Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 302 insertions, 0 deletions

diff --git a/image/Downscaler.cpp b/image/Downscaler.cpp
new file mode 100644
index 0000000000..5bf15f1469
--- /dev/null
+++ b/image/Downscaler.cpp
@@ -0,0 +1,302 @@
+/* -*- Mode: C++; tab-width: 2; 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 "Downscaler.h"
+
+#include <algorithm>
+#include <ctime>
+
+#include "mozilla/gfx/2D.h"
+
+using std::max;
+using std::swap;
+
+namespace mozilla {
+
+using gfx::IntRect;
+
+namespace image {
+
+Downscaler::Downscaler(const nsIntSize& aTargetSize)
+    : mTargetSize(aTargetSize),
+      mOutputBuffer(nullptr),
+      mWindowCapacity(0),
+      mLinesInBuffer(0),
+      mPrevInvalidatedLine(0),
+      mCurrentOutLine(0),
+      mCurrentInLine(0),
+      mHasAlpha(true),
+      mFlipVertically(false) {
+  MOZ_ASSERT(mTargetSize.width > 0 && mTargetSize.height > 0,
+             "Invalid target size");
+}
+
+Downscaler::~Downscaler() { ReleaseWindow(); }
+
+void Downscaler::ReleaseWindow() {
+  if (!mWindow) {
+    return;
+  }
+
+  for (int32_t i = 0; i < mWindowCapacity; ++i) {
+    delete[] mWindow[i];
+  }
+
+  mWindow = nullptr;
+  mWindowCapacity = 0;
+}
+
+nsresult Downscaler::BeginFrame(const nsIntSize& aOriginalSize,
+                                const Maybe<nsIntRect>& aFrameRect,
+                                uint8_t* aOutputBuffer, bool aHasAlpha,
+                                bool aFlipVertically /* = false */) {
+  MOZ_ASSERT(aOutputBuffer);
+  MOZ_ASSERT(mTargetSize != aOriginalSize,
+             "Created a downscaler, but not downscaling?");
+  MOZ_ASSERT(mTargetSize.width <= aOriginalSize.width,
+             "Created a downscaler, but width is larger");
+  MOZ_ASSERT(mTargetSize.height <= aOriginalSize.height,
+             "Created a downscaler, but height is larger");
+  MOZ_ASSERT(aOriginalSize.width > 0 && aOriginalSize.height > 0,
+             "Invalid original size");
+
+  // Only downscale from reasonable sizes to avoid using too much memory/cpu
+  // downscaling and decoding. 1 << 20 == 1,048,576 seems a reasonable limit.
+  if (aOriginalSize.width > (1 << 20) || aOriginalSize.height > (1 << 20)) {
+    NS_WARNING("Trying to downscale image frame that is too large");
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mFrameRect = aFrameRect.valueOr(nsIntRect(nsIntPoint(), aOriginalSize));
+  MOZ_ASSERT(mFrameRect.X() >= 0 && mFrameRect.Y() >= 0 &&
+                 mFrameRect.Width() >= 0 && mFrameRect.Height() >= 0,
+             "Frame rect must have non-negative components");
+  MOZ_ASSERT(nsIntRect(0, 0, aOriginalSize.width, aOriginalSize.height)
+                 .Contains(mFrameRect),
+             "Frame rect must fit inside image");
+  MOZ_ASSERT_IF(!nsIntRect(0, 0, aOriginalSize.width, aOriginalSize.height)
+                     .IsEqualEdges(mFrameRect),
+                aHasAlpha);
+
+  mOriginalSize = aOriginalSize;
+  mScale = gfx::MatrixScalesDouble(
+      double(mOriginalSize.width) / mTargetSize.width,
+      double(mOriginalSize.height) / mTargetSize.height);
+  mOutputBuffer = aOutputBuffer;
+  mHasAlpha = aHasAlpha;
+  mFlipVertically = aFlipVertically;
+
+  ReleaseWindow();
+
+  auto resizeMethod = gfx::ConvolutionFilter::ResizeMethod::LANCZOS3;
+  if (!mXFilter.ComputeResizeFilter(resizeMethod, mOriginalSize.width,
+                                    mTargetSize.width) ||
+      !mYFilter.ComputeResizeFilter(resizeMethod, mOriginalSize.height,
+                                    mTargetSize.height)) {
+    NS_WARNING("Failed to compute filters for image downscaling");
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // Allocate the buffer, which contains scanlines of the original image.
