float SampleEo(float _cosTheta, float _alpha)
{
return(Mathf.BiLerp(m_Eo, _cosTheta, _alpha));
// float X = Mathf.Saturate( _cosTheta ) * W;
// int X0 = (int) Mathf.Floor( X );
// float x = X - X0;
// X0 = Math.Min( W-1, X0 );
// int X1 = Math.Min( W-1, X0 + 1 );
//
// float Y = Mathf.Saturate( _alpha ) * H;
// int Y0 = (int) Mathf.Floor( Y );
// float y = Y - Y0;
// Y0 = Math.Min( H-1, Y0 );
// int Y1 = Math.Min( H-1, Y0 + 1 );
//
// float V00 = m_Eo[X0,Y0];
// float V10 = m_Eo[X1,Y0];
// float V01 = m_Eo[X0,Y1];
// float V11 = m_Eo[X1,Y1];
// float V0 = (1-x) * V00 + x * V10;
// float V1 = (1-x) * V01 + x * V11;
// float V = (1-y) * V0 + y * V1;
// return V;
}
void LoadMSBRDF(uint[] _sizes, FileInfo[] _irradianceTablesNames, FileInfo[] _albedoTablesNames, out Texture2D _irradianceTexture, out Texture2D _albedoTexture)
{
uint BRDFSCount = (uint)_sizes.Length;
if (_irradianceTablesNames.Length != BRDFSCount || _albedoTablesNames.Length != BRDFSCount)
{
throw new Exception("Irradiance and albedo textures count must match the amount of BRDFs computed from the size of the _sizes array!");
}
// Determine max texture size
uint textureSize = 0;
foreach (uint size in _sizes)
{
textureSize = Math.Max(textureSize, size);
}
// Create placeholders
ImageUtility.ImagesMatrix texE = new ImageUtility.ImagesMatrix();
texE.InitTexture2DArray(textureSize, textureSize, BRDFSCount, 1);
texE.AllocateImageFiles(ImageUtility.PIXEL_FORMAT.R32F, new ImageUtility.ColorProfile(ImageUtility.ColorProfile.STANDARD_PROFILE.LINEAR));
ImageUtility.ImagesMatrix texEavg = new ImageUtility.ImagesMatrix();
texEavg.InitTexture2DArray(textureSize, BRDFSCount, 1, 1);
texEavg.AllocateImageFiles(ImageUtility.PIXEL_FORMAT.R32F, new ImageUtility.ColorProfile(ImageUtility.ColorProfile.STANDARD_PROFILE.LINEAR));
float[][] albedoTables = new float[BRDFSCount][];
for (uint BRDFIndex = 0; BRDFIndex < BRDFSCount; BRDFIndex++)
{
uint size = _sizes[BRDFIndex];
// Read irradiance table
float[,] irradianceTable = new float[size, size];
using (FileStream S = _irradianceTablesNames[BRDFIndex].OpenRead())
using (BinaryReader R = new BinaryReader(S)) {
for (int Y = 0; Y < size; Y++)
{
for (int X = 0; X < size; X++)
{
irradianceTable[X, Y] = R.ReadSingle();
}
}
}
// Write content
if (size == textureSize)
{
// One-one correspondance
texE[BRDFIndex][0][0].WritePixels((uint _X, uint _Y, ref float4 _color) => {
_color.x = irradianceTable[_X, _Y];
});
}
else
{
// Needs scaling
texE[BRDFIndex][0][0].WritePixels((uint _X, uint _Y, ref float4 _color) => {
_color.x = Mathf.BiLerp(irradianceTable, (float)_X / textureSize, (float)_Y / textureSize);
});
}
// Read albedo table
float[] albedoTable = new float[size];
albedoTables[BRDFIndex] = albedoTable;
using (FileStream S = _albedoTablesNames[BRDFIndex].OpenRead())
using (BinaryReader R = new BinaryReader(S)) {
for (int Y = 0; Y < size; Y++)
{
albedoTable[Y] = R.ReadSingle();
}
}
}
// Build the entire albedo tables
texEavg[0][0][0].WritePixels((uint _X, uint _Y, ref float4 _color) => {
_color.x = Mathf.Lerp(albedoTables[_Y], (float)_X / textureSize);
});
// Create textures
_irradianceTexture = new Texture2D(m_device, texE, ImageUtility.COMPONENT_FORMAT.AUTO);
_albedoTexture = new Texture2D(m_device, texEavg, ImageUtility.COMPONENT_FORMAT.AUTO);
}
