Window improvements with a new approach

Source/Editor/Viewport/Previews/SkinnedModelPreview.cs

@@ -0,0 +1,188 @@
+using System;
+using FlaxEditor.GUI.ContextMenu;
+using FlaxEngine;
+using FlaxEngine.GUI;
+using FlaxEditor.Viewport.Widgets;
+
+namespace FlaxEditor.Viewport.Previews
+{
+    /// <summary>
+    /// Animation asset preview editor viewport.
+    /// </summary>
+    /// <seealso cref="AnimatedModelPreview" />
+    public class SkinnedModelPreview : AnimatedModelPreview
+    {
+        private bool _showCurrentLOD;
+        private ContextMenuButton _showCurrentLODButton;
+
+        /// <summary>
+        /// The "PreviewLODS" widget button context menu.
+        /// </summary>
+        private ContextMenu previewLODSWidgetButtonMenu;
+
+        /// <summary>
+        /// Gets or sets a value that shows LOD statistics
+        /// </summary>
+        public bool ShowCurrentLOD
+        {
+            get => _showCurrentLOD;
+            set
+            {
+                if (_showCurrentLOD == value)
+                    return;
+                _showCurrentLOD = value;
+                if (value)
+                    ShowDebugDraw = true;
+                if (_showCurrentLODButton != null)
+                    _showCurrentLODButton.Checked = value;
+            }
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SkinnedModelPreview"/> class.
+        /// </summary>
+        /// <param name="useWidgets">if set to <c>true</c> use widgets.</param>
+        public SkinnedModelPreview(bool useWidgets)
+        : base(useWidgets)
+        {
+            if (useWidgets)
+            {
+                // Show Current LOD
+                _showCurrentLODButton = ViewWidgetShowMenu.AddButton("Current LOD", button =>
+                {
+                    _showCurrentLOD = !_showCurrentLOD;
+                    _showCurrentLODButton.Icon = _showCurrentLOD ? Style.Current.CheckBoxTick : SpriteHandle.Invalid;
+                });
+                _showCurrentLODButton.IndexInParent = 2;
+
+                // PreviewLODS mode widget
+                var PreviewLODSMode = new ViewportWidgetsContainer(ViewportWidgetLocation.UpperRight);
+                previewLODSWidgetButtonMenu = new ContextMenu();
+                previewLODSWidgetButtonMenu.VisibleChanged += PreviewLODSWidgetMenuOnVisibleChanged;
+                var previewLODSModeButton = new ViewportWidgetButton("Preview LOD", SpriteHandle.Invalid, previewLODSWidgetButtonMenu)
+                {
+                    TooltipText = "Preview LOD properties",
+                    Parent = PreviewLODSMode,
+                };
+                PreviewLODSMode.Parent = this;
+            }
+        }
+
+        /// <summary>
+        /// Fill out all SkinnedModel LODS
+        /// </summary>
+        /// <param name="control"></param>
+        private void PreviewLODSWidgetMenuOnVisibleChanged(Control control)
+        {
+            if (!control.Visible)
+                return;
+
+            var skinned = _previewModel.SkinnedModel;
+            if (skinned && !skinned.WaitForLoaded() && skinned.IsLoaded)
+            {
+                previewLODSWidgetButtonMenu.ItemsContainer.DisposeChildren();
+                var lods = skinned.LODs.Length;
+                for (int i = -1; i < lods; i++)
+                {
+                    var index = i;
+                    var button = previewLODSWidgetButtonMenu.AddButton("LOD " + (index == -1 ? "Auto" : index));
+                    button.ButtonClicked += (button) => _previewModel.ForcedLOD = index;
+                    button.Checked = _previewModel.ForcedLOD == index;
+                    button.Tag = index;
+                    if (lods <= 1) return;
+                }
+            }
+        }
+
+        /// <inheritdoc />
+        private int ComputeLODIndex(SkinnedModel model, out float screenSize)
+        {
+            screenSize = 1.0f;
+            if (PreviewActor.ForcedLOD != -1)
+                return PreviewActor.ForcedLOD;
+
+            // Based on RenderTools::ComputeModelLOD
+            CreateProjectionMatrix(out var projectionMatrix);
+            float screenMultiple = 0.5f * Mathf.Max(projectionMatrix.M11, projectionMatrix.M22);
+            var sphere = PreviewActor.Sphere;
+            var viewOrigin = ViewPosition;
+            var distSqr = Vector3.DistanceSquared(ref sphere.Center, ref viewOrigin);
+            var screenRadiusSquared = Mathf.Square(screenMultiple * sphere.Radius) / Mathf.Max(1.0f, distSqr);
+            screenSize = Mathf.Sqrt((float)screenRadiusSquared) * 2.0f;
+
+            // Check if model is being culled
+            if (Mathf.Square(model.MinScreenSize * 0.5f) > screenRadiusSquared)
+                return -1;
+
+            // Skip if no need to calculate LOD
+            if (model.LoadedLODs == 0)
+                return -1;
+            var lods = model.LODs;
+            if (lods.Length == 0)
+                return -1;
+            if (lods.Length == 1)
+                return 0;
+
+            // Iterate backwards and return the first matching LOD
+            for (int lodIndex = lods.Length - 1; lodIndex >= 0; lodIndex--)
+            {
+                if (Mathf.Square(lods[lodIndex].ScreenSize * 0.5f) >= screenRadiusSquared)
+                {
+                    return lodIndex + PreviewActor.LODBias;
+                }
+            }
+
+            return 0;
+        }
+
+        /// <inheritdoc />
+        public override void Draw()
+        {
+            base.Draw();
+
+            var skinnedModel = _previewModel.SkinnedModel;
+            if (skinnedModel == null || !skinnedModel.IsLoaded)
+                return;
+            var lods = skinnedModel.LODs;
+            if (lods.Length == 0)
+            {
+                // Force show skeleton for models without geometry
+                ShowNodes = true;
+                return;
+            }
+            if (_showCurrentLOD)
+            {
+                var lodIndex = ComputeLODIndex(skinnedModel, out var screenSize);
+                var auto = _previewModel.ForcedLOD == -1;
+                string text = auto ? "LOD Automatic" : "";
+                text += auto ? string.Format("\nScreen Size: {0:F2}", screenSize) : "";
+                text += string.Format("\nCurrent LOD: {0}", lodIndex);
+                if (lodIndex != -1)
+                {
+                    lodIndex = Mathf.Clamp(lodIndex + PreviewActor.LODBias, 0, lods.Length - 1);
+                    var lod = lods[lodIndex];
+                    int triangleCount = 0, vertexCount = 0;
+                    for (int meshIndex = 0; meshIndex < lod.Meshes.Length; meshIndex++)
+                    {
+                        var mesh = lod.Meshes[meshIndex];
+                        triangleCount += mesh.TriangleCount;
+                        vertexCount += mesh.VertexCount;
+                    }
+                    text += string.Format("\nTriangles: {0:N0}\nVertices: {1:N0}", triangleCount, vertexCount);
+                }
+                var font = Style.Current.FontMedium;
+                var pos = new Float2(10, 50);
+                Render2D.DrawText(font, text, new Rectangle(pos + Float2.One, Size), Color.Black);
+                Render2D.DrawText(font, text, new Rectangle(pos, Size), Color.White);
+            }
+        }
+
+        /// <inheritdoc />
+        public override void OnDestroy()
+        {
+            _showCurrentLODButton = null;
+
+            base.OnDestroy();
+        }
+    }
+}