Draw the 'crystal hearts' stamp on the GMHS when the player beats the old version of the GMHS

The save data flag should be set by a Lua cutscene to be developed, so we don't need to set this flag.

Author: maddie480

SpringCollab2020Module.cs

@@ -52,6 +52,7 @@ public override void Load() {
             Everest.Events.Level.OnLoadBackdrop += onLoadBackdrop;
 
             IL.Celeste.Level.Reload += resetFlagsOnTimerResets;
+            IL.Celeste.OuiChapterPanel.Render += renderOldGMHSCompletionStamp;
 
             DecalRegistry.AddPropertyHandler("scale", (decal, attrs) => {
                 Vector2 scale = decal.Scale;
@@ -100,6 +101,7 @@ public override void Unload() {
             Everest.Events.Level.OnLoadBackdrop -= onLoadBackdrop;
 
             IL.Celeste.Level.Reload -= resetFlagsOnTimerResets;
+            IL.Celeste.OuiChapterPanel.Render -= renderOldGMHSCompletionStamp;
         }
 
         private Backdrop onLoadBackdrop(MapData map, BinaryPacker.Element child, BinaryPacker.Element above) {
@@ -139,5 +141,24 @@ private void resetFlagsOnTimerResets(ILContext il) {
                 });
             }
         }
+
+        private void renderOldGMHSCompletionStamp(ILContext il) {
+            ILCursor cursor = new ILCursor(il);
+
+            // draw the stamp just after the chapter card.
+            if (cursor.TryGotoNext(instr => instr.MatchStfld<OuiChapterPanel>("card"))
+                && cursor.TryGotoNext(MoveType.After, instr => instr.MatchCallvirt<MTexture>("Draw"))) {
+
+                Logger.Log("SpringCollab2020", $"Injecting GMHS stamp rendering at {cursor.Index} in IL for OuiChapterPanel.Render");
+
+                cursor.Emit(OpCodes.Ldarg_0);
+                cursor.EmitDelegate<Action<OuiChapterPanel>>(self => {
+                    // draw it only if the player beat old grandmaster heart side, and we're actually looking at it.
+                    if (self.Area.GetSID() == "SpringCollab2020/5-Grandmaster/ZZ-HeartSide" && SaveData.BeatOldGrandmasterHeartSide) {
+                        MTN.FileSelect["heart"].Draw(self.Position + new Vector2(-580f, 130f));
+                    }
+                });
+            }
+        }
     }
-}
+}

SpringCollab2020SaveData.cs

@@ -4,5 +4,7 @@
 namespace Celeste.Mod.SpringCollab2020 {
     public class SpringCollab2020SaveData : EverestModuleSaveData {
         public HashSet<string> ModifiedThemeMaps = new HashSet<string>() { };
+
+        public bool BeatOldGrandmasterHeartSide { get; set; } = false;
     }
 }