camera shake

3 files changed, 53 insertions, 11 deletions

diff --git a/src/camera.lua b/src/camera.lua
index 31bfe9e..add6ae4 100644
--- a/src/camera.lua
+++ b/src/camera.lua
@@ -1,5 +1,7 @@
 local DEFAULT_CAMERA_SMOOTHING = 30
 
+local SHAKE_NOISE_SPEED = 15
+
 Cam = {}
 Cam.__index = Cam
 
@@ -14,12 +16,24 @@ function Cam.new(x, y)
 
   self.smoothing = DEFAULT_CAMERA_SMOOTHING
 
+  self.shake_strength = 0
+  self.shake_timer_max = 0
+  self.shake_timer = 0
+
+  self.shake_damp = EASING_FUNCTIONS.Lerp
+  self.shake_noise = lmath.noise
+
   return self
 end
 
 function Cam:update(dt)
   self.realx = dlerp(self.realx, self.x, self.smoothing * dt)
   self.realy = dlerp(self.realy, self.y, self.smoothing * dt)
+
+  self.shake_timer = self.shake_timer - dt
+  if self.shake_timer < 0 then
+    self.shake_strength = 0
+  end
 end
 
 local active_cam = Cam.new()
@@ -28,6 +42,16 @@ function get_active_camera()
   return active_cam
 end
 
+function Cam:shake(strength, time)
+  if strength < self.shake_strength then
+    return
+  end
+  self.noise_seed = lmath.random() * 1000
+  self.shake_strength = strength
+  self.shake_timer = time
+  self.shake_timer_max = time
+end
+
 function set_active_camera(new_cam)
   active_cam = new_cam
 end
@@ -35,7 +59,23 @@ end
 function use_camera_transform()
   local w, h = SCR_WIDTH / 2, SCR_HEIGHT / 2
   lg.scale(active_cam.zoom)
-  lg.translate(
-    round(-active_cam.realx + w / active_cam.zoom),
-    round(-active_cam.realy + h / active_cam.zoom))
+  local ox, oy = round(-active_cam.realx + w / active_cam.zoom),
+                 round(-active_cam.realy + h / active_cam.zoom)
+
+  local shakex, shakey = 0, 0
+  if active_cam.shake_timer > 0 then
+    shakex = active_cam.shake_noise(
+      active_cam.shake_timer * SHAKE_NOISE_SPEED + active_cam.noise_seed)
+
+    shakey = active_cam.shake_noise(
+      -- 100 is a magic number to offset the x and y noise (so its not just a diagonal shake)
+      active_cam.shake_timer * SHAKE_NOISE_SPEED + active_cam.noise_seed, 100)
+
+    local anim = active_cam.shake_timer / active_cam.shake_timer_max
+    local strength = active_cam.shake_strength * active_cam.shake_damp(0, 1, anim)
+    shakex = shakex * strength
+    shakey = shakey * strength
+  end
+
+  lg.translate(ox + shakex, oy + shakey)
 end
diff --git a/src/init.lua b/src/init.lua
index 29cb64d..c77bb18 100644
--- a/src/init.lua
+++ b/src/init.lua
@@ -1,3 +1,12 @@
+li = love.image
+la = love.audio
+lg = love.graphics
+lf = love.filesystem
+lw = love.window
+lk = love.keyboard
+lm = love.mouse
+lmath = love.math
+
 require "src.events"
 require "src.ecs"
 require "src.utils"
@@ -29,14 +38,6 @@ register_input("Hot_Reload", {{"key", "r"}})
 register_input("Right_Click", {{"mouse", 2}})
 register_input("Left_Click",  {{"mouse", 1}})
 
-li = love.image
-la = love.audio
-lg = love.graphics
-lf = love.filesystem
-lw = love.window
-lk = love.keyboard
-lm = love.mouse
-lmath = love.math
 
 function init_global_systems()
   event_bind(global_on_update, "Body", body_sys)
diff --git a/src/objs/player.lua b/src/objs/player.lua
index 5c7da0f..6d15058 100644
--- a/src/objs/player.lua
+++ b/src/objs/player.lua
@@ -45,6 +45,7 @@ local function player_normal_state_update(player, state, dt)
       player.vy = -PLAYER_JUMP_FORCE
       player.jumps = player.jumps - 1
       new_speck_entity(player.x, player.y, "res/speck/test.speck.lua")
+      player.camera:shake(12, 0.1)
     end
   end
   if not is_input_pressed("Jump") and player.vy < -100 then