public SoftwareImage <T>[] Generate(int newSize)
{
var faces = new SoftwareImage <T> [6];
faces[0] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[1] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[2] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[3] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[4] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[5] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
var p = faces[0].PixelTransformer;
var rand = new Random();
for (int z = 0; z < 6; ++z)
{
for (int y = 0; y < newSize; ++y)
{
for (int x = 0; x < newSize; ++x)
{
////1. calculate center and a radius
////2. randomly generate samples within that radus
//// use stratify method and jittering
////3. check whether the sample is in the pixel (by scaling the already known maximum dimension to 1)
////4. if check succeeds, write the point sample to destination
var center = SkyboxHelper.CubeToDir(newSize, x, y, z);
var r = (float)Math.Atan(0.5 / newSize);
var sampler = new CircleDirectionalSampler(rand, center, r, 4);
T total = default;
for (int sample = 0; sample < sampler.SampleCount; ++sample)
{
var sampleDir = sampler.Sample(sample);
var color = SkyboxHelper.SampleEquirectangularMap(_image, sampleDir);
total = p.Add(total, color);
}
faces[z].GetPixel(x, y) = p.Scale(total, 1f / sampler.SampleCount);
}
}
}
return(faces);
}
public SoftwareImage <T>[] Generate(int newSize, int nSample)
{
var faces = new SoftwareImage <T> [6];
faces[0] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[1] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[2] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[3] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[4] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[5] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
var p = faces[0].PixelTransformer;
var rand = new Random();
for (int z = 0; z < 6; ++z)
{
for (int y = 0; y < newSize; ++y)
{
for (int x = 0; x < newSize; ++x)
{
var center = SkyboxHelper.CubeToDir(newSize, x, y, z);
center = Vector3.Normalize(center);
var sampler = new SphereDirectionalSampler(rand, center, (float)Math.PI / 2, nSample);
T total = default;
for (int sample = 0; sample < sampler.SampleCount; ++sample)
{
var sampleDir = sampler.Sample(sample);
var color = SkyboxHelper.SampleEquirectangularMap(_image, sampleDir);
total = p.Add(total, p.Scale(color, Vector3.Dot(center, sampleDir)));
}
faces[z].GetPixel(x, y) = p.Scale(total, 1f / sampler.SampleCount / (float)Math.PI);
}
}
}
return(faces);
}