C# 拾取、平移、旋转对象。我该怎么做？

导言

我目前正在使用TAO框架在OpenGL中绘制图形。下面列出的是我使用纹理或颜色绘制任意大小的框的代码，用户可以指定。如下图所示，这在绘图时也能很好地工作

该项目是用VB.NET2010编写的，但由于大部分内容都是在C语言的帮助下编写的，所以我用两种语言发布它，因为答案可能是C语言，然后翻译成VB.NET

问题

现在，我尝试开发的下一部分是选择一个对象并旋转/平移它的能力。我不知道该怎么做。我在网上查过，只找到了C#中的示例，这些示例很好，但大多数方法都不能产生正确的结果。我知道我需要给我相信我已经做过的事情命名。所以我的问题是如何做到这一点

我也可以完全放弃我现有的代码来绘制所有东西。我不确定

现有计划

代码

以下是我的初始加载函数：

Private Sub DrawInit()
    Gl.glClearColor(0.0F, 0.0F, 0.0F, 0.0F)
    Gl.glShadeModel(Gl.GL_SMOOTH)
    Gl.glClearDepth(1.0#)
    Gl.glEnable(Gl.GL_DEPTH_TEST)
    Gl.glDepthFunc(Gl.GL_LESS)
    Gl.glEnable(Gl.GL_STENCIL_TEST)
    Gl.glHint(Gl.GL_PERSPECTIVE_CORRECTION_HINT, Gl.GL_NICEST)

    Draw_Shapes()

End Sub

我的绘图功能

 Private Sub Draw_Shapes()
    draw_boxes()
End Sub

我的绘图框函数

Private Sub draw_boxes()



    Dim i As Integer = 0

    Dim startx As Integer = 0
    Dim starty As Integer = 0
    Dim startz As Integer = 0

    Dim deltax As Integer = 0
    Dim deltay As Integer = 0
    Dim deltaz As Integer = 0

    Dim front_face_color As Color
    Dim back_face_color As Color
    Dim top_face_color As Color
    Dim bottom_face_color As Color
    Dim left_face_color As Color
    Dim right_face_color As Color

    Dim front_face_texture As Bitmap
    Dim back_face_texture As Bitmap
    Dim top_face_texture As Bitmap
    Dim bottom_face_texture As Bitmap
    Dim left_face_texture As Bitmap
    Dim right_face_texture As Bitmap

    Dim front_face_num_textures As Point
    Dim back_face_num_textures As Point
    Dim top_face_num_textures As Point
    Dim bottom_face_num_textures As Point
    Dim left_face_num_textures As Point
    Dim right_face_num_textures As Point

    Dim front_texture As Boolean
    Dim back_texture As Boolean
    Dim top_texture As Boolean
    Dim bottom_texture As Boolean
    Dim left_texture As Boolean
    Dim right_texture As Boolean


    Do Until i = boxes.Length - 1
        startx = boxes(i).start_x
        starty = boxes(i).start_y
        startz = boxes(i).start_z
        deltax = boxes(i).delta_x
        deltay = boxes(i).delta_y
        deltaz = boxes(i).delta_z
        front_face_color = boxes(i).front_face_color
        back_face_color = boxes(i).back_face_color
        top_face_color = boxes(i).top_face_color
        bottom_face_color = boxes(i).bottom_face_color
        left_face_color = boxes(i).left_face_color
        right_face_color = boxes(i).right_face_color


        front_face_texture = boxes(i).front_face_texture
        back_face_texture = boxes(i).back_face_texture
        top_face_texture = boxes(i).top_face_texture
        bottom_face_texture = boxes(i).bottom_face_texture
        left_face_texture = boxes(i).left_face_texture
        right_face_texture = boxes(i).right_face_texture

        front_face_num_textures = boxes(i).front_face_num_textures
        back_face_num_textures = boxes(i).back_face_num_textures
        top_face_num_textures = boxes(i).top_face_num_textures
        bottom_face_num_textures = boxes(i).bottom_face_num_textures
        left_face_num_textures = boxes(i).left_face_num_textures
        right_face_num_textures = boxes(i).right_face_num_textures


        If front_face_texture Is Nothing Then
            front_texture = False
        Else
            front_texture = True
        End If

