Mouse Test

A grid of dots that react to the mouse cursor: each dot moves away from the pointer proportional to proximity, and its color shifts with color_from_hsv() based on how far it was pushed. This demo exercises mouse input (get_mouse_position(), is_cursor_on_screen(), set_mouse_cursor()), raymath functions (vector2_distance(), vector2_move_towards()), and draw_circle_v() / draw_line_v() for rendering.

Try it

Move your mouse over the canvas to interact with the dots.

Run

demo("mouse", package = "raylibr")

Source code

library(raylibr)

width <- 600
height <- 600

init_window(width, height, "R & Raylib: Mouse Test")

n <- 31
xs <- tail(head(seq(0, width, length.out = n), - 4), - 4)
ys <- tail(head(seq(0, height, length.out = n), - 4), - 4)

l <- 100

while(!window_should_close()) {

  mp <- get_mouse_position()

  begin_drawing()
  clear_background("black")

  if (is_cursor_on_screen()) {
    set_mouse_cursor(mouse_cursor$crosshair)
  } else {
    set_mouse_cursor(mouse_cursor$default)
  }

  for (x in xs) {
    for (y in ys) {
      from <- c(x, y)
      d <- vector2_distance(mp, from)
      m <- max(l - d, 0)
      to <- vector2_move_towards(from, mp, -m/4)
      dd <- vector2_distance(mp, to)
      if (dd < l/2) {
        draw_line_v(to, mp, "white")
      }
      draw_circle_v(to, 3, color_from_hsv(l - m, 0.9, 0.9))
    }
  }

  draw_fps(10, 10)
  end_drawing()
}

set_mouse_cursor(mouse_cursor$default)
close_window()