Nintendo 1504166 Programming Manual - Page 70

OBJ Rotation/Scaling Feature, OBJ Character Data Referenced with Rotation

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AGB Programming Manual Rendering Functions 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 ** * Double-Size Object Field Object Field x-axis OBJ Center BeHfoorriezoRnotatal tLioinne y-axis dx θ θ dmy dy dmx dx (distance moved in x direction, same line) = ( 1 / α ) cos θ dy (distance moved in y direction, same line) = - ( 1 / β ) sin θ dmx (distance moved in x direction, next line) = ( 1 / α ) sin θ dmy (distance moved in y direction, next line) = ( 1 /β ) cos θ α: Magnification along x-axis β: Magnification along y-axis 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. 70 D.C.N. AGB-06-0001-002B4

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AGB Programming Manual
Rendering Functions
©1999 - 2001 Nintendo of America Inc.
70
D.C.N. AGB-06-0001-002B4
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
dx
(distance moved in x direction, same line) =
( 1
/
α
)
cos
q
dy
(distance moved in y direction, same line) = - ( 1
/
β
)
sin
q
dmx
(distance moved in x direction, next line) =
( 1
/
α
)
sin
q
dmy
(distance moved in y direction, next line) =
( 1
/
β
)
cos
q
x-axis
y-axis
α
: Magnification along x-axis
β
: Magnification along y-axis
OBJ Character Data
θ
θ
dx
dy
dmy
dmx
OBJ Center
*
*
*
Horizontal Line
Before Rotation
Object Field
Double-Size Object Field
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.