Shakashaka

Shakashaka (Proof of Quilt) is a Japanese logic puzzle. Enter black triangles in the grid in such a way that white rectangular areas are formed in them.

Rules: Draw one of four possible black triangles (◢, ◣, ◤,◥) in some white cells; some white cells can also be left empty.
A number in a black cell indicates the number of triangle sides that are orthogonally adjacent to that cell. Black cells without a number can have any number of triangle sides adjacent to them.
The remaining white areas must all be rectangular. A rectangle can be oriented horizontally, vertically, or obliquely. Two white rectangles may not be orthogonally adjacent (but diagonally).