o3de/Gems/Camera/Code/Source/CameraComponentController.h

/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */

#pragma once

#include <AzCore/Asset/AssetCommon.h>
#include <AzCore/Component/Component.h>
#include <AzCore/Component/TransformBus.h>
#include <AzFramework/Components/CameraBus.h>
#include <AzFramework/Viewport/CameraState.h>
#include <Atom/RPI.Public/AuxGeom/AuxGeomFeatureProcessorInterface.h>
#include <Atom/RPI.Public/Base.h>
#include <Atom/RPI.Public/RenderPipeline.h>
#include <Atom/RPI.Public/ViewGroup.h>
#include <Atom/RPI.Public/ViewportContextBus.h>
#include <Atom/RPI.Public/ViewProviderBus.h>
#include <Atom/RPI.Public/XR/XRRenderingInterface.h>
#include <Atom/RPI.Public/XR/XRSpaceNotificationBus.h>
#include <Atom/RPI.Reflect/Image/AttachmentImageAsset.h>

namespace Camera
{
    static constexpr float DefaultFoV = 75.0f;
    static constexpr float MinFoV = std::numeric_limits<float>::epsilon();
    static constexpr float MaxFoV = AZ::RadToDeg(AZ::Constants::Pi);
    static constexpr float MinimumNearPlaneDistance = 0.001f;
    static constexpr float DefaultNearPlaneDistance = 0.2f;
    static constexpr float DefaultFarClipPlaneDistance = 1024.0f;
    static constexpr float DefaultFrustumDimension = 256.f;

    struct CameraComponentConfig final
        : public AZ::ComponentConfig
    {
        AZ_CLASS_ALLOCATOR(CameraComponentConfig, AZ::SystemAllocator)
        AZ_RTTI(CameraComponentConfig, "{064A5D64-8688-4188-B3DE-C80CE4BB7558}", AZ::ComponentConfig);

        static void Reflect(AZ::ReflectContext* context);

        float GetFarClipDistance() const;
        float GetNearClipDistance() const;
        AZ::EntityId GetEditorEntityId() const;

        AZ::u32 GetPerspectiveParameterVisibility() const;
        AZ::u32 GetOrthographicParameterVisibility() const;

        // Reflected members
        float m_fov = DefaultFoV;
        float m_nearClipDistance = DefaultNearPlaneDistance;
        float m_farClipDistance = DefaultFarClipPlaneDistance;
        float m_frustumWidth = DefaultFrustumDimension;
        float m_frustumHeight = DefaultFrustumDimension;
        bool m_specifyFrustumDimensions = false;
        bool m_makeActiveViewOnActivation = true;
        bool m_orthographic = false;
        bool m_allowPipelineChanges = false;
        float m_orthographicHalfWidth = 5.f;

        AZ::u64 m_editorEntityId = AZ::EntityId::InvalidEntityId;

        // Members for render to texture
        // The texture assets which is used for render to texture feature. It defines the resolution, format etc.
        AZ::Data::Asset<AZ::RPI::AttachmentImageAsset> m_renderTextureAsset;
        // The pass template name used for render pipeline's root template
        AZStd::string m_pipelineTemplate = "CameraPipeline";
    private:
        //! Check if experimental features are enabled
        AZ::u32 GetAllowPipelineChangesVisibility() const;
    };

    class CameraComponentController
        : public CameraBus::Handler
        , public CameraRequestBus::Handler
        , public AZ::TransformNotificationBus::Handler
        , public AZ::RPI::ViewportContextNotificationBus::Handler
        , public AZ::RPI::ViewProviderBus::Handler
        , public AZ::RPI::XRSpaceNotificationBus::Handler
    {
    public:
        AZ_TYPE_INFO(CameraComponentController, "{A27A0725-8C07-4BF2-BF95-B6CB0CBD01B8}");

        CameraComponentController() = default;
        explicit CameraComponentController(const CameraComponentConfig& config);

        //! Defines a callback for determining whether this camera should push itself to the top of the Atom camera stack.
        //! Used by the Editor to disable undesirable camera changes in edit mode.
        void SetShouldActivateFunction(AZStd::function<bool()> shouldActivateFunction);

        //! Defines a callback for determining whether this camera is currently locked by its transform.
        void SetIsLockedFunction(AZStd::function<bool()> isLockedFunction);

        // Controller interface
        static void Reflect(AZ::ReflectContext* context);
        static void GetRequiredServices(AZ::ComponentDescriptor::DependencyArrayType& required);
        static void GetProvidedServices(AZ::ComponentDescriptor::DependencyArrayType& provided);
        static void GetIncompatibleServices(AZ::ComponentDescriptor::DependencyArrayType& incompatible);

        void Init();
        void Activate(AZ::EntityId entityId);
        void Deactivate();
        void SetConfiguration(const CameraComponentConfig& config);
        const CameraComponentConfig& GetConfiguration() const;
        AZ::RPI::ViewportContextPtr GetViewportContext();