        If back_face_texture Is Nothing Then
            back_texture = False
        Else
            back_texture = True
        End If

        If top_face_texture Is Nothing Then
            top_texture = False
        Else
            top_texture = True
        End If

        If bottom_face_texture Is Nothing Then
            bottom_texture = False
        Else
            bottom_texture = True
        End If

        If left_face_texture Is Nothing Then
            left_texture = False
        Else
            left_texture = True
        End If

        If right_face_texture Is Nothing Then
            right_texture = False
        Else
            right_texture = True
        End If

        Gl.glLoadName(num_shapes)
        Gl.glNewList(i + 1, Gl.GL_COMPILE)



        draw_rectangular_face(front_texture, front_face_color, front_face_texture, New ThreeDPoint(startx, starty, startz), New ThreeDPoint(startx + deltax, starty, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz), New ThreeDPoint(startx, starty + deltay, startz), front_face_num_textures)

        draw_rectangular_face(back_texture, back_face_color, back_face_texture, New ThreeDPoint(startx, starty, startz), New ThreeDPoint(startx + deltax, starty, startz), New ThreeDPoint(startx + deltax, starty, startz + deltaz), New ThreeDPoint(startx, starty, startz + deltaz), back_face_num_textures)

        draw_rectangular_face(top_texture, top_face_color, top_face_texture, New ThreeDPoint(startx, starty, startz + deltaz), New ThreeDPoint(startx + deltax, starty, startz + deltaz), New ThreeDPoint(startx + deltax, starty + deltay, startz + deltaz), New ThreeDPoint(startx, starty + deltay, startz + deltaz), top_face_num_textures)

        draw_rectangular_face(bottom_texture, bottom_face_color, bottom_face_texture, New ThreeDPoint(startx, starty + deltay, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz + deltaz), New ThreeDPoint(startx, starty + deltay, startz + deltaz), bottom_face_num_textures)

        draw_rectangular_face(left_texture, left_face_color, left_face_texture, New ThreeDPoint(startx + deltax, starty, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz + deltaz), New ThreeDPoint(startx + deltax, starty, startz + deltaz), left_face_num_textures)

        draw_rectangular_face(right_texture, right_face_color, right_face_texture, New ThreeDPoint(startx, starty, startz), New ThreeDPoint(startx, starty + deltay, startz), New ThreeDPoint(startx, starty + deltay, startz + deltaz), New ThreeDPoint(startx, starty, startz + deltaz), right_face_num_textures)


        Gl.glEndList()

        num_shapes = num_shapes + 1

        i = i + 1
    Loop

我的画面功能

Private Sub draw_rectangular_face(ByVal texture As Boolean, ByVal face_color As Color, ByVal texture_image As Bitmap, ByVal point1 As ThreeDPoint, ByVal point2 As ThreeDPoint, ByVal point3 As ThreeDPoint, ByVal point4 As ThreeDPoint, ByVal num_textures As Point)

    If texture = True Then
        load_textures(texture_image)
    End If


    Gl.glBindTexture(Gl.GL_TEXTURE_2D, 1)

    If texture = True Then
        Gl.glEnable(Gl.GL_TEXTURE_2D) 'turn on for texture
    Else
        Gl.glDisable(Gl.GL_TEXTURE_2D) 'turn on for color
    End If


    Gl.glBegin(Gl.GL_QUADS)

    If texture = True Then
        Gl.glColor3f(1, 1, 1) 'turn on for texture
    Else
        Gl.glColor3f(face_color.R / 256, face_color.G / 256, face_color.B / 256) 'turn on for color
    End If


    Gl.glTexCoord2f(0, 0) : Gl.glVertex3f(point1.x, point1.y, point1.z)
    Gl.glTexCoord2f(num_textures.X, 0) : Gl.glVertex3f(point2.x, point2.y, point2.z)
    Gl.glTexCoord2f(num_textures.X, num_textures.Y) : Gl.glVertex3f(point3.x, point3.y, point3.z)
    Gl.glTexCoord2f(0, num_textures.Y) : Gl.glVertex3f(point4.x, point4.y, point4.z)

    Gl.glEnd()
End Sub

用于平移和旋转世界的My DrawScene事件：

Private Sub DrawScene()

