add music area change trigger

Author: mwhatters

Ahorn/triggers/musicAreaChangeTrigger.jl

@@ -0,0 +1,15 @@
+module SpringCollab2020MusicAreaChangeTrigger
+
+using ..Ahorn, Maple
+
+@mapdef Trigger "SpringCollab2020/MusicAreaChangeTrigger" MusicAreaChangeTrigger(x::Integer, y::Integer, width::Integer=Maple.defaultTriggerWidth, height::Integer=Maple.defaultTriggerHeight,
+	musicParam1::String="", musicParam2::String="", musicParam3::String="", enterValue::Number=1.0, exitValue::Number=0.0)
+
+const placements = Ahorn.PlacementDict(
+    "Music Area Change Trigger (Spring Collab 2020)" => Ahorn.EntityPlacement(
+        MusicAreaChangeTrigger,
+        "rectangle"
+    )
+)
+
+end

Triggers/MusicAreaChangeTrigger.cs

@@ -0,0 +1,53 @@
+using Celeste.Mod.Entities;
+using Microsoft.Xna.Framework;
+
+namespace Celeste.Mod.SpringCollab2020.Triggers {
+    [CustomEntity("SpringCollab2020/MusicAreaChangeTrigger")]
+    class MusicAreaChangeTrigger : Trigger {
+        private string musicParam1;
+        private string musicParam2;
+        private string musicParam3;
+        private float enterValue;
+        private float exitValue;
+
+        // this is used specifically for the expert lobby. On enter, it sets all given  parameter values
+        // to the enter value. On exit, it sets all parameter values to exit. Individual exit/enter values were not necessary so they were not added.
+        // this is hastily written code that could likely be refactored into a more widely useful trigger for FMOD'ers 
+
+        public MusicAreaChangeTrigger(EntityData data, Vector2 offset) : base(data, offset) {
+            musicParam1 = data.Attr("musicParam1");
+            musicParam2 = data.Attr("musicParam2");
+            musicParam3 = data.Attr("musicParam3");
+            enterValue = data.Float("enterValue", 1f);
+            exitValue = data.Float("exitValue", 0f);
+        }
+
+        public override void OnEnter(Player player) {
+            base.OnEnter(player);
+
+            if (!string.IsNullOrEmpty(musicParam1)) {
+                Audio.SetMusicParam(musicParam1, enterValue);
+            }
+            if (!string.IsNullOrEmpty(musicParam2)) {
+                Audio.SetMusicParam(musicParam2, enterValue);
+            }
+            if (!string.IsNullOrEmpty(musicParam3)) {
+                Audio.SetMusicParam(musicParam3, enterValue);
+            }
+        }
+
+        public override void OnLeave(Player player) {
+            base.OnLeave(player);
+
+            if (!string.IsNullOrEmpty(musicParam1)) {
+                Audio.SetMusicParam(musicParam1, exitValue);
+            }
+            if (!string.IsNullOrEmpty(musicParam2)) {
+                Audio.SetMusicParam(musicParam2, exitValue);
+            }
+            if (!string.IsNullOrEmpty(musicParam3)) {
+                Audio.SetMusicParam(musicParam3, exitValue);
+            }
+        }
+    }
+}