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#ifndef SHADER_MATHS_INCLUDED
#define SHADER_MATHS_INCLUDED
#include "UnityCG.cginc"
////////////////////////////////////////
// Maths functions
//
inline half3 safeNormalize(half3 inVec)
{
half dp3 = max(0.001f, dot(inVec, inVec));
return inVec * rsqrt(dp3);
}
inline float dotClamped(float3 a, float3 b)
{
#if (SHADER_TARGET < 30 || defined(SHADER_API_PS3))
return saturate(dot(a, b));
#else
return max(0.0h, dot(a, b));
#endif
}
inline float oneDividedBy(float value)
{
//Catches NANs
float sign_value = sign(value);
float sign_value_squared = sign_value*sign_value;
return sign_value_squared / ( value + sign_value_squared - 1.0);
}
inline half pow5 (half x)
{
return x*x*x*x*x;
}
inline float4 quat_from_axis_angle(float3 axis, float angleRadians)
{
float4 qr;
float half_angle = (angleRadians * 0.5);
qr.x = axis.x * sin(half_angle);
qr.y = axis.y * sin(half_angle);
qr.z = axis.z * sin(half_angle);
qr.w = cos(half_angle);
return qr;
}
inline float3 rotate_vertex_position(float3 position, float3 axis, float angleRadians)
{
float4 q = quat_from_axis_angle(axis, angleRadians);
float3 v = position.xyz;
return v + 2.0 * cross(q.xyz, cross(q.xyz, v) + q.w * v);
}
float3 EncodeFloatRGB(float value)
{
const float max24int = 256*256*256-1;
float3 decomp = floor( value * float3( max24int/(256*256), max24int/256, max24int ) ) / 255.0;
decomp.z -= decomp.y * 256.0;
decomp.y -= decomp.x * 256.0;
return decomp;
}
float DecodeFloatRGB(float3 decomp)
{
return dot( decomp.xyz, float3( 255.0/256, 255.0/(256*256), 255.0/(256*256*256) ) );
}
#endif // SHADER_MATHS_INCLUDED