VioGetBuf

Bindings:  C, MASM 

This call returns the address of the logical video buffer (LVB). 

 VioGetBuf    (LVBPtr, Length, VioHandle) 
 

 LVBPtr (PULONG) - output 
    Address of the selector and offset of the logical video buffer. 
    Applications should not assume the offset portion of this far address 
    is 0. 

 Length (PUSHORT) - output 
    Address of the length buffer in bytes.  The length is: number of rows 
    * number of columns * size of cell. 

 VioHandle (HVIO) - input 
    This must be zero unless the caller is a Presentation Manager 
    application, in which case it must be the value returned by VioGetPs. 

 rc (USHORT) - return 
    Return code descriptions are: 

    0         NO_ERROR 
    355       ERROR_VIO_MODE 
    430       ERROR_VIO_ILLEGAL_DURING_POPUP 
    436       ERROR_VIO_INVALID_HANDLE 
    465       ERROR_VIO_DETACHED 
 
 Remarks 

 An application using VioGetBuf can prepare a screen in the application's 
 own logical video buffer (LVB) offline.  When the application is in the 
 foreground, the physical screen buffer is updated from the LVB when 
 VioShowBuf is issued.  When the application runs in the background, the 
 physical screen buffer is updated when the application is switched to the 
 foreground. 

 Once VioGetBuf is issued, all VioWrtXX calls issued while the application 
 is running in the foreground are written to the physical display buffer 
 and LVB. If a VioGetPhysBuf is subsequently issued, then the  VioWrtXX 
 calls are only written to the physical display buffer.  They are no 
 longer written to the LVB. 

 VioGetMode may be used to determine the dimensions of the buffer. 

 If VioSetMode is issued following a VioGetBuf call, the size of the 
 logical video buffer is adjusted to correspond to the new mode.  There is 
 one logical video buffer per session (or presentation space if AVIO 
 application) that corresponds to the current mode on the current display 
 configuration. 

 
 PM Considerations 

 This function returns the address and length of the Advanced VIO 
 presentation space.  The presentation space may be used to directly 
 manipulate displayed information.