Reference for Processing version 1.2. If you have a previous version, use the reference included with your software. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing 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 is a good definition of "tangent" at Wikipedia: http://en.wikipedia.org/wiki/Tangent
Syntax
`curveTangent(a, b, c, d, t)`
Parameters
a int or float: coordinate of first point on the curve int or float: coordinate of first control point int or float: coordinate of second control point int or float: coordinate of second point on the curve float: value between 0 and 1
Usage Web & Application
Related curve()
curveVertex()
curvePoint()
bezierTangent()
Updated on June 14, 2010 12:05:29pm EDT