+  // pad to handle overreads by the simd code
+  size_t bufferLen = gfx::ConvolutionFilter::PadBytesForSIMD(
+      mOriginalSize.width * sizeof(uint32_t));
+  mRowBuffer.reset(new (fallible) uint8_t[bufferLen]);
+  if (MOZ_UNLIKELY(!mRowBuffer)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  // Zero buffer to keep valgrind happy.
+  memset(mRowBuffer.get(), 0, bufferLen);
+
+  // Allocate the window, which contains horizontally downscaled scanlines. (We
+  // can store scanlines which are already downscale because our downscaling
+  // filter is separable.)
+  mWindowCapacity = mYFilter.MaxFilter();
+  mWindow.reset(new (fallible) uint8_t*[mWindowCapacity]);
+  if (MOZ_UNLIKELY(!mWindow)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  bool anyAllocationFailed = false;
+  // pad to handle overreads by the simd code
+  const size_t rowSize = gfx::ConvolutionFilter::PadBytesForSIMD(
+      mTargetSize.width * sizeof(uint32_t));
+  for (int32_t i = 0; i < mWindowCapacity; ++i) {
+    mWindow[i] = new (fallible) uint8_t[rowSize];
+    anyAllocationFailed = anyAllocationFailed || mWindow[i] == nullptr;
+  }
+
+  if (MOZ_UNLIKELY(anyAllocationFailed)) {
+    // We intentionally iterate through the entire array even if an allocation
+    // fails, to ensure that all the pointers in it are either valid or nullptr.
+    // That in turn ensures that ReleaseWindow() can clean up correctly.
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  ResetForNextProgressivePass();
+
+  return NS_OK;
+}
+
+void Downscaler::SkipToRow(int32_t aRow) {
+  if (mCurrentInLine < aRow) {
+    ClearRow();
+    do {
+      CommitRow();
+    } while (mCurrentInLine < aRow);
+  }
+}
+
+void Downscaler::ResetForNextProgressivePass() {
+  mPrevInvalidatedLine = 0;
+  mCurrentOutLine = 0;
+  mCurrentInLine = 0;
+  mLinesInBuffer = 0;
+
+  if (mFrameRect.IsEmpty()) {
+    // Our frame rect is zero size; commit rows until the end of the image.
+    SkipToRow(mOriginalSize.height - 1);
+  } else {
+    // If we have a vertical offset, commit rows to shift us past it.
+    SkipToRow(mFrameRect.Y());
+  }
+}
+
+void Downscaler::ClearRestOfRow(uint32_t aStartingAtCol) {
+  MOZ_ASSERT(int64_t(aStartingAtCol) <= int64_t(mOriginalSize.width));
+  uint32_t bytesToClear =
+      (mOriginalSize.width - aStartingAtCol) * sizeof(uint32_t);
+  memset(mRowBuffer.get() + (aStartingAtCol * sizeof(uint32_t)), 0,
+         bytesToClear);
+}
+
+void Downscaler::CommitRow() {
+  MOZ_ASSERT(mOutputBuffer, "Should have a current frame");
+  MOZ_ASSERT(mCurrentInLine < mOriginalSize.height, "Past end of input");
+
+  if (mCurrentOutLine < mTargetSize.height) {
+    int32_t filterOffset = 0;
+    int32_t filterLength = 0;
+    mYFilter.GetFilterOffsetAndLength(mCurrentOutLine, &filterOffset,
+                                      &filterLength);
+
+    int32_t inLineToRead = filterOffset + mLinesInBuffer;
+    MOZ_ASSERT(mCurrentInLine <= inLineToRead, "Reading past end of input");
+    if (mCurrentInLine == inLineToRead) {
+      MOZ_RELEASE_ASSERT(mLinesInBuffer < mWindowCapacity,
+                         "Need more rows than capacity!");
+      mXFilter.ConvolveHorizontally(mRowBuffer.get(), mWindow[mLinesInBuffer++],
+                                    mHasAlpha);
+    }
+
+    MOZ_ASSERT(mCurrentOutLine < mTargetSize.height,
+               "Writing past end of output");
+
+    while (mLinesInBuffer >= filterLength) {
+      DownscaleInputLine();
+
+      if (mCurrentOutLine == mTargetSize.height) {
+        break;  // We're done.
