fix Image for non-existing textures in atlas

src/graphics/core/Atlas.cpp

@@ -34,6 +34,14 @@ const UVRegion& Atlas::get(const std::string& name) const {
     return regions.at(name);
 }
 
+std::optional<UVRegion> Atlas::getIf(const std::string& name) const {
+    const auto& found = regions.find(name);
+    if (found == regions.end()) {
+        return std::nullopt;
+    }
+    return found->second;
+}
+
 Texture* Atlas::getTexture() const {
     return texture.get();
 }

src/graphics/core/Atlas.hpp

@@ -5,6 +5,7 @@
 #include <string>
 #include <memory>
 #include <vector>
+#include <optional>
 #include <unordered_map>
 #include "../../maths/UVRegion.hpp"
 #include "../../typedefs.hpp"
@@ -31,6 +32,7 @@ public:
 
     bool has(const std::string& name) const;
     const UVRegion& get(const std::string& name) const;
+    std::optional<UVRegion> getIf(const std::string& name) const;
 
     Texture* getTexture() const;
     ImageData* getImage() const;

src/graphics/ui/elements/Image.cpp

@@ -30,14 +30,17 @@ void Image::draw(const DrawContext* pctx, Assets* assets) {
     } else {
         auto atlasName = this->texture.substr(0, separator);
         if (auto atlas = assets->get<Atlas>(atlasName)) {
-            texture = atlas->getTexture();
-            batch->texture(atlas->getTexture());
-            auto& region = atlas->get(this->texture.substr(separator+1));
-            batch->setRegion(region);
-            if (autoresize) {
-                setSize(glm::vec2(
-                    texture->getWidth()*region.getWidth(), 
-                    texture->getHeight()*region.getHeight()));
+            if (auto region = atlas->getIf(this->texture.substr(separator+1))) {
+                texture = atlas->getTexture();
+                batch->texture(atlas->getTexture());
+                batch->setRegion(*region);
+                if (autoresize) {
+                    setSize(glm::vec2(
+                        texture->getWidth()*region->getWidth(), 
+                        texture->getHeight()*region->getHeight()));
+                }
+            } else {
+                batch->texture(nullptr);
             }
         }
     }

src/logic/scripting/lua/libworld.cpp

@@ -26,7 +26,7 @@ static int l_world_get_list(lua::State* L) {
         lua::setfield(L, "name");
         
         auto assets = engine->getAssets();
-        std::string icon = "world:"+name+".icon";
+        std::string icon = "world#"+name+".icon";
         if (!AssetsLoader::loadExternalTexture(assets, icon, {
             worlds[i]/fs::path("icon.png"),
             worlds[i]/fs::path("preview.png")