/// <summary>
/// Ensures that the geometry buffers exist and have sufficient size.
/// </summary>
private void EnsureBuffers(ref ImDrawDataPtr drawDataPtr)
{
var dirty = false;
var vtxCount = 0;
var idxCount = 0;
for (var i = 0; i < drawDataPtr.CmdListsCount; i++)
{
var cmd = drawDataPtr.CmdListsRange[i];
vtxCount = Math.Max(vtxCount, cmd.VtxBuffer.Size);
idxCount = Math.Max(idxCount, cmd.IdxBuffer.Size);
}
if (vertexBuffer == null || vertexBuffer.VertexCount < vtxCount)
{
if (vertexBuffer != null)
{
vertexBuffer.Dispose();
}
vertexBuffer = DynamicVertexBuffer.Create(ImGuiVertex.VertexDeclaration, vtxCount);
dirty = true;
}
if (indexBuffer == null || indexBuffer.IndexCount < idxCount)
{
if (indexBuffer != null)
{
indexBuffer.Dispose();
}
indexBuffer = DynamicIndexBuffer.Create(IndexBufferElementType.Int16, idxCount);
dirty = true;
}
if (rasterizerState == null)
{
rasterizerState = RasterizerState.Create();
rasterizerState.ScissorTestEnable = true;
}
if (geometryStream == null || dirty)
{
this.geometryStream = GeometryStream.Create();
this.geometryStream.Attach(this.vertexBuffer);
this.geometryStream.Attach(this.indexBuffer);
}
}