m[0*4] = 2 / (right - left)
m[1*4] = 0
m[2*4] = 0
m[3*4] = -(right + left) / (right - left)

m[0*4+1] = 0
m[1*4+1] = 2 / (top - bottom)
m[2*4+1] = 0
m[3*4+1] = -(top + bottom) / (top - bottom)

m[0*4+2] = 0
m[1*4+2] = 0
m[2*4+2] = -2 / (farval - nearval)
m[3*4+2] = -(farval + nearval) / (farval - nearval)

m[0*4+3] = 0
m[1*4+3] = 0
m[2*4+3] = 0
m[3*4+3] = 1