61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
|
package engine
|
||
|
|
|
||
|
|
import "image"
|
||
|
|
|
||
|
|
// IntMatrix3 implements a 3x3 integer matrix.
|
||
|
|
type IntMatrix3 [3][3]int
|
||
|
|
|
||
|
|
// Apply applies the matrix to a vector to obtain a transformed vector.
|
||
|
|
func (a IntMatrix3) Apply(v Point3) Point3 {
|
||
|
|
return Point3{
|
||
|
|
X: v.X*a[0][0] + v.Y*a[0][1] + v.Z*a[0][2],
|
||
|
|
Y: v.X*a[1][0] + v.Y*a[1][1] + v.Z*a[1][2],
|
||
|
|
Z: v.X*a[2][0] + v.Y*a[2][1] + v.Z*a[2][2],
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Concat returns the matrix equivalent to applying matrix a and then b.
|
||
|
|
func (a IntMatrix3) Concat(b IntMatrix3) IntMatrix3 {
|
||
|
|
return IntMatrix3{
|
||
|
|
[3]int{
|
||
|
|
a[0][0]*b[0][0] + a[0][1]*b[1][0] + a[0][2]*b[2][0],
|
||
|
|
a[0][0]*b[0][1] + a[0][1]*b[1][1] + a[0][2]*b[2][1],
|
||
|
|
a[0][0]*b[0][2] + a[0][1]*b[1][2] + a[0][2]*b[2][2],
|
||
|
|
},
|
||
|
|
[3]int{
|
||
|
|
a[1][0]*b[0][0] + a[1][1]*b[1][0] + a[1][2]*b[2][0],
|
||
|
|
a[1][0]*b[0][1] + a[1][1]*b[1][1] + a[1][2]*b[2][1],
|
||
|
|
a[1][0]*b[0][2] + a[1][1]*b[1][2] + a[1][2]*b[2][2],
|
||
|
|
},
|
||
|
|
[3]int{
|
||
|
|
a[2][0]*b[0][0] + a[2][1]*b[1][0] + a[2][2]*b[2][0],
|
||
|
|
a[2][0]*b[0][1] + a[2][1]*b[1][1] + a[2][2]*b[2][1],
|
||
|
|
a[2][0]*b[0][2] + a[2][1]*b[1][2] + a[2][2]*b[2][2],
|
||
|
|
},
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// IntMatrix3x4 implements a 3 row, 4 column integer matrix, capable of
|
||
|
|
//describing any integer affine transformation.
|
||
|
|
type IntMatrix3x4 [3][4]int
|
||
|
|
|
||
|
|
// Apply applies the matrix to a vector to obtain a transformed vector.
|
||
|
|
func (a IntMatrix3x4) Apply(v Point3) Point3 {
|
||
|
|
return Point3{
|
||
|
|
X: v.X*a[0][0] + v.Y*a[0][1] + v.Z*a[0][2] + a[0][3],
|
||
|
|
Y: v.X*a[1][0] + v.Y*a[1][1] + v.Z*a[1][2] + a[1][3],
|
||
|
|
Z: v.X*a[2][0] + v.Y*a[2][1] + v.Z*a[2][2] + a[2][3],
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// IntMatrix2x3 implements a 2 row, 3 column matrix (as two Point3 row vectors).
|
||
|
|
type IntMatrix2x3 [2]Point3
|
||
|
|
|
||
|
|
// Apply applies the matrix to a vector to obtain a transformed vector.
|
||
|
|
func (a IntMatrix2x3) Apply(v Point3) image.Point {
|
||
|
|
return image.Point{
|
||
|
|
X: v.Dot(a[0]),
|
||
|
|
Y: v.Dot(a[1]),
|
||
|
|
}
|
||
|
|
}
|