vispy.visuals.transforms.base_transform module

API Issues to work out:

  • MatrixTransform and STTransform both have ‘scale’ and ‘translate’ attributes, but they are used in very different ways. It would be nice to keep this consistent, but how?

  • Need a transform.map_rect function that returns the bounding rectangle of a rect after transformation. Non-linear transforms might need to work harder at this, but we can provide a default implementation that works by mapping a selection of points across a grid within the original rect.

class vispy.visuals.transforms.base_transform.BaseTransform

Bases: object

BaseTransform is a base class that defines a pair of complementary coordinate mapping functions in both python and GLSL.

All BaseTransform subclasses define map() and imap() methods that map an object through the forward or inverse transformation, respectively.

The two class variables glsl_map and glsl_imap are instances of shaders.Function that define the forward- and inverse-mapping GLSL function code.

Optionally, an inverse() method returns a new transform performing the inverse mapping.

Note that although all classes should define both map() and imap(), it is not necessarily the case that imap(map(x)) == x; there may be instances where the inverse mapping is ambiguous or otherwise meaningless.

Isometric = None
Linear = None
NonScaling = None
Orthogonal = None
property dynamic

Boolean flag that indicates whether this transform is expected to change frequently.

Transforms that are flagged as dynamic will not be collapsed in ChainTransform.simplified. This allows changes to the transform to propagate through the chain without requiring the chain to be re-simplified.

glsl_imap = None
glsl_map = None
imap(obj)

Return obj mapped through the inverse transformation.

Parameters
objtuple (x,y) or (x,y,z)

array with shape (…, 2) or (…, 3)

property inverse

The inverse of this transform.

map(obj)

Return obj mapped through the forward transformation.

Parameters
objtuple (x,y) or (x,y,z)

array with shape (…, 2) or (…, 3)

shader_imap()

See shader_map.

shader_map()

Return a shader Function that accepts only a single vec4 argument and defines new attributes / uniforms supplying the Function with any static input.

update(*args)

Called to inform any listeners that this transform has changed.

class vispy.visuals.transforms.base_transform.InverseTransform(transform)

Bases: vispy.visuals.transforms.base_transform.BaseTransform

property Isometric
property Linear
property NonScaling
property Orthogonal
property shader_imap

See shader_map.

property shader_map

Return a shader Function that accepts only a single vec4 argument and defines new attributes / uniforms supplying the Function with any static input.