virtualx-engine/modules/mono/glue/cs_files/Transform2D.cs
2017-11-21 23:32:40 +01:00

356 lines
8.9 KiB
C#

using System;
using System.Runtime.InteropServices;
namespace Godot
{
[StructLayout(LayoutKind.Sequential)]
public struct Transform2D : IEquatable<Transform2D>
{
private static readonly Transform2D identity = new Transform2D
(
new Vector2(1f, 0f),
new Vector2(0f, 1f),
new Vector2(0f, 0f)
);
public Vector2 x;
public Vector2 y;
public Vector2 o;
public static Transform2D Identity
{
get { return identity; }
}
public Vector2 Origin
{
get { return o; }
}
public float Rotation
{
get { return Mathf.Atan2(y.x, o.y); }
}
public Vector2 Scale
{
get { return new Vector2(x.Length(), y.Length()); }
}
public Vector2 this[int index]
{
get
{
switch (index)
{
case 0:
return x;
case 1:
return y;
case 2:
return o;
default:
throw new IndexOutOfRangeException();
}
}
set
{
switch (index)
{
case 0:
x = value;
return;
case 1:
y = value;
return;
case 2:
o = value;
return;
default:
throw new IndexOutOfRangeException();
}
}
}
public float this[int index, int axis]
{
get
{
switch (index)
{
case 0:
return x[axis];
case 1:
return y[axis];
default:
throw new IndexOutOfRangeException();
}
}
set
{
switch (index)
{
case 0:
x[axis] = value;
return;
case 1:
y[axis] = value;
return;
default:
throw new IndexOutOfRangeException();
}
}
}
public Transform2D AffineInverse()
{
Transform2D inv = this;
float det = this[0, 0] * this[1, 1] - this[1, 0] * this[0, 1];
if (det == 0)
{
return new Transform2D
(
float.NaN, float.NaN,
float.NaN, float.NaN,
float.NaN, float.NaN
);
}
float idet = 1.0f / det;
float temp = this[0, 0];
this[0, 0] = this[1, 1];
this[1, 1] = temp;
this[0] *= new Vector2(idet, -idet);
this[1] *= new Vector2(-idet, idet);
this[2] = BasisXform(-this[2]);
return inv;
}
public Vector2 BasisXform(Vector2 v)
{
return new Vector2(Tdotx(v), Tdoty(v));
}
public Vector2 BasisXformInv(Vector2 v)
{
return new Vector2(x.Dot(v), y.Dot(v));
}
public Transform2D InterpolateWith(Transform2D m, float c)
{
float r1 = Rotation;
float r2 = m.Rotation;
Vector2 s1 = Scale;
Vector2 s2 = m.Scale;
// Slerp rotation
Vector2 v1 = new Vector2(Mathf.Cos(r1), Mathf.Sin(r1));
Vector2 v2 = new Vector2(Mathf.Cos(r2), Mathf.Sin(r2));
float dot = v1.Dot(v2);
// Clamp dot to [-1, 1]
dot = (dot < -1.0f) ? -1.0f : ((dot > 1.0f) ? 1.0f : dot);
Vector2 v = new Vector2();
if (dot > 0.9995f)
{
// Linearly interpolate to avoid numerical precision issues
v = v1.LinearInterpolate(v2, c).Normalized();
}
else
{
float angle = c * Mathf.Acos(dot);
Vector2 v3 = (v2 - v1 * dot).Normalized();
v = v1 * Mathf.Cos(angle) + v3 * Mathf.Sin(angle);
}
// Extract parameters
Vector2 p1 = Origin;
Vector2 p2 = m.Origin;
// Construct matrix
Transform2D res = new Transform2D(Mathf.Atan2(v.y, v.x), p1.LinearInterpolate(p2, c));
Vector2 scale = s1.LinearInterpolate(s2, c);
res.x *= scale;
res.y *= scale;
return res;
}
public Transform2D Inverse()
{
Transform2D inv = this;
// Swap
float temp = inv.x.y;
inv.x.y = inv.y.x;
inv.y.x = temp;
inv.o = inv.BasisXform(-inv.o);
return inv;
}
public Transform2D Orthonormalized()
{
Transform2D on = this;
Vector2 onX = on.x;
Vector2 onY = on.y;
onX.Normalize();
onY = onY - onX * (onX.Dot(onY));
onY.Normalize();
on.x = onX;
on.y = onY;
return on;
}
public Transform2D Rotated(float phi)
{
return this * new Transform2D(phi, new Vector2());
}
public Transform2D Scaled(Vector2 scale)
{
Transform2D copy = this;
copy.x *= scale;
copy.y *= scale;
copy.o *= scale;
return copy;
}
private float Tdotx(Vector2 with)
{
return this[0, 0] * with[0] + this[1, 0] * with[1];
}
private float Tdoty(Vector2 with)
{
return this[0, 1] * with[0] + this[1, 1] * with[1];
}
public Transform2D Translated(Vector2 offset)
{
Transform2D copy = this;
copy.o += copy.BasisXform(offset);
return copy;
}
public Vector2 Xform(Vector2 v)
{
return new Vector2(Tdotx(v), Tdoty(v)) + o;
}
public Vector2 XformInv(Vector2 v)
{
Vector2 vInv = v - o;
return new Vector2(x.Dot(vInv), y.Dot(vInv));
}
public Transform2D(Vector2 xAxis, Vector2 yAxis, Vector2 origin)
{
this.x = xAxis;
this.y = yAxis;
this.o = origin;
}
public Transform2D(float xx, float xy, float yx, float yy, float ox, float oy)
{
this.x = new Vector2(xx, xy);
this.y = new Vector2(yx, yy);
this.o = new Vector2(ox, oy);
}
public Transform2D(float rot, Vector2 pos)
{
float cr = Mathf.Cos(rot);
float sr = Mathf.Sin(rot);
x.x = cr;
y.y = cr;
x.y = -sr;
y.x = sr;
o = pos;
}
public static Transform2D operator *(Transform2D left, Transform2D right)
{
left.o = left.Xform(right.o);
float x0, x1, y0, y1;
x0 = left.Tdotx(right.x);
x1 = left.Tdoty(right.x);
y0 = left.Tdotx(right.y);
y1 = left.Tdoty(right.y);
left.x.x = x0;
left.x.y = x1;
left.y.x = y0;
left.y.y = y1;
return left;
}
public static bool operator ==(Transform2D left, Transform2D right)
{
return left.Equals(right);
}
public static bool operator !=(Transform2D left, Transform2D right)
{
return !left.Equals(right);
}
public override bool Equals(object obj)
{
if (obj is Transform2D)
{
return Equals((Transform2D)obj);
}
return false;
}
public bool Equals(Transform2D other)
{
return x.Equals(other.x) && y.Equals(other.y) && o.Equals(other.o);
}
public override int GetHashCode()
{
return x.GetHashCode() ^ y.GetHashCode() ^ o.GetHashCode();
}
public override string ToString()
{
return String.Format("({0}, {1}, {2})", new object[]
{
this.x.ToString(),
this.y.ToString(),
this.o.ToString()
});
}
public string ToString(string format)
{
return String.Format("({0}, {1}, {2})", new object[]
{
this.x.ToString(format),
this.y.ToString(format),
this.o.ToString(format)
});
}
}
}