Gewusst wie: Anzeigen und Auswählen von Netzen

Aktualisiert: November 2007

Sie können ein Array von Netzen erstellen und so anzeigen, dass ein Netz seine Farbe ändert, wenn es auf dem Gerät ausgewählt (angetippt) wird.

Hinweis:

Für verwaltete Direct3D Mobile-Anwendungen ist Windows Mobile, Version 5.0, für Pocket PCs und Smartphones erforderlich. Weitere Informationen über Windows Mobile-Software und SDKs finden Sie unter Externe Ressourcen für .NET Compact Framework.

Das Formular in diesem Codebeispiel verfügt über die folgenden Objekte:

  • Ein Mesh-Objekt für das aktive Netz.

  • Ein Array von neun verschiedenfarbigen Mesh-Objekten, die ausgewählt werden können.

  • Eine Vector3-Struktur, die die Netzspeicherorte definiert.

  • Zwei Vector3-Strukturen, die das umgebende Feld definieren.

  • Ein Device-Objekt.

Im Konstruktor des Formulars werden Einstellungen für die PresentationParameters-Eigenschaft des Geräts festgelegt, es wird das Device-Objekt erstellt, dem DeviceReset-Ereignis des Objekts der OnDeviceReset-Ereignishandler hinzugefügt und dann die OnDeviceReset-Methode aufgerufen. Anschließend wird mit der Erstellung der Netze begonnen. In der folgenden Tabelle werden die Methoden beschrieben, mit denen die Netze dargestellt und die Benutzerinteraktion ermöglicht wird.

Methode

Aktionen

OnDeviceReset

Erstellt die Netze, fügt sie an gegebenen Positionen im umgebenden Feld ein und definiert die Transformationsmatrizen.

OnPaint

Beginnt die Szene, zeichnet die Netze und beendet die Szene.

OnMouseDown

Veranschaulicht die Auswahl eines Netzes mithilfe einer Technik, die einen Strahl im logischen 3D-Raum erzeugt und darstellt, wie dieser Strahl ein Feld kreuzt.

Der Strahl stellt dar, wie der Schreibstift durch den 3D-Raum gedrückt wird. Das Feld stellt einen umgebenden Quader des 3D-Objekts dar. Wenn sich die beiden schneiden, hat der Benutzer auf eine Stelle geklickt, die im 3D-Objekt enthalten ist.

Beispiel

Das folgende Codebeispiel stellt ein vollständiges Formular bereit. Es zeigt verschiedenfarbige Mesh-Objekte an, die ausgewählt werden können. Wenn ein Netz ausgewählt wird, ändert sich seine Farbe.

Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports Microsoft.WindowsMobile.DirectX
Imports Microsoft.WindowsMobile.DirectX.Direct3D
Imports Microsoft.VisualBasic




Class MeshPickingHowto
    Inherits Form
    Private Const numberOfMeshes As Integer = 9
    Private meshes() As Mesh
    Private meshColors() As Color = {Color.Green, Color.Orange, Color.Purple, Color.Pink, Color.Violet, Color.Blue, Color.Yellow, Color.Brown, Color.Aquamarine}

    Private meshLocations() As Vector3
    Private meshBoundingBoxMinValues() As Vector3
    Private meshBoundingBoxMaxValues() As Vector3
    Private activeMesh As Mesh

    Private device As Device


    Public Sub New() 
        Dim present As PresentParameters

        Me.Text = "Mesh Picking"

        ' Enable the form to be closed.
        ' This is required so that Hwnd of the form changes.
        Me.MinimizeBox = False

        present = New PresentParameters()
        present.Windowed = True
        present.AutoDepthStencilFormat = DepthFormat.D16
        present.EnableAutoDepthStencil = True
        present.SwapEffect = SwapEffect.Discard

        device = New Device(0, DeviceType.Default, Me, CreateFlags.None, present)
        AddHandler device.DeviceReset, AddressOf OnDeviceReset
        OnDeviceReset(Nothing, EventArgs.Empty)

    End Sub


    Private Sub OnDeviceReset(ByVal sender As Object, ByVal e As EventArgs) 
        ' Meshes must be recreated whenever the device
        ' is reset, no matter which pool they are created in.
        meshes = New Mesh(numberOfMeshes) {}
        meshLocations = New Vector3(numberOfMeshes) {}
        meshBoundingBoxMinValues = New Vector3(numberOfMeshes) {}
        meshBoundingBoxMaxValues = New Vector3(numberOfMeshes) {}
        activeMesh = Nothing

        ' Create several meshes and associated data.
        Dim i As Integer
        For i = 0 To numberOfMeshes
            Dim vertexData As GraphicsStream

            meshes(i) = Mesh.Box(device, 1F, 1F, 1F)

