Formalize scene viewport navigation input helpers

editor/src/Viewport/SceneViewportEditorModes.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <cstdint>
+
+namespace XCEngine {
+namespace Editor {
+
+enum class SceneViewportToolMode : uint8_t {
+    ViewMove = 0,
+    Move,
+    Rotate,
+    Scale,
+    Transform
+};
+
+enum class SceneViewportPivotMode : uint8_t {
+    Pivot = 0,
+    Center
+};
+
+enum class SceneViewportTransformSpaceMode : uint8_t {
+    Global = 0,
+    Local
+};
+
+} // namespace Editor
+} // namespace XCEngine

editor/src/Viewport/SceneViewportNavigation.h

@@ -0,0 +1,279 @@
+#pragma once
+
+#include "IViewportHostService.h"
+#include "SceneViewportEditorModes.h"
+
+#include <imgui.h>
+
+namespace XCEngine {
+namespace Editor {
+
+struct SceneViewportToolShortcutRequest {
+    bool wantTextInput = false;
+    bool lookDragging = false;
+    bool panDragging = false;
+    bool pressedViewMove = false;
+    bool pressedMove = false;
+    bool pressedRotate = false;
+    bool pressedScale = false;
+};
+
+struct SceneViewportToolShortcutAction {
+    SceneViewportToolMode targetTool = SceneViewportToolMode::Move;
+    bool triggered = false;
+    bool cancelMoveGizmo = false;
+    bool cancelRotateGizmo = false;
+    bool cancelScaleGizmo = false;
+
+    bool HasAction() const {
+        return triggered;
+    }
+};
+
+inline bool CanUseSceneViewportToolShortcut(const SceneViewportToolShortcutRequest& request) {
+    return !request.wantTextInput && !request.lookDragging && !request.panDragging;
+}
+
+inline SceneViewportToolShortcutAction BuildSceneViewportToolShortcutAction(
+    const SceneViewportToolShortcutRequest& request) {
+    SceneViewportToolShortcutAction action = {};
+    if (!CanUseSceneViewportToolShortcut(request)) {
+        return action;
+    }
+
+    if (request.pressedViewMove) {
+        action.targetTool = SceneViewportToolMode::ViewMove;
+        action.triggered = true;
+        action.cancelMoveGizmo = true;
+        action.cancelRotateGizmo = true;
+        action.cancelScaleGizmo = true;
+    } else if (request.pressedMove) {
+        action.targetTool = SceneViewportToolMode::Move;
+        action.triggered = true;
+        action.cancelRotateGizmo = true;
+        action.cancelScaleGizmo = true;
+    } else if (request.pressedRotate) {
+        action.targetTool = SceneViewportToolMode::Rotate;
+        action.triggered = true;
+        action.cancelMoveGizmo = true;
+        action.cancelScaleGizmo = true;
+    } else if (request.pressedScale) {
+        action.targetTool = SceneViewportToolMode::Scale;
+        action.triggered = true;
+        action.cancelMoveGizmo = true;
+        action.cancelRotateGizmo = true;
+    }
+
+    return action;
+}
+
+struct SceneViewportNavigationState {
+    bool lookDragging = false;
+    bool panDragging = false;
+    int panDragButton = ImGuiMouseButton_Middle;
+};
+
+struct SceneViewportNavigationRequest {
+    SceneViewportNavigationState state = {};
+    bool hasInteractiveViewport = false;
+    bool viewportHovered = false;
+    bool usingViewMoveTool = false;
+    bool gizmoActive = false;
+    bool clickedLeft = false;
+    bool clickedRight = false;
+    bool clickedMiddle = false;
+    bool leftMouseDown = false;
+    bool rightMouseDown = false;
+    bool middleMouseDown = false;
+};
+
+struct SceneViewportNavigationUpdate {
+    SceneViewportNavigationState state = {};
+    bool beginLookDrag = false;
+    bool beginPanDrag = false;
+    bool beginLeftPanDrag = false;
+    bool beginMiddlePanDrag = false;
+};
+
+inline bool ShouldBeginSceneViewportNavigationDrag(
+    bool hasInteractiveViewport,
+    bool hovered,
+    bool activeDrag,
+    bool otherDrag,
+    bool gizmoActive,
+    bool clicked) {
+    return hasInteractiveViewport && hovered && !activeDrag && !otherDrag && !gizmoActive && clicked;
+}
+
+inline bool IsSceneViewportPanDragButtonDown(
+    const SceneViewportNavigationRequest& request,
+    int button) {
+    switch (button) {
+    case ImGuiMouseButton_Left:
+        return request.leftMouseDown;
+    case ImGuiMouseButton_Right:
+        return request.rightMouseDown;
+    case ImGuiMouseButton_Middle:
+    default:
+        return request.middleMouseDown;
+    }
+}
+
+inline SceneViewportNavigationUpdate UpdateSceneViewportNavigationState(
+    const SceneViewportNavigationRequest& request) {
+    SceneViewportNavigationUpdate update = {};
+    update.state = request.state;
+    update.beginLeftPanDrag = request.usingViewMoveTool
+        ? ShouldBeginSceneViewportNavigationDrag(
+            request.hasInteractiveViewport,
+            request.viewportHovered,
+            request.state.panDragging,
+            request.state.lookDragging,
+            request.gizmoActive,
+            request.clickedLeft)
+        : false;
+    update.beginLookDrag = ShouldBeginSceneViewportNavigationDrag(
