Developers
Overview
These functions interpret the input arguments as representation of vectors in n-dimensional space.
The precision of the mathematical operations on 32 bit floats is affected by the pragmas rs_fp_relaxed and rs_fp_full. See Mathematical Constants and Functions for details.
Different precision/speed tradeoffs can be achieved by using variants of the common math functions. Functions with a name starting with
- 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.
- fast_: May perform internal computations using 16 bit floats. Additionally, subnormal values may be flushed to zero, and rounding towards zero may be used.
Summary
| Functions | |
|---|---|
| cross | Cross product of two vectors |
| distance | Distance between two points |
| dot | Dot product of two vectors |
| fast_distance | Approximate distance between two points |
| fast_length | Approximate length of a vector |
| fast_normalize | Approximate normalized vector |
| length | Length of a vector |
| native_distance | Approximate distance between two points |
| native_length | Approximate length of a vector |
| native_normalize | Approximately normalize a vector |
| normalize | Normalize a vector |
Functions
cross : Cross product of two vectors
| float3 cross(float3 left_vector, float3 right_vector); | |
| float4 cross(float4 left_vector, float4 right_vector); |
Computes the cross product of two vectors.
distance : Distance between two points
| float distance(float left_vector, float right_vector); | |
| float distance(float2 left_vector, float2 right_vector); | |
| float distance(float3 left_vector, float3 right_vector); | |
| float distance(float4 left_vector, float4 right_vector); |
Compute the distance between two points.
See also fast_distance(), native_distance().
dot : Dot product of two vectors
| float dot(float left_vector, float right_vector); | |
| float dot(float2 left_vector, float2 right_vector); | |
| float dot(float3 left_vector, float3 right_vector); | |
| float dot(float4 left_vector, float4 right_vector); |
Computes the dot product of two vectors.
fast_distance : Approximate distance between two points
| float fast_distance(float left_vector, float right_vector); | Added in API level 17 |
| float fast_distance(float2 left_vector, float2 right_vector); | Added in API level 17 |
| float fast_distance(float3 left_vector, float3 right_vector); | Added in API level 17 |
| float fast_distance(float4 left_vector, float4 right_vector); | Added in API level 17 |
Computes the approximate distance between two points.
The precision is what would be expected from doing the computation using 16 bit floating point values.
See also distance(), native_distance().
fast_length : Approximate length of a vector
| float fast_length(float v); | Added in API level 17 |
| float fast_length(float2 v); | Added in API level 17 |
| float fast_length(float3 v); | Added in API level 17 |
| float fast_length(float4 v); | Added in API level 17 |
Computes the approximate length of a vector.
The precision is what would be expected from doing the computation using 16 bit floating point values.
See also length(), native_length().
fast_normalize : Approximate normalized vector
| float fast_normalize(float v); | Added in API level 17 |
| float2 fast_normalize(float2 v); | Added in API level 17 |
| float3 fast_normalize(float3 v); | Added in API level 17 |
| float4 fast_normalize(float4 v); | Added in API level 17 |
Approximately normalizes a vector.
For vectors of size 1, returns -1.f for negative values, 0.f for null values, and 1.f for positive values.
The precision is what would be expected from doing the computation using 16 bit floating point values.
See also normalize(), native_normalize().
length : Length of a vector
Computes the length of a vector.
See also fast_length(), native_length().
native_distance : Approximate distance between two points
| float native_distance(float left_vector, float right_vector); | Added in API level 21 |
| float native_distance(float2 left_vector, float2 right_vector); | Added in API level 21 |
| float native_distance(float3 left_vector, float3 right_vector); | Added in API level 21 |
| float native_distance(float4 left_vector, float4 right_vector); | Added in API level 21 |
Computes the approximate distance between two points.
See also distance(), fast_distance().
native_length : Approximate length of a vector
| float native_length(float v); | Added in API level 21 |
| float native_length(float2 v); | Added in API level 21 |
| float native_length(float3 v); | Added in API level 21 |
| float native_length(float4 v); | Added in API level 21 |
Compute the approximate length of a vector.
See also length(), fast_length().
native_normalize : Approximately normalize a vector
| float native_normalize(float v); | Added in API level 21 |
| float2 native_normalize(float2 v); | Added in API level 21 |
| float3 native_normalize(float3 v); | Added in API level 21 |
| float4 native_normalize(float4 v); | Added in API level 21 |
Approximately normalizes a vector.
See also normalize(), fast_normalize().
normalize : Normalize a vector
| float normalize(float v); | |
| float2 normalize(float2 v); | |
| float3 normalize(float3 v); | |
| float4 normalize(float4 v); |
Normalize a vector.
For vectors of size 1, returns -1.f for negative values, 0.f for null values, and 1.f for positive values.
See also fast_normalize(), native_normalize().