From 2d58bddd06410718ef3f457c746c34803a9ddbec Mon Sep 17 00:00:00 2001
From: Arceveti <73617174+Arceveti@users.noreply.github.com>
Date: Sun, 5 Sep 2021 12:18:00 -0700
Subject: [PATCH] Add fix for obj_resolve_object_collisions

---
 include/config.h           |  2 ++
 src/engine/surface_load.c  |  4 ++--
 src/game/interaction.h     |  3 +++
 src/game/obj_behaviors_2.c | 32 +++++++++++++++++++++++++-------
 4 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/include/config.h b/include/config.h
index 848112bb..0b0cf0bf 100644
--- a/include/config.h
+++ b/include/config.h
@@ -104,6 +104,8 @@
 //#define PUPPYCAM
 // Automatically calculate the optimal collision distance for an object based on its vertices.
 #define AUTO_COLLISION_DISTANCE
+// Makes obj_resolve_object_collisions work consistently
+#define FIX_RESOLVE_OBJ_COLLISIONS
 
 
 // HACKER QOL
diff --git a/src/engine/surface_load.c b/src/engine/surface_load.c
index 601b8a54..c3fdb3cc 100644
--- a/src/engine/surface_load.c
+++ b/src/engine/surface_load.c
@@ -828,13 +828,13 @@ void load_object_collision_model(void) {
 #endif
 
     // If the object collision is supposed to be loaded more than the
-    // drawing distance of 4000, extend the drawing range.
+    // drawing distance, extend the drawing range.
     if (gCurrentObject->oCollisionDistance > gCurrentObject->oDrawingDistance) {
         gCurrentObject->oDrawingDistance = gCurrentObject->oCollisionDistance;
     }
 
     // Update if no Time Stop, in range, and in the current room.
-    if (!(gTimeStopState & TIME_STOP_ACTIVE) && marioDist < gCurrentObject->oCollisionDistance
+    if (!(gTimeStopState & TIME_STOP_ACTIVE) && (marioDist < gCurrentObject->oCollisionDistance)
         && !(gCurrentObject->activeFlags & ACTIVE_FLAG_IN_DIFFERENT_ROOM)) {
         collisionData++;
         transform_object_vertices(&collisionData, vertexData);
diff --git a/src/game/interaction.h b/src/game/interaction.h
index 1b2457be..e601556a 100644
--- a/src/game/interaction.h
+++ b/src/game/interaction.h
@@ -38,6 +38,9 @@
 #define INTERACT_IGLOO_BARRIER  /* 0x40000000 */ (1 << 30)
 #define INTERACT_UNKNOWN_31     /* 0x80000000 */ (1 << 31)
 
+#ifdef FIX_RESOLVE_OBJ_COLLISIONS
+#define INTERACT_MASK_NO_OBJ_COLLISIONS (INTERACT_COIN | INTERACT_CAP | INTERACT_STRONG_WIND | INTERACT_STAR_OR_KEY | INTERACT_WARP | INTERACT_WATER_RING | INTERACT_FLAME)
+#endif
 
 // INTERACT_WARP
 #define INT_SUBTYPE_FADING_WARP 0x00000001
diff --git a/src/game/obj_behaviors_2.c b/src/game/obj_behaviors_2.c
index ae01edce..323074ea 100644
--- a/src/game/obj_behaviors_2.c
+++ b/src/game/obj_behaviors_2.c
@@ -549,16 +549,33 @@ static void obj_update_blinking(s32 *blinkTimer, s16 baseCycleLength, s16 cycleL
 
 static s32 obj_resolve_object_collisions(s32 *targetYaw) {
     struct Object *otherObject;
-    f32 dx;
-    f32 dz;
+    f32 dx, dz;
     s16 angle;
-    f32 radius;
-    f32 otherRadius;
-    f32 relativeRadius;
-    f32 newCenterX;
-    f32 newCenterZ;
+    f32 radius, otherRadius, relativeRadius;
 
     if (o->numCollidedObjs != 0) {
+#ifdef FIX_RESOLVE_OBJ_COLLISIONS
+        s32 i;
+        for ((i = 0); (i < o->numCollidedObjs); (i++)) {
+            otherObject = o->collidedObjs[i];
+            if (otherObject == gMarioObject) continue;
+            if (otherObject->oInteractType & INTERACT_MASK_NO_OBJ_COLLISIONS) continue;
+            dx             = (o->oPosX - otherObject->oPosX);
+            dz             = (o->oPosZ - otherObject->oPosZ);
+            radius         = ((          o->hurtboxRadius > 0) ?           o->hurtboxRadius :           o->hitboxRadius);
+            otherRadius    = ((otherObject->hurtboxRadius > 0) ? otherObject->hurtboxRadius : otherObject->hitboxRadius);
+            relativeRadius = (radius + otherRadius);
+            if ((sqr(dx) + sqr(dz)) > sqr(relativeRadius)) continue;
+            angle    = atan2s(dz, dx);
+            o->oPosX = (otherObject->oPosX + (relativeRadius * sins(angle)));
+            o->oPosZ = (otherObject->oPosZ + (relativeRadius * coss(angle)));
+            if ((targetYaw != NULL) && (abs_angle_diff(o->oMoveAngleYaw, angle) < 0x4000)) {
+                *targetYaw = (s16)((angle - o->oMoveAngleYaw) + angle + 0x8000);
+                return TRUE;
+            }
+        }
+#else
+        f32 newCenterX, newCenterZ;
         otherObject = o->collidedObjs[0];
         if (otherObject != gMarioObject) {
             //! If one object moves after collisions are detected and this code
@@ -588,6 +605,7 @@ static s32 obj_resolve_object_collisions(s32 *targetYaw) {
                 return TRUE;
             }
         }
+#endif
     }
 
     return FALSE;