Module curve

drawing curves, i.e. collections of points, on a canvas in a tools tab

A point is defined by its coordinates (x, y and z), and the color assigned to it (r, g, and b). A few constructors for points is given, for example make_color_point. Selectors allow access to the coordinates and color components, for example x_of.

A curve is a unary function which takes a number argument within the unit interval [0,1] and returns a point. If C is a curve, then the starting point of the curve is always C(0), and the ending point is always C(1).

A curve transformation is a function that takes a curve as argument and returns a curve. Examples of curve transformations are scale and translate.

A curve drawer is function that takes a number argument and returns a function that takes a curve as argument and visualises it in the output screen is shown in the Source Academy in the tab with the "Curves Canvas" icon (image). The following example uses the curve drawer draw_connected_full_view to display a curve called unit_circle.

import { make_point, draw_connected_full_view } from "curve";
function unit_circle(t) {
  return make_point(math_sin(2 * math_PI * t),
                    math_cos(2 * math_PI * t));
}
draw_connected_full_view(100)(unit_circle);
Copy

draws a full circle in the display tab.

Author

Lee Zheng Han

Author

Ng Yong Xiang