Plane& Plane::setFromCoplanarPoints( const Vector3& a, const Vector3& b, const Vector3& c) {
auto v1 = Vector3();
auto v2 = Vector3();
auto normal = v1.subVectors( c, b ).cross( v2.subVectors( a, b ) ).normalize();
// Q: should an error be thrown if normal is zero (e.g. degenerate plane)?
setFromNormalAndCoplanarPoint( normal, a );
return *this;
}
Plane& Plane::applyMatrix4( const Matrix4& matrix, const Matrix3& normalMatrix) {
auto v1 = Vector3();
auto v2 = Vector3();
//auto m1 = Matrix3();
// compute new normal based on theory here:
// http://www.songho.ca/opengl/gl_normaltransform.html
auto newNormal = v1.copy( normal ).applyMatrix3( normalMatrix );
auto newCoplanarPoint = coplanarPoint( v2 );
newCoplanarPoint.applyMatrix4( matrix );
setFromNormalAndCoplanarPoint( newNormal, newCoplanarPoint );
return *this;
}
Plane& Plane::applyMatrix4(const Matrix4& matrix, const Matrix3* optionalNormalMatrix)
{
Vector3 v1;
Vector3 v2;
// compute new normal based on theory here:
// http://www.songho.ca/opengl/gl_normaltransform.html
Matrix3 normalMatrix;
if (!optionalNormalMatrix) {
optionalNormalMatrix = &(normalMatrix.getNormalMatrix(matrix));
}
Vector3 newNormal = v1.copy( normal() ).applyMatrix3( *optionalNormalMatrix );
Vector3 newCoplanarPoint = coplanarPoint();
newCoplanarPoint.applyMatrix4( matrix );
setFromNormalAndCoplanarPoint( newNormal, newCoplanarPoint );
return *this;
}