Corrupt Display

[jbracey2004]

When I run the sample, it comes up like this: Any idea what's going on here?

[NogginBops]

Hi, sorry for delayed response.

Can you tell me what OS, .NET version, and GPU you are using?

If you have some more time, would you be able to send a RenderDoc capture so I can look into what I going on? https://renderdoc.org/docs/how/how_capture_frame.html After you have the captured frame you can just save the capture to a file and send it to me.

[jbracey2004]

Here are a couple of snapshots I took

Snapshots_202006021815.zip

This is on Windows 10 Home 10.0.19041, Visual Studio 2019, .NET Framework Version 4.7.2, Rendering with the Intel UHD 620, OpenGL 3.3

[NogginBops]

Thanks a lot for the captures!

Just pushed a fix. If you can test this issue with the latest commit that would be great.

[jbracey2004]

Hey. Sorry for the late reply. Thanks for the update version. I tested the new version, and found that the GUI initially displays correctly. I ran into a new issue. When I mouse over one of the menus, the entire GUI disappears. I attempted to get the capture via RenderDoc, but I could not get RenderDoc to start the program. Then I fell asleep. I will attempt to get that capture of this occuring later today.

[NogginBops]

@jbracey2004 I just created a opengl3.3 branch that actually adhers to the functions available in 3.3 (it used a few 4.5 features). So I think the issue should be solved in that branch.

Would much appreciate if you could test and see if the issue is fixed. 🙂 (If you could test both the master and the opengl3.3 branch that would be fantastic)

[jbracey2004]

I was able to get the sample on the master branch to work correctly by having the buffers deleted before recreating them when resizing. Below is the corrected code:

uint totalVBSize = (uint)(draw_data.TotalVtxCount * Unsafe.SizeOf<ImDrawVert>());
if (totalVBSize > _vertexBufferSize)
{
    int newSize = (int)Math.Max(_vertexBufferSize * 1.5f, totalVBSize);
    GL.DeleteBuffer(_vertexBuffer);
    Util.CreateVertexBuffer("ImGui", out _vertexBuffer);
    GL.NamedBufferData(_vertexBuffer, newSize, IntPtr.Zero, BufferUsageHint.DynamicDraw);
    GL.VertexArrayVertexBuffer(_vertexArray, 0, _vertexBuffer, IntPtr.Zero, Unsafe.SizeOf<ImDrawVert>());
    _vertexBufferSize = newSize;
    Console.WriteLine($"Resized vertex buffer to new size {_vertexBufferSize}");
}
uint totalIBSize = (uint)(draw_data.TotalIdxCount * sizeof(ushort));
if (totalIBSize > _indexBufferSize)
{
    int newSize = (int)Math.Max(_indexBufferSize * 1.5f, totalIBSize);
    GL.DeleteBuffer(_indexBuffer);
    Util.CreateElementBuffer("ImGui", out _indexBuffer);
    GL.NamedBufferData(_indexBuffer, newSize, IntPtr.Zero, BufferUsageHint.DynamicDraw);
    GL.VertexArrayElementBuffer(_vertexArray, _indexBuffer);
    _indexBufferSize = newSize;
    Console.WriteLine($"Resized index buffer to new size {_indexBufferSize}");
}

Also note, I also have a forked version that uses the old-fashioned glBuffer calls instead of the glNamedBuffer calls. It seems to be able to resize buffers without having to delete and recreate them.

Also, I have tested the app on the opengl3.3 branch. That one works too.

[NogginBops]

@jbracey2004 I thought I would let you know that I just discovered a problem with the projection matrix that is used, and it's making the text blurry. When creating the projection matrix the call should look like this:

Matrix4 mvp = Matrix4.CreateOrthographicOffCenter(
                0.0f,
                io.DisplaySize.X,
                io.DisplaySize.Y,
                0.0f,
                -1.0f,
                1.0f);

The change is that the first argument is changed from -1.0 to 0.0.