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page.title=RenderScript Vector Math Functions
@jd:body
<div class='renderscript'>
<h2>Overview</h2>
<p> These functions interpret the input arguments as representation of vectors in
n-dimensional space.
</p>
<p> The precision of the mathematical operations on 32 bit floats is affected by the pragmas
rs_fp_relaxed and rs_fp_full. See <a href='rs_math.html'>Mathematical Constants and Functions</a> for details.
</p>
<p> Different precision/speed tradeoffs can be achieved by using variants of the common math
functions. Functions with a name starting with<ul>
<li>native_: May have custom hardware implementations with weaker precision. Additionally,
subnormal values may be flushed to zero, rounding towards zero may be used, and NaN and
infinity input may not be handled correctly.</li>
<li>fast_: May perform internal computations using 16 bit floats. Additionally, subnormal
values may be flushed to zero, and rounding towards zero may be used.</li>
</ul>
</p>
<h2>Summary</h2>
<table class='jd-sumtable'><tbody>
<tr><th colspan='2'>Functions</th></tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:cross'>cross</a>
</td>
<td class='jd-descrcol' width='100%'>
Cross product of two vectors
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:distance'>distance</a>
</td>
<td class='jd-descrcol' width='100%'>
Distance between two points
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:dot'>dot</a>
</td>
<td class='jd-descrcol' width='100%'>
Dot product of two vectors
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:fast_distance'>fast_distance</a>
</td>
<td class='jd-descrcol' width='100%'>
Approximate distance between two points
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:fast_length'>fast_length</a>
</td>
<td class='jd-descrcol' width='100%'>
Approximate length of a vector
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:fast_normalize'>fast_normalize</a>
</td>
<td class='jd-descrcol' width='100%'>
Approximate normalized vector
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:length'>length</a>
</td>
<td class='jd-descrcol' width='100%'>
Length of a vector
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:native_distance'>native_distance</a>
</td>
<td class='jd-descrcol' width='100%'>
Approximate distance between two points
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:native_length'>native_length</a>
</td>
<td class='jd-descrcol' width='100%'>
Approximate length of a vector
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:native_normalize'>native_normalize</a>
</td>
<td class='jd-descrcol' width='100%'>
Approximately normalize a vector
</td>
</tr>
<tr class='alt-color api apilevel-1'>
<td class='jd-linkcol'>
<a href='rs_vector_math.html#android_rs:normalize'>normalize</a>
</td>
<td class='jd-descrcol' width='100%'>
Normalize a vector
</td>
</tr>
</tbody></table>
<h2>Functions</h2>
<a name='android_rs:cross'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>cross</span>
<span class='normal'>: Cross product of two vectors</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td><a href='rs_value_types.html#android_rs:float3'>float3</a> cross(<a href='rs_value_types.html#android_rs:float3'>float3</a> left_vector, <a href='rs_value_types.html#android_rs:float3'>float3</a> right_vector);
</td>
<td> </td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float4'>float4</a> cross(<a href='rs_value_types.html#android_rs:float4'>float4</a> left_vector, <a href='rs_value_types.html#android_rs:float4'>float4</a> right_vector);
</td>
<td> </td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Computes the cross product of two vectors.
</p>
</div>
</div>
<a name='android_rs:distance'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>distance</span>
<span class='normal'>: Distance between two points</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float distance(float left_vector, float right_vector);
</td>
<td> </td>
</tr>
<tr>
<td>float distance(<a href='rs_value_types.html#android_rs:float2'>float2</a> left_vector, <a href='rs_value_types.html#android_rs:float2'>float2</a> right_vector);
</td>
<td> </td>
</tr>
<tr>
<td>float distance(<a href='rs_value_types.html#android_rs:float3'>float3</a> left_vector, <a href='rs_value_types.html#android_rs:float3'>float3</a> right_vector);
</td>
<td> </td>
</tr>
<tr>
<td>float distance(<a href='rs_value_types.html#android_rs:float4'>float4</a> left_vector, <a href='rs_value_types.html#android_rs:float4'>float4</a> right_vector);
</td>
<td> </td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Compute the distance between two points.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:fast_distance'>fast_distance</a>(), <a href='rs_vector_math.html#android_rs:native_distance'>native_distance</a>().
