//
// Copyright 2016 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// BufferNULL.cpp:
//    Implements the class methods for BufferNULL.
//

#include "libANGLE/renderer/null/BufferNULL.h"
#include "common/unsafe_buffers.h"

#include "common/debug.h"
#include "common/utilities.h"
#include "libANGLE/Context.h"
#include "libANGLE/angletypes.h"
#include "libANGLE/renderer/null/ContextNULL.h"

namespace rx
{

BufferNULL::BufferNULL(const gl::BufferState &state, AllocationTrackerNULL *allocationTracker)
    : BufferImpl(state), mAllocationTracker(allocationTracker)
{
    ASSERT(mAllocationTracker != nullptr);
}

BufferNULL::~BufferNULL()
{
    bool memoryReleaseResult = mAllocationTracker->updateMemoryAllocation(mData.size(), 0);
    ASSERT(memoryReleaseResult);
}

angle::Result BufferNULL::setDataWithUsageFlags(const gl::Context *context,
                                                gl::BufferBinding target,
                                                GLeglClientBufferEXT clientBuffer,
                                                const void *data,
                                                size_t size,
                                                gl::BufferUsage usage,
                                                GLbitfield flags,
                                                gl::BufferStorage bufferStorage,
                                                BufferFeedback *feedback,
                                                gl::ZeroFillRequired zeroFillRequired)
{
    ANGLE_CHECK_GL_ALLOC(GetImplAs<ContextNULL>(context),
                         mAllocationTracker->updateMemoryAllocation(mData.size(), size));

    mData.resize(size, 0);

    const void *dataForImpl = data;
    if (zeroFillRequired == gl::ZeroFillRequired::Yes)
    {
        const angle::MemoryBuffer *scratchBuffer = nullptr;
        ANGLE_CHECK_GL_ALLOC(
            GetImplAs<ContextNULL>(context),
            context->getZeroFilledBuffer(static_cast<size_t>(size), &scratchBuffer));
        dataForImpl = scratchBuffer->data();
    }

    if (size > 0 && dataForImpl != nullptr)
    {
        ANGLE_UNSAFE_TODO(memcpy(mData.data(), dataForImpl, size));
    }
    return angle::Result::Continue;
}

angle::Result BufferNULL::setData(const gl::Context *context,
                                  gl::BufferBinding target,
                                  const void *data,
                                  size_t size,
                                  gl::BufferUsage usage,
                                  BufferFeedback *feedback,
                                  gl::ZeroFillRequired zeroFillRequired)
{
    ANGLE_CHECK_GL_ALLOC(GetImplAs<ContextNULL>(context),
                         mAllocationTracker->updateMemoryAllocation(mData.size(), size));

    mData.resize(size, 0);
    if (size > 0 && data != nullptr)
    {
        ANGLE_UNSAFE_TODO(memcpy(mData.data(), data, size));
    }
    return angle::Result::Continue;
}

angle::Result BufferNULL::setSubData(const gl::Context *context,
                                     gl::BufferBinding target,
                                     const void *data,
                                     size_t size,
                                     size_t offset,
                                     BufferFeedback *feedback)
{
    if (size > 0)
    {
        ANGLE_UNSAFE_TODO(memcpy(mData.data() + offset, data, size));
    }
    return angle::Result::Continue;
}

angle::Result BufferNULL::copySubData(const gl::Context *context,
                                      BufferImpl *source,
                                      GLintptr sourceOffset,
                                      GLintptr destOffset,
                                      GLsizeiptr size,
                                      BufferFeedback *feedback)
{
    BufferNULL *sourceNULL = GetAs<BufferNULL>(source);
    if (size > 0)
    {
        ANGLE_UNSAFE_TODO(
            memcpy(mData.data() + destOffset, sourceNULL->mData.data() + sourceOffset, size));
    }
    return angle::Result::Continue;
}

angle::Result BufferNULL::map(const gl::Context *context,
                              GLenum access,
                              void **mapPtr,
                              BufferFeedback *feedback)
{
    *mapPtr = mData.data();
    return angle::Result::Continue;
}

angle::Result BufferNULL::mapRange(const gl::Context *context,
                                   size_t offset,
                                   size_t length,
                                   GLbitfield access,
                                   void **mapPtr,
                                   BufferFeedback *feedback)
{
    *mapPtr = ANGLE_UNSAFE_TODO(mData.data() + offset);
    return angle::Result::Continue;
}

angle::Result BufferNULL::unmap(const gl::Context *context,
                                GLboolean *result,
                                BufferFeedback *feedback)
{
    *result = GL_TRUE;
    return angle::Result::Continue;
}

angle::Result BufferNULL::getIndexRange(const gl::Context *context,
                                        gl::DrawElementsType type,
                                        size_t offset,
                                        size_t count,
                                        bool primitiveRestartEnabled,
                                        gl::IndexRange *outRange)
{
    *outRange = gl::ComputeIndexRange(type, ANGLE_UNSAFE_TODO(mData.data() + offset), count,
                                      primitiveRestartEnabled);
    return angle::Result::Continue;
}

uint8_t *BufferNULL::getDataPtr()
{
    return mData.data();
}

const uint8_t *BufferNULL::getDataPtr() const
{
    return mData.data();
}

}  // namespace rx