Refactor scene viewport state into local sessions

editor/app/Features/Scene/SceneViewportSession.cpp

@@ -0,0 +1,116 @@
+#include "Scene/SceneViewportSession.h"
+
+#include "Scene/EditorSceneRuntime.h"
+
+namespace XCEngine::UI::Editor::App {
+
+namespace {
+
+std::uint64_t CombineSceneViewportRequestRevisions(
+    std::uint64_t sceneContentRevision,
+    std::uint64_t sceneViewCameraRevision) {
+    constexpr std::uint64_t kRevisionMixConstant = 0x9e3779b97f4a7c15ull;
+    return sceneContentRevision ^
+        (sceneViewCameraRevision + kRevisionMixConstant +
+         (sceneContentRevision << 6u) +
+         (sceneContentRevision >> 2u));
+}
+
+} // namespace
+
+SceneViewportSession::SceneViewportSession() {
+    Reset();
+}
+
+void SceneViewportSession::Reset() {
+    m_cameraController.Reset();
+    m_toolMode = SceneToolMode::Translate;
+    m_toolSpaceMode = SceneToolSpaceMode::World;
+    m_toolPivotMode = SceneToolPivotMode::Pivot;
+    m_cameraRevision = 0u;
+}
+
+EditorSceneCameraSnapshot SceneViewportSession::BuildCameraSnapshot() const {
+    EditorSceneCameraSnapshot snapshot = {};
+    snapshot.valid = true;
+    snapshot.position = m_cameraController.GetPosition();
+    snapshot.forward = m_cameraController.GetForward();
+    snapshot.right = m_cameraController.GetRight();
+    snapshot.up = m_cameraController.GetUp();
+    snapshot.verticalFovDegrees = 60.0f;
+    snapshot.nearClipPlane = 0.03f;
+    snapshot.farClipPlane = 2000.0f;
+    snapshot.orbitDistance = m_cameraController.GetDistance();
+    return snapshot;
+}
+
+SceneViewportRenderRequest SceneViewportSession::BuildRenderRequest(
+    const EditorSceneRuntime& sceneRuntime) const {
+    SceneViewportRenderRequest request = {};
+    request.camera = BuildCameraSnapshot();
+    request.requestRevision =
+        BuildRequestRevision(sceneRuntime.GetSceneContentRevision());
+    if (const std::optional<EditorSceneObjectId> selectedId =
+            sceneRuntime.GetSelectedObjectId();
+        selectedId.has_value()) {
+        request.selectedObjectIds.push_back(selectedId.value());
+        request.selectedHelpers =
+            sceneRuntime.BuildSelectedViewportHelperSnapshots();
+    }
+    return request;
+}
+
+void SceneViewportSession::ApplyCameraInput(
+    const SceneViewportCameraInputState& input) {
+    m_cameraController.ApplyInput(input);
+    IncrementCameraRevision();
+}
+
+bool SceneViewportSession::FocusSelection(
+    const EditorSceneRuntime& sceneRuntime) {
+    SceneTransformSnapshot snapshot = {};
+    if (!sceneRuntime.CaptureSelectedTransformSnapshot(snapshot)) {
+        return false;
+    }
+
+    m_cameraController.Focus(snapshot.position);
+    IncrementCameraRevision();
+    return true;
+}
+
+SceneToolMode SceneViewportSession::GetToolMode() const {
+    return m_toolMode;
+}
+
+SceneToolSpaceMode SceneViewportSession::GetToolSpaceMode() const {
+    return m_toolSpaceMode;
+}
+
+SceneToolPivotMode SceneViewportSession::GetToolPivotMode() const {
+    return m_toolPivotMode;
+}
+
+void SceneViewportSession::SetToolMode(SceneToolMode mode) {
+    m_toolMode = mode;
+}
+
+void SceneViewportSession::SetToolSpaceMode(SceneToolSpaceMode mode) {
+    m_toolSpaceMode = mode;
+}
+
+void SceneViewportSession::SetToolPivotMode(SceneToolPivotMode mode) {
+    m_toolPivotMode = mode;
+}
+
+void SceneViewportSession::IncrementCameraRevision() {
+    ++m_cameraRevision;
+}
+
+std::uint64_t SceneViewportSession::BuildRequestRevision(
+    std::uint64_t sceneContentRevision) const {
+    return CombineSceneViewportRequestRevisions(
+        sceneContentRevision,
+        m_cameraRevision);
+}
+
+} // namespace XCEngine::UI::Editor::App