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, 38 insertions, 0 deletions

diff --git a/src/net/manaserv/effecthandler.cpp b/src/net/manaserv/effecthandler.cpp
index 2df3fe0b..7051bedd 100644
--- a/src/net/manaserv/effecthandler.cpp
+++ b/src/net/manaserv/effecthandler.cpp
@@ -25,6 +25,8 @@
 #include "effectmanager.h"
 #include "log.h"
 
+#include "gui/viewport.h"
+
 #include "net/messagein.h"
 
 #include "net/manaserv/manaserv_protocol.h"
@@ -36,6 +38,7 @@ EffectHandler::EffectHandler()
     static const Uint16 _messages[] = {
         GPMSG_CREATE_EFFECT_POS,
         GPMSG_CREATE_EFFECT_BEING,
+        GPMSG_SHAKE,
         0
     };
     handledMessages = _messages;
@@ -51,6 +54,9 @@ void EffectHandler::handleMessage(Net::MessageIn &msg)
         case GPMSG_CREATE_EFFECT_BEING:
             handleCreateEffectBeing(msg);
             break;
+        case GPMSG_SHAKE:
+            handleShake(msg);
+            break;
         default:
             break;
     }
@@ -75,4 +81,36 @@ void EffectHandler::handleCreateEffectBeing(Net::MessageIn &msg)
         logger->log("Warning: CreateEffect called for unknown being #%d", bid);
 }
 
+void EffectHandler::handleShake(Net::MessageIn &msg)
+{
+    int16_t intensityX = 0;
+    int16_t intensityY = 0;
+    float decay;
+    int duration;
+
+    switch (msg.getUnreadLength())
+    {
+        case 4:
+            intensityX =  msg.readInt16();
+            intensityY =  msg.readInt16();
+            viewport->shakeScreen(intensityX, intensityY);
+            break;
+        case 6:
+            intensityX =  msg.readInt16();
+            intensityY =  msg.readInt16();
+            decay =  msg.readInt16() / 10000.0f;
+            viewport->shakeScreen(intensityX, intensityY, decay);
+            break;
+        case 8:
+            intensityX =  msg.readInt16();
+            intensityY =  msg.readInt16();
+            decay =  msg.readInt16() / 10000.0f;
+            duration =  msg.readInt16();
+            viewport->shakeScreen(intensityX, intensityY, decay, duration);
+            break;
+        default:
+            logger->log("Warning: Received GPMSG_SHAKE message with unexpected length of %d bytes", msg.getUnreadLength());
+    }
+}
+
 } // namespace ManaServ