/// <summary>
/// Prepare VBO content and upload it to the GPU.
/// </summary>
private void PrepareDataBuffers()
{
if (useVBO &&
scene != null &&
scene.Triangles > 0)
{
GL.EnableClientState(ArrayCap.VertexArray);
if (scene.HasNormals())
{
GL.EnableClientState(ArrayCap.NormalArray);
}
if (scene.HasColors())
{
GL.EnableClientState(ArrayCap.ColorArray);
}
// Vertex array: [color] [normal] coord
GL.BindBuffer(BufferTarget.ArrayBuffer, VBOid[0]);
int vertexBufferSize = scene.VertexBufferSize(true, false, true, true);
GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)vertexBufferSize, IntPtr.Zero, BufferUsageHint.StaticDraw);
IntPtr videoMemoryPtr = GL.MapBuffer(BufferTarget.ArrayBuffer, BufferAccess.WriteOnly);
unsafe
{
stride = scene.FillVertexBuffer((float *)videoMemoryPtr.ToPointer(), true, false, true, true);
}
GL.UnmapBuffer(BufferTarget.ArrayBuffer);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
// Index buffer
GL.BindBuffer(BufferTarget.ElementArrayBuffer, VBOid[1]);
GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(scene.Triangles * 3 * sizeof(uint)), IntPtr.Zero, BufferUsageHint.StaticDraw);
videoMemoryPtr = GL.MapBuffer(BufferTarget.ElementArrayBuffer, BufferAccess.WriteOnly);
unsafe
{
scene.FillIndexBuffer((uint *)videoMemoryPtr.ToPointer());
}
GL.UnmapBuffer(BufferTarget.ElementArrayBuffer);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
}
else
{
GL.DisableClientState(ArrayCap.VertexArray);
GL.DisableClientState(ArrayCap.NormalArray);
GL.DisableClientState(ArrayCap.ColorArray);
if (useVBO)
{
GL.BindBuffer(BufferTarget.ArrayBuffer, VBOid[0]);
GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)0, IntPtr.Zero, BufferUsageHint.StaticDraw);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, VBOid[1]);
GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)0, IntPtr.Zero, BufferUsageHint.StaticDraw);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
}
}
}