+        request.hasInteractiveViewport,
+        request.viewportHovered,
+        request.state.lookDragging,
+        request.state.panDragging,
+        request.gizmoActive,
+        request.clickedRight);
+    update.beginMiddlePanDrag = ShouldBeginSceneViewportNavigationDrag(
+        request.hasInteractiveViewport,
+        request.viewportHovered,
+        request.state.panDragging,
+        request.state.lookDragging,
+        request.gizmoActive,
+        request.clickedMiddle);
+    update.beginPanDrag = update.beginLeftPanDrag || update.beginMiddlePanDrag;
+
+    if (update.beginLookDrag) {
+        update.state.lookDragging = true;
+        update.state.panDragging = false;
+    }
+    if (update.beginPanDrag) {
+        update.state.panDragging = true;
+        update.state.lookDragging = false;
+        update.state.panDragButton = update.beginLeftPanDrag
+            ? ImGuiMouseButton_Left
+            : ImGuiMouseButton_Middle;
+    }
+
+    if (update.state.lookDragging && !request.rightMouseDown) {
+        update.state.lookDragging = false;
+    }
+    if (update.state.panDragging &&
+        !IsSceneViewportPanDragButtonDown(request, update.state.panDragButton)) {
+        update.state.panDragging = false;
+        update.state.panDragButton = ImGuiMouseButton_Middle;
+    }
+
+    return update;
+}
+
+struct SceneViewportCaptureRequest {
+    SceneViewportNavigationState state = {};
+    bool moveGizmoActive = false;
+    bool rotateGizmoActive = false;
+    bool scaleGizmoActive = false;
+};
+
+struct SceneViewportCaptureFlags {
+    bool captureMouse = false;
+    bool captureKeyboard = false;
+};
+
+inline SceneViewportCaptureFlags BuildSceneViewportCaptureFlags(
+    const SceneViewportCaptureRequest& request) {
+    SceneViewportCaptureFlags flags = {};
+    flags.captureMouse =
+        request.state.lookDragging ||
+        request.state.panDragging ||
+        request.moveGizmoActive ||
+        request.rotateGizmoActive ||
+        request.scaleGizmoActive;
+    flags.captureKeyboard = request.state.lookDragging;
+    return flags;
+}
+
+inline bool CanResolveSceneViewportInteraction(
+    bool hasInteractiveViewport,
+    bool viewportHovered,
+    bool usingViewMoveTool,
+    const SceneViewportNavigationState& navigationState,
+    bool gizmoActive) {
+    return hasInteractiveViewport &&
+        viewportHovered &&
+        !usingViewMoveTool &&
+        !navigationState.lookDragging &&
+        !navigationState.panDragging &&
+        !gizmoActive;
+}
+
+struct SceneViewportInputBuildRequest {
+    SceneViewportNavigationState state = {};
+    ImVec2 viewportSize = ImVec2(0.0f, 0.0f);
+    ImVec2 mouseDelta = ImVec2(0.0f, 0.0f);
+    float mouseWheel = 0.0f;
+    float deltaTime = 0.0f;
+    bool viewportHovered = false;
+    bool viewportFocused = false;
+    bool wantTextInput = false;
+    bool fastMove = false;
+    bool focusSelectionKeyPressed = false;
+    bool moveForwardKeyDown = false;
+    bool moveBackwardKeyDown = false;
+    bool moveRightKeyDown = false;
+    bool moveLeftKeyDown = false;
+    bool moveUpKeyDown = false;
+    bool moveDownKeyDown = false;
+};
+
+inline SceneViewportInput BuildSceneViewportInput(const SceneViewportInputBuildRequest& request) {
+    SceneViewportInput input = {};
+    input.viewportSize = request.viewportSize;
+    input.deltaTime = request.deltaTime;
+    input.hovered = request.viewportHovered;
+    input.focused =
+        request.viewportFocused ||
+        request.state.lookDragging ||
+        request.state.panDragging;
+    input.mouseWheel =
+        (request.viewportHovered && !request.state.lookDragging)
+        ? request.mouseWheel
+        : 0.0f;
+    input.flySpeedDelta =
+        (request.viewportHovered && request.state.lookDragging)
+        ? request.mouseWheel
+        : 0.0f;
+    input.looking = request.state.lookDragging;
+    input.orbiting = false;
+    input.panning = request.state.panDragging;
+    input.fastMove = request.fastMove;
+    input.focusSelectionRequested =
+        input.focused &&
+        !request.wantTextInput &&
+        request.focusSelectionKeyPressed;
+
+    if (request.state.lookDragging && !request.wantTextInput) {
+        input.moveForward =
+            (request.moveForwardKeyDown ? 1.0f : 0.0f) -
+            (request.moveBackwardKeyDown ? 1.0f : 0.0f);
+        input.moveRight =
+            (request.moveRightKeyDown ? 1.0f : 0.0f) -
+            (request.moveLeftKeyDown ? 1.0f : 0.0f);
+        input.moveUp =
+            (request.moveUpKeyDown ? 1.0f : 0.0f) -
+            (request.moveDownKeyDown ? 1.0f : 0.0f);
+    }
+
+    if (request.state.lookDragging || request.state.panDragging) {
+        input.mouseDelta = request.mouseDelta;
+    }
+
+    return input;
+}
+
+} // namespace Editor
+} // namespace XCEngine