1 files changed, 374 insertions, 0 deletions
diff --git a/gfx/2d/DataSurfaceHelpers.cpp b/gfx/2d/DataSurfaceHelpers.cpp
new file mode 100644
index 000000000..87ef00fcd
--- /dev/null
+++ b/gfx/2d/DataSurfaceHelpers.cpp
@@ -0,0 +1,374 @@
+/* -*- 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 <cstring>
+
+#include "2D.h"
+#include "DataSurfaceHelpers.h"
+#include "Logging.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/PodOperations.h"
+#include "Tools.h"
+
+namespace mozilla {
+namespace gfx {
+
+already_AddRefed<DataSourceSurface>
+CreateDataSourceSurfaceFromData(const IntSize& aSize,
+                                SurfaceFormat aFormat,
+                                const uint8_t* aData,
+                                int32_t aDataStride)
+{
+  RefPtr<DataSourceSurface> srcSurface =
+      Factory::CreateWrappingDataSourceSurface(const_cast<uint8_t*>(aData),
+                                               aDataStride,
+                                               aSize,
+                                               aFormat);
+  RefPtr<DataSourceSurface> destSurface =
+      Factory::CreateDataSourceSurface(aSize, aFormat, false);
+
+  if (!srcSurface || !destSurface) {
+    return nullptr;
+  }
+
+  if (CopyRect(srcSurface,
+               destSurface,
+               IntRect(IntPoint(), srcSurface->GetSize()),
+               IntPoint())) {
+    return destSurface.forget();
+  }
+
+  return nullptr;
+}
+
+already_AddRefed<DataSourceSurface>
+CreateDataSourceSurfaceWithStrideFromData(const IntSize &aSize,
+                                          SurfaceFormat aFormat,
+                                          int32_t aStride,
+                                          const uint8_t* aData,
+                                          int32_t aDataStride)
+{
+  RefPtr<DataSourceSurface> srcSurface =
+      Factory::CreateWrappingDataSourceSurface(const_cast<uint8_t*>(aData),
+                                               aDataStride,
+                                               aSize,
+                                               aFormat);
+  RefPtr<DataSourceSurface> destSurface =
+      Factory::CreateDataSourceSurfaceWithStride(aSize, aFormat, aStride, false);
+
+  if (!srcSurface || !destSurface) {
+    return nullptr;
+  }
+
+  if (CopyRect(srcSurface,
+               destSurface,
+               IntRect(IntPoint(), srcSurface->GetSize()),
+               IntPoint())) {
+    return destSurface.forget();
+  }
+
+  return nullptr;
+}
+
+uint8_t*
+DataAtOffset(DataSourceSurface* aSurface,
+             const DataSourceSurface::MappedSurface* aMap,
+             IntPoint aPoint)
+{
+  if (!SurfaceContainsPoint(aSurface, aPoint)) {
+    MOZ_CRASH("GFX: sample position needs to be inside surface!");
+  }
+
+  MOZ_ASSERT(Factory::CheckSurfaceSize(aSurface->GetSize()),
+             "surface size overflows - this should have been prevented when the surface was created");
+
+  uint8_t* data = aMap->mData + aPoint.y * aMap->mStride +
+    aPoint.x * BytesPerPixel(aSurface->GetFormat());
+
+  if (data < aMap->mData) {
+    MOZ_CRASH("GFX: out-of-range data access");
+  }
+
+  return data;
+}
+
+// This check is safe against integer overflow.
+bool
+SurfaceContainsPoint(SourceSurface* aSurface, const IntPoint& aPoint)
+{
+  IntSize size = aSurface->GetSize();
+  return aPoint.x >= 0 && aPoint.x < size.width &&
+         aPoint.y >= 0 && aPoint.y < size.height;
+}
+
+void
+ConvertBGRXToBGRA(uint8_t* aData, const IntSize &aSize, const int32_t aStride)
+{
+  int height = aSize.height, width = aSize.width * 4;
+
+  for (int row = 0; row < height; ++row) {
+    for (int column = 0; column < width; column += 4) {
+#ifdef IS_BIG_ENDIAN
+      aData[column] = 0xFF;
+#else
+      aData[column + 3] = 0xFF;
+#endif
+    }
+    aData += aStride;
+  }
+}
+
+void
+CopySurfaceDataToPackedArray(uint8_t* aSrc, uint8_t* aDst, IntSize aSrcSize,
+                             int32_t aSrcStride, int32_t aBytesPerPixel)
+{
+  MOZ_ASSERT(aBytesPerPixel > 0,
+             "Negative stride for aDst not currently supported");
+  MOZ_ASSERT(BufferSizeFromStrideAndHeight(aSrcStride, aSrcSize.height) > 0,
+             "How did we end up with a surface with such a big buffer?");
+
+  int packedStride = aSrcSize.width * aBytesPerPixel;
+
+  if (aSrcStride == packedStride) {
+    // aSrc is already packed, so we can copy with a single memcpy.