+      }
+
+      mYFilter.GetFilterOffsetAndLength(mCurrentOutLine, &filterOffset,
+                                        &filterLength);
+    }
+  }
+
+  mCurrentInLine += 1;
+
+  // If we're at the end of the part of the original image that has data, commit
+  // rows to shift us to the end.
+  if (mCurrentInLine == (mFrameRect.Y() + mFrameRect.Height())) {
+    SkipToRow(mOriginalSize.height - 1);
+  }
+}
+
+bool Downscaler::HasInvalidation() const {
+  return mCurrentOutLine > mPrevInvalidatedLine;
+}
+
+DownscalerInvalidRect Downscaler::TakeInvalidRect() {
+  if (MOZ_UNLIKELY(!HasInvalidation())) {
+    return DownscalerInvalidRect();
+  }
+
+  DownscalerInvalidRect invalidRect;
+
+  // Compute the target size invalid rect.
+  if (mFlipVertically) {
+    // We need to flip it. This will implicitly flip the original size invalid
+    // rect, since we compute it by scaling this rect.
+    invalidRect.mTargetSizeRect =
+        IntRect(0, mTargetSize.height - mCurrentOutLine, mTargetSize.width,
+                mCurrentOutLine - mPrevInvalidatedLine);
+  } else {
+    invalidRect.mTargetSizeRect =
+        IntRect(0, mPrevInvalidatedLine, mTargetSize.width,
+                mCurrentOutLine - mPrevInvalidatedLine);
+  }
+
+  mPrevInvalidatedLine = mCurrentOutLine;
+
+  // Compute the original size invalid rect.
+  invalidRect.mOriginalSizeRect = invalidRect.mTargetSizeRect;
+  invalidRect.mOriginalSizeRect.ScaleRoundOut(mScale.xScale, mScale.yScale);
+
+  return invalidRect;
+}
+
+void Downscaler::DownscaleInputLine() {
+  MOZ_ASSERT(mOutputBuffer);
+  MOZ_ASSERT(mCurrentOutLine < mTargetSize.height,
+             "Writing past end of output");
+
+  int32_t filterOffset = 0;
+  int32_t filterLength = 0;
+  mYFilter.GetFilterOffsetAndLength(mCurrentOutLine, &filterOffset,
+                                    &filterLength);
+
+  int32_t currentOutLine = mFlipVertically
+                               ? mTargetSize.height - (mCurrentOutLine + 1)
+                               : mCurrentOutLine;
+  MOZ_ASSERT(currentOutLine >= 0);
+
+  uint8_t* outputLine =
+      &mOutputBuffer[currentOutLine * mTargetSize.width * sizeof(uint32_t)];
+  mYFilter.ConvolveVertically(mWindow.get(), outputLine, mCurrentOutLine,
+                              mXFilter.NumValues(), mHasAlpha);
+
+  mCurrentOutLine += 1;
+
+  if (mCurrentOutLine == mTargetSize.height) {
+    // We're done.
+    return;
+  }
+
+  int32_t newFilterOffset = 0;
+  int32_t newFilterLength = 0;
+  mYFilter.GetFilterOffsetAndLength(mCurrentOutLine, &newFilterOffset,
+                                    &newFilterLength);
+
+  int diff = newFilterOffset - filterOffset;
+  MOZ_ASSERT(diff >= 0, "Moving backwards in the filter?");
+
+  // Shift the buffer. We're just moving pointers here, so this is cheap.
+  mLinesInBuffer -= diff;
+  mLinesInBuffer = std::min(std::max(mLinesInBuffer, 0), mWindowCapacity);
+
+  // If we already have enough rows to satisfy the filter, there is no need
+  // to swap as we won't be writing more before the next convolution.
+  if (filterLength > mLinesInBuffer) {
+    for (int32_t i = 0; i < mLinesInBuffer; ++i) {
+      swap(mWindow[i], mWindow[filterLength - mLinesInBuffer + i]);
+    }
+  }
+}
+
+}  // namespace image
+}  // namespace mozilla