simple projectiles

main.lua

@@ -11,9 +11,26 @@ local function clamp_angle(value)
     return value
 end
 
+local function make_projectile(position)
+    local projectile = { position=table.deepcopy(position), speed=3 }
+
+    projectile.draw = function(self, id)
+        local current_width = playdate.graphics.getLineWidth()
+        playdate.graphics.setLineWidth(2)
+        local angle_rad = math.rad(self.position.theta)
+        local dx, dy = self.speed * math.cos(angle_rad), self.speed * math.sin(angle_rad)
+        local new_x, new_y = self.position.x + dx, self.position.y + dy
+        playdate.graphics.drawLine(self.position.x,self.position.y,  new_x,new_y)
+        playdate.graphics.setLineWidth(current_width)
+        self.position.x, self.position.y = new_x, new_y
+    end
+
+    return projectile
+end
+
 local function make_player(x, y, width, height, screen)
     local crankPosition = playdate.getCrankPosition()
-    local player = { position={ x=x, y=y, theta=crankPosition}, width=width, height=height, screen=screen }
+    local player = { position={ x=x, y=y, theta=crankPosition}, width=width, height=height, screen=screen, projectiles={} }
 
     player.draw = function(self)
         local w, h, transform = self.width / 2, self.height / 2, playdate.geometry.affineTransform.new()
@@ -22,6 +39,10 @@ local function make_player(x, y, width, height, screen)
         transform:rotate(self.position.theta, self.position.x, self.position.y)
         local transformedPolygon = transform:transformedPolygon(polygon)
         playdate.graphics.drawPolygon(transformedPolygon)
+
+        for i, projectile in ipairs(self.projectiles) do
+            projectile:draw(i)
+        end
     end
 
     player.translate = function(self, offset_theta, amount)
@@ -42,6 +63,11 @@ local function make_player(x, y, width, height, screen)
         self:rotate(change)
     end
 
+    player.shoot_projectile = function(self)
+        local projectile = make_projectile(self.position)
+        table.insert(self.projectiles, projectile)
+    end
+
     return player
 end
 
@@ -58,6 +84,8 @@ function playdate.update()
     if playdate.buttonIsPressed(playdate.kButtonLeft) then player:translate(270, 1) end
     if playdate.buttonIsPressed(playdate.kButtonRight) then player:translate(90, 1) end
 
+    if playdate.buttonJustPressed(playdate.kButtonA) then player:shoot_projectile() end
+
     player:handle_crank()
     player:draw()
 end