Add mouse cell selection with camera, controller, game mode

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Config/DefaultEngine.ini

@@ -2,6 +2,7 @@
 
 [/Script/EngineSettings.GameMapsSettings]
 GameDefaultMap=/Engine/Maps/Templates/OpenWorld
+GlobalDefaultGameMode=/Script/Tactica.TacticaGameMode
 
 [/Script/Engine.RendererSettings]
 r.AllowStaticLighting=False

Source/Tactica/Private/GridCell.cpp

@@ -1,6 +1,7 @@
 #include "GridCell.h"
 #include "Components/StaticMeshComponent.h"
 #include "Engine/StaticMesh.h"
+#include "Materials/MaterialInstanceDynamic.h"
 #include "UObject/ConstructorHelpers.h"
 
 AGridCell::AGridCell()
@@ -23,4 +24,34 @@ AGridCell::AGridCell()
 	MeshComponent->SetRelativeScale3D(FVector(0.95f, 0.95f, 0.1f));
 	// 板の上面がActorの原点の高さに来るよう、厚さの半分(5cm)下げる
 	MeshComponent->SetRelativeLocation(FVector(0.0f, 0.0f, -5.0f));
+
+	// カーソルのレイキャスト(Visibilityチャンネル)に当たるようにする
+	MeshComponent->SetCollisionEnabled(ECollisionEnabled::QueryOnly);
+	MeshComponent->SetCollisionResponseToAllChannels(ECR_Ignore);
+	MeshComponent->SetCollisionResponseToChannel(ECC_Visibility, ECR_Block);
+
+	// 標準マテリアルを割り当てる(色パラメータ"Color"を持つ)
+	static ConstructorHelpers::FObjectFinder<UMaterialInterface> BaseMaterial(
+		TEXT("/Engine/BasicShapes/BasicShapeMaterial.BasicShapeMaterial"));
+	if (BaseMaterial.Succeeded())
+	{
+		MeshComponent->SetMaterial(0, BaseMaterial.Object);
+	}
+}
+
+void AGridCell::BeginPlay()
+{
+	Super::BeginPlay();
+
+	DynamicMaterial = MeshComponent->CreateDynamicMaterialInstance(0);
+	SetHighlighted(false);
+}
+
+void AGridCell::SetHighlighted(bool bHighlighted)
+{
+	if (DynamicMaterial)
+	{
+		DynamicMaterial->SetVectorParameterValue(TEXT("Color"),
+			bHighlighted ? HighlightColor : NormalColor);
+	}
 }

Source/Tactica/Private/TacticaCameraPawn.cpp

@@ -0,0 +1,15 @@
+#include "TacticaCameraPawn.h"
+#include "Camera/CameraComponent.h"
+
+ATacticaCameraPawn::ATacticaCameraPawn()
+{
+	PrimaryActorTick.bCanEverTick = false;
+
+	Camera = CreateDefaultSubobject<UCameraComponent>(TEXT("Camera"));
+	SetRootComponent(Camera);
+
+	// 3x3グリッド(中心 (100,100))を斜め上から見下ろす位置。
+	// 配置したPawnのActor位置を変えれば調整できる
+	Camera->SetRelativeLocation(FVector(-250.0f, 100.0f, 450.0f));
+	Camera->SetRelativeRotation(FRotator(-60.0f, 0.0f, 0.0f));
+}

Source/Tactica/Private/TacticaGameMode.cpp

@@ -0,0 +1,9 @@
+#include "TacticaGameMode.h"
+#include "TacticaPlayerController.h"
+#include "TacticaCameraPawn.h"
+
+ATacticaGameMode::ATacticaGameMode()
+{
+	DefaultPawnClass = ATacticaCameraPawn::StaticClass();
+	PlayerControllerClass = ATacticaPlayerController::StaticClass();
+}

