Move screen shaking effect into a proper method in the client proxy, fix earthquake's version not working and add screen shake to meteor, lightning hammer and shockwave

src/main/java/electroblob/wizardry/client/ClientProxy.java

@@ -29,7 +29,6 @@ import electroblob.wizardry.item.ItemScroll;
 import electroblob.wizardry.item.ItemSpellBook;
 import electroblob.wizardry.item.ItemWand;
 import electroblob.wizardry.packet.*;
-import electroblob.wizardry.potion.PotionSlowTime;
 import electroblob.wizardry.registry.Spells;
 import electroblob.wizardry.registry.WizardrySounds;
 import electroblob.wizardry.spell.*;
@@ -195,6 +194,11 @@ public class ClientProxy extends CommonProxy {
 		if(Minecraft.getMinecraft().player == player) WizardryClientEventHandler.playBlinkEffect();
 	}
 
+	@Override
+	public void shakeScreen(EntityPlayer player, float intensity){
+		if(Minecraft.getMinecraft().player == player) WizardryClientEventHandler.shakeScreen(intensity);
+	}
+
 	@Override
 	public Set<String> getSpellHUDSkins(){
 		return GuiSpellDisplay.getSkinKeys();

src/main/java/electroblob/wizardry/client/WizardryClientEventHandler.java

@@ -68,11 +68,21 @@ public final class WizardryClientEventHandler {
 	private static int blinkEffectTimer;
 	/** The number of ticks the blink effect lasts for. */
 	private static final int BLINK_EFFECT_DURATION = 8;
+
+	/** The remaining time for which the screen shake effect will be active. */
+	private static int screenShakeCounter = 0;
+	private static final float SHAKINESS = 0.5f;
 	
-	/** Starts the first person blink overlay effect. */
+	/** Starts the first-person blink overlay effect. */
 	public static void playBlinkEffect(){
 		blinkEffectTimer = BLINK_EFFECT_DURATION;
 	}
+
+	/** Starts the client-side screen shake effect. */
+	public static void shakeScreen(float intensity){
+		screenShakeCounter = (int)(intensity / SHAKINESS);
+		Minecraft.getMinecraft().player.rotationPitch -= intensity * 0.5f; // Start halfway down
+	}
 	
 	@SubscribeEvent
 	public static void onPlayerTickEvent(TickEvent.PlayerTickEvent event){
@@ -81,6 +91,12 @@ public final class WizardryClientEventHandler {
 
 			if(blinkEffectTimer > 0) blinkEffectTimer--;
 
+			if(screenShakeCounter > 0){
+				float magnitude = screenShakeCounter * SHAKINESS;
+				Minecraft.getMinecraft().player.rotationPitch += screenShakeCounter % 2 == 0 ? magnitude : -magnitude;
+				screenShakeCounter--;
+			}
+
 			// Only seems to work here...
 //			EntityLiving victim = Possession.getPossessee(Minecraft.getMinecraft().player);
 //			if(victim != null && victim.getHeldItemMainhand().isEmpty()){