46 lines
1.7 KiB
Plaintext
46 lines
1.7 KiB
Plaintext
;;;; raylib [core] example - input keys
|
|
;;;;
|
|
;;;; examples/core/core_input_keys.c. Faithful, and the only thing worth noting
|
|
;;;; is a Flan rule rather than a raylib one.
|
|
;;;;
|
|
;;;; The C moves the ball by writing `ballPosition.x += 2.0f` on a local
|
|
;;;; struct. Flan has the same thing — a local IS an assignable place
|
|
;;;; (spec-memory.md) — but the local has to be a `once` here rather than a
|
|
;;;; `let` inside the loop, because a `let` binding is rebound every iteration
|
|
;;;; and the position has to survive between frames. The C's variable is
|
|
;;;; outside its while loop for the same reason; this is that, spelled with the
|
|
;;;; storage the language has.
|
|
;;;;
|
|
;;;; `ball.x = ...` works on a struct field of a global: a field of an
|
|
;;;; assignable place is itself one.
|
|
|
|
import rl "vendor:raylib"
|
|
|
|
const screen-width = 800
|
|
const screen-height = 450
|
|
|
|
once ball: rl/Vector2
|
|
|
|
fn main() -> ()
|
|
rl/init-window(screen-width, screen-height,
|
|
"raylib [core] example - input keys")
|
|
defer rl/close-window()
|
|
ball = rl/Vector2{.x f32(screen-width / 2) .y f32(screen-height / 2)}
|
|
rl/set-target-fps(60)
|
|
until rl/window-should-close()
|
|
;; Update. is-key-down and not is-key-pressed: this is meant to repeat for as
|
|
;; long as the key is held, which is the whole difference between the two.
|
|
if rl/is-key-down(:key-right)
|
|
ball.x += 2.0
|
|
if rl/is-key-down(:key-left)
|
|
ball.x -= 2.0
|
|
if rl/is-key-down(:key-up)
|
|
ball.y -= 2.0
|
|
if rl/is-key-down(:key-down)
|
|
ball.y += 2.0
|
|
;; Draw
|
|
rl/with-drawing:
|
|
rl/clear-background(rl/raywhite)
|
|
rl/draw-text("move the ball with arrow keys", 10, 10, 20, rl/darkgray)
|
|
rl/draw-circle-v(ball, 50.0, rl/maroon)
|