| // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // This file contains a helper template class used to access bit fields in |
| // unsigned int_ts. |
| |
| #ifndef GPU_COMMAND_BUFFER_COMMON_BITFIELD_HELPERS_H_ |
| #define GPU_COMMAND_BUFFER_COMMON_BITFIELD_HELPERS_H_ |
| |
| namespace gpu { |
| |
| // Bitfield template class, used to access bit fields in unsigned int_ts. |
| template<int shift, int length> class BitField { |
| public: |
| static const unsigned int kShift = shift; |
| static const unsigned int kLength = length; |
| // the following is really (1<<length)-1 but also work for length == 32 |
| // without compiler warning. |
| static const unsigned int kMask = 1U + ((1U << (length-1)) - 1U) * 2U; |
| |
| // Gets the value contained in this field. |
| static unsigned int Get(unsigned int container) { |
| return (container >> kShift) & kMask; |
| } |
| |
| // Makes a value that can be or-ed into this field. |
| static unsigned int MakeValue(unsigned int value) { |
| return (value & kMask) << kShift; |
| } |
| |
| // Changes the value of this field. |
| static void Set(unsigned int *container, unsigned int field_value) { |
| *container = (*container & ~(kMask << kShift)) | MakeValue(field_value); |
| } |
| }; |
| |
| } // namespace gpu |
| |
| #endif // GPU_COMMAND_BUFFER_COMMON_BITFIELD_HELPERS_H_ |