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10.2.7 Virtual Display
int seVirtInit(DWORD Width, DWORD Height)
int seMainWinVirtInit(DWORD Width, DWORD Height)
int seSubWinVirtInit(DWORD Width, DWORD Height)
int seMainAndSubWinVirtInit(DWORD width, DWORD height)
Description:
Note
Parameters:
Return Value:
Programming Notes and Examples
Issue Date: 01/02/23
These functions prepare the S1D13706 to display a virtual image.
"Virtual Image" describes the condition where the image contained in display memory is
larger than the physical display. In this situation the physical display is used as a window
into the larger display memory area (display surface). Panning (right/left) and scrolling
(up/down) are used to move the display in order to view the entire image a portion at a
time.
seVirtInit() prepares the current active surface for a virtual image display. Memory is allo-
cated based on width, height and the current color depth.
seMainWinVirtInit() initializes and allocates memory for the main window based on width
and height and color depth.
seSubWinVirtInit() initializes and allocates memory for the sub-window based on current
width and height and color depth.
seMainAndSubWinVirtInit() initializes and allocates one block of memory for both the
main window and sub-window based on width and height and color depth.
Memory previously allocated for the given display surface is released then reallocated to
the larger size.
The width programmed may be larger than that requested in the respective function ar-
gument. This is to ensure that the value programmed into the address offset registers is a
multiple of 4 bytes. For example, suppose seVirtInit(240, 320) is called in SwivelView
90° and at 1 bits-per-pixel. Since four bytes corresponds to 32 pixels in 1 bits-per-pixel
mode, the width must be a multiple of 32. Since 240 is not a multiple of 32, the width is
automatically changed to the next available multiple, which in this case is 256.
Width
The desired virtual width of the display in pixels.
Width must be a multiple of the number of pixels contained in one
dword of display memory. In other words, Width must be a multiple
of 32 ÷ bits-per-pixel.
Height
The desired virtual height of the display in pixels.
The HAL performs internal memory management to ensure that all
display surfaces have sufficient memory for operation. The Height
parameter is required so the HAL can determine the amount of
memory the application requires for the virtual image.
ERR_OK
ERR_HAL_BAD_ARG
The function completed successfully.
The requested virtual dimensions are smaller than
the physical display size.
Page 87
S1D13706
X31B-G-003-03
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