physics.sk

###
const map = [
	[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ],
	[ 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 ],
	[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ]
]
###

const map = [
	[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
	[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
	[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
	[ 0, 0, 0, 0, 0, 0, 0, 0, 1, 0 ],
	[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ]
]

namespace Game {
	const GRID = 20

	var hero Entity
}

namespace Entity {
	var ALL = List<Entity>.new
}

class Point {
	var x double
	var y double

	def clone Point {
		return Point.new(x, y)
	}
}

class Entity {
	var position Point
	var velocity Point
	var width double
	var height double
	var friction double
	var mass double

	def new(x double, y double, width double, height double) {
		self.width = width
		self.height = height

		self.position = Point.new(x, y)
		self.velocity = Point.new(0, 0)

		friction = 0
		mass = 1
	}

	def collision(r Entity) bool {
		return position.x < r.position.x + r.width &&
			position.x + width > r.position.x &&
			position.y < r.position.y + r.height &&
			position.y + height > r.position.y
	}

	def update {
		for e in ALL {
			if e != self {
				if collision(e) {
					###
					var px = velocity.x * mass + e.velocity.x * e.mass
					var py = velocity.y * mass + e.velocity.y * e.mass

					var qtyMvt = Point.new(0, 0)

					qtyMvt.x = px * (mass / (mass + e.mass))
					qtyMvt.y = py * (mass / (mass + e.mass))

					velocity.x = qtyMvt.x / mass
					velocity.y = qtyMvt.y / mass
					###

					e.velocity.x /= friction * (mass + e.mass)
					e.velocity.y /= friction * (mass + e.mass)
					velocity = e.velocity.clone
				}
			}
		}

		position.x += velocity.x
		position.y += velocity.y

		###
		var collision = false

		for y in 0 .. map.count - 1 {
			for x in 0 .. map[y].count - 1 {
				var tile = map[y][x]

				if tile == 1 {
					var xOverlaps = position.x < (x + 1) * Game.GRID &&
						position.x + width > x * Game.GRID

					var yOverlaps = position.y < (y + 1) * Game.GRID &&
						position.y + height > y * Game.GRID

					collision = xOverlaps && yOverlaps

					if collision {
						console.log("AHH")
					}
				}
			}
		}
		###
	}

	def getCol(x int, y int) bool {
		return map[y][x] == 1
	}

	def draw(ctx CanvasRenderingContext2D) {
		ctx.fillStyle = "rgb(128, 128, 0)"
		ctx.fillRect(position.x as int, position.y as int, width, height)
	}
}

class Player : Entity {
	def new(x double, y double) {
		super(x, y, 20, 20)

		friction = 1
		mass = 20
	}

	over draw(ctx CanvasRenderingContext2D) {
		ctx.fillStyle = "rgb(0, 0, 255)"
		ctx.fillRect(position.x as int, position.y as int, width, height)
	}
}

class Crate : Entity {
	def new(x double, y double) {
		super(x, y, 20, 20)

		friction = 0
		mass = 10
	}

	over draw(ctx CanvasRenderingContext2D) {
		ctx.fillStyle = "rgb(128, 142, 0)"
		ctx.fillRect(position.x as int, position.y as int, width, height)
	}
}

# APPLICATION
# -----------
var ctx CanvasRenderingContext2D
var kb = input.Keyboard.new

def tick {
	Entity.ALL[0].velocity.x = 0
	Entity.ALL[0].velocity.y = 0

	if kb.down(Key.Left) {
		Entity.ALL[0].velocity.x -= 3
	}

	if kb.down(Key.Right) {
		Entity.ALL[0].velocity.x += 2
	}

	if kb.down(Key.Up) {
		Entity.ALL[0].velocity.y -= 2
	}

	if kb.down(Key.Down) {
		Entity.ALL[0].velocity.y += 2
	}

	ctx.clearRect(0, 0, 640, 480)

	###
	ctx.fillStyle = "rgb(0, 0, 0)"

	for y in 0 .. map.count - 1 {
		for x in 0 .. map[y].count - 1 {
			if map[y][x] == 1 {
				ctx.fillRect(x * Game.GRID, y * Game.GRID, Game.GRID, Game.GRID)
			}
		}
	}
	###

	for entity in Entity.ALL {
		entity.update
	}

	for entity in Entity.ALL {
		entity.draw(ctx)
	}

	requestAnimationFrame(=> tick)
}

@entry
def main {
	var images = {
		"player": "player.png",
		"wall":   "wall.png",
		"ground": "ground.png",

		"font":  "font.png",
		"font2": "font2.png",

		"barrel":   "block-barrel.png",
		"mine":     "block-mine.png",
		"dynamite": "block-dynamite.png",
		"crate":    "block-crate.png",

		"bullet":               "bullet-normal.png",
		"rocketLauncherBullet": "bullet-rocket-launcher.png",
		"grenade":              "bullet-grenade.png",
		"miniatures":           "miniatures-weapons.png",

		"bonusIncreaseHealth": "bonus-increase-health.png"
	}

	Img.setPath("assets/img")
	Img.setCallback(=> run)
	Img.load(images)
}

def run {
	var canvas = document.getElementById("app") as HTMLCanvasElement
	canvas.width = 640
	canvas.height = 480
	ctx = canvas.getContext2D

	ctx.scale(2, 2)

	Entity.ALL.append(Player.new(20, 20))
	Entity.ALL.append(Crate.new(150, 150))
	Entity.ALL.append(Crate.new(180, 220))

	Game.hero = Entity.ALL[0]

	tick
}