Tooling

Source/Salty/World/WorldMapSubsystem.h

@@ -0,0 +1,121 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Subsystems/WorldSubsystem.h"
+#include "WorldMapSubsystem.generated.h"
+
+class UWorldMapDefinition;
+
+UENUM(BlueprintType)
+enum class EWorldMapMarkerShape : uint8
+{
+	/** A filled disc. Anything that is just somewhere. */
+	Dot,
+	/** An unfilled ring, so it does not hide what is under it. Objectives, regions of interest. */
+	Ring,
+	/** A cross. Reads at one pixel where a dot does not, which is what a waypoint needs when zoomed out. */
+	Cross,
+	/** A triangle pointing along Heading. The body you are in, and anything else with a facing. */
+	Arrow
+};
+
+/**
+ * Something to draw on the map at a place in the world. Purely a UI concern - nothing here is replicated and
+ * nothing gameplay does depends on a marker existing.
+ */
+USTRUCT(BlueprintType)
+struct SALTY_API FWorldMapMarker
+{
+	GENERATED_BODY()
+
+	/** Centimetres, world space. Z is ignored; the map is a plan. */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "World Map")
+	FVector WorldLocation = FVector::ZeroVector;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "World Map")
+	FText Label;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "World Map")
+	FLinearColor Colour = FLinearColor::White;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "World Map")
+	EWorldMapMarkerShape Shape = EWorldMapMarkerShape::Dot;
+
+	/** World yaw in degrees for Arrow: 0 points along world +X, which is to the right on the map. */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "World Map")
+	float HeadingDegrees = 0.f;
+
+	/** Drawn size in pixels, so a marker stays the same size however far the map is zoomed out. */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "World Map")
+	float SizePx = 7.f;
+};
+
+/**
+ * The map's registry: which definition this level has a map from, and what is on it.
+ *
+ * A world subsystem because a map belongs to a map. Markers are registered by whoever owns the thing being
+ * marked - an actor in BeginPlay, unregistering in EndPlay - rather than found by the map, because a widget
+ * that ran GetAllActorsOfClass to draw itself would be exactly the world search the conventions forbid.
+ *
+ * The local player's own body is deliberately NOT a registered marker: it moves every frame, and a registry
+ * entry rewritten every frame is a registry being used as a variable. The widget asks for it instead.
+ */
+UCLASS()
+class SALTY_API UWorldMapSubsystem : public UWorldSubsystem
+{
+	GENERATED_BODY()
+
+public:
+	virtual bool ShouldCreateSubsystem(UObject* Outer) const override;
+	virtual void Deinitialize() override;
+
+	/**
+	 * The definition whose Level is this world, loading it the first time it is asked for. Null when this level
+	 * has no map, which is the normal answer in L_Gym and is not an error.
+	 */
+	UFUNCTION(BlueprintCallable, Category = "World Map")
+	const UWorldMapDefinition* GetDefinition() const;
+
+	/** Adds a marker and returns its handle. Keep the handle; it is the only way to move or remove it. */
+	UFUNCTION(BlueprintCallable, Category = "World Map")
+	FGuid AddMarker(const FWorldMapMarker& Marker);
+
+	/** Replaces a marker wholesale. False when the handle is not one of ours. */
+	UFUNCTION(BlueprintCallable, Category = "World Map")
+	bool UpdateMarker(const FGuid& Handle, const FWorldMapMarker& Marker);
+
+	UFUNCTION(BlueprintCallable, Category = "World Map")
+	bool RemoveMarker(const FGuid& Handle);
+
+	const TMap<FGuid, FWorldMapMarker>& GetMarkers() const { return Markers; }
+
+	/**
+	 * Where the local player is, as a marker, or false when there is no local body to speak of - a dedicated
+	 * server, or a client before possession. The heading is the control rotation rather than the body's, because
+	 * on a map a player expects the arrow to point where they are looking.
+	 */
+	UFUNCTION(BlueprintCallable, Category = "World Map")
+	bool GetLocalPlayerMarker(FWorldMapMarker& OutMarker) const;
+
+	/**
+	 * Emits world_map_opened. Every way of opening the map calls this - the console command today, a HUD key
+	 * when there is one - so the count is of maps opened and not of the ways of opening them.
+	 */
+	UFUNCTION(BlueprintCallable, Category = "World Map")
+	void NoteMapOpened(FName LayerId, float MetresPerPixel, const FString& OpenedBy);
+
+	/** Raised when a marker is added, moved or removed. The widget subscribes; it never polls. */
+	DECLARE_MULTICAST_DELEGATE(FOnWorldMapMarkersChanged);
+	FOnWorldMapMarkersChanged OnMarkersChanged;
+
+private:
+	/** Every WorldMap definition whose Level is this world. Searched once; the answer, including none, sticks. */
+	void ResolveDefinition() const;
+
+	UPROPERTY(Transient)
+	mutable TObjectPtr<const UWorldMapDefinition> Definition;
+
+	mutable bool bResolved = false;
+
+	TMap<FGuid, FWorldMapMarker> Markers;
+};