Start of dynamic camera in C++

GravityStomp/Config/DefaultEngine.ini

@@ -54,6 +54,7 @@ AppliedDefaultGraphicsPerformance=Maximum
 +ActiveGameNameRedirects=(OldGameName="/Script/TP_ThirdPerson",NewGameName="/Script/GravityStomp")
 +ActiveClassRedirects=(OldClassName="TP_ThirdPersonGameMode",NewClassName="GravityStompGameMode")
 +ActiveClassRedirects=(OldClassName="TP_ThirdPersonCharacter",NewClassName="GravityStompCharacter")
+WorldSettingsClassName=/Script/GravityStompGame.GSWorldSettings
 
 [/Script/AndroidFileServerEditor.AndroidFileServerRuntimeSettings]
 bEnablePlugin=True

GravityStomp/Source/GravityStompGame/Camera/GSCameraActor.cpp

@@ -0,0 +1,115 @@
+// Gravity Stomp Copyright Kevin Poretti
+
+#include "Camera/GSCameraActor.h"
+
+// UE includes
+#include "Kismet/KismetMathLibrary.h"
+#include "World/GSWorldSettings.h"
+
+AGSCameraActor::AGSCameraActor()
+{
+    PanSpeed = 100.0f;
+    ZoomSpeed = 100.0f;
+}
+
+
+void AGSCameraActor::Tick(float DeltaSeconds)
+{
+    Super::Tick(DeltaSeconds);
+
+    FBox2D ScreenBoundingBox = GetBoundingBoxFromViewportPercentage(0);
+
+    // bounding box of what is considered the "edge" of the screen
+    // when characters are outside of this box the camera should pan or zoom out
+    FBox2D EdgeBoundingBox = GetBoundingBoxFromViewportPercentage(0.15);
+
+    // bounding box of what is considered the "center" of the screen
+    // when all characters are inside of this box the camera should zoom in
+    FBox2D CenterBoundingBox = GetBoundingBoxFromViewportPercentage(0.15);
+
+    // debug
+    FVector2D ScreenBoxCenter = GetBoxCenter(ScreenBoundingBox);
+    float ScreenHeight, ScreenWidth;
+    GetBoxDimensions(ScreenBoundingBox, ScreenHeight, ScreenWidth);
+    DrawDebugBox(GetWorld(), FVector(0.0f, ScreenBoxCenter.X, ScreenBoxCenter.Y), FVector(0.0f, ScreenWidth/2, ScreenHeight/2), 
+    FColor::Magenta, false, -1, 0, 2.0f);
+
+    FVector CurrLocation = GetActorLocation();
+    float ZoomMove = ZoomDirection * ZoomSpeed * DeltaSeconds;
+    FVector2D PanMove = PanDirection * PanSpeed * DeltaSeconds;
+    FVector2D NewPan = FVector2D(CurrLocation.Y + PanMove.X, CurrLocation.Z + PanMove.Y);
+    NewPan = ClampCameraLocationToStageBounds(NewPan, ScreenBoundingBox);
+
+    FVector NewLocation = FVector(CurrLocation.X + ZoomMove, NewPan.X, NewPan.Y);
+    SetActorLocation(NewLocation);
+}
+
+
+FBox2D AGSCameraActor::GetBoundingBoxFromViewportPercentage(float ScreenPercentage) const
+{
+    APlayerController* PC = GetWorld()->GetFirstPlayerController();
+    int32 SizeX, SizeY;
+    PC->GetViewportSize(SizeX, SizeY);
+    float MinX = ((float)SizeX) * ScreenPercentage;
+    float MinY = ((float)SizeY) * ScreenPercentage;
+    float MaxX = ((float)SizeX) * (1 - ScreenPercentage);
+    float MaxY = ((float)SizeY) * (1 - ScreenPercentage);
+    FVector TopRight = GetWorldLocationFromScreenCoords(MaxX, MinY);
+    FVector BottomLeft = GetWorldLocationFromScreenCoords(MinX, MaxY);
+
+    FBox2D Result;
+    Result.Min = FVector2D(BottomLeft.Y, BottomLeft.Z);
+    Result.Max = FVector2D(TopRight.Y, TopRight.Z);
+    return Result;
+}
+
+
+FVector2D AGSCameraActor::GetBoxCenter(FBox2D Box) const
+{
+    return FVector2D((Box.Min.X + Box.Max.X) / 2.0f, (Box.Min.Y + Box.Max.Y) / 2.0f);
+}
+
+
+void AGSCameraActor::GetBoxDimensions(FBox2D Box, float& BoxHeight, float& BoxWidth) const
+{
+    BoxWidth = FMath::Abs(Box.Max.X - Box.Min.X);
+    BoxHeight = FMath::Abs(Box.Max.Y - Box.Min.Y);
+}
+
+
+FVector AGSCameraActor::GetWorldLocationFromScreenCoords(float InX, float InY) const
+{
+    APlayerController* PC = GetWorld()->GetFirstPlayerController();
+    FVector WorldLocation;
+    FVector WorldDirection;
+    PC->DeprojectScreenPositionToWorld(InX, InY, WorldLocation, WorldDirection);
+
+    FPlane XPlane = UKismetMathLibrary::MakePlaneFromPointAndNormal(FVector::ZeroVector, FVector::ForwardVector);
+    // NOTE: 10000 is a big enough number to make sure the intersection goes through the X = 0 plane
+    // there is probably a more elegant way to do this
+    float T;
+    FVector Result = FVector::ZeroVector;
+    UKismetMathLibrary::LinePlaneIntersection(WorldLocation, WorldLocation + (WorldDirection * 10000), XPlane, T, Result);
+    return Result;    
+}
+
+
+FVector2D AGSCameraActor::ClampCameraLocationToStageBounds(FVector2D CameraLocation, FBox2D ScreenBox) const
+{
+    AGSWorldSettings* WS = Cast<AGSWorldSettings>(GetWorld()->GetWorldSettings());
+    FBox2D StageBounds = WS->StageBounds;
+
+    float ScreenHeight, ScreenWidth;
+    GetBoxDimensions(ScreenBox, ScreenHeight, ScreenWidth);
+    float HalfHeight = ScreenHeight / 2;
+    float HalfWidth = ScreenWidth / 2;
+
+    float MinStageX = StageBounds.Min.X + HalfWidth;
+    float MinStageY = StageBounds.Min.Y + HalfHeight;
+    float MaxStageX = StageBounds.Max.X - HalfWidth;
+    float MaxStageY = StageBounds.Max.Y - HalfHeight;
+
+    float FinalX = FMath::Clamp(CameraLocation.X, MinStageX, MaxStageX);
+    float FinalY = FMath::Clamp(CameraLocation.Y, MinStageY, MaxStageY);
+    return FVector2D(FinalX, FinalY);
+}

