The document handle, returned by cpdf_open().
The value of transition can be
|0 for none,|
|1 for two lines sweeping across the screen reveal the page,|
|2 for multiple lines sweeping across the screen reveal the page,|
|3 for a box reveals the page,|
|4 for a single line sweeping across the screen reveals the page,|
|5 for the old page dissolves to reveal the page,|
|6 for the dissolve effect moves from one screen edge to another,|
|7 for the old page is simply replaced by the new page (default)|
The value of duration is the number of seconds between page flipping.