curveTangent() / Reference / Processing.org

Name

curveTangent()

Description

Calculates the tangent of a point on a curve. There's a good definition of tangent on Wikipedia.

Examples

```
size(400, 400);
noFill();
curve(20, 104, 292, 96, 292, 244, 60, 260); 
int steps = 6;
for (int i = 0; i <= steps; i++) {
  float t = i / float(steps);
  float x = curvePoint(20, 292, 292, 60, t);
  float y = curvePoint(104, 96, 244, 260, t);
  //ellipse(x, y, 20, 20);
  float tx = curveTangent(20, 292, 292, 60, t);
  float ty = curveTangent(104, 96, 244, 260, t);
  float a = atan2(ty, tx);
  a -= PI/2.0;
  line(x, y, cos(a)*32 + x, sin(a)*32 + y);
}
```

Syntax

curveTangent(a, b, c, d, t)

Parameters

a(float)coordinate of first point on the curve
b(float)coordinate of first control point
c(float)coordinate of second control point
d(float)coordinate of second point on the curve
t(float)value between 0 and 1

Return

float

Related

Creative Commons License

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