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我正在尝试使用 SharpGL 在使用 gl.VertexPointer() 和 gl.DrawArrays() 的 WPF 应用程序中进行渲染。但我不能让它渲染一个正方形。背景清除为绿色，我可以在 WPF 面板的左下方看到 FPS 绘图。为正方形添加代码时，FPS 文本也消失了，我只有一个空白屏幕。

我正在做与 C++ 项目中完全相同的事情，它工作得很好。我不知道我错过了什么或做错了什么。

XAML

<Window x:Class="NodePlusPlus.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:NodePlusPlus"
        xmlns:gl="clr-namespace:SharpGL.WPF;assembly=SharpGL.WPF"
        mc:Ignorable="d"
        Title="MainWindow" Height="900" Width="1600" Background="#FF202020">
    <Grid x:Name="MainGrid">
        
        <gl:OpenGLControl x:Name="glPanel" DrawFPS="True" />

    </Grid>
</Window>

C＃

        public MainWindow()
        {
            InitializeComponent();

            glPanel.OpenGLInitialized += glPanel_OpenGLInitialized;
            glPanel.OpenGLDraw += glPanel_OpenGLDraw;
            glPanel.Resized += glPanel_Resized;
        }

        private void glPanel_Resized(object sender, SharpGL.WPF.OpenGLRoutedEventArgs args)
        {
            OpenGL gl = args.OpenGL;
            gl.Ortho2D(0, Width, 0, Height);
        }

        private void glPanel_OpenGLInitialized(object sender, SharpGL.WPF.OpenGLRoutedEventArgs args)
        {
            OpenGL gl = args.OpenGL;

            gl.Hint(OpenGL.GL_PERSPECTIVE_CORRECTION_HINT, OpenGL.GL_FASTEST);
            gl.ShadeModel(OpenGL.GL_SMOOTH);
            gl.Enable(OpenGL.GL_CULL_FACE);
            gl.Enable(OpenGL.GL_TEXTURE_2D);
            gl.Enable(OpenGL.GL_BLEND);
            gl.Enable(OpenGL.GL_DEPTH_TEST);
            gl.BlendFunc(OpenGL.GL_SRC_ALPHA, OpenGL.GL_ONE_MINUS_SRC_ALPHA);
            gl.EnableClientState(OpenGL.GL_VERTEX_ARRAY);
            gl.EnableClientState(OpenGL.GL_TEXTURE_COORD_ARRAY);
            gl.ClearColor(0.0f, 1.0f, 0.0f, 0.1f);
        }

        private void glPanel_OpenGLDraw(object sender, SharpGL.WPF.OpenGLRoutedEventArgs args)
        {
            OpenGL gl = args.OpenGL;

            // Clear the color and depth buffers
            gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT | OpenGL.GL_DEPTH_BUFFER_BIT);
            gl.LoadIdentity();
            
            // Build a rectangle
            float Width     = 100.0f;
            float Height    = 100.0f;
            float[] vertices = new float[18];
            vertices[0]  = 0;       vertices[1] = 0;        vertices[2] = 0.0f;
            vertices[3]  = 0;       vertices[4] = Height;   vertices[5] = 0.0f;
            vertices[6]  = Width;   vertices[7] = Height;   vertices[8] = 0.0f;

            vertices[9]  = 0;       vertices[10] = 0;       vertices[11] = 0.0f;
            vertices[12] = Width;   vertices[13] = Height;  vertices[14] = 0.0f;
            vertices[15] = Width;   vertices[16] = 0;       vertices[17] = 0.0f;


            // If I remove this whole Begin()-End() section, it will render the Open GL FPS.  With this draw code here, it does not render the FPS.
            gl.Begin(OpenGL.GL_TRIANGLES);

            gl.Translate(0.0f, 0.0f, 0.0f);
            gl.Color(0.0f, 0.0f, 0.0f, 1.0f);
            gl.VertexPointer(3, 0, vertices);
            gl.DrawArrays(OpenGL.GL_TRIANGLES, 0, 6);

            gl.End();

            gl.Flush();
        }

使用绘图代码... OpenGL 绘制

没有绘图代码... OpenGL无绘图

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1 回答 1

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正如@BDL 所提到的，glBegin()在glEnd()这种情况下不使用。

正如@Rabbid76 提到的，glEnableClientState(OpenGL.GL_TEXTURE_COORD_ARRAY)应该删除，因为我没有使用纹理坐标。

谢谢你们的帮助！

在特定示例中还需要删除gl.Enable(OpenGL.GL_CULL_FACE)来绘制我的正方形。正如@Rabbid76 提到的，默认的缠绕顺序是逆时针的。我的顶点顺时针缠绕。

最终结果

        private void glPanel_OpenGLInitialized(object sender, SharpGL.WPF.OpenGLRoutedEventArgs args)
        {
            OpenGL gl = args.OpenGL;

            gl.Hint(OpenGL.GL_PERSPECTIVE_CORRECTION_HINT, OpenGL.GL_FASTEST);
            gl.ShadeModel(OpenGL.GL_SMOOTH);
            gl.Enable(OpenGL.GL_TEXTURE_2D);
            gl.Enable(OpenGL.GL_BLEND);
            gl.Enable(OpenGL.GL_DEPTH_TEST);
            gl.BlendFunc(OpenGL.GL_SRC_ALPHA, OpenGL.GL_ONE_MINUS_SRC_ALPHA);
            gl.EnableClientState(OpenGL.GL_VERTEX_ARRAY);
            gl.ClearColor(0.0f, 1.0f, 0.0f, 0.1f);
        }

        private void glPanel_OpenGLDraw(object sender, SharpGL.WPF.OpenGLRoutedEventArgs args)
        {
            OpenGL gl = args.OpenGL;

            // Clear the color and depth buffers
            gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT | OpenGL.GL_DEPTH_BUFFER_BIT);
            gl.LoadIdentity();
            
            // Build a rectangle
            float Width     = 100.0f;
            float Height    = 100.0f;
            float[] vertices = new float[18];
            vertices[0]  = 0;       vertices[1] = 0;        vertices[2] = 0.0f;
            vertices[3]  = 0;       vertices[4] = Height;   vertices[5] = 0.0f;
            vertices[6]  = Width;   vertices[7] = Height;   vertices[8] = 0.0f;

            vertices[9]  = 0;       vertices[10] = 0;       vertices[11] = 0.0f;
            vertices[12] = Width;   vertices[13] = Height;  vertices[14] = 0.0f;
            vertices[15] = Width;   vertices[16] = 0;       vertices[17] = 0.0f;

            gl.Translate(0.0f, 0.0f, 0.0f);
            gl.Color(0.0f, 0.0f, 0.0f, 1.0f);
            gl.VertexPointer(3, 0, vertices);
            gl.DrawArrays(OpenGL.GL_TRIANGLES, 0, 6);

            gl.Flush();
        }
于 2021-12-11T22:21:27.447 回答