hacking layering

1 files changed, 76 insertions, 0 deletions

diff --git a/enemy.lua b/enemy.lua
new file mode 100644
index 0000000..9732e98
--- /dev/null
+++ b/enemy.lua
@@ -0,0 +1,76 @@
+local Enemy = {}
+local Entity = require("entity")
+Enemy.__index = Enemy
+setmetatable(Enemy, { __index = Entity })
+
+function Enemy.new(spawnX, spawnY, width, height, physicsWidth, physicsHeight)
+    local self = setmetatable(Entity:new(spawnX or 0, spawnY or 0, width or 16, height or 16, physicsWidth or width or 8, physicsHeight or height or 8), Enemy)
+    self.direction = math.random(1, 2) == 1 and 1 or -1
+    self.speed = 20
+    self.turnDelay = 0.35
+    self.turning   = false
+    self.turnTimer = 0
+    return self
+end
+
+function Enemy:setWorldContext(world)
+    self.world = world
+    self:enablePhysics(world.physicsWorld, "dynamic")
+end
+
+function Enemy:noPathAhead()
+    if not self.world then return false end
+
+    local frontX
+    if self.direction == 1 then
+        frontX = self.x + self.physicsWidth * 1.5 + 1
+    else
+        frontX = self.x + self.physicsWidth * 0.5 - 1
+    end
+
+    local midY   = self.y + self.physicsHeight * 0.5
+    local belowY = self.y + self.physicsHeight + 1
+
+    local wallAhead  = self.world:isTileSolidAtPixel(frontX, midY)
+    local floorAhead = self.world:isTileSolidAtPixel(frontX, belowY)
+
+    return wallAhead or not floorAhead
+end
+
+function Enemy:patrolPlatform(dt)
+    self:syncFromPhysicsBody()
+
+    if self.turning then
+        self.turnTimer = self.turnTimer - dt
+        if self.turnTimer <= 0 then
+            self.direction = self.direction * -1
+            self.turning   = false
+        end
+        if self.body then
+            local _, vy = self.body:getLinearVelocity()
+            self.body:setLinearVelocity(0, vy)
+        end
+        return
+    end
+
+    if self:noPathAhead() then
+        self.turning   = true
+        self.turnTimer = self.turnDelay
+    end
+
+    if self.body then
+        local _, vy = self.body:getLinearVelocity()
+        self.body:setLinearVelocity(self.speed * self.direction, vy)
+    end
+end
+
+function Enemy:update(dt)
+    self:patrolPlatform(dt)
+end
+
+function Enemy:draw()
+    --bug: texture is drawn shifted by half width to the left
+    love.graphics.draw(self.texture, self.x + self.physicsWidth / 2, self.y)
+end
+
+return Enemy
\ No newline at end of file