Question

我必须遵循以下代码：

    public void BeginDraw()
    {
        if(bufferMaterial != null)
        {
            bufferMaterial.Textures[0].Surface.BindFramebuffer();
            beganDraw = true;
        }
    }
    public void EndDraw()
    {
        if (beganDraw)
        {
            beganDraw = false;
            GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
            if (bufferMaterial != null)
            {
                GL.BindBuffer(BufferTarget.ArrayBuffer, screenMesh.VBO);
                GL.BindVertexArray(VAO);
                GL.BindBuffer(BufferTarget.ElementArrayBuffer, screenMesh.VEO);
                bufferMaterial.Use();
                screenMesh.ApplyDrawHints(bufferMaterial.Shader);
                GL.DrawElements(PrimitiveType.Triangles, 2, DrawElementsType.UnsignedInt, 0);
                GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
                GL.BindVertexArray(0);
                GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
                GL.UseProgram(0);
            }
        }
    }

在这两个之间我绘制了我的场景，因此应该将图像绘制到bufferMaterial.Textures [0] .Surface。

现在“screenMesh”创建如下：

        screenMesh = new Mesh();
        screenMesh.SetVertices(new float[] {
            0,0,
            1,0,
            1,1,
            0,1
        });
        screenMesh.SetIndices(new uint[] {
            0,3,2,
            0,1,2
        });
        screenMesh.SetDrawHints(new VertexObjectDrawHint("pos", 2, 2, 0));

- ＆GT; 2个组件，步幅为2,0，偏移

着色器看起来像这样：

++++++++
Screenbuffer
++++++++

[Shader vertexScreen]
#version 150 core

in vec2 pos;
uniform float _time;
uniform sampler2D tex;
void main() {
    gl_Position = vec4(pos, -1, 1);
}
[Shader fragmentScreen]
#version 150 core
#define PI 3.1415926535897932384626433832795

out vec4 outColor;
uniform float _time;
uniform sampler2D tex;
//texture2D(tex, 
void main() {
    outColor = vec4(1,1,1,1);
}

现在，我希望这会在屏幕上绘制一个白色矩形，但屏幕保持黑色。我玩了一下screenMesh的指数，所以可能会关闭，但它们永远不可见......

我不需要像这样的着色器的任何投影矩阵吗？

网格类：http://pastebin.com/PcwEYqGH

编辑：好的，现在渲染缓冲区，但我仍然需要让深度缓冲区正常工作！表面创建代码如下所示：

public void Create(int width, int height, SurfaceFormat format)
    {
        Width = width;
        Height = height;
        textureHandle = GL.GenTexture();
        //bind texture
        GL.BindTexture(TextureTarget.Texture2D, textureHandle);
        Log.Error("Bound Texture: " + GL.GetError());
        GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Nearest);
        GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Nearest);
        GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)format.WrapMode);
        GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)format.WrapMode);

        Log.Error("Created Texture Parameters: " + GL.GetError());
        GL.TexImage2D(TextureTarget.Texture2D, 0, format.InternalFormat, Width, Height, 0, format.PixelFormat, format.SourceType, format.Pixels);
        Log.Error("Created Image: " + GL.GetError());
        //unbind texture
        GL.BindTexture(TextureTarget.Texture2D, 0);
        //create depthbuffer
        if (format.DepthBuffer)
        {
            GL.GenRenderbuffers(1, out dbHandle);
            GL.BindRenderbuffer(RenderbufferTarget.Renderbuffer, dbHandle);
            GL.RenderbufferStorage(RenderbufferTarget.Renderbuffer, RenderbufferStorage.DepthComponent24, Width, Height);
        }

        //create fbo
        fboHandle = GL.GenFramebuffer();
        GL.BindFramebuffer(FramebufferTarget.Framebuffer, fboHandle);
        GL.FramebufferTexture2D(FramebufferTarget.FramebufferExt, FramebufferAttachment.ColorAttachment0Ext, TextureTarget.Texture2D, textureHandle, 0);
        if(format.DepthBuffer)
            GL.FramebufferRenderbuffer(FramebufferTarget.FramebufferExt, FramebufferAttachment.DepthAttachment, RenderbufferTarget.Renderbuffer, dbHandle);
        GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
        Log.Error("Created Framebuffer: " + GL.GetError());

    }

这是绑定它的代码：

public void BindTexture(TextureUnit slot = TextureUnit.Texture0)
    {
        GL.ActiveTexture(slot);
        GL.BindTexture(TextureTarget.Texture2D, textureHandle);

    }
    public void BindFramebuffer()
    {
        GL.BindFramebuffer(FramebufferTarget.Framebuffer, fboHandle);
    }

然而，如果启用深度缓冲区，屏幕将再次变黑。

编辑：忘记清除深度缓冲区！

Answer 1

您的平局电话有问题：

GL.DrawElements(PrimitiveType.Triangles, 2, DrawElementsType.UnsignedInt, 0);

第二个参数是用于渲染的索引数。只有2个指数，这对于一个完整的三角形是不够的。索引数组中有6个索引，因此它应该是：

GL.DrawElements(PrimitiveType.Triangles, 6, DrawElementsType.UnsignedInt, 0);

除此之外，我还无法找到您正在使用的Mesh类的代码或文档，因此无法确定网格中存储的顶点数据是否设置正确。

在OpenGL（OpenTK）中显示简单图像的最简单方法是什么？

1 个答案: