/// <summary>
/// Checks the brightness of each pixel and returns a vector representing the average direction of the brightness. Also fills
/// out a histogram since it's touching all the pixels anyhow.
/// </summary>
/// <param name="map">Where do we get our brightness information from?</param>
/// <param name="face">Which face of the cubemap are we looking at right now?</param>
/// <param name="mipLevel">Which mip-map level do we pull color data from? Generaly, we don't want to be parsing lots of pixels.</param>
/// <param name="histogram">The histogram we're filling out</param>
private static Vector3 GetWeightedDirection(Cubemap map, CubemapFace face, int mipLevel, ref Histogram histogram)
{
// TODO: Switch to nativeArray
Color[] colors = map.GetPixels(face, mipLevel);
int width = Mathf.Max(map.width >> mipLevel);
float texelSize = 2f / width;
float start = -1f + texelSize / 2f;
float scale = 1f / (width * width);
Vector3 result = Vector3.zero;
for (int y = 0; y < width; y++)
{
float yP = -(start + texelSize * y);
for (int x = 0; x < width; x++)
{
float xP = start + texelSize * x;
Color color = colors[x + y * width];
float intensity = color.grayscale;
histogram.Add(color.r, color.g, color.b, intensity);
// TODO: get rid of this inner loop normalize
result += new Vector3(xP, yP, 1).normalized *intensity;
}
}
return(result * scale);
}
/// <summary>
/// Checks the cubemap for the average direction of the light! (not normalized) Fills out a histogram for color data as long as we're in there digging through all the pixels.
/// </summary>
public Vector3 GetWeightedDirection(ref Histogram histogram)
{
int mipLevel = (int)(Mathf.Log(map.width) / Mathf.Log(2)) - 2;
return(GetWeightedDirection(map, mipLevel, ref histogram).normalized);
}