Core examples

R/core.R

@@ -230,7 +230,6 @@ get_screen_width <- function() {
 get_screen_height <- function() {
         .Call(.C_GetScreenHeight_R)
 }
-
 #' @family Windows-related functions
 #' @title Get number of connected monitors
 #'
@@ -708,6 +707,7 @@ get_world_to_screen_ex <- function(position, camera, width, height) {
 #' @title Get the screen space position for a 2d camera world space position
 #' @param position Vector2.
 #' @param camera Camera2D
+#' @return Unnamed integer vector of length 2 containing x and y coords
 #'
 #' @export
 get_world_to_screen_2d <- function(position, camera) {
@@ -718,6 +718,7 @@ get_world_to_screen_2d <- function(position, camera) {
 #' @title Get the world space position for a 2d camera screen space position
 #' @param position Vector2.
 #' @param camera Camera2D
+#' @return Unnamed integer vector of length 2 containing x and y coords
 #'
 #' @export
 get_screen_to_world_2d <- function(position, camera) {

R/example_core_2d_camera_platformer.R

@@ -0,0 +1,330 @@
+#' @name core_2d_platformer
+#' @rdname core_2d_platformer
+#' @family Core examples
+#' @title 2D camera platformer
+#'
+#' @description
+#' This example shows multiple ways to update 2D camera with custom functions.
+#' Also, collision detection functionality is implemented with basic mathematical
+#' and R-base functions.
+#'
+#' Example contributed for `raylib` library by arvyy (@arvyy) and reviewed by
+#' Ramon Santamaria (@raysan5)
+#'
+#' Copyright (c) 2019 arvyy (@arvyy)
+#'
+#' Example modified for `raylib.R`
+#'
+#' @examplesIf interactive()
+#' ######################
+#' # Pre-initialization #
+#' ######################
+#'
+#' G <- 400
+#' player_jump_spd <- 350
+#' player_hor_spd <- 200
+#'
+#' # 'player' object constructor
+#' Player <- function(x, y, speed, can_jump) {
+#'         list(position = Vector2(x, y),
+#'              speed = speed,
+#'              can_jump = can_jump)
+#' }
+#'
+#'
+#' # 'environment item' object constructor
+#' EnvItem <- function(x, y, width, height, blocking, color, alpha = 255) {
+#'         list(rect = Rectangle(x, y, width, height),
+#'              blocking = blocking,
+#'              color = Color(color, alpha))
+#' }
+#'
+#' # 'player update' function
+#' update_player <- function(player, env_items, env_items_length, delta) {
+#'
+#'         if (is_key_down(keyboard_key$KEY_LEFT))
+#'                 player$position["x"] <- player$position["x"] - player_hor_spd * delta
+#'
+#'         if (is_key_down(keyboard_key$KEY_RIGHT))
+#'                 player$position["x"] <- player$position["x"] + player_hor_spd * delta
+#'
+#'         if (is_key_down(keyboard_key$KEY_SPACE) && isTRUE(player$can_jump)) {
+#'                 player$speed <- player$speed - player_jump_spd
+#'                 player$can_jump <- FALSE
+#'
+#'         }
+#'
+#'         hit_obstacle <- FALSE
+#'
+#'         collisions <- sapply(
+#'                 env_items, \(env_item) {
+#'                         env_item$blocking &&
+#'                                 env_item$rect["x"] <= player$position["x"] &&
+#'                                 (env_item$rect["x"] + env_item$rect["width"] >= player$position["x"]) &&
+#'                                 env_item$rect["y"] >= player$position["y"] &&
+#'                                 (env_item$rect["y"] < player$position["y"] + player$speed * delta)
+#'                 })
+#'
+#'         coll_i <- which(collisions)
+#'
+#'         if (sum(coll_i) > 0) {
+#'                 hit_obstacle <- TRUE
+#'                 player$speed <- 0
+#'                 player$position["y"] <- env_items[[coll_i]]$rect["y"]
+#'         }
+#'
+#'         if (!hit_obstacle) {
+#'                 player$position["y"] <- player$position["y"] + player$speed * delta
+#'                 player$speed <- player$speed + G * delta
+#'                 player$can_jump <- FALSE
+#'
+#'         } else
+#'                 player$can_jump <- TRUE
+#'
+#'         return(player)
+#' }
+#'
+#' # camera update functions
+#' update_camera_center <- function(camera, player, env_items, env_items_length, delta, width, height) {
+#'
+#'         camera$offset <- Vector2(width/2, height/2)
+#'         camera$target <- player$position
+#'
+#'         return(camera)
+#' }
+#'
+#' update_camera_center_inside_map <- function(camera, player, env_items, env_items_length, delta, width, height) {
+#'
+#'         camera$target <- player$position
+#'         camera$offset <- Vector2(width/2, height/2)
+#'
+#'         min_x <- min_y <- 1000
+#'         max_x <- max_y <- -1000
+#'
+#'         for (i in 1:env_items_length) {
+#'                 min_x <- min(env_items[[i]]$rect["x"], min_x)
+#'                 max_x <- max(env_items[[i]]$rect["x"] + env_items[[i]]$rect["width"], max_x)
+#'                 min_y <- min(env_items[[i]]$rect["y"], min_y)