</p>
</div>
</div>
<a name='android_rs:dot'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>dot</span>
<span class='normal'>: Dot product of two vectors</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float dot(float left_vector, float right_vector);
</td>
<td> </td>
</tr>
<tr>
<td>float dot(<a href='rs_value_types.html#android_rs:float2'>float2</a> left_vector, <a href='rs_value_types.html#android_rs:float2'>float2</a> right_vector);
</td>
<td> </td>
</tr>
<tr>
<td>float dot(<a href='rs_value_types.html#android_rs:float3'>float3</a> left_vector, <a href='rs_value_types.html#android_rs:float3'>float3</a> right_vector);
</td>
<td> </td>
</tr>
<tr>
<td>float dot(<a href='rs_value_types.html#android_rs:float4'>float4</a> left_vector, <a href='rs_value_types.html#android_rs:float4'>float4</a> right_vector);
</td>
<td> </td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Computes the dot product of two vectors.
</p>
</div>
</div>
<a name='android_rs:fast_distance'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>fast_distance</span>
<span class='normal'>: Approximate distance between two points</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float fast_distance(float left_vector, float right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td>float fast_distance(<a href='rs_value_types.html#android_rs:float2'>float2</a> left_vector, <a href='rs_value_types.html#android_rs:float2'>float2</a> right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td>float fast_distance(<a href='rs_value_types.html#android_rs:float3'>float3</a> left_vector, <a href='rs_value_types.html#android_rs:float3'>float3</a> right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td>float fast_distance(<a href='rs_value_types.html#android_rs:float4'>float4</a> left_vector, <a href='rs_value_types.html#android_rs:float4'>float4</a> right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Computes the approximate distance between two points.
</p>
<p> The precision is what would be expected from doing the computation using 16 bit floating
point values.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:distance'>distance</a>(), <a href='rs_vector_math.html#android_rs:native_distance'>native_distance</a>().
</p>
</div>
</div>
<a name='android_rs:fast_length'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>fast_length</span>
<span class='normal'>: Approximate length of a vector</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float fast_length(float v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td>float fast_length(<a href='rs_value_types.html#android_rs:float2'>float2</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td>float fast_length(<a href='rs_value_types.html#android_rs:float3'>float3</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td>float fast_length(<a href='rs_value_types.html#android_rs:float4'>float4</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Computes the approximate length of a vector.
</p>
<p> The precision is what would be expected from doing the computation using 16 bit floating
point values.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:length'>length</a>(), <a href='rs_vector_math.html#android_rs:native_length'>native_length</a>().
</p>
</div>
</div>
<a name='android_rs:fast_normalize'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>fast_normalize</span>
<span class='normal'>: Approximate normalized vector</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float fast_normalize(float v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float2'>float2</a> fast_normalize(<a href='rs_value_types.html#android_rs:float2'>float2</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float3'>float3</a> fast_normalize(<a href='rs_value_types.html#android_rs:float3'>float3</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float4'>float4</a> fast_normalize(<a href='rs_value_types.html#android_rs:float4'>float4</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 17</a>
</td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Approximately normalizes a vector.
</p>
<p> For vectors of size 1, returns -1.f for negative values, 0.f for null values, and 1.f for
positive values.
</p>
<p> The precision is what would be expected from doing the computation using 16 bit floating
point values.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:normalize'>normalize</a>(), <a href='rs_vector_math.html#android_rs:native_normalize'>native_normalize</a>().
