/// <summary>
/// Determines whether a ray intersects the specified sphere.
/// </summary>
/// <param name="ray">The ray which will be tested for intersection.</param>
/// <param name="sphere">A sphere that will be tested for intersection.</param>
/// <returns>Distance at which the ray intersects the sphere or null if there is no intersection.</returns>
public static double?Intersects(Rayd ray, Spherei sphere)
{
var distance = sphere.Center - ray.Position;
var pyth = Vector.AbsoluteSquared(distance);
var rr = sphere.Radius * sphere.Radius;
if (pyth <= rr)
{
return(0);
}
double dot = Vector.Dot(distance, ray.Direction);
if (dot < 0)
{
return(null);
}
var temp = pyth - (dot * dot);
if (temp > rr)
{
return(null);
}
return((double)(dot - Functions.Sqrt(rr - temp)));
}
/// <summary>
/// Returns the squared distance between two points.
/// </summary>
/// <param name="value1">The first point.</param>
/// <param name="value2">The second point.</param>
/// <returns>The squared distance between value1 and value2.</returns>
public static double DistanceSquared(Point2d value1, Point2d value2)
{
return(Vector.AbsoluteSquared(value2 - value1));
}
public static bool Contains(Spherel sphere, Point3l point)
{
return(Vector.AbsoluteSquared(sphere.Center - point) <= sphere.Radius * sphere.Radius);
}
public static void Fit(ColordBlock block, ColordSet colors, Options options, bool isBC1)
{
Vector3d maxColor = Vector3d.Zero;
Vector3d minColor = Vector3d.One;
foreach (Vector3d color in colors.Points)
{
minColor = Vector.Min(minColor, color);
maxColor = Vector.Max(maxColor, color);
}
Vector3d inset = (maxColor - minColor) / 8.0;
minColor = Vector.Clamp(minColor + inset, Vector3d.Zero, Vector3d.One);
maxColor = Vector.Clamp(maxColor - inset, Vector3d.Zero, Vector3d.One);
Vector3d color0 = minColor;
Vector3d color1 = maxColor;
Vector3d color2;
Vector3d color3;
if (isBC1 & colors.IsTransparent)
{
//need alpha coding, co <= c1
var max = Vector.Pack(5, 6, 5, Color.Quantize(5, 6, 5, (Colord)maxColor));
var min = Vector.Pack(5, 6, 5, Color.Quantize(5, 6, 5, (Colord)minColor));
if (max <= min)
{
color0 = maxColor;
color1 = minColor;
}
}
if (!isBC1 || (Vector.Pack(5, 6, 5, Color.Quantize(5, 6, 5, (Colord)color0)) > Vector.Pack(5, 6, 5, Color.Quantize(5, 6, 5, (Colord)color1))))
{
color2 = Vector.Lerp(color0, color1, 1.0 / 3.0);
color3 = Vector.Lerp(color0, color1, 2.0 / 3.0);
}
else
{
color2 = Vector.Lerp(color0, color1, 1.0 / 2.0);
color3 = new Vector3d(0.0);
}
for (int y = 0; y < colors.Height; ++y)
{
for (int x = 0; x < colors.Width; ++x)
{
Vector3d color = colors.Points[x, y];
double d0 = Vector.AbsoluteSquared(Vector.Modulate(options.Metric, (color0 - color)));
double d1 = Vector.AbsoluteSquared(Vector.Modulate(options.Metric, (color1 - color)));
double d2 = Vector.AbsoluteSquared(Vector.Modulate(options.Metric, (color2 - color)));
double d3 = Vector.AbsoluteSquared(Vector.Modulate(options.Metric, (color3 - color)));
int b0 = d0 > d3 ? 1 : 0;
int b1 = d1 > d2 ? 1 : 0;
int b2 = d0 > d2 ? 1 : 0;
int b3 = d1 > d3 ? 1 : 0;
int b4 = d2 > d3 ? 1 : 0;
int x0 = b1 & b2;
int x1 = b0 & b3;
int x2 = b0 & b4;
block.Indices[x + (y * 4)] = (x2 | ((x0 | x1) << 1));
}
}
block.Colord0 = (int)Vector.Pack(5, 6, 5, Color.Quantize(5, 6, 5, (Colord)color0));
block.Colord0 = (int)Vector.Pack(5, 6, 5, Color.Quantize(5, 6, 5, (Colord)color0));
}
/// <summary>
/// Returns the squared distance between two points.
/// </summary>
/// <param name="value1">The first point.</param>
/// <param name="value2">The second point.</param>
/// <returns>The squared distance between value1 and value2.</returns>
public static float DistanceSquared(Point3f value1, Point3f value2)
{
return(Vector.AbsoluteSquared(value2 - value1));
}
public static bool Contains(Circlef circle, Point2f point)
{
return(Vector.AbsoluteSquared(circle.Center - point) <= circle.Radius * circle.Radius);
}
/// <summary>
/// Returns the squared distance between two points.
/// </summary>
/// <param name="value1">The first point.</param>
/// <param name="value2">The second point.</param>
/// <returns>The squared distance between value1 and value2.</returns>
public static long DistanceSquared(Point2l value1, Point2l value2)
{
return(Vector.AbsoluteSquared(value2 - value1));
}
