>Transformation operations

# Transformation operations

## Name

Transformation operations -- Transformations which can be applied to bpaths or vpaths.

## Synopsis

 ``` ArtVpath* art_vpath_perturb (ArtVpath *src); ArtVpath* art_vpath_affine_transform (const ArtVpath *src, const double matrix[6]); ArtBpath* art_bpath_affine_transform (const ArtBpath *src, const double matrix[6]);```

## Description

Once vpaths and bpaths are constructed, it is possible to apply a number of transformations to these vector paths: art_vpath_perturb should not be really used by applications (but you might have to use it so...) but art_vpath_affine_transform and art_bpath_affine_transform are both widely used to apply affine transformations.

## Details

### art_vpath_perturb ()

 `ArtVpath* art_vpath_perturb (ArtVpath *src);`

Perturbs each of the points by a small random amount. This is helpful for cheating in cases when algorithms haven't attained numerical stability yet.

 src : Source vpath. Returns : Newly allocated vpath containing perturbed src.

### art_vpath_affine_transform ()

 ```ArtVpath* art_vpath_affine_transform (const ArtVpath *src, const double matrix[6]);```

Computes the affine transform of the vpath, using matrix as the transform. matrix is stored in the same format as PostScript, ie. x' = matrix[0] * x + matrix[2] * y + matrix[4] y' = matrix[1] * x + matrix[3] * y + matrix[5]

 src : Source vpath to transform. matrix : Affine transform. Returns : the newly allocated vpath resulting from the transform.

### art_bpath_affine_transform ()

 ```ArtBpath* art_bpath_affine_transform (const ArtBpath *src, const double matrix[6]);```

Affine transform the bezpath, returning a newly allocated ArtBpath (allocated using art_alloc()).

Result (x', y') = (matrix[0] * x + matrix[2] * y + matrix[4], matrix[1] * x + matrix[3] * y + matrix[5])

 src : The source ArtBpath. matrix : The affine transform. Returns : the transformed ArtBpath.