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-rw-r--r--gfx/layers/BufferUnrotate.cpp64
1 files changed, 64 insertions, 0 deletions
diff --git a/gfx/layers/BufferUnrotate.cpp b/gfx/layers/BufferUnrotate.cpp
new file mode 100644
index 000000000..224818773
--- /dev/null
+++ b/gfx/layers/BufferUnrotate.cpp
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * 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>
+
+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;
+ }
+}
+