;;
;; WASM-4: https://wasm4.org/docs

(import "env" "memory" (memory 1))

;; ┌───────────────────────────────────────────────────────────────────────────┐
;; │                                                                           │
;; │ Drawing Functions                                                         │
;; │                                                                           │
;; └───────────────────────────────────────────────────────────────────────────┘
(; Copies pixels to the framebuffer. ;)
(import "env" "blit" (func $blit (param i32 i32 i32 i32 i32 i32)))

(; Copies a subregion within a larger sprite atlas to the framebuffer. ;)
(import "env" "blitSub" (func $blitSub (param i32 i32 i32 i32 i32 i32 i32 i32 i32)))

(; Draws a line between two points. ;)
(import "env" "line" (func $line (param i32 i32 i32 i32)))

(; Draws a horizontal line. ;)
(import "env" "hline" (func $hline (param i32 i32 i32)))

(; Draws a vertical line. ;)
(import "env" "vline" (func $vline (param i32 i32 i32)))

(; Draws an oval (or circle). ;)
(import "env" "oval" (func $oval (param i32 i32 i32 i32)))

(; Draws a rectangle. ;)
(import "env" "rect" (func $rect (param i32 i32 i32 i32)))

(; Draws text using the built-in system font. ;)
(import "env" "text" (func $text (param i32 i32 i32)))

;; ┌───────────────────────────────────────────────────────────────────────────┐
;; │                                                                           │
;; │ Sound Functions                                                           │
;; │                                                                           │
;; └───────────────────────────────────────────────────────────────────────────┘
(; Plays a sound tone. ;)
(import "env" "tone" (func $tone (param i32 i32 i32 i32)))

;; ┌───────────────────────────────────────────────────────────────────────────┐
;; │                                                                           │
;; │ Storage Functions                                                         │
;; │                                                                           │
;; └───────────────────────────────────────────────────────────────────────────┘
(; Reads up to `size` bytes from persistent storage into the pointer `dest`. ;)
(import "env" "diskr" (func $diskr (param i32 i32) (result i32)))

(; Writes up to `size` bytes from the pointer `src` into persistent storage. ;)
(import "env" "diskw" (func $diskw (param i32 i32) (result i32)))

(; Prints a message to the debug console. ;)
(import "env" "trace" (func $trace (param i32)))


;; ┌───────────────────────────────────────────────────────────────────────────┐
;; │                                                                           │
;; │ Memory Addresses                                                          │
;; │                                                                           │
;; └───────────────────────────────────────────────────────────────────────────┘

(global $PALETTE0 i32 (i32.const 0x04))
(global $PALETTE1 i32 (i32.const 0x08))
(global $PALETTE2 i32 (i32.const 0x0c))
(global $PALETTE3 i32 (i32.const 0x10))
(global $DRAW_COLORS i32 (i32.const 0x14))
(global $GAMEPAD1 i32 (i32.const 0x16))
(global $GAMEPAD2 i32 (i32.const 0x17))
(global $GAMEPAD3 i32 (i32.const 0x18))
(global $GAMEPAD4 i32 (i32.const 0x19))
(global $MOUSE_X i32 (i32.const 0x1a))
(global $MOUSE_Y i32 (i32.const 0x1c))
(global $MOUSE_BUTTONS i32 (i32.const 0x1e))
(global $SYSTEM_FLAGS i32 (i32.const 0x1f))
(global $NETPLAY i32 (i32.const 0x20))
(global $FRAMEBUFFER i32 (i32.const 0xa0))

(global $BUTTON_1 i32 (i32.const 1))
(global $BUTTON_2 i32 (i32.const 2))
(global $BUTTON_LEFT i32 (i32.const 16))
(global $BUTTON_RIGHT i32 (i32.const 32))
(global $BUTTON_UP i32 (i32.const 64))
(global $BUTTON_DOWN i32 (i32.const 128))

(global $MOUSE_LEFT i32 (i32.const 1))
(global $MOUSE_RIGHT i32 (i32.const 2))
(global $MOUSE_MIDDLE i32 (i32.const 4))

(global $SYSTEM_PRESERVE_FRAMEBUFFER i32 (i32.const 1))
(global $SYSTEM_HIDE_GAMEPAD_OVERLAY i32 (i32.const 2))


(global $BLIT_2BPP i32 (i32.const 1))
(global $BLIT_1BPP i32 (i32.const 0))
(global $BLIT_FLIP_X i32 (i32.const 2))
(global $BLIT_FLIP_Y i32 (i32.const 4))
(global $BLIT_ROTATE i32 (i32.const 8))


(global $TONE_PULSE1 i32 (i32.const 0))
(global $TONE_PULSE2 i32 (i32.const 1))
(global $TONE_TRIANGLE i32 (i32.const 2))
(global $TONE_NOISE i32 (i32.const 3))
(global $TONE_MODE1 i32 (i32.const 0))
(global $TONE_MODE2 i32 (i32.const 4))
(global $TONE_MODE3 i32 (i32.const 8))
(global $TONE_MODE4 i32 (i32.const 12))
(global $TONE_PAN_LEFT i32 (i32.const 16))
(global $TONE_PAN_RIGHT i32 (i32.const 32))
(global $TONE_NOTE_MODE i32 (i32.const 64))


;; smiley
(data (i32.const 0x19a0) "\c3\81\24\24\00\24\99\c3")

(data (i32.const 0x19a8) "Hello from Wat!\00")

(data (i32.const 0x19b8) "Press X to blink\00")

(func (export "start")
)

(func (export "update")
  (local $gamepad i32)

  ;; *DRAW_COLORS = 2
  (i32.store16 (global.get $DRAW_COLORS) (i32.const 2))

  ;; text("Hello from Wat!", 10, 10);
  (call $text (i32.const 0x19a8) (i32.const 10) (i32.const 10))

  ;; uint8_t gamepad = *GAMEPAD1;
  (local.set $gamepad (i32.load8_u (global.get $GAMEPAD1)))

  ;; if (gamepad & BUTTON_1) {
  ;;     *DRAW_COLORS = 4;
  ;; }
  (if (i32.and (local.get $gamepad) (global.get $BUTTON_1))
    (then
      (i32.store16 (global.get $DRAW_COLORS) (i32.const 4))
    ))

  ;; blit(smiley, 76, 76, 8, 8, BLIT_1BPP);
  (call $blit (i32.const 0x19a0) (i32.const 76) (i32.const 76) (i32.const 8) (i32.const 8) (global.get $BLIT_1BPP))

  ;; text("Press X to blink", 16, 90);
  (call $text (i32.const 0x19b8) (i32.const 16) (i32.const 90))
)