
Page 44
Epson Research and Development
Vancouver Design Center
S1D13A05
Programming Notes and Examples
X40A-G-003-04
Issue Date: 2002/08/21
7.6 Limitations
7.6.1 SwivelView 0° and 180°
In SwivelView 0° and 180°, the Main Window Line Address Offset Register (REG[44h])
requires the panel width to be a multiple of (32
÷ bits-per-pixel). If this is not the case, then
the Main Window Line Address Offset Register must be programmed to a longer line
which meets this requirement. This longer line creates a virtual image where the width is
Main Window Line Address Offset Register
× (32 ÷ bits-per-pixel).
In SwivelView 0°, this virtual image should be drawn in display memory as left justified,
and in SwivelView 180°, this virtual image should be drawn in display memory as right
justified.
A left-justified image is one drawn in display memory such that each of the image’s lines
only use the left most portion of the line width defined by the line address offset register
(i.e. starting at horizontal position 0).
A right-justified image is one drawn in display memory such that each of the image’s lines
only use the right most portion of the line width defined by the line address offset register
(i.e. starting at a non-zero horizontal position which is the virtual width - image width).
7.6.2 SwivelView 90° and 270°
In SwivelView 90° and 270°, the Main Window Line Address Offset Register (REG[44h])
requires the panel height to be a multiple of (32
÷ bits-per-pixel). If this is not the case, then
the Main Window Line Address Offset Register must be programmed to a longer line
which meets this requirement. This longer line creates a virtual image whose width is Main
Window Line Address Offset Register
× (32 ÷ bits-per-pixel).
In SwivelView 270°, this virtual image should be drawn in display memory as left justified,
and in SwivelView 90°, this virtual image should be drawn in display memory as right
justified.
A left-justified image is one drawn in display memory such that each of the image’s lines
only use the left most portion of the line width defined by the line address offset register
(i.e. starting at horizontal position 0).
A right-justified image is one drawn in display memory such that each of the image’s lines
only use the right most portion of the line width defined by the line address offset register
(i.e. starting at a non-zero horizontal position which is the virtual width - image width).