NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 1007 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
Move/Draw
5.28.5.15
When this bit is 0, the current X, Y pointers will be moved but without any pixels being drawn. When
this bit is 1, the pixels should be drawn.
Clipping
5.28.5.16
The clipping function supports clipped drawing writes inside or outside of any rectangular region in
display memory during Graphics Engine operation. This chip supports both rectangle clipping for
BitBLTs and line clipping for Bresenham Line. When enabled, the clipping function simply masks
writes within or outside of the clipping window. Note that the clipping function is available only in X/Y
addressing mode.
Rotation and Scaling Up/Down
5.28.5.17
The main function is to support the rotation or scaling up/down in any rectangular region in display
memory during Graphics Engine operation. For the 2D rotation, it can rotate left or right 45, 90 or 180
degrees, and it also supports the flip/flop, mirror or up-side-down pictures. Just as the rectangle
clipping for BitBLTs and line clipping for Bresenham Line, when a clip flag is enabled, the clipping
function simply masks writes inside or outside the clipping window. Users can trun on the rectangle
clipping functions for their different and special view effect. In image scale up/down function, both
programmable horizontal and vertical N/M scaling up/down factors are provided for resizing the image.
In order to scale up (1+N/M) or scale down (N/M), the value of N must be equal or less than M. Scale
up supports for 1.0 ~ 1.996.
Only the source color controlled transparency is supported during the rotation or scaling size
processes. Transparent source colors (a color, or color space) can overwrite or not overwrite the
background destination.
The graphic engine rotation control operates with all parameters with reference to the first octant
(octant 0). A 3-bit octant code is specified as shown in following figure.
Figure 5.28-4 Rotation Operation Octant
+X
+Y
000
Scale Down
001
R45
111
Mirror
110
X180
011
L90
101
R90
100
Up-Side-Down
010
L45