bluflame/intromat/Intromat/Views/Preview2DView.xaml.cs

using System;
using System.Reactive.Disposables;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using Intromat.Graphics;
using Intromat.Pipelines;
using Intromat.ViewModels.Previews;
using ReactiveUI;
using SharpDX.Direct3D11;
using Splat;

namespace Intromat.Views
{
    /// <summary>
    /// Interaction logic for Preview2DView.xaml
    /// </summary>
    public partial class Preview2DView : IViewFor<DxTexturePreviewViewModel>
    {
        private DisplayTexturePipeline? _pipeline;
        
        public static readonly DependencyProperty ViewModelProperty = DependencyProperty.Register(nameof(ViewModel),
            typeof(DxTexturePreviewViewModel), typeof(Preview2DView), new PropertyMetadata(null));

        public Preview2DView()
        {
            InitializeComponent();
            
            this.WhenActivated(d =>
            {
                _pipeline = Locator.Current.GetService<DisplayTexturePipeline>()!;
                this.WhenAnyObservable(v => v.ViewModel!.TextureValue).Subscribe(textureValue =>
                {
                    var srv = textureValue?.ShaderResourceView;
                    if (srv != null)
                    {
                        _pipeline.ShaderResourceView = srv;
                        _dxView.Render();
                    }
                }).DisposeWith(d);
                _dxView.SetUpdateHandler(UpdateFrameAction);
            });
        }

        private void UpdateFrameAction(Device device, DeviceContext context)
        {
            var graphicsAnalysis = Locator.Current.GetService<DxHost>()?._graphicsAnalysis;
            graphicsAnalysis?.BeginCapture();
            _pipeline?.Apply();
            graphicsAnalysis?.EndCapture();
        }

        private void OnDxViewMouseWheel(object sender, MouseWheelEventArgs e)
        {
            var element = (UIElement)sender;
            var position = e.GetPosition(element);
            var transform = (MatrixTransform)element.RenderTransform;
            var matrix = transform.Matrix;
            var scale = e.Delta >= 0 ? 1.1 : (1.0 / 1.1); // choose appropriate scaling factor

            matrix.ScaleAtPrepend(scale, scale, position.X, position.Y);
            transform.Matrix = matrix;
        }

        object? IViewFor.ViewModel
        {
            get => ViewModel;
            set => ViewModel = (DxTexturePreviewViewModel?)value;
        }
        
        public DxTexturePreviewViewModel? ViewModel
        {
            get => (DxTexturePreviewViewModel?)GetValue(ViewModelProperty);
            set => SetValue(ViewModelProperty, value);
        }
    }
}