added examples for level 1.6

world1/06_adding-some-action/creating bullets/main.lua

@@ -0,0 +1,74 @@
+player = {
+  x = 150,
+  y = 150,
+  xvel = 0,
+  yvel = 0,
+  rotation = 0
+}
+
+bullets = {}
+
+-- Function to create bullets
+function shot()
+  table.insert(bullets, {x = player.x, y = player.y, speed = 1000, rotation = player.rotation})
+end
+
+local ANGACCEL      = 4
+local ACCELERATION  = 400
+
+function love.update(dt)
+  if love.keyboard.isDown"right" then
+    -- rotate clockwise
+    player.rotation = player.rotation + ANGACCEL*dt
+  end
+  if love.keyboard.isDown"left" then
+    -- rotate counter-clockwise
+    player.rotation = player.rotation - ANGACCEL*dt
+  end
+  if love.keyboard.isDown"down" then
+    -- decelerate / accelerate backwards
+    player.xvel = player.xvel - ACCELERATION*dt * math.cos(player.rotation)
+    player.yvel = player.yvel - ACCELERATION*dt * math.sin(player.rotation)
+  end
+  if love.keyboard.isDown"up" then
+    -- accelerate
+    player.xvel = player.xvel + ACCELERATION*dt * math.cos(player.rotation)
+    player.yvel = player.yvel + ACCELERATION*dt * math.sin(player.rotation)
+  end
+
+  if love.keyboard.isDown" " then
+    shot()
+  end
+
+  player.x = player.x + player.xvel*dt
+  player.y = player.y + player.yvel*dt
+
+  -- Update all bullets
+  for _, bullet in ipairs(bullets) do
+    bullet.x = bullet.x + math.cos(bullet.rotation) * bullet.speed * dt
+    bullet.y = bullet.y + math.sin(bullet.rotation) * bullet.speed * dt
+  end
+
+  -- for dragging
+  player.xvel = player.xvel * 0.99
+  player.yvel = player.yvel * 0.99
+
+end
+
+function love.draw()
+    -- Draw all bullets
+  for _, bullet in ipairs(bullets) do
+    love.graphics.setColor(255,255,255)
+    love.graphics.circle("fill", bullet.x, bullet.y, 2)
+  end
+
+  love.graphics.print("Qtde. de tiros: " .. #bullets, 10, 10)
+
+  love.graphics.setColor(80, 80, 80)
+  love.graphics.translate(player.x, player.y)
+  love.graphics.rotate(player.rotation)
+  love.graphics.rectangle("fill", -50, -10, 100, 20)
+  love.graphics.setColor(200, 200, 200)
+  love.graphics.line(20, 0, 50, 0)
+
+end

world1/06_adding-some-action/destroying bullets/main.lua

@@ -0,0 +1,92 @@
+player = {
+  x = 150,
+  y = 150,
+  xvel = 0,
+  yvel = 0,
+  rotation = 0
+}
+
+bullets = {}
+bullets.trash = {} -- auxiliary table to remove bullets from memory
+
+-- Function to create bullets
+function shot()
+  table.insert(bullets, {x = player.x, y = player.y, speed = 1000, rotation = player.rotation})
+end
+
+function destroy_bullets()
+  for i,v in ipairs(bullets.trash) do
+    table.remove(bullets, i)
+  end
+
+  bullets.trash = {}
+end
+
+local ANGACCEL      = 4
+local ACCELERATION  = 400
+
+function love.update(dt)
+  if love.keyboard.isDown"right" then
+    -- rotate clockwise
+    player.rotation = player.rotation + ANGACCEL*dt
+  end
+  if love.keyboard.isDown"left" then
+    -- rotate counter-clockwise
+    player.rotation = player.rotation - ANGACCEL*dt
+  end
+  if love.keyboard.isDown"down" then
+    -- decelerate / accelerate backwards
+    player.xvel = player.xvel - ACCELERATION*dt * math.cos(player.rotation)
+    player.yvel = player.yvel - ACCELERATION*dt * math.sin(player.rotation)
+  end
+  if love.keyboard.isDown"up" then
+    -- accelerate
+    player.xvel = player.xvel + ACCELERATION*dt * math.cos(player.rotation)
+    player.yvel = player.yvel + ACCELERATION*dt * math.sin(player.rotation)
+  end
+
+  if love.keyboard.isDown" " then
+    shot()
+  end
+
+  player.x = player.x + player.xvel*dt
+  player.y = player.y + player.yvel*dt
+
+  -- Update all bullets
+  for _, bullet in ipairs(bullets) do
+    bullet.x = bullet.x + math.cos(bullet.rotation) * bullet.speed * dt
+    bullet.y = bullet.y + math.sin(bullet.rotation) * bullet.speed * dt
+
+  -- if a bullet go outside from screen, then it will be destroyed
+    if bullet.x > love.graphics.getWidth() or bullet.x < 0 then
+      table.insert(bullets.trash, bullet)
+    end
+    if bullet.y > love.graphics.getHeight() or bullet.y < 0 then
+      table.insert(bullets.trash, bullet)
+    end
+  end
+
+  -- for dragging
+  player.xvel = player.xvel * 0.99
+  player.yvel = player.yvel * 0.99
+
+  -- verify if have some bullet on trash to destroy it
+  destroy_bullets()
+
+end
+
+function love.draw()
+    -- Draw all bullets
+  for _, bullet in ipairs(bullets) do
+    love.graphics.setColor(255,255,255)
+    love.graphics.circle("fill", bullet.x, bullet.y, 2)
+  end
+
+  love.graphics.setColor(80, 80, 80)
+  love.graphics.translate(player.x, player.y)
+  love.graphics.rotate(player.rotation)
+  love.graphics.rectangle("fill", -50, -10, 100, 20)
+  love.graphics.setColor(200, 200, 200)
+  love.graphics.line(20, 0, 50, 0)
+
+end