public float GetLengthSq()
{
return(Line2D.GetLengthSq(v2.x - v1.x, v2.y - v1.y));
}
public float GetNearestOnLine(Vector2D p)
{
return(Line2D.GetNearestOnLine(v1, v2, p));
}
public Vector2D GetCoordinatesAt(float u)
{
return(Line2D.GetCoordinatesAt(v1, v2, u));
}
public float GetSideOfLine(Vector2D p)
{
return(Line2D.GetSideOfLine(v1, v2, p));
}
public float GetDistanceToLineSq(Vector2D p, bool bounded)
{
return(Line2D.GetDistanceToLineSq(v1, v2, p, bounded));
}
public bool GetIntersection(Line2D ray)
{
return(Line2D.GetIntersection(v1, v2, ray.v1.x, ray.v1.y, ray.v2.x, ray.v2.y));
}
public bool GetIntersection(Line2D ray, out float u_ray, out float u_line)
{
return(Line2D.GetIntersection(v1, v2, ray.v1.x, ray.v1.y, ray.v2.x, ray.v2.y, out u_ray, out u_line));
}
public bool GetIntersection(float x3, float y3, float x4, float y4, out float u_ray, out float u_line)
{
return(Line2D.GetIntersection(v1, v2, x3, y3, x4, y4, out u_ray, out u_line));
}
public bool GetIntersection(float x3, float y3, float x4, float y4)
{
return(Line2D.GetIntersection(v1, v2, x3, y3, x4, y4));
}
// Cohen-Sutherland algorithm
public static Line2D ClipToRectangle(Line2D line, RectangleF rect, out bool intersects)
{
int flags1 = MapSet.GetCSFieldBits(line.v1, rect);
int flags2 = MapSet.GetCSFieldBits(line.v2, rect);
intersects = false;
Line2D result = line;
while (true)
{
if (flags1 == 0 && flags2 == 0)
{
// Line is fully inside the box
intersects = true;
return(result);
}
if ((flags1 & flags2) != 0)
{
// Both points are in the same outer area
intersects = false;
return(new Line2D());
}
float x, y;
int outFlags = flags1 != 0 ? flags1 : flags2;
if ((outFlags & 0x1) > 0) // Top
{
x = result.v1.x + (result.v2.x - result.v1.x) * (rect.Top - result.v1.y) / (result.v2.y - result.v1.y);
y = rect.Top;
}
else if ((outFlags & 0x2) > 0) // Bottom
{
x = result.v1.x + (result.v2.x - result.v1.x) * (rect.Bottom - result.v1.y) / (result.v2.y - result.v1.y);
y = rect.Bottom;
}
else if ((outFlags & 0x4) > 0) // Left
{
y = result.v1.y + (result.v2.y - result.v1.y) * (rect.Left - result.v1.x) / (result.v2.x - result.v1.x);
x = rect.Left;
}
else if ((outFlags & 0x8) > 0) // Right
{
y = result.v1.y + (result.v2.y - result.v1.y) * (rect.Right - result.v1.x) / (result.v2.x - result.v1.x);
x = rect.Right;
}
else
{
intersects = true;
return(result);
}
if (outFlags == flags1)
{
result.v1 = new Vector2D(x, y);
flags1 = MapSet.GetCSFieldBits(result.v1, rect);
}
else
{
result.v2 = new Vector2D(x, y);
flags2 = MapSet.GetCSFieldBits(result.v2, rect);
}
}
}
//mxd. This tests if given lines intersects
public static bool GetIntersection(Line2D line1, Line2D line2)
{
return(GetIntersection(line1.v1, line1.v2, line2.v1.x, line2.v1.y, line2.v2.x, line2.v2.y));
}
// Constructor
public ProjectedFrustum2D(Vector2D pos, float xyangle, float zangle, float near, float far, float fov)
{
Vector2D[] forwards = new Vector2D[4];
Vector2D[] downwards = new Vector2D[4];
Vector2D[] corners = new Vector2D[4];
// Initialize
this.pos = pos;
this.xyangle = xyangle;
this.zangle = zangle;
this.near = near;
this.far = far;
this.fov = fov;
// Make the corners for a forward frustum
// The corners are in this order: Left-Far, Right-Far, Left-Near, Right-Near
float fovhalf = fov * 0.5f;
float fovhalfcos = (float)Math.Cos(fovhalf);
float farsidelength = far / fovhalfcos;
float nearsidelength = near / fovhalfcos;
forwards[0] = pos + Vector2D.FromAngle(xyangle - fovhalf, farsidelength);
forwards[1] = pos + Vector2D.FromAngle(xyangle + fovhalf, farsidelength);
forwards[2] = pos + Vector2D.FromAngle(xyangle - fovhalf, nearsidelength);
forwards[3] = pos + Vector2D.FromAngle(xyangle + fovhalf, nearsidelength);
// Make the corners for a downward frustum
// The corners are in the same order as above
//float farradius = far * (float)Math.Tan(fovhalf) * Angle2D.SQRT2;
float farradius = (float)(far * 0.5f * Angle2D.SQRT2);
downwards[0] = pos + Vector2D.FromAngle(xyangle - Angle2D.PI * 0.25f, farradius);
downwards[1] = pos + Vector2D.FromAngle(xyangle + Angle2D.PI * 0.25f, farradius);
downwards[2] = pos + Vector2D.FromAngle(xyangle - Angle2D.PI * 0.75f, farradius);
downwards[3] = pos + Vector2D.FromAngle(xyangle + Angle2D.PI * 0.75f, farradius);
// Interpolate between the two to make the final corners depending on the z angle
float d = Math.Abs((float)Math.Sin(zangle));
corners[0] = forwards[0] * (1.0f - d) + downwards[0] * d;
corners[1] = forwards[1] * (1.0f - d) + downwards[1] * d;
corners[2] = forwards[2] * (1.0f - d) + downwards[2] * d;
corners[3] = forwards[3] * (1.0f - d) + downwards[3] * d;
// Make the frustum lines
// Note that the lines all have their right side inside the frustum!
lines = new Line2D[4];
lines[0] = new Line2D(corners[2], corners[0]);
lines[1] = new Line2D(corners[1], corners[3]);
lines[2] = new Line2D(corners[3], corners[2]);
lines[3] = new Line2D(corners[0], corners[1]);
// Calculate the circle center
center = (corners[0] + corners[1] + corners[2] + corners[3]) * 0.25f;
// Calculate the radius from the center to the farthest corner
float radius2 = 0.0f;
for (int i = 0; i < corners.Length; i++)
{
float distance2 = (float)Vector2D.DistanceSq(center, corners[i]);
if (distance2 > radius2)
{
radius2 = distance2;
}
}
radius = (float)Math.Sqrt(radius2);
}