        // CameraBus::Handler interface
        AZ::EntityId GetCameras() override;

        // CameraRequestBus::Handler interface
        float GetFovDegrees() override;
        float GetFovRadians() override;
        float GetNearClipDistance() override;
        float GetFarClipDistance() override;
        float GetFrustumWidth() override;
        float GetFrustumHeight() override;
        bool IsOrthographic() override;
        float GetOrthographicHalfWidth() override;
        void SetFovDegrees(float fov) override;
        void SetFovRadians(float fov) override;
        void SetNearClipDistance(float nearClipDistance) override;
        void SetFarClipDistance(float farClipDistance) override;
        void SetFrustumWidth(float width) override;
        void SetFrustumHeight(float height) override;
        void SetOrthographic(bool orthographic) override;
        void SetOrthographicHalfWidth(float halfWidth) override;
        void SetXRViewQuaternion(const AZ::Quaternion& viewQuat, uint32_t xrViewIndex) override;

        void MakeActiveView() override;
        bool IsActiveView() override;

        AZ::Vector3 ScreenToWorld(const AZ::Vector2& screenPosition, float depth) override;
        AZ::Vector3 ScreenNdcToWorld(const AZ::Vector2& screenNdcPosition, float depth) override;
        AZ::Vector2 WorldToScreen(const AZ::Vector3& worldPosition) override;
        AZ::Vector2 WorldToScreenNdc(const AZ::Vector3& worldPosition) override;

        // AZ::TransformNotificationBus::Handler interface
        void OnTransformChanged(const AZ::Transform& local, const AZ::Transform& world) override;

        // AZ::RPI::ViewportContextNotificationBus::Handler interface
        void OnViewportSizeChanged(AzFramework::WindowSize size) override;
        void OnViewportDefaultViewChanged(AZ::RPI::ViewPtr view) override;

        // AZ::RPI::ViewProviderBus::Handler interface
        AZ::RPI::ViewPtr GetView() const override;
        AZ::RPI::ViewPtr GetStereoscopicView(AZ::RPI::ViewType viewType) const override;

        ///////////////////////////////////////////////////////////////////////
        // AZ::RPI::XRSpaceNotificationBus::Handler Overrides
        void OnXRSpaceLocationsChanged(
            const AZ::Transform& HeadRelativeToBaseSpaceTm,
            const AZ::Transform& LeftEyeRelativeToHeadTm,
            const AZ::Transform& RightEyeRelativeToHeadTm) override;
        ///////////////////////////////////////////////////////////////////////

    private:
        AZ_DISABLE_COPY(CameraComponentController);

        void CreateRenderPipelineForTexture();

        void ActivateAtomView();
        void DeactivateAtomView();
        void UpdateCamera();
        void SetupAtomAuxGeom(AZ::RPI::ViewportContextPtr viewportContext);
        AzFramework::CameraState GetCameraState();

        CameraComponentConfig m_config;
        AZ::EntityId m_entityId;

        // Atom integration
        AZ::RPI::ViewGroupPtr m_atomCameraViewGroup = nullptr;

        AZ::RPI::AuxGeomDrawPtr m_atomAuxGeom;
       
        bool m_updatingTransformFromEntity = false;
        bool m_isActiveView = false;

        AZStd::function<bool()> m_shouldActivateFn;
        AZStd::function<bool()> m_isLockedFn = []{ return false; };

        // for render to texture
        AZ::RPI::RenderPipelinePtr m_renderToTexturePipeline;

        //! From this point onwards the member variables are only applicable
        //! when the XRRenderingInterface is active.
        AZ::RPI::XRRenderingInterface* m_xrSystem = nullptr;
        AZ::u32 m_numSterescopicViews = 0;

        // Remarks, When using the XR Gem the world camera transform will be:
        // entityWorldTm = m_xrCameraToBaseSpaceTm * baseSpaceToHeadTm
        // And for each Eye it will be:
        // leftEyeWorldTm = m_xrCameraToBaseSpaceTm * baseSpaceToHeadTm * HeadToLeftEyeTm;
        // rightEyeWorldTm = m_xrCameraToBaseSpaceTm * baseSpaceToHeadTm * HeadToRightEyeTm;
        AZ::Transform m_xrCameraToBaseSpaceTm;
        AZ::Transform m_xrBaseSpaceToHeadTm; // Comes from the XR System
        AZ::Transform m_xrHeadToLeftEyeTm; // Comes from the XR System
        AZ::Transform m_xrHeadToRightEyeTm; // Comes from the XR System
    };
} // namespace Camera