public static float3 MaxSpace(float3 a, float b)
{
a.x = DeviceFunction.Max(a.x, b);
a.y = DeviceFunction.Max(a.y, b);
a.z = DeviceFunction.Max(a.z, b);
return(a);
}
public static float CubeDE(float3 p, float3 c, float di)
{
float3 o = S(p, c);
float d = DeviceFunction.Max(DeviceFunction.Abs(o.x), DeviceFunction.Max(DeviceFunction.Abs(o.y), DeviceFunction.Abs(o.z)));
return(d - di / 2);
}
public static float NewSoftShadow(float3 p, float3 d, float shadowStrength, int iterations, float side, float3 seed, float3 shift, float minDist, float maxDist, float minAngle)
{
float darkness = 1;
float prevDist = float.MaxValue;
float dist = minDist / 100;
float angle = 1;
float totalDist = minDist;
float oldNewIntDist = 0;
float legLength = 0;
while (totalDist < maxDist)
{
dist = ScaledDE(A(p, M(d, totalDist)), iterations, side, seed, shift);
oldNewIntDist = dist * dist / (2 * prevDist);
legLength = DeviceFunction.Sqrt(dist * dist - oldNewIntDist * oldNewIntDist);
angle = shadowStrength * legLength / DeviceFunction.Max(0, totalDist - oldNewIntDist);
darkness = DeviceFunction.Min(darkness, angle);
prevDist = dist;
totalDist += dist;
if (dist < 0)
{
return(0);
}
if (darkness < minAngle)
{
return(0);
}
}
return(darkness);
}
public static void MarchRay(deviceptr <float3> directions, deviceptr <byte> pixelValues, float3 camera,
float3 light, float2 cols, float minDist, float maxDist, int maxstep, int bytes, int width, int iterations,
float side, float3 seed, float3 shift, float shadowStrength, float ambientOccStrength)
{
int i = blockIdx.x * blockDim.x + threadIdx.x;
int j = blockIdx.y * blockDim.y + threadIdx.y;
int h = Index(i, j, width);
float3 p = camera;
int stepnum = 0;
float dist = minDist + 1;
float totalDist = 0;
while (totalDist < maxDist && dist > minDist)
{
dist = ScaledDE(p, iterations, side, seed, shift);
p = A(p, M(directions[h], dist));
totalDist += dist;
stepnum++;
if (stepnum == maxstep)
{
break;
}
}
float brightness = 0;
if (DeviceFunction.Abs(dist) <= minDist)
{
float3 off = S(light, p);
float lightVectorLength = L(off);
off = D(off, lightVectorLength);
float shadow = 1;
float diffuseCalculated = 0;
float normalAngle = O(off, Normal(p, iterations, side, seed, shift, minDist));
if (normalAngle > 0)
{
shadow = NewSoftShadow(p, off, shadowStrength, iterations, side, seed, shift, minDist, lightVectorLength, 0.01f);
diffuseCalculated = DeviceFunction.Max(cols.y * shadow * normalAngle, 0);
}
brightness += diffuseCalculated + cols.x / (1 + stepnum * ambientOccStrength);
brightness = DeviceFunction.Min(DeviceFunction.Max(brightness, 0), 1);
float col = Orbit(p, iterations, side, seed, shift);
pixelValues[h * 3] = (byte)(Blue(col) * brightness * byte.MaxValue);
pixelValues[h * 3 + 1] = (byte)(Green(col) * brightness * byte.MaxValue);
pixelValues[h * 3 + 2] = (byte)(Red(col) * brightness * byte.MaxValue);
}
else
{
pixelValues[h * 3] = 0;
pixelValues[h * 3 + 1] = 0;
pixelValues[h * 3 + 2] = 0;
}
}
private static void SampleKernel(GpuShapeInfo shape, GpuSpaceInfo space, Matrix transformation, float maxDistance, bool revert)
{
var start = space.Bounds.Length * (blockIdx.x * blockDim.x + threadIdx.x) / blockDim.x / gridDim.x;
var end = space.Bounds.Length * (blockIdx.x * blockDim.x + threadIdx.x + 1) / blockDim.x / gridDim.x;
var inversedTransformation = transformation.Inverse();
for (int voxelIndex = start; voxelIndex < end; voxelIndex++)
{
var voxel = space.Voxels.Get(voxelIndex);
var spaceCoordinates = space.Bounds.At(voxelIndex);
var spacePosition = spaceCoordinates.AsVertex();
var shapePosition = transformation * spacePosition;
var shapeCoordinates = DiscreteCoordinates.Floor(shapePosition);
for (int partIndex = 0; partIndex < 8; partIndex++)
{
var partCoordinates = shapeCoordinates.Move(partIndex % 2, (partIndex >> 1) % 2, (partIndex >> 2) % 2);
var warpedPartCoordinates = shape.Bounds.Warp(partCoordinates);
ref var cell = ref shape.Voxels[shape.Bounds.Index(warpedPartCoordinates)];
var distance = Vector.Between(warpedPartCoordinates.AsVertex(), cell.NearestIntersection).Length;
var normal = Vector.Between(
spacePosition,
inversedTransformation * (shapePosition + cell.Normal)
).Normalize() * (revert ? -1 : 1);
var weight = DeviceFunction.Max(0f, 1f - distance / maxDistance);
var factor =
(1 - DeviceFunction.Abs(partCoordinates.X - shapePosition.X)) *
(1 - DeviceFunction.Abs(partCoordinates.Y - shapePosition.Y)) *
(1 - DeviceFunction.Abs(partCoordinates.Z - shapePosition.Z));
voxel.Weight += weight * factor;
voxel.Normal += normal * factor * weight;
}
space.Voxels.Set(voxelIndex, voxel);
}
public static float TrapezoidWave(float loc)
{
return(DeviceFunction.Min(DeviceFunction.Max(DeviceFunction.Abs(loc - 3), 0) - 1, 1));
}