    Gl.glClear(Gl.GL_COLOR_BUFFER_BIT Or Gl.GL_DEPTH_BUFFER_BIT Or Gl.GL_STENCIL_BUFFER_BIT)
    Gl.glLoadIdentity()
    'move reference?
    Gl.glTranslatef(camera_xloc, camera_yloc, camera_zloc)
    ' Gl.glTranslatef(0.0F, 0.0F, -20.0F)


    'rotate
    Gl.glRotatef(camera_xrot, 1, 0, 0)
    Gl.glRotatef(camera_yrot, 0, 1, 0)
    Gl.glRotatef(camera_zrot, 0, 0, 1)

    Dim i As Integer = 1
    Do Until i > num_shapes
        Gl.glCallList(i)
        i = i + 1
    Loop
    Gl.glFlush()
    Application.DoEvents()
    Gdi.SwapBuffers(hDC)



    If intialload = 0 Then
        intialload = 1
        RaiseEvent initial_load_completed()
    End If
End Sub

我尝试过将shape#1转换为10001000，但没有成功：

Gl.glLoadName(num_shapes)
        Gl.glNewList(i + 1, Gl.GL_COMPILE)



        If num_shapes = 1 Then
            Gl.glPushMatrix()
            Gl.glTranslatef(1000, 1000, 1000)
        End If


        draw_rectangular_face(front_texture, front_face_color, front_face_texture, New ThreeDPoint(startx, starty, startz), New ThreeDPoint(startx + deltax, starty, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz), New ThreeDPoint(startx, starty + deltay, startz), front_face_num_textures)

        draw_rectangular_face(back_texture, back_face_color, back_face_texture, New ThreeDPoint(startx, starty, startz), New ThreeDPoint(startx + deltax, starty, startz), New ThreeDPoint(startx + deltax, starty, startz + deltaz), New ThreeDPoint(startx, starty, startz + deltaz), back_face_num_textures)

        draw_rectangular_face(top_texture, top_face_color, top_face_texture, New ThreeDPoint(startx, starty, startz + deltaz), New ThreeDPoint(startx + deltax, starty, startz + deltaz), New ThreeDPoint(startx + deltax, starty + deltay, startz + deltaz), New ThreeDPoint(startx, starty + deltay, startz + deltaz), top_face_num_textures)

        draw_rectangular_face(bottom_texture, bottom_face_color, bottom_face_texture, New ThreeDPoint(startx, starty + deltay, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz + deltaz), New ThreeDPoint(startx, starty + deltay, startz + deltaz), bottom_face_num_textures)

        draw_rectangular_face(left_texture, left_face_color, left_face_texture, New ThreeDPoint(startx + deltax, starty, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz), New ThreeDPoint(startx + deltax, starty + deltay, startz + deltaz), New ThreeDPoint(startx + deltax, starty, startz + deltaz), left_face_num_textures)

        draw_rectangular_face(right_texture, right_face_color, right_face_texture, New ThreeDPoint(startx, starty, startz), New ThreeDPoint(startx, starty + deltay, startz), New ThreeDPoint(startx, starty + deltay, startz + deltaz), New ThreeDPoint(startx, starty, startz + deltaz), right_face_num_textures)

        If num_shapes = 1 Then
            Gl.glPopMatrix()
        End If



        Gl.glEndList()

---

这个问题要完全回答有点宽泛。拾取、旋转和平移是三种不同的任务，需要不同的方法。要拾取一个对象，请通过光标发射一条光线，并查看击中的对象。平移可以通过在平面上投影对象来完成，旋转可以通过各种轨迹球实现来处理。我建议你针对一个具体问题提出一个新问题。请同时展示您迄今为止所做的尝试。拾取是一项非常常见的任务。至于选择和“通过对象拍摄光线”，那么我如何用对象的现有坐标建立对象列表？您应该将它们放在内存中的某个位置。不然你怎么能画这些东西呢<代码>框似乎是一个很好的起点。我添加了我用来旋转和平移世界的“DrawScene”sub。我没有意识到我必须将对象的信息存储到tao框架之外的列表中，但我可以做到这一点。我的下一个问题是，如何翻译一个对象，而不是像我在绘图场景中那样翻译所有对象？我还更新了我在翻译方面所做的尝试。