Microsoft.Xna.Framework.Graphics.ConstantBuffer.PlatformApply C# (CSharp) Method

        public unsafe void PlatformApply(GraphicsDevice device, ShaderProgram program)
        {
            // NOTE: We assume here the program has 
            // already been set on the device.

            // If the program changed then lookup the
            // uniform again and apply the state.
            if (_shaderProgram != program)
            {
                var location = program.GetUniformLocation(_name);
                if (location == -1)
                    return;

                _shaderProgram = program;
                _location = location;
                _dirty = true;
            }

            // If the shader program is the same, the effect may still be different and have different values in the buffer
            if (!Object.ReferenceEquals(this, _lastConstantBufferApplied))
                _dirty = true;

            // If the buffer content hasn't changed then we're
            // done... use the previously set uniform state.
            if (!_dirty)
                return;

            fixed (byte* bytePtr = _buffer)
            {
                // TODO: We need to know the type of buffer float/int/bool
                // and cast this correctly... else it doesn't work as i guess
                // GL is checking the type of the uniform.

                GL.Uniform4(_location, _buffer.Length / 16, (float*)bytePtr);
                GraphicsExtensions.CheckGLError();
            }

            // Clear the dirty flag.
            _dirty = false;

            _lastConstantBufferApplied = this;
        }
    }