Replaces the current projection matrix with an orthographic projection matrix.
See cogl-ortho-matrix to see how the matrix is calculated.
This function copies the arguments from OpenGL's
glOrtho even though they are unnecessarily confusing due to the z near and z
far arguments actually being a "distance" from the origin, where negative values are behind the viewer, instead of coordinates for the z
clipping planes which would have been consistent with the left, right bottom and top arguments.
The coordinate for the left clipping plane
The coordinate for the right clipping plane
The coordinate for the bottom clipping plane
The coordinate for the top clipping plane