A method includes: obtaining one or more parameters of a geometric merge (GEO) inter prediction mode for a current coding block; defining a size of a subblock that is smaller than a size of the current coding block; specifying a position of the subblock within the current coding block, so that either two or three sides of the subblock coincide with sides of the current coding block; determining one or more allowed split directions of a triangle partitioning mode (TPM) for the subblock depending on which of the sides of the subblock coincide with the sides of the current coding block; and obtaining one or more predicted samples for the current coding block by using the TPM partitioning performed for the subblock in accordance with the size of the subblock, the position of the subblock within the current coding block and a TPM split direction of the subblock.