gfx/2d/BufferUnrotate.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "BufferUnrotate.h"
   8
   9 #include <algorithm>  // min & max
  10 #include <cstdlib>
  11 #include <stdint.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15
  16 namespace mozilla {
  17 namespace gfx {
  18
  19 void BufferUnrotate(uint8_t* aBuffer, int aByteWidth, int aHeight,
  20                     int aByteStride, int aXBoundary, int aYBoundary) {
  21   if (aXBoundary != 0) {
  22     uint8_t* line = new uint8_t[aByteWidth];
  23     uint32_t smallStart = 0;
  24     uint32_t smallLen = aXBoundary;
  25     uint32_t smallDest = aByteWidth - aXBoundary;
  26     uint32_t largeStart = aXBoundary;
  27     uint32_t largeLen = aByteWidth - aXBoundary;
  28     uint32_t largeDest = 0;
  29     if (aXBoundary > aByteWidth / 2) {
  30       smallStart = aXBoundary;
  31       smallLen = aByteWidth - aXBoundary;
  32       smallDest = 0;
  33       largeStart = 0;
  34       largeLen = aXBoundary;
  35       largeDest = smallLen;
  36     }
  37
  38     for (int y = 0; y < aHeight; y++) {
  39       int yOffset = y * aByteStride;
  40       memcpy(line, &aBuffer[yOffset + smallStart], smallLen);
  41       memmove(&aBuffer[yOffset + largeDest], &aBuffer[yOffset + largeStart],
  42               largeLen);
  43       memcpy(&aBuffer[yOffset + smallDest], line, smallLen);
  44     }
  45
  46     delete[] line;
  47   }
  48
  49   if (aYBoundary != 0) {
  50     uint32_t smallestHeight = std::min(aHeight - aYBoundary, aYBoundary);
  51     uint32_t largestHeight = std::max(aHeight - aYBoundary, aYBoundary);
  52     uint32_t smallOffset = 0;
  53     uint32_t largeOffset = aYBoundary * aByteStride;
  54     uint32_t largeDestOffset = 0;
  55     uint32_t smallDestOffset = largestHeight * aByteStride;
  56     if (aYBoundary > aHeight / 2) {
  57       smallOffset = aYBoundary * aByteStride;
  58       largeOffset = 0;
  59       largeDestOffset = smallestHeight * aByteStride;
  60       smallDestOffset = 0;
  61     }
  62
  63     uint8_t* smallestSide = new uint8_t[aByteStride * smallestHeight];
  64     memcpy(smallestSide, &aBuffer[smallOffset], aByteStride * smallestHeight);
  65     memmove(&aBuffer[largeDestOffset], &aBuffer[largeOffset],
  66             aByteStride * largestHeight);
  67     memcpy(&aBuffer[smallDestOffset], smallestSide,
  68            aByteStride * smallestHeight);
  69     delete[] smallestSide;
  70   }
  71 }
  72
  73 }  // namespace gfx
  74 }  // namespace mozilla