From 278dd9b1d2859cf8f725f4eee0e4bf62ca02b201 Mon Sep 17 00:00:00 2001
From: duncanspumpkin <duncans_pumpkin@hotmail.co.uk>
Date: Tue, 12 Nov 2019 20:11:48 +0000
Subject: [PATCH] Remove global variables from
 get_map_coordinates_from_pos_window

---
 src/openrct2/interface/Viewport.cpp | 55 +++++++++++++++++------------
 1 file changed, 33 insertions(+), 22 deletions(-)

diff --git a/src/openrct2/interface/Viewport.cpp b/src/openrct2/interface/Viewport.cpp
index afad6a699f..7f17dadfb3 100644
--- a/src/openrct2/interface/Viewport.cpp
+++ b/src/openrct2/interface/Viewport.cpp
@@ -43,7 +43,6 @@ uint8_t gShowConstuctionRightsRefCount;
 rct_viewport g_viewport_list[MAX_VIEWPORT_COUNT];
 rct_viewport* g_music_tracking_viewport;
 
-static TileElement* _interaction_element = nullptr;
 static std::unique_ptr<JobPool> _paintJobs;
 
 int16_t gSavedViewX;
@@ -58,10 +57,12 @@ static uint32_t _currentImageType;
 
 static rct_drawpixelinfo _viewportDpi1;
 static rct_drawpixelinfo _viewportDpi2;
-static uint8_t _interactionSpriteType;
-static int16_t _interactionMapX;
-static int16_t _interactionMapY;
-static uint16_t _interactionFlags;
+struct InteractionInfo
+{
+    CoordsXY loc;
+    TileElement* element;
+    uint8_t SpriteType;
+};
 
 static void viewport_paint_weather_gloom(rct_drawpixelinfo* dpi);
 
@@ -1260,12 +1261,12 @@ void viewport_set_visibility(uint8_t mode)
  * Originally checked 0x0141F569 at start
  *  rct2: 0x00688697
  */
-static void store_interaction_info(paint_struct* ps)
+static std::optional<InteractionInfo> GetInteractionInfoFromPS(paint_struct* ps, uint16_t flags)
 {
     if (ps->sprite_type == VIEWPORT_INTERACTION_ITEM_NONE
         || ps->sprite_type == 11 // 11 as a type seems to not exist, maybe part of the typo mentioned later on.
         || ps->sprite_type > VIEWPORT_INTERACTION_ITEM_BANNER)
-        return;
+        return {};
 
     uint16_t mask;
     if (ps->sprite_type == VIEWPORT_INTERACTION_ITEM_BANNER)
@@ -1274,13 +1275,17 @@ static void store_interaction_info(paint_struct* ps)
     else
         mask = 1 << (ps->sprite_type - 1);
 
-    if (!(_interactionFlags & mask))
+    if (flags & mask)
     {
-        _interactionSpriteType = ps->sprite_type;
-        _interactionMapX = ps->map_x;
-        _interactionMapY = ps->map_y;
-        _interaction_element = ps->tileElement;
+        return {};
     }
+
+    InteractionInfo info = {
+        { ps->map_x, ps->map_y },
+        ps->tileElement,
+        ps->sprite_type,
+    };
+    return { info };
 }
 
 /**
@@ -1574,10 +1579,11 @@ static bool is_sprite_interacted_with(rct_drawpixelinfo* dpi, int32_t imageId, i
  *
  *  rct2: 0x0068862C
  */
-static void set_interaction_info_from_paint_session(paint_session* session)
+static InteractionInfo set_interaction_info_from_paint_session(paint_session* session, uint16_t flags)
 {
     paint_struct* ps = &session->PaintHead;
     rct_drawpixelinfo* dpi = &session->DPI;
+    InteractionInfo info{};
 
     while ((ps = ps->next_quadrant_ps) != nullptr)
     {
@@ -1588,7 +1594,10 @@ static void set_interaction_info_from_paint_session(paint_session* session)
             ps = next_ps;
             if (is_sprite_interacted_with(dpi, ps->image_id, ps->x, ps->y))
             {
-                store_interaction_info(ps);
+                if (auto newInfo = GetInteractionInfoFromPS(ps, flags); newInfo)
+                {
+                    info = *newInfo;
+                }
             }
             next_ps = ps->children;
         }
@@ -1598,12 +1607,16 @@ static void set_interaction_info_from_paint_session(paint_session* session)
             if (is_sprite_interacted_with(
                     dpi, attached_ps->image_id, (attached_ps->x + ps->x) & 0xFFFF, (attached_ps->y + ps->y) & 0xFFFF))
             {
-                store_interaction_info(ps);
+                if (auto newInfo = GetInteractionInfoFromPS(ps, flags); newInfo)
+                {
+                    info = *newInfo;
+                }
             }
         }
 
         ps = old_ps;
     }
+    return info;
 }
 
 /**
@@ -1645,8 +1658,7 @@ void get_map_coordinates_from_pos_window(
     rct_window* window, ScreenCoordsXY screenCoords, int32_t flags, CoordsXY& mapCoords, int32_t* interactionType,
     TileElement** tileElement, rct_viewport** viewport)
 {
-    _interactionFlags = flags & 0xFFFF;
-    _interactionSpriteType = 0;
+    InteractionInfo info{};
     if (window != nullptr && window->viewport != nullptr)
     {
         rct_viewport* myviewport = window->viewport;
@@ -1674,20 +1686,19 @@ void get_map_coordinates_from_pos_window(
             paint_session* session = paint_session_alloc(dpi, myviewport->flags);
             paint_session_generate(session);
             paint_session_arrange(session);
-            set_interaction_info_from_paint_session(session);
+            info = set_interaction_info_from_paint_session(session, flags & 0xFFFF);
             paint_session_free(session);
         }
         if (viewport != nullptr)
             *viewport = myviewport;
     }
     if (interactionType != nullptr)
-        *interactionType = _interactionSpriteType;
+        *interactionType = info.SpriteType;
 
-    mapCoords.x = _interactionMapX;
-    mapCoords.y = _interactionMapY;
+    mapCoords = info.loc;
 
     if (tileElement != nullptr)
-        *tileElement = _interaction_element;
+        *tileElement = info.element;
 }
 
 /**