            ' Arrange the boxes in a grid, with each
            ' successive box farther in the distance.
            meshLocations(i) = New Vector3((i Mod 3) * 2 - 2, i / 3 * 2 - 2, i)

            ' Compute the bounding box for a mesh.
            Dim description As VertexBufferDescription = meshes(i).VertexBuffer.Description
            vertexData = meshes(i).VertexBuffer.Lock(0, 0, LockFlags.ReadOnly)
            Geometry.ComputeBoundingBox(vertexData, meshes(i).NumberVertices, description.VertexFormat, meshBoundingBoxMinValues(i), meshBoundingBoxMaxValues(i))
            meshes(i).VertexBuffer.Unlock()
        Next i
        ' Set the transformation matrices.
        device.Transform.Projection = Matrix.PerspectiveFovRH(System.Convert.ToSingle(Math.PI) / 4F, System.Convert.ToSingle(Me.ClientSize.Width) / System.Convert.ToSingle(Me.ClientSize.Height), 0.001F, 40)

        device.Transform.View = Matrix.LookAtRH(New Vector3(0, 2, - 7), New Vector3(0, 0, 0), New Vector3(0, 1, 0))

        device.RenderState.Ambient = Color.White

    End Sub


    Protected Overrides Sub OnPaintBackground(ByVal e As PaintEventArgs) 
        ' Do nothing.
    End Sub

    Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs) 
        Dim material As New Material()

        ' Begin the scene and clear the back buffer to black.
        device.BeginScene()
        device.Clear(ClearFlags.Target Or ClearFlags.ZBuffer, Color.Black, 1F, 0)

        ' Draw each mesh to the screen.
        ' The active mesh is drawn in red.
        Dim i As Integer
        For i = 0 To numberOfMeshes
            If activeMesh Is meshes(i) Then
                material.Ambient = Color.Red
            Else
                material.Ambient = meshColors(i)
            End If
            device.Transform.World = Matrix.Translation(meshLocations(i))
            device.Material = material
            meshes(i).DrawSubset(0)
        Next i

        ' Finish the scene and present it on the screen.
        device.EndScene()
        device.Present()

    End Sub


    ' This method demonstrates picking.
    Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs) 
        ' The technique used here is to create a ray through the entire
        ' logical 3-D space, and then perform an intersection test
        ' for the bounding box and ray.
        Dim i As Integer
        For i = 0 To numberOfMeshes
            Dim nearVector As New Vector3(e.X, e.Y, 0)
            Dim farVector As New Vector3(e.X, e.Y, 1)

            ' Create ray.
            nearVector.Unproject(device.Viewport, device.Transform.Projection, device.Transform.View, Matrix.Translation(meshLocations(i)))

            farVector.Unproject(device.Viewport, device.Transform.Projection, device.Transform.View, Matrix.Translation(meshLocations(i)))

            farVector.Subtract(nearVector)

            ' Perform intersection test for the bounding box and ray.
            If Geometry.BoxBoundProbe(meshBoundingBoxMinValues(i), meshBoundingBoxMaxValues(i), nearVector, farVector) Then
                ' Perform operation on detection of click on mesh object.
                ' In this case, you designate the mesh as the active
                ' mesh and invalidate the window so that it is redrawn.
                activeMesh = meshes(i)
                Me.Invalidate()
                Exit For
            End If
        Next i

    End Sub


    Shared Sub Main() 
        Application.Run(New MeshPickingHowto())

    End Sub
End Class
using System;
using System.Drawing;
using System.Windows.Forms;
using Microsoft.WindowsMobile.DirectX;
using Microsoft.WindowsMobile.DirectX.Direct3D;

namespace MeshPick
{
    class MeshPickingHowto : Form
    {
        const int numberOfMeshes = 9;
        Mesh [] meshes;
        Color [] meshColors = new Color [] { Color.Green, Color.Orange,
            Color.Purple, Color.Pink, Color.Violet, Color.Blue, Color.Yellow,
            Color.Brown, Color.Aquamarine };

        Vector3 [] meshLocations;
        Vector3 [] meshBoundingBoxMinValues;
        Vector3 [] meshBoundingBoxMaxValues;
        Mesh activeMesh;

        Device device;

        public MeshPickingHowto()
        {
            PresentParameters present;

            this.Text = "Mesh Picking";

