/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <algorithm> // min & max

#include <cstdlib>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

namespace mozilla {

namespace gfx {

void BufferUnrotate(uint8_t* aBuffer, int aByteWidth, int aHeight,

                    int aByteStride, int aXBoundary, int aYBoundary)

{

  if (aXBoundary != 0) {

    uint8_t* line = new uint8_t[aByteWidth];

    uint32_t smallStart = 0;

    uint32_t smallLen = aXBoundary;

    uint32_t smallDest = aByteWidth - aXBoundary;

    uint32_t largeStart = aXBoundary;

    uint32_t largeLen = aByteWidth - aXBoundary;

    uint32_t largeDest = 0;

    if (aXBoundary > aByteWidth / 2) {

      smallStart = aXBoundary;

      smallLen = aByteWidth - aXBoundary;

      smallDest = 0;

      largeStart = 0;

      largeLen = aXBoundary;

      largeDest = smallLen;

    }

    for (int y = 0; y < aHeight; y++) {

      int yOffset = y * aByteStride;

      memcpy(line, &aBuffer[yOffset + smallStart], smallLen);

      memmove(&aBuffer[yOffset + largeDest], &aBuffer[yOffset + largeStart], largeLen);

      memcpy(&aBuffer[yOffset + smallDest], line, smallLen);

    }

    delete[] line;

  }

  if (aYBoundary != 0) {

    uint32_t smallestHeight = std::min(aHeight - aYBoundary, aYBoundary);

    uint32_t largestHeight = std::max(aHeight - aYBoundary, aYBoundary);

    uint32_t smallOffset = 0;

    uint32_t largeOffset = aYBoundary * aByteStride;

    uint32_t largeDestOffset = 0;

    uint32_t smallDestOffset = largestHeight * aByteStride;

    if (aYBoundary > aHeight / 2) {

      smallOffset = aYBoundary * aByteStride;

      largeOffset = 0;

      largeDestOffset = smallestHeight * aByteStride;

      smallDestOffset = 0;

    }

    uint8_t* smallestSide = new uint8_t[aByteStride * smallestHeight];

    memcpy(smallestSide, &aBuffer[smallOffset], aByteStride * smallestHeight);

    memmove(&aBuffer[largeDestOffset], &aBuffer[largeOffset], aByteStride * largestHeight);

    memcpy(&aBuffer[smallDestOffset], smallestSide, aByteStride * smallestHeight);

    delete[] smallestSide;

  }

}

} // namespace gfx

} // namespace mozilla