Getting Started • raylibr

Installation

raylibr is not yet on CRAN. Install the development version from GitHub:

pak::pak("jeroenjanssens/raylibr")

raylibr works on macOS, Linux, and Windows. It also runs in the browser via webR.

Your first image

The quickest way to see raylibr in action is raylibr_screenshot(). It creates a hidden window, runs your drawing code, and returns the result as an image:

raylibr_screenshot(function() {
  draw_circle(200L, 150L, 80.0, "yellow")
})

raylibr image

The default canvas is 400x300 pixels with a black background. Everything you draw appears on top.

You can compose multiple shapes in a single screenshot:

raylibr_screenshot(function() {
  draw_rectangle(50L, 50L, 300L, 200L, "midnightblue")
  draw_circle(200L, 150L, 60.0, "gold")
  draw_triangle(
    c(200, 70), c(140, 190), c(260, 190),
    color_alpha("white", 0.5)
  )
  draw_text("raylibr", 145L, 220L, 30L, "white")
})

raylibr image

The game loop

Raylib renders frame by frame: each iteration of a loop draws one frame to the screen. This is different from R’s typical batch execution model.

The classic pattern looks like this:

init_window(800L, 600L, "My Game")
set_target_fps(60L)

while (!window_should_close()) {
  begin_drawing()
  clear_background("black")
  draw_text("Hello!", 300L, 280L, 40L, "white")
  end_drawing()
}

close_window()

For code that needs to work both on desktop and in the browser (via webR), use run_game_loop() instead of a while loop:

run_game_loop(
  init_fn = function() {
    init_window(800L, 600L, "My Game")
    set_target_fps(60L)
  },
  update_fn = function() {
    begin_drawing()
    clear_background("black")
    draw_text("Hello!", 300L, 280L, 40L, "white")
    end_drawing()
  },
  cleanup_fn = close_window
)

Conventions

raylibr follows a few consistent conventions:

snake_case names. Raylib’s DrawCircle() becomes draw_circle().

Integers need L. Width, height, pixel coordinates, and font sizes are integers. Write 200L, not 200.

R color names work everywhere. Any function that takes a color accepts R’s 657 built-in color names: "red", "steelblue", "grey90", etc. See the Colors guide for details.

Vectors map to R numerics. A Raylib Vector2 is c(x, y), a Vector3 is c(x, y, z), and a Vector4 is c(x, y, z, w). A Raylib Matrix is a 4x4 R matrix.

Structs

Some Raylib types have dedicated constructors:

rec <- rectangle(10, 20, 300, 200)
rec$width
#> [1] 300

cam <- camera_3d(c(4, 4, 4))
cam$fovy
#> [1] 70

bb <- bounding_box(c(-1, -1, -1), c(1, 1, 1))
bb$min
#>  x  y  z 
#> -1 -1 -1

Other constructors include color(), ray(), camera_2d(), ray_collision(), and transform().

Check types with predicates:

is_rectangle(rec)
#> [1] TRUE
is_color("red")
#> [1] TRUE

Enums

Raylib enums are available as named lists:

flag$window_resizable
#> [1] 4
key$space
#> [1] 32
mouse_button$left
#> [1] 0
camera_mode$orbital
#> [1] 2

Use them with functions like set_config_flags(flag$window_resizable) or is_key_pressed(key$space).

What’s next

Drawing 2D Shapes — circles, rectangles, lines, and more
Drawing 3D — cubes, spheres, and cameras
Colors — R color names, transparency, HSV, and blending
Text & Fonts — rendering text and loading custom fonts
Images & Textures — loading, generating, and drawing images
Input — keyboard, mouse, and gamepad
Audio — sound effects and music
Camera — 2D and 3D camera systems
Shaders — GLSL shaders and post-processing
raygui — immediate-mode GUI widgets
raymath — vector, matrix, and quaternion math
webR — running raylibr in the browser