gl viewport

NResUI/ImGuiUI/ViewportPanel.cs

@@ -0,0 +1,124 @@
+using System.Numerics;
+using ImGuiNET;
+using NResUI.Abstractions;
+using NResUI.Rendering.Viewport;
+using NResUI.Rendering.Viewport.Meshes;
+using Silk.NET.OpenGL;
+using Silk.NET.Windowing;
+
+namespace NResUI.ImGuiUI;
+
+public sealed class ViewportPanel : IImGuiPanel
+{
+    private readonly ViewportRenderer _renderer;
+    private readonly ViewportScene _scene;
+    private readonly ViewportCamera _camera = new();
+    private readonly ViewportInputController _inputController = new();
+
+    public ViewportPanel(GL gl, IWindow window)
+    {
+        var cubeMesh = PrimitiveMeshes.CreateCube(gl);
+        var gridMesh = PrimitiveMeshes.CreateWorldGrid(gl);
+
+        _scene = ViewportScene.CreateDefaultCubeScene(cubeMesh, gridMesh);
+        _renderer = new ViewportRenderer(gl, window);
+    }
+
+    public void OnImGuiRender()
+    {
+        if (!ImGui.Begin("Viewport"))
+        {
+            ImGui.End();
+            return;
+        }
+
+        DrawSelectionStatus();
+        DrawGridToggle();
+
+        var imageSize = ImGui.GetContentRegionAvail();
+        if (imageSize.X < 32 || imageSize.Y < 32)
+        {
+            ImGui.TextDisabled("Viewport is too small.");
+            ImGui.End();
+            return;
+        }
+
+        var textureId = _renderer.Render(
+            width: Math.Max(1, (int)imageSize.X),
+            height: Math.Max(1, (int)imageSize.Y),
+            scene: _scene,
+            camera: _camera);
+
+        ImGui.Image(
+            (IntPtr)textureId,
+            imageSize,
+            new Vector2(0, 1),
+            new Vector2(1, 0));
+
+        var viewportHovered = ImGui.IsItemHovered();
+        var imageMin = ImGui.GetItemRectMin();
+
+        DrawViewportHelpOverlay();
+
+        _inputController.Handle(
+            _scene,
+            _camera,
+            viewportHovered,
+            imageMin,
+            imageSize);
+
+        ImGui.End();
+    }
+
+    private void DrawSelectionStatus()
+    {
+        var selectedPiece = _scene.SelectedPiece;
+        if (selectedPiece != null)
+            ImGui.Text($"Selected: {selectedPiece.Name}");
+        else
+            ImGui.TextDisabled("Selected: none");
+    }
+
+    private void DrawGridToggle()
+    {
+        var grid = _scene.Grid;
+        if (grid == null)
+            return;
+
+        var isVisible = grid.IsVisible;
+        if (ImGui.Checkbox("Show grid", ref isVisible))
+            grid.IsVisible = isVisible;
+    }
+
+    private static void DrawViewportHelpOverlay()
+    {
+        var drawList = ImGui.GetWindowDrawList();
+
+        var imageMin = ImGui.GetItemRectMin();
+        var imageMax = ImGui.GetItemRectMax();
+
+        const string helpText = "LMB click: select / deselect\nMMB drag: rotate\nMouse wheel: zoom";
+
+        var textSize = ImGui.CalcTextSize(helpText);
+        var padding = new Vector2(8.0f, 6.0f);
+
+        var boxMin = new Vector2(
+            imageMin.X + 8.0f,
+            imageMax.Y - textSize.Y - padding.Y * 2.0f - 8.0f);
+
+        var boxMax = new Vector2(
+            boxMin.X + textSize.X + padding.X * 2.0f,
+            boxMin.Y + textSize.Y + padding.Y * 2.0f);
+
+        drawList.AddRectFilled(
+            boxMin,
+            boxMax,
+            ImGui.GetColorU32(new Vector4(0.0f, 0.0f, 0.0f, 0.45f)),
+            4.0f);
+
+        drawList.AddText(
+            boxMin + padding,
+            ImGui.GetColorU32(new Vector4(1.0f, 1.0f, 1.0f, 0.9f)),
+            helpText);
+    }
+}