From a1cd02c61cb1bca643f632528a20f6e8927c933c Mon Sep 17 00:00:00 2001
From: Ted John <ted@brambles.org>
Date: Sat, 22 Aug 2020 15:39:58 +0100
Subject: [PATCH] Disable closer zoom levels for software rendering

---
 src/openrct2/Context.cpp             |  2 ++
 src/openrct2/interface/Viewport.cpp  | 13 +++++++++++++
 src/openrct2/interface/Window.cpp    | 13 +++++++++++++
 src/openrct2/interface/Window.h      |  1 +
 src/openrct2/interface/ZoomLevel.hpp |  5 +----
 5 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/openrct2/Context.cpp b/src/openrct2/Context.cpp
index edcb7f89d0..f49d4712c6 100644
--- a/src/openrct2/Context.cpp
+++ b/src/openrct2/Context.cpp
@@ -535,6 +535,8 @@ namespace OpenRCT2
                     }
                 }
             }
+
+            window_check_all_valid_zoom();
         }
 
         void DisposeDrawingEngine() final override
diff --git a/src/openrct2/interface/Viewport.cpp b/src/openrct2/interface/Viewport.cpp
index 24b44553ff..e60912e653 100644
--- a/src/openrct2/interface/Viewport.cpp
+++ b/src/openrct2/interface/Viewport.cpp
@@ -17,6 +17,7 @@
 #include "../core/Guard.hpp"
 #include "../core/JobPool.hpp"
 #include "../drawing/Drawing.h"
+#include "../drawing/IDrawingEngine.h"
 #include "../paint/Paint.h"
 #include "../peep/Staff.h"
 #include "../ride/Ride.h"
@@ -1926,3 +1927,15 @@ void viewport_set_saved_view()
         gSavedViewRotation = get_current_rotation();
     }
 }
+
+ZoomLevel ZoomLevel::min()
+{
+    if (drawing_engine_get_type() == DRAWING_ENGINE_OPENGL)
+    {
+        return -2;
+    }
+    else
+    {
+        return 0;
+    }
+}
diff --git a/src/openrct2/interface/Window.cpp b/src/openrct2/interface/Window.cpp
index 5044c31ac1..7db1cd7f29 100644
--- a/src/openrct2/interface/Window.cpp
+++ b/src/openrct2/interface/Window.cpp
@@ -1001,6 +1001,19 @@ void window_viewport_centre_tile_around_cursor(rct_window* w, int16_t map_x, int
                         centreLoc->y + rebased_y + (offset_y / w->viewport->zoom) };
 }
 
+/**
+ * For all windows with viewports, ensure they do not have a zoom level less than the minimum.
+ */
+void window_check_all_valid_zoom()
+{
+    window_visit_each([](rct_window* w) {
+        if (w->viewport != nullptr && w->viewport->zoom < ZoomLevel::min())
+        {
+            window_zoom_set(w, ZoomLevel::min(), false);
+        }
+    });
+}
+
 void window_zoom_set(rct_window* w, ZoomLevel zoomLevel, bool atCursor)
 {
     rct_viewport* v = w->viewport;
diff --git a/src/openrct2/interface/Window.h b/src/openrct2/interface/Window.h
index 993870aabb..3adaa4c06b 100644
--- a/src/openrct2/interface/Window.h
+++ b/src/openrct2/interface/Window.h
@@ -724,6 +724,7 @@ void window_rotate_camera(rct_window* w, int32_t direction);
 void window_viewport_get_map_coords_by_cursor(
     rct_window* w, int16_t* map_x, int16_t* map_y, int16_t* offset_x, int16_t* offset_y);
 void window_viewport_centre_tile_around_cursor(rct_window* w, int16_t map_x, int16_t map_y, int16_t offset_x, int16_t offset_y);
+void window_check_all_valid_zoom();
 void window_zoom_set(rct_window* w, ZoomLevel zoomLevel, bool atCursor);
 void window_zoom_in(rct_window* w, bool atCursor);
 void window_zoom_out(rct_window* w, bool atCursor);
diff --git a/src/openrct2/interface/ZoomLevel.hpp b/src/openrct2/interface/ZoomLevel.hpp
index 97a8ee1a05..6b12bb23e2 100644
--- a/src/openrct2/interface/ZoomLevel.hpp
+++ b/src/openrct2/interface/ZoomLevel.hpp
@@ -136,10 +136,7 @@ public:
             return lhs >> rhs._level;
     }
 
-    static constexpr ZoomLevel min()
-    {
-        return -2;
-    }
+    static ZoomLevel min();
 
     static constexpr ZoomLevel max()
     {