Create park preview images from scenario meta objects

src/openrct2-ui/windows/ScenarioSelect.cpp

@@ -26,6 +26,9 @@
 #include <openrct2/localisation/Formatting.h>
 #include <openrct2/localisation/Localisation.Date.h>
 #include <openrct2/localisation/LocalisationService.h>
+#include <openrct2/object/ObjectManager.h>
+#include <openrct2/object/ObjectRepository.h>
+#include <openrct2/object/ScenarioMetaObject.h>
 #include <openrct2/park/ParkPreview.h>
 #include <openrct2/ride/RideData.h>
 #include <openrct2/scenario/Scenario.h>
@@ -190,29 +193,24 @@ namespace OpenRCT2::Ui::Windows
 
             auto& bgWorker = GetContext()->GetBackgroundWorker();
             auto& path = _highlightedScenario->Path;
-
-            _previewLoadJob = bgWorker.addJob(
-                [path]() {
-                    try
-                    {
-                        auto fs = FileStream(path, FileMode::open);
+            auto& name = _highlightedScenario->InternalName;
 
             ClassifiedFileInfo info;
-                        if (!TryClassifyFile(&fs, &info))
-                            return ParkPreview{};
+            if (!TryClassifyFile(path, &info))
+                return;
 
             if (info.Type == FileType::park)
             {
+                _previewLoadJob = bgWorker.addJob(
+                    [path, name]() {
+                        try
+                        {
+                            auto fs = FileStream(path, FileMode::open);
                             auto& objectRepository = GetContext()->GetObjectRepository();
                             auto parkImporter = ParkImporter::CreateParkFile(objectRepository);
                             parkImporter->LoadFromStream(&fs, false, true, path.c_str());
                             return parkImporter->GetParkPreview();
                         }
-                        else
-                        {
-                            return ParkPreview{};
-                        }
-                    }
                         catch (const std::exception& e)
                         {
                             LOG_ERROR("Could not get preview for \"%s\" due to %s", path.c_str(), e.what());
@@ -230,6 +228,43 @@ namespace OpenRCT2::Ui::Windows
                         scenarioSelectWnd->UpdateParkPreview(preview);
                     });
             }
+            else if (info.Type == FileType::scenario)
+            {
+                SourceDescriptor source{};
+                if (!ScenarioSources::TryGetByName(name, &source))
+                    return;
+
+                auto& objManager = GetContext()->GetObjectManager();
+
+                // Unload current scenario meta object if it's not the one we need
+                auto* loadedObject = objManager.GetLoadedObject(ObjectType::scenarioMeta, 0);
+                if (loadedObject != nullptr && loadedObject->GetIdentifier() != source.textObjectId)
+                {
+                    objManager.UnloadObjects({ loadedObject->GetDescriptor() });
+                    loadedObject = nullptr;
+                }
+
+                // Load the relevant scenario meta file if it hasn't been loaded yet
+                if (loadedObject == nullptr)
+                {
+                    loadedObject = objManager.LoadObject(source.textObjectId);
+                    if (loadedObject == nullptr)
+                        return;
+                }
+
+                auto* scenarioMetaObj = reinterpret_cast<ScenarioMetaObject*>(loadedObject);
+
+                ParkPreview preview{};
+                preview.images.push_back(scenarioMetaObj->GetMiniMapImage());
+                preview.images.push_back(scenarioMetaObj->GetPreviewImage());
+
+                _preview = preview;
+            }
+            else
+            {
+                return;
+            }
+        }
 
         void UpdateParkPreview(const ParkPreview& preview)
         {

src/openrct2/object/ScenarioMetaObject.cpp

@@ -51,12 +51,36 @@ std::string ScenarioMetaObject::GetScenarioDetails()
     return GetStringTable().GetString(ObjectStringID::SCENARIO_DETAILS);
 }
 
-ImageIndex ScenarioMetaObject::GetMiniMapImageIndex() const
+PreviewImage ScenarioMetaObject::GetMiniMapImage() const
 {
-    return _imageOffsetId;
+    PreviewImage preview{};
+    preview.type = PreviewImageType::miniMap;
+
+    auto* g1 = GfxGetG1Element(_imageOffsetId);
+    if (g1 == nullptr)
+        return preview;
+
+    preview.width = g1->width;
+    preview.height = g1->height;
+
+    std::copy_n(g1->offset, g1->width * g1->height, preview.pixels);
+
+    return preview;
 }
 
-ImageIndex ScenarioMetaObject::GetPreviewImageIndex() const
+PreviewImage ScenarioMetaObject::GetPreviewImage() const
 {
-    return _imageOffsetId + 1;
+    PreviewImage preview{};
+    preview.type = PreviewImageType::screenshot;
+
+    auto* g1 = GfxGetG1Element(_imageOffsetId + 1);
+    if (g1 == nullptr)
+        return preview;
+
+    preview.width = g1->width;
+    preview.height = g1->height;
+
+    std::copy_n(g1->offset, g1->width * g1->height, preview.pixels);
+
+    return preview;
 }

src/openrct2/object/ScenarioMetaObject.h

@@ -10,6 +10,7 @@
 #pragma once
 
 #include "../core/IStream.hpp"
+#include "../park/ParkPreview.h"
 #include "Object.h"
 
 #include <string>
@@ -30,6 +31,6 @@ public:
     std::string GetParkName();
     std::string GetScenarioDetails();
 
-    ImageIndex GetMiniMapImageIndex() const;
-    ImageIndex GetPreviewImageIndex() const;
+    OpenRCT2::PreviewImage GetMiniMapImage() const;
+    OpenRCT2::PreviewImage GetPreviewImage() const;
 };