GravityStomp/Source/GravityStompGame/Camera/GSCameraActor.h

@@ -0,0 +1,45 @@
+// Gravity Stomp Copyright Kevin Poretti
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Camera/CameraActor.h"
+#include "GSCameraActor.generated.h"
+
+/**
+ * 
+ */
+UCLASS(showcategories=(Input))
+class GRAVITYSTOMPGAME_API AGSCameraActor : public ACameraActor
+{
+	GENERATED_BODY()
+
+public:
+    UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Camera Settings")
+	float PanSpeed;
+
+	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Camera Settings")
+	float ZoomSpeed;
+
+	UPROPERTY(BlueprintReadWrite)
+	FVector2D PanDirection;
+
+	UPROPERTY(BlueprintReadWrite)
+	float ZoomDirection;
+
+	AGSCameraActor();
+
+protected:
+	virtual void Tick(float DeltaSeconds) override;
+
+private:
+    FBox2D GetBoundingBoxFromViewportPercentage(float ScreenPercentage) const;
+
+    FVector2D GetBoxCenter(FBox2D Box) const;
+
+    void GetBoxDimensions(FBox2D Box, float& BoxHeight, float& BoxWidth) const;
+
+	FVector GetWorldLocationFromScreenCoords(float InX, float InY) const;
+
+	FVector2D ClampCameraLocationToStageBounds(FVector2D CameraLocation, FBox2D ScreenBox) const;
+};

GravityStomp/Source/GravityStompGame/GravityStompGame.Build.cs

@@ -22,7 +22,7 @@ public class GravityStompGame : ModuleRules
 				"CoreUObject", 
 				"Engine", 
 				"InputCore", 
-				"EnhancedInput" 
+				"EnhancedInput",
 			}
 		);
 	}

GravityStomp/Source/GravityStompGame/World/GSWorldSettings.cpp

@@ -0,0 +1,10 @@
+// Gravity Stomp Copyright Kevin Poretti
+
+
+#include "World/GSWorldSettings.h"
+
+AGSWorldSettings::AGSWorldSettings()
+{
+    StageBounds.Min = FVector2D(-2000.0f, 0.0f);
+    StageBounds.Max = FVector2D(2000.0f, 2250.0f);
+}

GravityStomp/Source/GravityStompGame/World/GSWorldSettings.h

@@ -0,0 +1,22 @@
+// Gravity Stomp Copyright Kevin Poretti
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "GameFramework/WorldSettings.h"
+#include "GSWorldSettings.generated.h"
+
+/**
+ * 
+ */
+UCLASS()
+class GRAVITYSTOMPGAME_API AGSWorldSettings : public AWorldSettings
+{
+	GENERATED_BODY()
+
+public:
+    AGSWorldSettings();
+
+	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Gravity Stomp Settings")
+	FBox2D StageBounds;
+};