From d06472f57b2d89f9be10724a706ec770e1f6294b Mon Sep 17 00:00:00 2001
From: Rokas Puzonas <rokas.puz@gmail.com>
Date: Mon, 27 Jun 2022 13:42:26 +0000
Subject: [PATCH] basic character controller with aiming

---
 src/data/controls.lua   | 12 ++++++++
 src/states/main.lua     | 43 ++++++++++++++++++++++++++-
 src/systems/physics.lua | 13 +++++++++
 src/systems/player.lua  | 65 +++++++++++++++++++++++++++++++++++++++++
 src/systems/sprite.lua  | 10 +++++++
 5 files changed, 142 insertions(+), 1 deletion(-)
 create mode 100644 src/data/controls.lua
 create mode 100644 src/systems/physics.lua
 create mode 100644 src/systems/player.lua
 create mode 100644 src/systems/sprite.lua

diff --git a/src/data/controls.lua b/src/data/controls.lua
new file mode 100644
index 0000000..118e4cc
--- /dev/null
+++ b/src/data/controls.lua
@@ -0,0 +1,12 @@
+
+return {
+	move_up = "w",
+	move_down = "s",
+	move_left = "a",
+	move_right = "d",
+
+	aim_up = "up",
+	aim_down = "down",
+	aim_left = "left",
+	aim_right = "right",
+}
diff --git a/src/states/main.lua b/src/states/main.lua
index e7e9c0f..9e58cc4 100644
--- a/src/states/main.lua
+++ b/src/states/main.lua
@@ -1,7 +1,48 @@
 local MainState = {}
+local pprint = require("lib.pprint")
+local nata   = require("lib.nata")
+local Vec    = require("lib.brinevector")
+
+function MainState:enter()
+	self.ecs = nata.new{
+		groups = {
+			physical = {filter = {"pos", "vel"}},
+			player = {filter = {"pos", "acc", "speed", "score"}},
+			sprite = {filter = {"sprite"}}
+		},
+		systems = {
+			require("systems.physics"),
+			require("systems.player"),
+			require("systems.sprite"),
+		},
+		data = {}
+	}
+
+	self.ecs:queue{
+		pos = Vec(100, 100),
+		vel = Vec(0, 0),
+		acc = Vec(),
+		score = 0,
+		sprite = {},
+		speed = 100
+	}
+end
+
+function MainState:update(dt)
+	self.ecs:flush()
+	self.ecs:emit("update", dt)
+
+	if love.keyboard.isDown("escape") then
+		love.event.quit()
+	end
+end
+
+function MainState:mousemoved(...)
+	self.ecs:emit("mousemoved", ...)
+end
 
 function MainState:draw()
-	love.graphics.rectangle("fill", 20, 20, 100, 100)
+	self.ecs:emit("draw")
 end
 
 return MainState
diff --git a/src/systems/physics.lua b/src/systems/physics.lua
new file mode 100644
index 0000000..f63df4e
--- /dev/null
+++ b/src/systems/physics.lua
@@ -0,0 +1,13 @@
+local Physics = {}
+
+function Physics:update(dt)
+	for _, e in ipairs(self.pool.groups.physical.entities) do
+		if e.acc then
+			e.vel = e.vel + e.acc * dt
+		end
+
+		e.pos = e.pos + e.vel * dt
+	end
+end
+
+return Physics
diff --git a/src/systems/player.lua b/src/systems/player.lua
new file mode 100644
index 0000000..5e20e6e
--- /dev/null
+++ b/src/systems/player.lua
@@ -0,0 +1,65 @@
+local Player = {}
+local pprint = require("lib.pprint")
+local data   = require("data")
+local Vec    = require("lib.brinevector")
+
+local controls = data.controls
+
+local function getDirection(up_key, down_key, left_key, right_key)
+	local dx = (love.keyboard.isDown(right_key) and 1 or 0)
+							- (love.keyboard.isDown(left_key) and 1 or 0)
+	local dy = (love.keyboard.isDown(down_key) and 1 or 0)
+							- (love.keyboard.isDown(up_key) and 1 or 0)
+	return Vec(dx, dy).normalized
+end
+
+function Player:getMoveDirection()
+	return getDirection(
+		controls.move_up,
+		controls.move_down,
+		controls.move_left,
+		controls.move_right
+	)
+end
+
+function Player:getAimDirection(player)
+	if self.use_mouse_aim then
+		return (Vec(love.mouse.getPosition()) - player.pos).normalized
+	else
+		return getDirection(
+			controls.aim_up,
+			controls.aim_down,
+			controls.aim_left,
+			controls.aim_right
+		)
+	end
+end
+
+function Player:update(dt)
+	local move_direction = self:getMoveDirection()
+
+	if love.keyboard.isDown(controls.aim_up, controls.aim_down, controls.aim_left, controls.aim_right) then
+		self.use_mouse_aim = false
+	end
+
+	for _, e in ipairs(self.pool.groups.player.entities) do
+		e.aim_dir = self:getAimDirection(e)
+		e.acc = move_direction * e.speed
+	end
+end
+
+function Player:mousemoved()
+	self.use_mouse_aim = true
+end
+
+function Player:draw()
+	for _, e in ipairs(self.pool.groups.player.entities) do
+		if e.aim_dir.x ~= 0 or e.aim_dir.y ~= 0 then
+			love.graphics.setColor(0.8, 0.2, 0.2)
+			local aim_pos = e.pos + e.aim_dir * 25
+			love.graphics.circle("fill", aim_pos.x, aim_pos.y, 10)
+		end
+	end
+end
+
+return Player
diff --git a/src/systems/sprite.lua b/src/systems/sprite.lua
new file mode 100644
index 0000000..9336b23
--- /dev/null
+++ b/src/systems/sprite.lua
@@ -0,0 +1,10 @@
+local Sprite = {}
+
+function Sprite:draw()
+	for _, e in ipairs(self.pool.groups.sprite.entities) do
+			love.graphics.setColor(1, 1, 1)
+		love.graphics.circle("fill", e.pos.x, e.pos.y, 20)
+	end
+end
+
+return Sprite