# curveTangent 1
# https://processing.org/reference/curveTangent_.html

noFill()
curve(5, 26, 73, 24, 73, 61, 15, 65)
steps <- 6
for (i in 0:steps) {
    t <- i/steps
    x <- curvePoint(5, 73, 73, 15, t)
    y <- curvePoint(26, 24, 61, 65, t)
    # ellipse(x, y, 5, 5)
    tx <- curveTangent(5, 73, 73, 15, t)
    ty <- curveTangent(26, 24, 61, 65, t)
    a <- atan2(ty, tx)
    a = a - HALF_PI
    line(x, y, cos(a) * 8 + x, sin(a) * 8 + y)
}