</p>
</div>
</div>
<a name='android_rs:length'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>length</span>
<span class='normal'>: Length of a vector</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float length(float v);
</td>
<td> </td>
</tr>
<tr>
<td>float length(<a href='rs_value_types.html#android_rs:float2'>float2</a> v);
</td>
<td> </td>
</tr>
<tr>
<td>float length(<a href='rs_value_types.html#android_rs:float3'>float3</a> v);
</td>
<td> </td>
</tr>
<tr>
<td>float length(<a href='rs_value_types.html#android_rs:float4'>float4</a> v);
</td>
<td> </td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Computes the length of a vector.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:fast_length'>fast_length</a>(), <a href='rs_vector_math.html#android_rs:native_length'>native_length</a>().
</p>
</div>
</div>
<a name='android_rs:native_distance'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>native_distance</span>
<span class='normal'>: Approximate distance between two points</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float native_distance(float left_vector, float right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td>float native_distance(<a href='rs_value_types.html#android_rs:float2'>float2</a> left_vector, <a href='rs_value_types.html#android_rs:float2'>float2</a> right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td>float native_distance(<a href='rs_value_types.html#android_rs:float3'>float3</a> left_vector, <a href='rs_value_types.html#android_rs:float3'>float3</a> right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td>float native_distance(<a href='rs_value_types.html#android_rs:float4'>float4</a> left_vector, <a href='rs_value_types.html#android_rs:float4'>float4</a> right_vector);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Computes the approximate distance between two points.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:distance'>distance</a>(), <a href='rs_vector_math.html#android_rs:fast_distance'>fast_distance</a>().
</p>
</div>
</div>
<a name='android_rs:native_length'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>native_length</span>
<span class='normal'>: Approximate length of a vector</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float native_length(float v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td>float native_length(<a href='rs_value_types.html#android_rs:float2'>float2</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td>float native_length(<a href='rs_value_types.html#android_rs:float3'>float3</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td>float native_length(<a href='rs_value_types.html#android_rs:float4'>float4</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Compute the approximate length of a vector.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:length'>length</a>(), <a href='rs_vector_math.html#android_rs:fast_length'>fast_length</a>().
</p>
</div>
</div>
<a name='android_rs:native_normalize'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>native_normalize</span>
<span class='normal'>: Approximately normalize a vector</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float native_normalize(float v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float2'>float2</a> native_normalize(<a href='rs_value_types.html#android_rs:float2'>float2</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float3'>float3</a> native_normalize(<a href='rs_value_types.html#android_rs:float3'>float3</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float4'>float4</a> native_normalize(<a href='rs_value_types.html#android_rs:float4'>float4</a> v);
</td>
<td> Added in <a href='http://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels'>API level 21</a>
</td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Approximately normalizes a vector.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:normalize'>normalize</a>(), <a href='rs_vector_math.html#android_rs:fast_normalize'>fast_normalize</a>().
</p>
</div>
</div>
<a name='android_rs:normalize'></a>
<div class='jd-details'>
<h4 class='jd-details-title'>
<span class='sympad'>normalize</span>
<span class='normal'>: Normalize a vector</span>
</h4>
<div class='jd-details-descr'>
<table class='jd-tagtable'><tbody>
<tr>
<td>float normalize(float v);
</td>
<td> </td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float2'>float2</a> normalize(<a href='rs_value_types.html#android_rs:float2'>float2</a> v);
</td>
<td> </td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float3'>float3</a> normalize(<a href='rs_value_types.html#android_rs:float3'>float3</a> v);
</td>
<td> </td>
</tr>
<tr>
<td><a href='rs_value_types.html#android_rs:float4'>float4</a> normalize(<a href='rs_value_types.html#android_rs:float4'>float4</a> v);
</td>
<td> </td>
</tr>
</tbody></table>
</div>
<div class='jd-tagdata jd-tagdescr'>
<p> Normalize a vector.
</p>
<p> For vectors of size 1, returns -1.f for negative values, 0.f for null values, and 1.f for
positive values.
</p>
<p> See also <a href='rs_vector_math.html#android_rs:fast_normalize'>fast_normalize</a>(), <a href='rs_vector_math.html#android_rs:native_normalize'>native_normalize</a>().
</p>
</div>
</div>
</div>