michael@0: /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <algorithm> // min & max
michael@0: #include <cstdlib>
michael@0: #include <stdint.h>
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include <string.h>
michael@0: 
michael@0: void BufferUnrotate(uint8_t* aBuffer, int aByteWidth, int aHeight,
michael@0:                     int aByteStride, int aXBoundary, int aYBoundary)
michael@0: {
michael@0:   if (aXBoundary != 0) {
michael@0:     uint8_t* line = new uint8_t[aByteWidth];
michael@0:     uint32_t smallStart = 0;
michael@0:     uint32_t smallLen = aXBoundary;
michael@0:     uint32_t smallDest = aByteWidth - aXBoundary;
michael@0:     uint32_t largeStart = aXBoundary;
michael@0:     uint32_t largeLen = aByteWidth - aXBoundary;
michael@0:     uint32_t largeDest = 0;
michael@0:     if (aXBoundary > aByteWidth / 2) {
michael@0:       smallStart = aXBoundary;
michael@0:       smallLen = aByteWidth - aXBoundary;
michael@0:       smallDest = 0;
michael@0:       largeStart = 0;
michael@0:       largeLen = aXBoundary;
michael@0:       largeDest = smallLen;
michael@0:     }
michael@0: 
michael@0:     for (int y = 0; y < aHeight; y++) {
michael@0:       int yOffset = y * aByteStride;
michael@0:       memcpy(line, &aBuffer[yOffset + smallStart], smallLen);
michael@0:       memmove(&aBuffer[yOffset + largeDest], &aBuffer[yOffset + largeStart], largeLen);
michael@0:       memcpy(&aBuffer[yOffset + smallDest], line, smallLen);
michael@0:     }
michael@0: 
michael@0:     delete[] line;
michael@0:   }
michael@0: 
michael@0:   if (aYBoundary != 0) {
michael@0:     uint32_t smallestHeight = std::min(aHeight - aYBoundary, aYBoundary);
michael@0:     uint32_t largestHeight = std::max(aHeight - aYBoundary, aYBoundary);
michael@0:     uint32_t smallOffset = 0;
michael@0:     uint32_t largeOffset = aYBoundary * aByteStride;
michael@0:     uint32_t largeDestOffset = 0;
michael@0:     uint32_t smallDestOffset = largestHeight * aByteStride;
michael@0:     if (aYBoundary > aHeight / 2) {
michael@0:       smallOffset = aYBoundary * aByteStride;
michael@0:       largeOffset = 0;
michael@0:       largeDestOffset = smallestHeight * aByteStride;
michael@0:       smallDestOffset = 0;
michael@0:     }
michael@0: 
michael@0:     uint8_t* smallestSide = new uint8_t[aByteStride * smallestHeight];
michael@0:     memcpy(smallestSide, &aBuffer[smallOffset], aByteStride * smallestHeight);
michael@0:     memmove(&aBuffer[largeDestOffset], &aBuffer[largeOffset], aByteStride * largestHeight);
michael@0:     memcpy(&aBuffer[smallDestOffset], smallestSide, aByteStride * smallestHeight);
michael@0:     delete[] smallestSide;
michael@0:   }
michael@0: }
michael@0: