist>
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<listitem>
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<para>
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Two fixed point numbers can be directly added and subtracted.
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</para>
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</listitem>
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<listitem>
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<para>
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To add other numerical type to a fixed point number it has to be first
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converted to fixed point.
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</para>
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</listitem>
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<listitem>
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<para>
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A fixed point number can be directly multiplied or divided by an integer.
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</para>
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</listitem>
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<listitem>
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<para>
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Two fixed point numbers can only be multiplied and divided by the provided
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#CLUTTER_FIXED_MUL (aka #CFX_MUL) and #CLUTTER_FIXED_DIV (aka #CFX_DIV) macros.
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</para>
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</listitem>
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</itemizedlist>
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</section>
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<!-- ##### SECTION See_Also ##### -->
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<para>
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</para>
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<!-- ##### SECTION Stability_Level ##### -->
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<!-- ##### TYPEDEF ClutterFixed ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_Q ##### -->
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<para>
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Number of bits used to store fractional part of #ClutterFixed.
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</para>
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<!-- ##### MACRO CFX_ONE ##### -->
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<para>
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#ClutterFixed representation of 1.
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</para>
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<!-- ##### MACRO CFX_MAX ##### -->
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<para>
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Maximum number representable by #ClutterFixed.
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</para>
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<!-- ##### MACRO CFX_MIN ##### -->
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<para>
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Minumum number representable by #ClutterFixed.
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</para>
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<!-- ##### TYPEDEF ClutterAngle ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_PI ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_2PI ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_PI_2 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_PI_4 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_120 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_180 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_240 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_360 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_60 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_255 ##### -->
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<para>
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</para>
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<!-- ##### MACRO CFX_DIV ##### -->
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<para>
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Alias for #CLUTTER_FIXED_DIV.
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</para>
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<!-- ##### MACRO CFX_INT ##### -->
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<para>
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Alias for #CLUTTER_FIXED_INT.
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</para>
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<!-- ##### MACRO CFX_MUL ##### -->
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<para>
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Alias for #CLUTTER_FIXED_MUL.
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</para>
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<!-- ##### MACRO CLUTTER_FIXED_TO_FLOAT ##### -->
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<para>
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Macro for converting #ClutterFixed to single precission floating point.
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</para>
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@x: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FIXED_TO_DOUBLE ##### -->
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<para>
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Macro for converting #ClutterFixed to double precission floating point.
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</para>
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@x: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FLOAT_TO_FIXED ##### -->
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<para>
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Macro for converting floating point numbers to #ClutterFixed.
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</para>
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@x: double or float
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<!-- ##### MACRO CLUTTER_FLOAT_TO_INT ##### -->
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<para>
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Macro for converting floating point numbers to intergers; this conversion
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is significantly faster that casting floats to int.
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</para>
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@x: float
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<!-- ##### MACRO CLUTTER_INT_TO_FIXED ##### -->
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<para>
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Macro for converting integers to #ClutterFixed.
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</para>
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@x: int
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<!-- ##### MACRO CLUTTER_FIXED_INT ##### -->
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<para>
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Macro to obtain integer part of #ClutterFixed.
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</para>
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@x: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FIXED_FRACTION ##### -->
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<para>
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Macro to obtain the fraction of #ClutterFixed.
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</para>
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@x: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FIXED_FLOOR ##### -->
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<para>
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Macro to obtain greatest integer smaller than given #ClutterFixed.
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</para>
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@x: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FIXED_CEIL ##### -->
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<para>
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Macro to obtain smallest integer greater than given #ClutterFixed.
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</para>
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@x: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FIXED_MUL ##### -->
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<para>
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Macro for multiplication of two #ClutterFixed numbers.
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</para>
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@x: #ClutterFixed
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@y: #ClutterFixed
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<!-- ##### MACRO CLUTTER_FIXED_DIV ##### -->
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<para>
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Macro for difvision of two #ClutterFixed numbers.
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</para>
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@x: #ClutterFixed
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@y: #ClutterFixed
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<!-- ##### MACRO clutter_cosi ##### -->
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<para>
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</para>
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@angle:
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<!-- ##### MACRO clutter_cosx ##### -->
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<para>
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</para>
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@angle:
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<!-- ##### FUNCTION clutter_sini ##### -->
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<para>
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</para>
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@angle:
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@Returns:
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<!-- ##### FUNCTION clutter_sinx ##### -->
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<para>
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</para>
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@angle:
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@Returns:
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<!-- ##### FUNCTION clutter_sqrti ##### -->
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<para>
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</para>
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@x:
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@Returns:
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<!-- ##### FUNCTION clutter_sqrtx ##### -->
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<para>
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</para>
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@x:
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@Returns:
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