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// 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_
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