/// <summary>
/// Calculates the UVs of a <see cref="Vertex"/> from the data in <paramref name="texInfo"/>, <paramref name="matrix"/>
/// and <paramref name="texture"/> and returns a <see cref="Vertex"/> with the UVs set.
/// </summary>
/// <param name="vertex">The <see cref="Vertex"/> to calculate UVs for.</param>
/// <param name="texInfo">The <see cref="TextureInfo"/> defining the UV axes for this <see cref="Vertex"/>.</param>
/// <param name="dims">The width and height of the texture applied on this <see cref="Vertex"/>'s surface.</param>
/// <returns>The passed <see cref="Vertex"/> with UVs calculated.</returns>
public static Vertex CalcUV(this Vertex vertex, TextureInfo texInfo, Vector2 dims)
{
Matrix4x4 matrix = texInfo.BuildTexMatrix().inverse;
Vector3 textureCoord = matrix.MultiplyPoint3x4(vertex.position);
vertex.uv0 = new Vector2((texInfo.UAxis.sqrMagnitude * textureCoord.x + texInfo.Translation.x) / dims.x,
(texInfo.VAxis.sqrMagnitude * textureCoord.y + texInfo.Translation.y) / dims.y);
return(vertex);
}
/// <summary>
/// Calculates the UVs on all vertices in this <see cref="Mesh"/> given a <see cref="TextureInfo"/>
/// containing U and V axis projections.
/// </summary>
/// <param name="mesh">This <see cref="Mesh"/>.</param>
/// <param name="textureInfo">
/// A <see cref="TextureInfo"/> containing axes for projecting the texture onto the <see cref="Face"/> this
/// <see cref="Mesh"/> was created from.
/// </param>
/// <param name="dims">
/// The width and height of the <see cref="Texture2D"/> bring projected onto the <see cref="Face"/> this
/// <see cref="Mesh"/> was created from.
/// </param>
public static void CalculateUVs(this Mesh mesh, TextureInfo textureInfo, Vector2 dims)
{
Vector2[] uv = new Vector2[mesh.vertices.Length];
Matrix4x4 textureMatrixInverse = textureInfo.BuildTexMatrix().inverse;
for (int i = 0; i < uv.Length; ++i)
{
Vector3 transformVertex = textureMatrixInverse.MultiplyPoint3x4(mesh.vertices[i]);
Vector2 uv0 = textureInfo.CalculateUV(transformVertex, dims);
uv[i] = uv0;
}
mesh.uv = uv;
}
