This reference is for Processing 3.0+. If you have a previous version, use the reference included with your software in the Help menu. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing Core Javadoc and Libraries Javadoc.

Name

### curveTangent()

Examples
```noFill();
curve(5, 26, 73, 24, 73, 61, 15, 65);
int steps = 6;
for (int i = 0; i <= steps; i++) {
float t = i / float(steps);
float x = curvePoint(5, 73, 73, 15, t);
float y = curvePoint(26, 24, 61, 65, t);
//ellipse(x, y, 5, 5);
float tx = curveTangent(5, 73, 73, 15, t);
float ty = curveTangent(26, 24, 61, 65, t);
float a = atan2(ty, tx);
a -= PI/2.0;
line(x, y, cos(a)*8 + x, sin(a)*8 + y);
}
```
Description Calculates the tangent of a point on a curve. There's a good definition of tangent on Wikipedia.
Syntax
`curveTangent(a, b, c, d, t)`
Parameters
a float: coordinate of first control point on the curve float: coordinate of first point float: coordinate of first point float: coordinate of second control point on the curve float: value between 0 and 1
Returnsfloat
Relatedcurve()
curveVertex()
curvePoint()
bezierTangent()
Updated on January 1, 2021 03:38:08am EST