curveTangent()曲线切线

Name

curveTangent()曲线切线

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.

计算曲线上的点的正切值。在维基百科上有一个很好的切线定义。

Syntax

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

Parameters

Returns

float

Related

curve()
curveVertex()
curvePoint()
bezierTangent()