CODEWITHSUNDEEP
c#graphicsmonogame
Doodles
Doodles

Reputation: 109

Monogame Vertex Buffer acting weird

I've exhausted my brain and have come to you for help.

I recently started working on a project to test out Monogame, and quickly ran into an issue, I'm not sure if it's my fault or Mono's.

I have a system where a level has a bunch of static instances added to it (the geometry), then this geometry is saved to a separate class to render it all. The plan was to use vertex and index buffers and use GraphicsDevice.DrawPrimitives, but this is where i run into issues.

The top image is what it should look like, the bottom one is what it actually looks like:

What it looks like when using array mode What it looks like when using buffer mode

And here is the relevant code. Right now setting the mode to Array works fine, but Buffer is messed up, so i know that the vertices are being added right, and the arrays are right, and the effect is right, only the buffers are wrong.

    public void End()
    {
        _vertices = _tempVertices.ToArray();
        _vCount = _vertices.Length;
        _indices = _tempIndices.ToArray();
        _iCount = _indices.Length;

        _vBuffer = new VertexBuffer(_graphics, typeof(VertexPositionColorTexture),
            _vCount, BufferUsage.WriteOnly);
        _vBuffer.SetData(_vertices, 0, _vCount);

        _iBuffer = new IndexBuffer(_graphics, IndexElementSize.ThirtyTwoBits,
            _iCount, BufferUsage.WriteOnly);
        _iBuffer.SetData(_indices, 0, _iCount);  

        _tempIndices.Clear();
        _tempVertices.Clear();

        _primitiveCount = _iCount / 3;

        _canDraw = true;
    }

    public void Render()
    {
        if (_canDraw)
        {
            switch (DrawMode)
            {
                case Mode.Buffered:
                    _graphics.Indices = _iBuffer;
                    _graphics.SetVertexBuffer(_vBuffer);

                    _graphics.DrawPrimitives(PrimitiveType.TriangleList, 0, _primitiveCount);
                    break;

                case Mode.Array:
                    _graphics.DrawUserIndexedPrimitives<VertexPositionColorTexture>
                        (PrimitiveType.TriangleList, _vertices, 0, _vCount,
                        _indices, 0, _primitiveCount);
                    break;
            }
        }
        else
            throw new InvalidOperationException("End must be called before this can be rendered");
    }

Anyone have any idea what I'm missing here? Thanks.

Upvotes: 3

Views: 1250

Answers (1)

Doodles
Doodles

Reputation: 109

I figured it out, after hours of trying everything. I may actually be an idiot.

Instead of using indexed drawing, I was simply trying to draw non-indexed primitives.

In the Render() method, i simply changed 

_graphics.DrawPrimitives(PrimitiveType.TriangleList, 0, _primitiveCount);

to:

_graphics.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, _vCount, 0, _primitiveCount);

And voila, it all works now.

Upvotes: 3

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