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Release 0.2 (8/21/2010)

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planar.Affine – 2D Affine Transforms

class planar.Affine

Two dimensional immutable vector.

Affine(x, y)

static identity()
Return the identity transform.
static rotation()
Create a rotation transform at the specified angle, optionally about the specified anchor point.
static scale()
Create a scaling transform from a scalar or vector, optionally about an anchor point.
static shear()
Create a shear transform from a vector, optionally about an anchor point.
static translation()
Create a translation transform from an offset vector.
almost_equals
Compare transforms for approximate equality.
column_vectors
The values of the transform as three 2D column vectors
determinant
The determinant of the transform matrix. This value is equal to the area scaling factor when the transform is applied to a shape.
is_conformal
True if the transform is conformal, i.e., if angles between points are preserved after applying the transform, within rounding limits. This implies that the transform has no effective shear.
is_degenerate
True if this transform is degenerate, which means that it will collapse a shape to an effective area of zero. Degenerate transforms cannot be inverted.
is_identity
True if this transform equals the identity matrix, within rounding limits.
is_orthonormal
True if the transform is orthonormal, which means that thetransform represents a rigid motion, which has no effective scaling orshear. Mathematically, this means that the axis vectors of thetransform matrix are perpendicular and unit-length. Applying anorthonormal transform to a shape always results in a congruent shape.
is_rectilinear
True if the transform is rectilinear, i.e., whether a shape would remain axis-aligned, within rounding limits, after applying the transform.
itransform
Transform a sequence of points or vectors in place.