Members
Rotation |
Direction |
0° |
East |
- Default Value:
MAIN_DIAGONAL
number
static
Reflection about the main diagonal.
- Default Value:
MIRROR_HORIZONTAL
number
static
- Default Value:
MIRROR_VERTICAL
number
static
- Default Value:
Rotation |
Direction |
-90°/270°↻ |
North |
- Default Value:
Rotation |
Direction |
-45°/315°↻ |
Northeast |
- Default Value:
Rotation |
Direction |
-135°/225°↻ |
Northwest |
- Default Value:
REVERSE_DIAGONAL
number
static
Reflection about reverse diagonal.
- Default Value:
Rotation |
Direction |
90°↻ |
South |
- Default Value:
Rotation |
Direction |
45°↻ |
Southeast |
- Default Value:
Rotation |
Direction |
135°↻ |
Southwest |
- Default Value:
Rotation |
Direction |
180° |
West |
- Default Value:
Methods
Composes the two D8 operations.
Taking ^
as reflection:
|
E=0 |
S=2 |
W=4 |
N=6 |
E^=8 |
S^=10 |
W^=12 |
N^=14 |
E=0 |
E |
S |
W |
N |
E^ |
S^ |
W^ |
N^ |
S=2 |
S |
W |
N |
E |
S^ |
W^ |
N^ |
E^ |
W=4 |
W |
N |
E |
S |
W^ |
N^ |
E^ |
S^ |
N=6 |
N |
E |
S |
W |
N^ |
E^ |
S^ |
W^ |
E^=8 |
E^ |
N^ |
W^ |
S^ |
E |
N |
W |
S |
S^=10 |
S^ |
E^ |
N^ |
W^ |
S |
E |
N |
W |
W^=12 |
W^ |
S^ |
E^ |
N^ |
W |
S |
E |
N |
N^=14 |
N^ |
W^ |
S^ |
E^ |
N |
W |
S |
E |
This is a Cayley table
Name |
Type |
Description |
rotationSecond |
GD8Symmetry
|
Second operation, which
is the row in the above cayley table.
|
rotationFirst |
GD8Symmetry
|
First operation, which
is the column in the above cayley table.
|
Returns:
Approximates the vector V(dx,dy)
into one of the
eight directions provided by groupD8
.
Name |
Type |
Description |
dx |
number
|
X-component of the vector
|
dy |
number
|
Y-component of the vector
|
Returns:
Type |
Description |
GD8Symmetry
|
Approximation of the vector into
one of the eight symmetries. |
Name |
Type |
Description |
rotation |
GD8Symmetry
|
symmetry whose opposite
is needed. Only rotations have opposite symmetries while
reflections don't.
|
Returns:
Type |
Description |
GD8Symmetry
|
The opposite symmetry of rotation |
isVertical
(rotation) boolean
static
Checks if the rotation angle is vertical, i.e. south
or north. It doesn't work for reflections.
Name |
Type |
Description |
rotation |
GD8Symmetry
|
The number to check.
|
Returns:
Type |
Description |
boolean
|
Whether or not the direction is vertical |
matrixAppendRotationInv
(matrix, rotation, tx, ty) void
static
Helps sprite to compensate texture packer rotation.
Name |
Type |
Default |
Description |
matrix |
Matrix
|
|
sprite world matrix
|
rotation |
GD8Symmetry
|
|
The rotation factor to use.
|
tx |
number
|
0
|
sprite anchoring
|
ty |
number
|
0
|
sprite anchoring
|
rotate180
(rotation) number
static
Adds 180 degrees to rotation, which is a commutative
operation.
Name |
Type |
Description |
rotation |
number
|
The number to rotate.
|
Returns:
Type |
Description |
number
|
Rotated number |
Returns:
Name |
Type |
Description |
ind |
GD8Symmetry
|
sprite rotation angle.
|
Returns:
Type |
Description |
GD8Symmetry
|
The X-component of the U-axis
after rotating the axes. |
Name |
Type |
Description |
ind |
GD8Symmetry
|
sprite rotation angle.
|
Returns:
Type |
Description |
GD8Symmetry
|
The Y-component of the U-axis
after rotating the axes. |
Name |
Type |
Description |
ind |
GD8Symmetry
|
sprite rotation angle.
|
Returns:
Type |
Description |
GD8Symmetry
|
The X-component of the V-axis
after rotating the axes. |
Name |
Type |
Description |
ind |
GD8Symmetry
|
sprite rotation angle.
|
Returns:
Type |
Description |
GD8Symmetry
|
The Y-component of the V-axis
after rotating the axes. |