+#'                 max_y <- max(env_items[[i]]$rect["y"] + env_items[[i]]$rect["height"], max_y)
+#'         }
+#'
+#'         max <- get_world_to_screen_2d(Vector2(max_x, max_y), camera)
+#'         min <- get_world_to_screen_2d(Vector2(min_x, min_y), camera)
+#'
+#'         if (max[1] < width) camera$offset["x"] <- width - (max[1] - width/2)
+#'         if (max[2] < height) camera$offset["y"] <- height - (max[2] - height/2)
+#'         if (min[1] > 0) camera$offset["x"] <- width/2 - min[1]
+#'         if (min[2] > 0) camera$offset["y"] <- height/2 - min[2]
+#'
+#'         return(camera)
+#' }
+#'
+#' update_camera_center_smooth_follow <- function(camera, player, env_items, env_items_length, delta, width, height) {
+#'
+#'         min_speed <- 30
+#'         min_effect_length <- 10
+#'         fraction_speed <- 0.8
+#'
+#'         camera$offset <- Vector2(width/2, height/2)
+#'
+#'         diff <- player$position - camera$target
+#'         veclength <- sqrt(sum(sapply(diff, \(x) x^2)))
+#'
+#'         if (veclength > min_effect_length) {
+#'                 speed <- max(fraction_speed * veclength, min_speed)
+#'                 camera$target <- camera$target + diff*(speed * delta / veclength)
+#'         }
+#'         return(camera)
+#' }
+#'
+#' update_camera_even_out_on_landing <- function(camera, player, env_items, env_items_length, delta, width, height) {
+#'
+#'         even_out_speed <- 700
+#'
+#'         camera$offset <- Vector2(width/2, height/2)
+#'         camera$target["x"] <- player$position["x"]
+#'
+#'         if (isTRUE(.update_camera_even_out_env[["evening_out"]])) {
+#'
+#'                 if (.update_camera_even_out_env[["even_out_target"]] > camera$target["y"]) {
+#'                         camera$target["y"] <- camera$target["y"] + even_out_speed * delta
+#'                         if (camera$target["y"] > .update_camera_even_out_env[["even_out_target"]]) {
+#'                                 camera$target["y"] <- .update_camera_even_out_env[["even_out_target"]]
+#'                                 .update_camera_even_out_env[["evening_out"]] <- FALSE
+#'                         }
+#'                 } else {
+#'                         camera$target["y"] <- camera$target["y"] - even_out_speed*delta
+#'                         if (camera$target["y"] < .update_camera_even_out_env[["even_out_target"]]) {
+#'                                 camera$target["y"] <- .update_camera_even_out_env[["even_out_target"]]
+#'                                 .update_camera_even_out_env[["evening_out"]] <- FALSE
+#'                         }
+#'                 }
+#'         } else if (isTRUE(player$can_jump) && player$speed == 0 && player$position["y"] != camera$target["y"]) {
+#'                 .update_camera_even_out_env[["evening_out"]] <- TRUE
+#'                 .update_camera_even_out_env[["even_out_target"]] <- player$position["y"]
+#'         }
+#'
+#'         return(camera)
+#' }
+#'
+#' # environement needed for `update_even_out_on_landing` camera updater
+#' .update_camera_even_out_env <- new.env()
+#' .update_camera_even_out_env[["evening_out"]] <- FALSE
+#' .update_camera_even_out_env[["even_out_target"]] <- NULL
+#'
+#' update_camera_player_bound_push <- function(camera, player, env_items, env_items_length, delta, width, height) {
+#'
+#'         bbox <- Vector2(0.2, 0.2)
+#'
+#'         bbox_world_min <- get_screen_to_world_2d(
+#'                 Vector2((1 - bbox["x"]) * 0.5 * width, (1 - bbox["y"] * 0.5 * height)),
+#'                 camera)
+#'
+#'         bbox_world_max <- get_screen_to_world_2d(
+#'                 Vector2((1 + bbox["x"]) * 0.5 * width, (1 + bbox["y"] * 0.5 * height)),
+#'                 camera)
+#'
+#'         camera$offset <- Vector2((1 - bbox["x"]) * 0.5 * width, (1 - bbox["y"]) * 0.5 * height)
+#'
+#'         if (player$position["x"] < bbox_world_min[1])
+#'                 camera$target["x"] <- player$position["x"]
+#'         if (player$position["y"] < bbox_world_min[2])
+#'                 camera$target["y"] <- player$position["y"]
+#'         if (player$position["x"] > bbox_world_max[1])
+#'                 camera$target["x"] <- bbox_world_min[1] + (player$position["x"] - bbox_world_max[1])
+#'         if (player$position["y"] > bbox_world_max[2])
+#'                 camera$target["y"] <- bbox_world_min[2] + (player$position["y"] - bbox_world_max[2])
+#'
+#'         return(camera)
+#'
+#' }
+#'
+#' ##################
+#' # Initialization #
+#' ##################
+#'
+#' play_game <- function() {
+#'
+#'         screen_width <- 800
+#'         screen_height <- 450
+#'
+#'         init_window(screen_width, screen_height, "raylib [core] example - 2d camera")
+#'         on.exit(close_window())
+#'
+#'         player <- Player(x = 400, y = 280, speed = 0, can_jump = FALSE)
+#'
+#'         env_items <- list(
+#'                 EnvItem(0, 0, 1000, 400, FALSE, raylib_color$LIGHTGRAY),
