/* Calculate light scattering value at point */
private CalculatedInscatter CalculateForPoint(Vector2 point)
{
Vector2 closestPoint = GetClosestColourNeighbour((int)point.x, (int)point.y);
double sigma_s = GetSigmaFromClassified(point);
HDRPixelFloat thisColour = originalSkyImage.GetPixel((int)point.x, (int)point.y).AsFloat();
HDRPixelFloat closeColour = originalSkyImage.GetPixel((int)closestPoint.x, (int)closestPoint.y).AsFloat();
HDRPixelFloat thisBG = backgroundSkyImage.GetPixel((int)point.x, (int)point.y).AsFloat();
HDRPixelFloat closeBG = backgroundSkyImage.GetPixel((int)closestPoint.x, (int)closestPoint.y).AsFloat();
CalculatedInscatter toReturn = new CalculatedInscatter();
double da_r = CalculateDaForColour(thisColour.R, closeColour.R, thisBG.R, closeBG.R, sigma_s);
double da_g = CalculateDaForColour(thisColour.G, closeColour.G, thisBG.G, closeBG.G, sigma_s);
double da_b = CalculateDaForColour(thisColour.B, closeColour.B, thisBG.B, closeBG.B, sigma_s);
toReturn.da = (da_r + da_g + da_b) / 3;
float Lia_r = (float)CalculateLiaForColour(thisColour.R, thisBG.R, toReturn.da, sigma_s);
float Lia_g = (float)CalculateLiaForColour(thisColour.G, thisBG.G, toReturn.da, sigma_s);
float Lia_b = (float)CalculateLiaForColour(thisColour.B, thisBG.B, toReturn.da, sigma_s);
toReturn.Lia = new Vector3(Lia_r, Lia_g, Lia_b);
return(toReturn);
}
/* Get the closest colour value within a radius of a pixel */
private Vector2 GetClosestColourNeighbour(int initialX, int initialY, int radius = 5)
{
HDRPixelFloat targetColour = originalSkyImage.GetPixel(initialX, initialY).AsFloat();
float closestColourMatch = int.MaxValue;
Vector2 closestMatchPos = new Vector2(0, 0);
for (int x = initialX - radius; x < initialX + radius; x++)
{
for (int y = initialY - radius; y < initialY + radius; y++)
{
if (x == initialX && y == initialY)
{
continue;
}
if (x < 0 || y < 0)
{
continue;
}
if (x >= originalSkyImage.Width || y >= originalSkyImage.Height)
{
continue;
}
HDRPixelFloat thisColour = originalSkyImage.GetPixel(x, y).AsFloat();
float thisColourDiff = ColourDiff(targetColour, thisColour);
if (thisColourDiff < closestColourMatch)
{
closestMatchPos.x = x;
closestMatchPos.y = y;
closestColourMatch = thisColourDiff;
}
}
}
return(closestMatchPos);
}
public HDRPixelFloat AsFloat()
{
HDRPixelFloat asFloat = new HDRPixelFloat();
asFloat.FromRGBE(R, G, B, E);
return(asFloat);
}
/* Get the difference in colour values between two given colours */
private float ColourDiff(HDRPixelFloat colour1, HDRPixelFloat colour2)
{
float r = colour1.R - colour2.R;
if (r < 0)
{
r *= -1;
}
float g = colour1.G - colour2.G;
if (g < 0)
{
g *= -1;
}
float b = colour1.B - colour2.B;
if (b < 0)
{
b *= -1;
}
return(r + g + b);
}
