public float Distance(float3 pos, int iterations)
{
float3 z = pos;
var dr = 1.0F;
var r = 0.0F;
for (var i = 0; i < iterations; i++)
{
r = MathFunctions.length(z);
if (r > DEPTH_OF_FIELD)
{
break;
}
var theta = MathFunctions.acosf(z.z / r);
var phi = MathFunctions.atan2f(z.y, z.x);
float r2 = r * r;
float r4 = r2 * r2;
float r7 = r * r2 * r4;
float r8 = r7 * r;
dr = r7 * 8.0F * dr + 1.0F;
var zr = r8;
theta = theta * 8.0F;
phi = phi * 8.0F;
float costheta, sintheta, cosphi, sinphi;
MathFunctions.sincosf(theta, out sintheta, out costheta);
MathFunctions.sincosf(phi, out sinphi, out cosphi);
z.x = sintheta * cosphi;
z.y = sinphi * sintheta;
z.z = costheta;
z = (z * zr) + pos;
}
return(0.5F * MathFunctions.logf(r) * r / dr);
}
public void Render(cudaSurfaceObject_t surface, int cWidth, int cHeight, int iterations, float3 viewDirection, float3 nearFieldLocation, float3 eyeLocation, float3 lightDirection)
{
int cHalfWidth = cWidth / 2;
float pixel = ((float)DEPTH_OF_FIELD) / (((cHeight + cWidth) / 2.0F));
float halfPixel = pixel / 2.0F;
float smallStep = 0.01F;
float bigStep = 0.02F;
for (int y = threadIdx.y + blockIdx.y * blockDim.y; y < cHeight; y += blockDim.y * gridDim.y)
{
var ny = y - cHeight / 2;
float3 tempViewDirectionY = viewDirection;
float3 tempViewDirectionX1 = viewDirection;
MathFunctions.turnOrthogonal(ref tempViewDirectionY);
MathFunctions.crossProduct(ref tempViewDirectionY, viewDirection);
tempViewDirectionY = tempViewDirectionY * (ny * pixel);
MathFunctions.turnOrthogonal(ref tempViewDirectionX1);
for (int x = threadIdx.x + blockDim.x * blockIdx.x; x < cWidth; x += blockDim.x * gridDim.x)
{
int nx = x - cHalfWidth;
float3 pixelLocation = nearFieldLocation;
float3 tempViewDirectionX2 = tempViewDirectionX1 * (nx * pixel);
pixelLocation = pixelLocation + tempViewDirectionX2 + tempViewDirectionY;
float3 rayLocation = pixelLocation;
float3 rayDirection = rayLocation - eyeLocation;
MathFunctions.normalize(ref rayDirection);
var distanceFromCamera = 0.0;
var d = Distance(rayLocation, iterations);
int i = 0;
for (; i < MAX_ITER; i++)
{
if (d < halfPixel)
{
break;
}
//Increase rayLocation with direction and d:
rayDirection = rayDirection * d;
rayLocation = rayLocation + rayDirection;
//And reset ray direction:
MathFunctions.normalize(ref rayDirection);
//Move the pixel location:
distanceFromCamera = MathFunctions.length(nearFieldLocation - rayLocation);
if (distanceFromCamera > DEPTH_OF_FIELD)
{
break;
}
d = Distance(rayLocation, iterations);
}
if (distanceFromCamera < DEPTH_OF_FIELD && distanceFromCamera > 0)
{
rayLocation.x -= smallStep;
var locationMinX = Distance(rayLocation, iterations);
rayLocation.x += bigStep;
var locationPlusX = Distance(rayLocation, iterations);
rayLocation.x -= smallStep;
rayLocation.y -= smallStep;
var locationMinY = Distance(rayLocation, iterations);
rayLocation.y += bigStep;
var locationPlusY = Distance(rayLocation, iterations);
rayLocation.y -= smallStep;
rayLocation.z -= smallStep;
var locationMinZ = Distance(rayLocation, iterations);
rayLocation.z += bigStep;
var locationPlusZ = Distance(rayLocation, iterations);
rayLocation.z -= smallStep;
float3 normal = new float3();
//Calculate the normal:
normal.x = (locationMinX - locationPlusX);
normal.y = (locationMinY - locationPlusY);
normal.z = (locationMinZ - locationPlusZ);
MathFunctions.normalize(ref normal);
//Calculate the ambient light:
var dotNL = MathFunctions.dotProduct(lightDirection, normal);
var diff = MathFunctions.saturate(dotNL);
//Calculate specular light:
float3 halfway = rayDirection + lightDirection;
MathFunctions.normalize(ref halfway);
var dotNH = MathFunctions.dotProduct(halfway, normal);
float s = MathFunctions.saturate(dotNH);
float s2 = s * s;
float s4 = s2 * s2;
float s8 = s4 * s4;
float s16 = s8 * s8;
float s32 = s16 * s16;
float spec = s * s2 * s32; // s^35
var shad = shadow(lightDirection, rayLocation, iterations, 1.0F, DEPTH_OF_FIELD, 16.0F) + 0.25F;
var brightness = (10.0F + (200.0F + spec * 45.0F) * shad * diff) / 270.0F;
var red = 10 + (380 * brightness);
var green = 10 + (280 * brightness);
var blue = (180 * brightness);
red = MathFunctions.clamp(red, 0, 255.0F);
green = MathFunctions.clamp(green, 0, 255.0F);
blue = MathFunctions.clamp(blue, 0, 255.0F);
uchar4 color = new uchar4();
color.x = (byte)red;
color.y = (byte)green;
color.z = (byte)blue;
TextureHelpers.surf2Dwrite(color, surface, x * sizeof(int), y);
}
else
{
uchar4 color = new uchar4();
color.x = (byte)(155.0F + MathFunctions.clamp(i * 1.5F, 0.0F, 100.0F));
color.y = ((byte)(205.0F + MathFunctions.clamp(i * 1.5F, 0.0F, 50.0F)));
color.z = 255;
TextureHelpers.surf2Dwrite(color, surface, x * sizeof(int), y);
}
}
}
}
