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

package w4

import "unsafe"

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Platform Constants                                                        │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

const SCREEN_SIZE int = 160

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

var PALETTE = (*[4]uint32)(unsafe.Pointer(uintptr(0x04)))
var DRAW_COLORS = (*uint16)(unsafe.Pointer(uintptr(0x14)))
var GAMEPAD1 = (*uint8)(unsafe.Pointer(uintptr(0x16)))
var GAMEPAD2 = (*uint8)(unsafe.Pointer(uintptr(0x17)))
var GAMEPAD3 = (*uint8)(unsafe.Pointer(uintptr(0x18)))
var GAMEPAD4 = (*uint8)(unsafe.Pointer(uintptr(0x19)))
var MOUSE_X = (*int16)(unsafe.Pointer(uintptr(0x1a)))
var MOUSE_Y = (*int16)(unsafe.Pointer(uintptr(0x1c)))
var MOUSE_BUTTONS = (*uint8)(unsafe.Pointer(uintptr(0x1e)))
var SYSTEM_FLAGS = (*uint8)(unsafe.Pointer(uintptr(0x1f)));
var NETPLAY = (*uint8)(unsafe.Pointer(uintptr(0x20)));
var FRAMEBUFFER = (*[6400]uint8)(unsafe.Pointer(uintptr(0xa0)))

const BUTTON_1 byte = 1
const BUTTON_2 byte = 2
const BUTTON_LEFT byte = 16
const BUTTON_RIGHT byte = 32
const BUTTON_UP byte = 64
const BUTTON_DOWN byte = 128

const MOUSE_LEFT byte = 1
const MOUSE_RIGHT byte = 2
const MOUSE_MIDDLE byte = 4

const SYSTEM_PRESERVE_FRAMEBUFFER byte = 1
const SYSTEM_HIDE_GAMEPAD_OVERLAY byte = 2

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Drawing Functions                                                         │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/** Copies pixels to the framebuffer. */
//go:export blit
func Blit(sprite *byte, x int, y int, width uint, height uint, flags uint)

/** Copies a subregion within a larger sprite atlas to the framebuffer. */
//go:export blitSub
func BlitSub(sprite *byte, x int, y int, width uint, height uint,
	srcX uint, srcY uint, stride int, flags uint)

const BLIT_2BPP = 1
const BLIT_1BPP = 0
const BLIT_FLIP_X = 2
const BLIT_FLIP_Y = 4
const BLIT_ROTATE = 8

/** Draws a line between two points. */
//go:export line
func Line(x1 int, y1 int, x2 int, y2 int)

/** Draws a horizontal line. */
//go:export hline
func HLine(x int, y int, len uint)

/** Draws a vertical line. */
//go:export vline
func VLine(x int, y int, len uint)

/** Draws an oval (or circle). */
//go:export oval
func Oval(x int, y int, width uint, height uint)

/** Draws a rectangle. */
//go:export rect
func Rect(x int, y int, width uint, height uint)

/** Draws text using the built-in system font. */
//go:export textUtf8
func Text(text string, x int, y int)

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Sound Functions                                                           │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/** Plays a sound tone. */
//go:export tone
func Tone(frequency uint, duration uint, volume uint, flags uint)

const TONE_PULSE1 = 0
const TONE_PULSE2 = 1
const TONE_TRIANGLE = 2
const TONE_NOISE = 3
const TONE_MODE1 = 0
const TONE_MODE2 = 4
const TONE_MODE3 = 8
const TONE_MODE4 = 12
const TONE_PAN_LEFT = 16
const TONE_PAN_RIGHT = 32

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Storage Functions                                                         │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/** Reads up to `size` bytes from persistent storage into the pointer `destPtr`. */
//go:export diskr
func DiskR(ptr unsafe.Pointer, count uint) uint

/** Writes up to `size` bytes from the pointer `srcPtr` into persistent storage. */
//go:export diskw
func DiskW(src unsafe.Pointer, count uint) uint

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Other Functions                                                           │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/** Prints a message to the debug console. */
//go:export traceUtf8
func Trace(str string)

// TinyGo requires a main function, so provide one
//go:linkname main main.main
func main() {}