The
float4
structure encapsulates 4 float
values and can be used to represent a 4-element vector or a row of a 4-column matrix:struct float4 { float4() {}; float4(float s) : x(s), y(s), z(s), w(s) {} float4(float x, float y, float z, float w) : x(x), y(y), z(z), w(w) {} float x, y, z, w; inline float4 operator*(float s) const { return float4(x*s, y*s, z*s, w*s); } inline float4 operator+(const float4& a) const { return float4(x+a.x, y+a.y, z+a.z, w+a.w); } }; // dot product of two float4 vectors inline float dot(const float4& a, const float4& b) { return a.x * b.x + a.y * b.y + a.z * b.z + a.w * b.w; }Similar to the
float4
datatype, we define another common type: float3
. It can be used, for example, for representing 3D vectors.struct float3 { float3() {}; float3(float s) : x(s), y(s), z(s) {} float3(float x, float y, float z) : x(x), y(y), z(z) {} float x, y, z; inline float3 operator*(float s) const { return float3(x*s, y*s, z*s); } inline float3 operator+(const float3& a) const { return float3(x+a.x, y+a.y, z+a.z); } }; // dot product of two float3 vectors inline float dot(const float3& a, const float3& b) { return a.x * b.x + a.y * b.y + a.z * b.z; }The
float2
datatype contains 2 float elements:struct float3 { float2() {}; float2(float s) : x(s), y(s) {} float2(float x, float y) : x(x), y(y) {} float x, y; };