Obj Rotation/Scaling Feature - Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual

AGB Programming Manual

6.3.4 OBJ Rotation/Scaling Feature

The rotation and scaling feature for OBJ is essentially the same as that for
BG.
OBJ Character Data Referenced with Rotation
OBJ Character Data
y-axis dmy
dmx
When an OBJ is displayed, the OBJ character data are referenced
horizontally, beginning from the left-uppermost position. Rotation display
can be achieved by adding an angle to the reference direction. The center
of rotation is fixed at the center of the OBJ field. If a reference point
surpasses the specified OBJ size, it becomes transparent.
©1999 - 2001 Nintendo of America Inc.
*
dx (distance moved in x direction, same line) = ( 1 /
dx
dy (distance moved in y direction, same line) = - ( 1 /
dmx (distance moved in x direction, next line) = ( 1 /
dy
dmy (distance moved in y direction, next line) = ( 1 /
OBJ Center
: Magnification along x-axis
: Magnification along y-axis
70
Rendering Functions
x-axis
) cos
) sin
) sin
) cos
D.C.N. AGB-06-0001-002B4