UltimateZoneBuilder/Source/Plugins/BuilderModes/VisualModes/TexturePlane.cs
2020-05-21 14:20:02 +02:00

49 lines
1.3 KiB
C#
Executable file

#region === Copyright (c) 2010 Pascal van der Heiden ===
using CodeImp.DoomBuilder.Geometry;
#endregion
namespace CodeImp.DoomBuilder.BuilderModes
{
internal struct TexturePlane
{
// Geometry coordinates (left-top, right-top and right-bottom)
public Vector3D vlt;
public Vector3D vrt;
public Vector3D vrb;
// Texture coordinates on the points above
public Vector2D tlt;
public Vector2D trt;
public Vector2D trb;
// This returns interpolated texture coordinates for the point p on the plane defined by vlt, vrt and vrb
public Vector2D GetTextureCoordsAt(Vector3D p)
{
// Delta vectors
Vector3D v31 = vrb - vlt;
Vector3D v21 = vrt - vlt;
Vector3D vp1 = p - vlt;
// Compute dot products
double d00 = Vector3D.DotProduct(v31, v31);
double d01 = Vector3D.DotProduct(v31, v21);
double d02 = Vector3D.DotProduct(v31, vp1);
double d11 = Vector3D.DotProduct(v21, v21);
double d12 = Vector3D.DotProduct(v21, vp1);
// Compute barycentric coordinates
double invd = 1.0f / (d00 * d11 - d01 * d01);
double u = (d11 * d02 - d01 * d12) * invd;
double v = (d00 * d12 - d01 * d02) * invd;
// Delta texture coordinates
Vector2D t21 = trt - tlt;
Vector2D t31 = trb - tlt;
// Lerp
return tlt + t31 * u + t21 * v;
}
}
}