Implemented a screen shake effect system in the viewport class.

The screen can either be "nudged" in a random direction with a specific
intensity or you can define an exact x and y intensity, decay factor and
duration. On a tmwAthena server an effect is triggered when the player
character dies. A method for stopping all shake effects is also
implemented, but not used yet. I added a netcode message for Manaserv to
trigger an effect server-sided. Because our protocol has currently no way
to transport floating point values, the decay is transported as a fixed
point value with 4 decimals which is entirely sufficient for this purpose.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/gui/viewport.h b/src/gui/viewport.h
index 93e36b5b..f4db806b 100644
--- a/src/gui/viewport.h
+++ b/src/gui/viewport.h
@@ -29,6 +29,8 @@
 
 #include <guichan/mouselistener.hpp>
 
+#include <list>
+
 class ActorSprite;
 class Being;
 class BeingPopup;
@@ -153,6 +155,22 @@ class Viewport : public WindowContainer, public gcn::MouseListener,
          */
         void hideBeingPopup();
 
+        /**
+         * Makes the screen shake in a random direction
+         */
+        void shakeScreen(int intensity);
+
+        /**
+         * Makes the screen shake in a specific direction
+         */
+        void shakeScreen(float x, float y, float decay = 0.95f, unsigned duration = 0);
+
+        /**
+         * Stops all active screen shake effects
+         */
+        void shakeScreenStop()
+        { mShakeEffects.clear(); }
+
         void event(Channels channel, const Mana::Event &event);
 
     private:
@@ -190,6 +208,16 @@ class Viewport : public WindowContainer, public gcn::MouseListener,
         float mPixelViewY;           /**< Current viewpoint in pixels. */
         int mShowDebugPath;         /**< Show a path from player to pointer. */
 
+        struct ShakeEffect
+        {
+            float x;
+            float y;
+            float decay;
+            unsigned duration;
+        };
+        typedef std::list<ShakeEffect> ShakeEffects;
+        ShakeEffects mShakeEffects;
+
         bool mPlayerFollowMouse;
 
         int mLocalWalkTime; /**< Timestamp before the next walk can be sent. */