Pica: Add command processor.

src/video_core/command_processor.h

@@ -0,0 +1,31 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/bit_field.h"
+#include "common/common_types.h"
+
+#include "pica.h"
+
+namespace Pica {
+
+namespace CommandProcessor {
+
+union CommandHeader {
+    u32 hex;
+
+    BitField< 0, 16, u32> cmd_id;
+    BitField<16,  4, u32> parameter_mask;
+    BitField<20, 11, u32> extra_data_length;
+    BitField<31,  1, u32> group_commands;
+};
+static_assert(std::is_standard_layout<CommandHeader>::value == true, "CommandHeader does not use standard layout");
+static_assert(sizeof(CommandHeader) == sizeof(u32), "CommandHeader has incorrect size!");
+
+void ProcessCommandList(const u32* list, u32 size);
+
+} // namespace
+
+} // namespace