Source/Tactica/Private/TacticaPlayerController.cpp

@@ -0,0 +1,62 @@
+#include "TacticaPlayerController.h"
+#include "GridCell.h"
+#include "Components/InputComponent.h"
+#include "InputCoreTypes.h"
+
+DEFINE_LOG_CATEGORY_STATIC(LogTacticaInput, Log, All);
+
+ATacticaPlayerController::ATacticaPlayerController()
+{
+	bShowMouseCursor = true;
+}
+
+void ATacticaPlayerController::SetupInputComponent()
+{
+	Super::SetupInputComponent();
+
+	if (InputComponent)
+	{
+		InputComponent->BindKey(EKeys::LeftMouseButton, IE_Pressed, this,
+			&ATacticaPlayerController::OnClick);
+	}
+}
+
+void ATacticaPlayerController::PlayerTick(float DeltaTime)
+{
+	Super::PlayerTick(DeltaTime);
+
+	AGridCell* Cell = GetCellUnderCursor();
+	if (Cell == HoveredCell)
+	{
+		return;
+	}
+
+	if (HoveredCell)
+	{
+		HoveredCell->SetHighlighted(false);
+	}
+	HoveredCell = Cell;
+	if (HoveredCell)
+	{
+		HoveredCell->SetHighlighted(true);
+	}
+}
+
+AGridCell* ATacticaPlayerController::GetCellUnderCursor() const
+{
+	FHitResult Hit;
+	if (GetHitResultUnderCursor(ECC_Visibility, false, Hit))
+	{
+		return Cast<AGridCell>(Hit.GetActor());
+	}
+	return nullptr;
+}
+
+void ATacticaPlayerController::OnClick()
+{
+	if (const AGridCell* Cell = GetCellUnderCursor())
+	{
+		UE_LOG(LogTacticaInput, Log, TEXT("Cell clicked: (%d, %d)"),
+			Cell->GridCoord.X, Cell->GridCoord.Y);
+	}
+}

Source/Tactica/Public/GridCell.h

@@ -5,6 +5,7 @@
 #include "GridCell.generated.h"
 
 class UStaticMeshComponent;
+class UMaterialInstanceDynamic;
 
 UCLASS()
 class TACTICA_API AGridCell : public AActor
@@ -29,4 +30,23 @@ public:
 	// 歩行可能か
 	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Grid")
 	bool bIsWalkable = true;
+
+	// 通常時の色
+	UPROPERTY(EditAnywhere, Category = "Grid|Highlight")
+	FLinearColor NormalColor = FLinearColor(0.15f, 0.15f, 0.15f);
+
+	// ハイライト時の色
+	UPROPERTY(EditAnywhere, Category = "Grid|Highlight")
+	FLinearColor HighlightColor = FLinearColor(1.0f, 0.8f, 0.1f);
+
+	// ハイライトのON/OFF
+	void SetHighlighted(bool bHighlighted);
+
+protected:
+	virtual void BeginPlay() override;
+
+private:
+	// 色変更用のダイナミックマテリアル
+	UPROPERTY()
+	TObjectPtr<UMaterialInstanceDynamic> DynamicMaterial;
 };

Source/Tactica/Public/TacticaCameraPawn.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "GameFramework/Pawn.h"
+#include "TacticaCameraPawn.generated.h"
+
+class UCameraComponent;
+
+// 固定の俯瞰カメラ
+UCLASS()
+class TACTICA_API ATacticaCameraPawn : public APawn
+{
+	GENERATED_BODY()
+
+public:
+	ATacticaCameraPawn();
+
+	UPROPERTY(VisibleAnywhere, Category = "Camera")
+	TObjectPtr<UCameraComponent> Camera;
+};

Source/Tactica/Public/TacticaGameMode.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "GameFramework/GameModeBase.h"
+#include "TacticaGameMode.generated.h"
+
+UCLASS()
+class TACTICA_API ATacticaGameMode : public AGameModeBase
+{
+	GENERATED_BODY()
+
+public:
+	ATacticaGameMode();
+};

Source/Tactica/Public/TacticaPlayerController.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "GameFramework/PlayerController.h"
+#include "TacticaPlayerController.generated.h"
+
+class AGridCell;
+
+UCLASS()
+class TACTICA_API ATacticaPlayerController : public APlayerController
+{
+	GENERATED_BODY()
+
+public:
+	ATacticaPlayerController();
+
+protected:
+	virtual void SetupInputComponent() override;
+	virtual void PlayerTick(float DeltaTime) override;
+
+private:
+	// カーソル下のマスを返す(なければnullptr)
+	AGridCell* GetCellUnderCursor() const;
+
+	void OnClick();
+
+	// 現在ハイライト中のマス
+	UPROPERTY()
+	TObjectPtr<AGridCell> HoveredCell;
+};