nicheware.platform.utilities.common.graphics.interpolate
Functions for performing different interpolations between two points.
| Function group | Functions |
|---|---|
| interpolation | get-options, interpolate |
Interpolation is done between two n-dimension co-ordinates/points.
It can be used for calculating curves or lines in an n-dimensional spaces or filling in a colour spectrum between two colours in a colour model.
The following interpolation types are supported:
| Type | Description |
|---|---|
| linear | direct linear interpolation |
| quadratic-bezier | a quadratic bezier interpolation between to two points and one control point. |
| cubic-bezier | a cubic bezier interpolation between the two points, using two control points. |
| ease-in | a quadratic bezier interpolation, where the control point is selected using the ease factor and end point. |
| ease-out | a quadratic bezier interpolation, where the control point is selected using the ease factor and end point. |
| ease-in-out | a cubic bezier interpolation, where the two control points are selected using the ease factors and end point. |
| step-up | computes a fix step up for each dimension. |
| step-down | computes a fixed step down for each dimension. |
The variable interpolation-types is a vector of all the valid interpolation keywords.
get-options
(get-options options)(get-options options start end)Get options for use in interpolation by merging defaults with given options.
- options: User provided options which will override (merge with) the default options.
- start: 3 arity optional argument. Start control point for interpolation. vector of co-ordindates.
- end: 3 arity optional argument. End control point for interpolation. vector of co-ordindates.
- returns: map of options used for interpolation.
Default options:
{:type :linear
:ease default-ease
:control1 start
:control2 end
:step {:fraction default-step-fraction :ranges end}}
interpolate
multimethod
Performs interpolation between the two given points, creating the specified number of interleaving points. The type of interpolation is determined by the options argument, of which the :type field will determine the type of interpolation used.
- start: n-dimension vector marking start of transformation
- end: n-dimension vector marking end of transformation
- num-points: Number of interleaving points between start and end to return, using the interpolation function defined by options
- options: Set of options defining attributes of the interpolation function to be used. See below
- returns: vector of n-dimension vector, with each of the num-points entries being along the interpolation space.
Options is of the form:
{:type :linear | :ease-in | :ease-out | :ease-in-out | :cubic-bezier | :quadratic-bezier | :step-up | :step-down
:control1 [...] - Control point 1 (eg quadratic-bezier and cubic-bezier)
:control2 [...] - Control point 2 (eg cubic-bezier)
:ease <0 to 0.5> - ratio of easing. Defaults to 0.42
:step { :fraction <0 to 1> - What fraction of range for each co-ord to step up or down
:ranges [x x x x]} - Range of each dimension incoming points,
used to calculate a different step per dimension
:active-dimensions [true|false ...] - Indicate which dimension to modify during interpolation
Any not modified will use the value of the start for that dimension.
}