mirror of
https://github.com/aharabada/glitchy-engine-beef.git
synced 2026-09-05 21:01:52 +00:00
101 lines
2.8 KiB
HLSL
101 lines
2.8 KiB
HLSL
#ifndef __SHADER_HELPERS_HLSL__
|
|
#define __SHADER_HELPERS_HLSL__
|
|
|
|
#define PI 3.14159265358979323846f
|
|
|
|
/*
|
|
* Calculates the weighted sum of two normal vectors.
|
|
* nrm1: The first normal vector
|
|
* nrm2: The second normal vector
|
|
* a: The weight factor for nrm1
|
|
* b: The weight factor for nrm2
|
|
*/
|
|
float3 BlendNormals(float3 nrm1, float3 nrm2, float a, float b)
|
|
{
|
|
return normalize(float3(a * nrm1.x / nrm1.z + b * nrm2.x / nrm2.z,
|
|
a * nrm1.y / nrm1.z + b * nrm2.y / nrm2.z,
|
|
1.0f));
|
|
}
|
|
|
|
/*
|
|
* Scales a normal vector by a factor where 0 results in the vector (0, 0, 1)
|
|
* nrm: The normal vector
|
|
* a: The scaling factor
|
|
*/
|
|
float3 ScaleNormal(float3 nrm1, float a)
|
|
{
|
|
return normalize(float3(a * nrm1.x / nrm1.z,
|
|
a * nrm1.y / nrm1.z,
|
|
1.0f));
|
|
}
|
|
|
|
/*
|
|
* Scales a normal vector by a factor where 0 results in the vector (0, 0, 1)
|
|
* nrm: The normal vector
|
|
* a: The scaling factor
|
|
*/
|
|
float3 ScaleNormal(float3 nrm1, float2 a)
|
|
{
|
|
return normalize(float3(a.x * nrm1.x / nrm1.z,
|
|
a.y * nrm1.y / nrm1.z,
|
|
1.0f));
|
|
}
|
|
|
|
/*
|
|
* Reconstructs the z-component of a normalized normal vector from a two-component value
|
|
* cnrm: The x- and y-components of a normalized normal vector
|
|
*/
|
|
float3 DecompressNormal(float2 cnrm)
|
|
{
|
|
return float3(cnrm, sqrt(1.0 - cnrm.x * cnrm.x - cnrm.y * cnrm.y));
|
|
}
|
|
|
|
/*
|
|
* Reconstructs the tangent space from a normal and a tangent
|
|
* normal: The surface normal
|
|
* tangent: The surface tangent
|
|
* sigma: Defines the handedness of the tangent space matrix. 1.0 if it is right handend. -1.0 if it is left handed
|
|
*/
|
|
float3x3 ConstructTangentSpace(float3 normal, float3 tangent, float3 sigma)
|
|
{
|
|
float3 n = normalize(normal);
|
|
float3 t = normalize(tangent - n * dot(tangent, n));
|
|
float3 b = cross(n, t) * sigma;
|
|
|
|
return float3x3(t, b, n);
|
|
}
|
|
|
|
/**
|
|
* Calculates the luminance of an rgb-value.
|
|
* @param rgb The rgb color.
|
|
* @return The luminance of the given rgb color.
|
|
*/
|
|
float ColorToLuminance(float3 rgb)
|
|
{
|
|
return dot(rgb, float3(0.212639,0.715169,0.072192));
|
|
}
|
|
|
|
/**
|
|
* Extrancts the handedness of the bitangent that is encoded in the z-component of the tangent.
|
|
* @param tangentz The z-component of the tangent with the handedness encoded.
|
|
* @return The handedness of the bitangent (bitangent = handedness * tangent x normal)
|
|
*/
|
|
float GetBitangentHandedness(float tangentz)
|
|
{
|
|
// handedness is in least significant bit of tangent.z
|
|
uint z = asuint(tangentz);
|
|
return (z & 1) > 0 ? 1.0 : -1.0;
|
|
}
|
|
|
|
/**
|
|
* Transforms the given texture coordinates using the provided UV transform.
|
|
* @param texcoords The texture coordinates to transform.
|
|
* @param uvTransform the UV transform. X, Y: UV offset | Z, W: UV scaling.
|
|
* @return The transformed uv coordinates.
|
|
*/
|
|
float2 TransformTexcoords(float2 texcoords, float4 uvTransform)
|
|
{
|
|
return uvTransform.xy + uvTransform.zw * texcoords;
|
|
}
|
|
|
|
#endif // __SHADER_HELPERS_HLSL__ |