Maintainer | diagrams-discuss@googlegroups.com |
---|---|
Safe Haskell | None |
Diagrams defines the core library of primitives forming the basis of an embedded domain-specific language for describing and rendering diagrams.
The Transform
module defines generic transformations
parameterized by any vector space.
- data u :-: v = (u :-* v) :-: (v :-* u)
- (<->) :: (HasLinearMap u, HasLinearMap v) => (u -> v) -> (v -> u) -> u :-: v
- linv :: (u :-: v) -> v :-: u
- lapp :: (VectorSpace v, Scalar u ~ Scalar v, HasLinearMap u) => (u :-: v) -> u -> v
- data Transformation v = Transformation (v :-: v) (v :-: v) v
- inv :: HasLinearMap v => Transformation v -> Transformation v
- transp :: Transformation v -> v :-: v
- transl :: Transformation v -> v
- apply :: HasLinearMap v => Transformation v -> v -> v
- papply :: HasLinearMap v => Transformation v -> Point v -> Point v
- fromLinear :: AdditiveGroup v => (v :-: v) -> (v :-: v) -> Transformation v
- class (HasBasis v, HasTrie (Basis v), VectorSpace v) => HasLinearMap v
- class HasLinearMap (V t) => Transformable t where
- transform :: Transformation (V t) -> t -> t
- newtype TransInv t = TransInv {
- unTransInv :: t
- translation :: HasLinearMap v => v -> Transformation v
- translate :: (Transformable t, HasLinearMap (V t)) => V t -> t -> t
- scaling :: (HasLinearMap v, Fractional (Scalar v)) => Scalar v -> Transformation v
- scale :: (Transformable t, Fractional (Scalar (V t)), Eq (Scalar (V t))) => Scalar (V t) -> t -> t
Transformations
Invertible linear transformations
(v1 :-: v2)
is a linear map paired with its inverse.
HasLinearMap v => Monoid (:-: v v) | Invertible linear maps from a vector space to itself form a monoid under composition. |
HasLinearMap v => Semigroup (:-: v v) |
(<->) :: (HasLinearMap u, HasLinearMap v) => (u -> v) -> (v -> u) -> u :-: vSource
Create an invertible linear map from two functions which are assumed to be linear inverses.
lapp :: (VectorSpace v, Scalar u ~ Scalar v, HasLinearMap u) => (u :-: v) -> u -> vSource
Apply a linear map to a vector.
General transformations
data Transformation v Source
General (affine) transformations, represented by an invertible linear map, its transpose, and a vector representing a translation component.
By the transpose of a linear map we mean simply the linear map corresponding to the transpose of the map's matrix representation. For example, any scale is its own transpose, since scales are represented by matrices with zeros everywhere except the diagonal. The transpose of a rotation is the same as its inverse.
The reason we need to keep track of transposes is because it turns out that when transforming a shape according to some linear map L, the shape's normal vectors transform according to L's inverse transpose. This is exactly what we need when transforming bounding functions, which are defined in terms of perpendicular (i.e. normal) hyperplanes.
Transformation (v :-: v) (v :-: v) v |
HasLinearMap v => Monoid (Transformation v) | |
HasLinearMap v => Semigroup (Transformation v) | Transformations are closed under composition; |
HasLinearMap v => HasOrigin (Transformation v) | |
HasLinearMap v => Transformable (Transformation v) | |
(HasLinearMap v, ~ * v (V a), Transformable a) => Action (Transformation v) a | Transformations can act on transformable things. |
Newtype (QDiagram b v m) (DUALTree (DownAnnots v) (UpAnnots b v m) () (Prim b v)) |
inv :: HasLinearMap v => Transformation v -> Transformation vSource
Invert a transformation.
transp :: Transformation v -> v :-: vSource
Get the transpose of a transformation (ignoring the translation component).
transl :: Transformation v -> vSource
Get the translational component of a transformation.
apply :: HasLinearMap v => Transformation v -> v -> vSource
Apply a transformation to a vector. Note that any translational component of the transformation will not affect the vector, since vectors are invariant under translation.
papply :: HasLinearMap v => Transformation v -> Point v -> Point vSource
Apply a transformation to a point.
fromLinear :: AdditiveGroup v => (v :-: v) -> (v :-: v) -> Transformation vSource
Create a general affine transformation from an invertible linear transformation and its transpose. The translational component is assumed to be zero.
The Transformable class
class (HasBasis v, HasTrie (Basis v), VectorSpace v) => HasLinearMap v Source
HasLinearMap
is a poor man's class constraint synonym, just to
help shorten some of the ridiculously long constraint sets.
(HasBasis v, HasTrie (Basis v), VectorSpace v) => HasLinearMap v |
class HasLinearMap (V t) => Transformable t whereSource
Type class for things t
which can be transformed.
transform :: Transformation (V t) -> t -> tSource
Apply a transformation to an object.
Translational invariance
TransInv
is a wrapper which makes a transformable type
translationally invariant; the translational component of
transformations will no longer affect things wrapped in
TransInv
.
TransInv | |
|
Vector space independent transformations
Most transformations are specific to a particular vector space, but a few can be defined generically over any vector space.
translation :: HasLinearMap v => v -> Transformation vSource
Create a translation.
translate :: (Transformable t, HasLinearMap (V t)) => V t -> t -> tSource
Translate by a vector.
scaling :: (HasLinearMap v, Fractional (Scalar v)) => Scalar v -> Transformation vSource
Create a uniform scaling transformation.