Class STTransform

vispy/visuals/transforms/linear.py:54–313

Transform performing only scale and translate, in that order. Parameters ---------- scale : array-like Scale factors for X, Y, Z axes. translate : array-like Scale factors for X, Y, Z axes.

class STTransform(BaseTransform):
    """Transform performing only scale and translate, in that order.

    Parameters
    ----------
    scale : array-like
        Scale factors for X, Y, Z axes.
    translate : array-like
        Scale factors for X, Y, Z axes.
    """

    glsl_map = """
        vec4 st_transform_map(vec4 pos) {
            return vec4(pos.xyz * $scale.xyz + $translate.xyz * pos.w, pos.w);
        }
    """

    glsl_imap = """
        vec4 st_transform_imap(vec4 pos) {
            return vec4((pos.xyz - $translate.xyz * pos.w) / $scale.xyz,
                        pos.w);
        }
    """

    Linear = True
    Orthogonal = True
    NonScaling = False
    Isometric = False

    def __init__(self, scale=None, translate=None):
        super(STTransform, self).__init__()

        self._scale = np.ones(4, dtype=np.float32)
        self._translate = np.zeros(4, dtype=np.float32)

        s = ((1.0, 1.0, 1.0, 1.0) if scale is None else
             as_vec4(scale, default=(1., 1., 1., 1.)))
        t = ((0.0, 0.0, 0.0, 0.0) if translate is None else
             as_vec4(translate, default=(0., 0., 0., 0.)))
        self._set_st(s, t)
        self._update_shaders()

    @arg_to_vec4
    def map(self, coords):
        """Map coordinates

        Parameters
        ----------
        coords : array-like
            Coordinates to map.

        Returns
        -------
        coords : ndarray
            Coordinates.
        """
        m = np.empty(coords.shape)
        m[:, :3] = (coords[:, :3] * self.scale[np.newaxis, :3] +