+#'                 EnvItem(0, 400, 1000, 200, TRUE, raylib_color$GRAY),
+#'                 EnvItem(300, 200, 400, 10, TRUE, raylib_color$GRAY),
+#'                 EnvItem(250, 300, 100, 10, TRUE, raylib_color$GRAY),
+#'                 EnvItem(650, 300, 100, 10, TRUE, raylib_color$GRAY)
+#'         )
+#'
+#'         env_items_length <- length(env_items)
+#'
+#'         camera <- Camera2D(target = player$position,
+#'                            offset = Vector2(screen_width/2, screen_height/2),
+#'                            rotation = 0,
+#'                            zoom = 1)
+#'
+#'         # set up camera updaters
+#'         camera_updaters <- list(
+#'                 update = list(
+#'                         descr = "Follow player center",
+#'                         func = update_camera_center
+#'                 ),
+#'                 update_inside_map = list(
+#'                   descr = "Follow player center, but clamp to map edges",
+#'                   func = update_camera_center_inside_map
+#'                 ),
+#'                 update_smooth_follow = list(
+#'                         descr = "Follow player center;\nsmoothed",
+#'                         func = update_camera_center_smooth_follow
+#'                 ),
+#'                 update_even_out_on_landing = list(
+#'                         descr = "Follow player center horizontally;\nupdate player center vertically after landing",
+#'                         func = update_camera_even_out_on_landing
+#'                 ),
+#'                 update_player_bound_push = list(
+#'                   descr = "Player push camera on getting too close to screen edge",
+#'                   func = update_camera_player_bound_push
+#'                 )
+#'         )
+#'
+#'         camera_option = 1
+#'
+#'         set_target_fps(60)
+#'
+#'         ##################
+#'         # Main game loop #
+#'         ##################
+#'
+#'         while(!window_should_close()) {
+#'
+#'                 # to implement
+#'                 delta_time <- get_frame_time()
+#'                 # delta_time <- 1/60
+#'
+#'                 player <- update_player(player, env_items, env_items_length, delta_time)
+#'
+#'                 camera$zoom <- camera$zoom + get_mouse_wheel_move()*0.05
+#'
+#'                 if (camera$zoom > 3)
+#'                         camera$zoom = 3
+#'                 else if (camera$zoom < 0.25)
+#'                         camera$zoom = 0.25
+#'
+#'                 if (is_key_pressed(keyboard_key$KEY_R)) {
+#'                         camera$zoom <- 1
+#'                         player$position <- Vector2(400, 280)
+#'                 }
+#'
+#'                 if (is_key_pressed(keyboard_key$KEY_C)) {
+#'                         camera_option <- camera_option %% length(camera_updaters) + 1
+#'                 }
+#'
+#'                 # update the camera!
+#'                 camera <- do.call(what = camera_updaters[[camera_option]]$func,
+#'                                   args = list(
+#'                                           camera = camera,
+#'                                           player = player,
+#'                                           env_items = env_items,
+#'                                           env_items_length = env_items_length,
+#'                                           delta = delta_time,
+#'                                           width = screen_width,
+#'                                           height = screen_height
+#'                                   ))
+#'
+#'                 begin_drawing()
+#'
+#'                 clear_background(raylib_color$LIGHTGRAY)
+#'
+#'                 begin_mode_2d(camera)
+#'
+#'                 invisible(lapply(env_items, \(x) { draw_rectangle_rec(x$rect, x$color) }))
+#'
+#'                 player_rect <- Rectangle(player$position["x"] - 20, player$position["y"] - 40, 40, 40)
+#'                 draw_rectangle_rec(player_rect, raylib_color$RED)
+#'
+#'                 end_mode_2d()
+#'
+#'                 DrawText("Controls:", 20, 20, 10, raylib_color$BLACK);
+#'                 DrawText("- Right/Left to move", 40, 40, 10, raylib_color$DARKGRAY);
+#'                 DrawText("- Space to jump", 40, 60, 10, raylib_color$DARKGRAY);
+#'                 DrawText("- Mouse Wheel to Zoom in-out, R to reset zoom", 40, 80, 10, raylib_color$DARKGRAY);
+#'                 DrawText("- C to change camera mode", 40, 100, 10, raylib_color$DARKGRAY);
+#'                 DrawText("Current camera mode:", 20, 120, 10, raylib_color$BLACK);
+#'                 DrawText(camera_updaters[[camera_option]]$descr, 40, 140, 10, raylib_color$DARKGRAY);
+#'
+#'                 end_drawing()
+#'
+#'         }
+#' }
+#'
+#' ###################
+#' # LAUNCH THE GAME #
+#' ###################
+#'
+#' play_game()
+NULL