            // Enable the form to be closed.
            // This is required so that Hwnd of the form changes.
            this.MinimizeBox = false;

            present = new PresentParameters();
            present.Windowed = true;
            present.AutoDepthStencilFormat = DepthFormat.D16;
            present.EnableAutoDepthStencil = true;
            present.SwapEffect = SwapEffect.Discard;

            device = new Device(0, DeviceType.Default, this,
                                CreateFlags.None, present);
            device.DeviceReset += new EventHandler(OnDeviceReset);
            OnDeviceReset(null, EventArgs.Empty);
        }

        private void OnDeviceReset(object sender, EventArgs e)
        {
            // Meshes must be recreated whenever the device
            // is reset, no matter which pool they are created in.

            meshes = new Mesh[numberOfMeshes];
            meshLocations = new Vector3[numberOfMeshes];
            meshBoundingBoxMinValues = new Vector3[numberOfMeshes];
            meshBoundingBoxMaxValues = new Vector3[numberOfMeshes];
            activeMesh = null;
            // Create several meshes and associated data.
            for (int i = 0; i < numberOfMeshes; i++)
            {
                GraphicsStream vertexData;

                meshes[i] = Mesh.Box(device, 1.0f, 1.0f, 1.0f);

                // Arrange the boxes in a grid, with each
                // successive box farther in the distance.
                meshLocations[i] = new Vector3(((i % 3) * 2) - 2,
                                            ((i / 3) * 2) - 2, i);

                // Compute the bounding box for a mesh.
                VertexBufferDescription description =
                    meshes[i].VertexBuffer.Description;
                vertexData = meshes[i].VertexBuffer.Lock
                                         (0, 0, LockFlags.ReadOnly);
                Geometry.ComputeBoundingBox(vertexData,
                    meshes[i].NumberVertices,description.VertexFormat,
                    out meshBoundingBoxMinValues[i],
                    out meshBoundingBoxMaxValues[i]);
                meshes[i].VertexBuffer.Unlock();
            }
            // Set the transformation matrices.
            device.Transform.Projection = Matrix.PerspectiveFovRH(
               (float)Math.PI/4.0F,
               (float)this.ClientSize.Width / (float)this.ClientSize.Height,
               0.001f, 40);

            device.Transform.View = Matrix.LookAtRH(new Vector3(0, 2, -7),
                new Vector3(0, 0, 0), new Vector3(0, 1, 0));

            device.RenderState.Ambient = Color.White;
        }

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            // Do nothing.
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            Material material = new Material();

            // Begin the scene and clear the back buffer to black.
            device.BeginScene();
            device.Clear(ClearFlags.Target | ClearFlags.ZBuffer,
                        Color.Black, 1.0f, 0);

            // Draw each mesh to the screen.
            // The active mesh is drawn in red.
            for (int i = 0; i < numberOfMeshes; i++)
            {
                if (activeMesh == meshes[i])
                    material.Ambient = Color.Red;
                else
                    material.Ambient = meshColors[i];

                device.Transform.World = Matrix.Translation(meshLocations[i]);
                device.Material = material;
                meshes[i].DrawSubset(0);
            }

            // Finish the scene and present it on the screen.
            device.EndScene();
            device.Present();
        }

        // This method demonstrates picking.
        protected override void OnMouseDown(MouseEventArgs e)
        {
            // The technique used here is to create a ray through the entire
            // logical 3-D space, and then perform an intersection test
            // for the bounding box and ray.
            for (int i = 0; i < numberOfMeshes; i++)
            {
                Vector3 nearVector = new Vector3(e.X, e.Y, 0);
                Vector3 farVector = new Vector3(e.X, e.Y, 1);

                // Create ray.

                nearVector.Unproject(device.Viewport,
                            device.Transform.Projection,
                            device.Transform.View,
                            Matrix.Translation(meshLocations[i]));

                farVector.Unproject(device.Viewport,
                            device.Transform.Projection,
                            device.Transform.View,
                            Matrix.Translation(meshLocations[i]));

                farVector.Subtract(nearVector);

                // Perform intersection test for the bounding box and ray.

                if (Geometry.BoxBoundProbe(meshBoundingBoxMinValues[i],
                    meshBoundingBoxMaxValues[i], nearVector, farVector))
                {
                    // Perform operation on detection of click on mesh object.
                    // In this case, you designate the mesh as the active
                    // mesh and invalidate the window so that it is redrawn.

                    activeMesh = meshes[i];
                    this.Invalidate();
                    break;
                }
            }
        }

        static void Main()
        {
            Application.Run(new MeshPickingHowto());
        }
    }
}

Kompilieren des Codes

Für dieses Beispiel sind Verweise auf die folgenden Namespaces erforderlich:

Siehe auch

Konzepte

Gewusst-wie-Themen für .NET Compact Framework

Weitere Ressourcen

Mobile Direct3D-Programmierung in .NET Compact Framework