directional camera shake

1 files changed, 39 insertions, 16 deletions

diff --git a/src/camera.lua b/src/camera.lua
index 81f1657..e128c69 100644
--- a/src/camera.lua
+++ b/src/camera.lua
@@ -19,6 +19,7 @@ function Cam.new(x, y)
   self.shake_strength = 0
   self.shake_timer_max = 0
   self.shake_timer = 0
+  self.shake_direction = 0
 
   self.shake_damp = EASING_FUNCTIONS.Lerp
   self.shake_noise = lmath.noise
@@ -42,10 +43,15 @@ function get_active_camera()
   return active_cam
 end
 
-function Cam:shake(strength, time)
+function Cam:shake(strength, time, angle)
   if strength < self.shake_strength then
     return
   end
+
+  self.shake_direction = angle -- if nil we just ignore it and randomize
+  if self.shake_direction then
+    self.shake_direction = math.rad(self.shake_direction)
+  end
   self.noise_seed = lmath.random() * 1000
   self.shake_strength = strength
   self.shake_timer = time
@@ -56,27 +62,44 @@ function set_active_camera(new_cam)
   active_cam = new_cam
 end
 
-function use_camera_transform()
-  local w, h = SCR_WIDTH / 2, SCR_HEIGHT / 2
-  lg.scale(active_cam.zoom)
-  local ox, oy = -active_cam.realx + w / active_cam.zoom,
-                 -active_cam.realy + h / active_cam.zoom
+function Cam:getshake()
+  if self.shake_timer < 0 then
+    return 0, 0
+  end
 
   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)
+  if self.shake_direction then
+    local size = self.shake_noise(
+      self.shake_timer * SHAKE_NOISE_SPEED + self.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)
+    shakex = math.cos(self.shake_direction) * size
+    shakey = math.sin(self.shake_direction) * size
+
+  else
+    shakex = self.shake_noise(
+      self.shake_timer * SHAKE_NOISE_SPEED + self.noise_seed)
 
-    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
+    shakey = self.shake_noise(
+      -- 100 is a magic number to offset the x and y noise (so its not just a diagonal shake)
+      self.shake_timer * SHAKE_NOISE_SPEED + self.noise_seed, 100)
   end
 
+  local anim = self.shake_timer / self.shake_timer_max
+  local strength = self.shake_strength * self.shake_damp(0, 1, anim)
+
+  shakex = shakex * strength
+  shakey = shakey * strength
+  return shakex, shakey
+end
+
+function use_camera_transform()
+  local w, h = SCR_WIDTH / 2, SCR_HEIGHT / 2
+  lg.scale(active_cam.zoom)
+  local ox, oy = -active_cam.realx + w / active_cam.zoom,
+                 -active_cam.realy + h / active_cam.zoom
+  
+  local shakex, shakey = active_cam:getshake()
+
   lg.translate(
     round(ox + shakex),
     round(oy + shakey))