+    memcpy(aDst, aSrc, packedStride * aSrcSize.height);
+  } else {
+    // memcpy one row at a time.
+    for (int row = 0; row < aSrcSize.height; ++row) {
+      memcpy(aDst, aSrc, packedStride);
+      aSrc += aSrcStride;
+      aDst += packedStride;
+    }
+  }
+}
+
+void
+CopyBGRXSurfaceDataToPackedBGRArray(uint8_t* aSrc, uint8_t* aDst,
+                                    IntSize aSrcSize, int32_t aSrcStride)
+{
+  int packedStride = aSrcSize.width * 3;
+
+  uint8_t* srcPx = aSrc;
+  uint8_t* dstPx = aDst;
+
+  for (int row = 0; row < aSrcSize.height; ++row) {
+    for (int col = 0; col < aSrcSize.width; ++col) {
+      dstPx[0] = srcPx[0];
+      dstPx[1] = srcPx[1];
+      dstPx[2] = srcPx[2];
+      // srcPx[3] (unused or alpha component) dropped on floor
+      srcPx += 4;
+      dstPx += 3;
+    }
+    srcPx = aSrc += aSrcStride;
+    dstPx = aDst += packedStride;
+  }
+}
+
+UniquePtr<uint8_t[]>
+SurfaceToPackedBGRA(DataSourceSurface *aSurface)
+{
+  SurfaceFormat format = aSurface->GetFormat();
+  if (format != SurfaceFormat::B8G8R8A8 && format != SurfaceFormat::B8G8R8X8) {
+    return nullptr;
+  }
+
+  IntSize size = aSurface->GetSize();
+
+  UniquePtr<uint8_t[]> imageBuffer(
+    new (std::nothrow) uint8_t[size.width * size.height * sizeof(uint32_t)]);
+  if (!imageBuffer) {
+    return nullptr;
+  }
+
+  DataSourceSurface::MappedSurface map;
+  if (!aSurface->Map(DataSourceSurface::MapType::READ, &map)) {
+    return nullptr;
+  }
+
+  CopySurfaceDataToPackedArray(map.mData, imageBuffer.get(), size,
+                               map.mStride, 4 * sizeof(uint8_t));
+
+  aSurface->Unmap();
+
+  if (format == SurfaceFormat::B8G8R8X8) {
+    // Convert BGRX to BGRA by setting a to 255.
+    ConvertBGRXToBGRA(imageBuffer.get(), size, size.width * sizeof(uint32_t));
+  }
+
+  return imageBuffer;
+}
+
+uint8_t*
+SurfaceToPackedBGR(DataSourceSurface *aSurface)
+{
+  SurfaceFormat format = aSurface->GetFormat();
+  MOZ_ASSERT(format == SurfaceFormat::B8G8R8X8, "Format not supported");
+
+  if (format != SurfaceFormat::B8G8R8X8) {
+    // To support B8G8R8A8 we'd need to un-pre-multiply alpha
+    return nullptr;
+  }
+
+  IntSize size = aSurface->GetSize();
+
+  uint8_t* imageBuffer = new (std::nothrow) uint8_t[size.width * size.height * 3 * sizeof(uint8_t)];
+  if (!imageBuffer) {
+    return nullptr;
+  }
+
+  DataSourceSurface::MappedSurface map;
+  if (!aSurface->Map(DataSourceSurface::MapType::READ, &map)) {
+    delete [] imageBuffer;
+    return nullptr;
+  }
+
+  CopyBGRXSurfaceDataToPackedBGRArray(map.mData, imageBuffer, size,
+                                      map.mStride);
+
+  aSurface->Unmap();
+
+  return imageBuffer;
+}
+
+void
+ClearDataSourceSurface(DataSourceSurface *aSurface)
+{
+  DataSourceSurface::MappedSurface map;
+  if (!aSurface->Map(DataSourceSurface::MapType::WRITE, &map)) {
+    MOZ_ASSERT(false, "Failed to map DataSourceSurface");
+    return;
+  }
+
+  // We avoid writing into the gaps between the rows here since we can't be
+  // sure that some drivers don't use those bytes.
+
+  uint32_t width = aSurface->GetSize().width;
+  uint32_t bytesPerRow = width * BytesPerPixel(aSurface->GetFormat());
+  uint8_t* row = map.mData;
+  // converting to size_t here because otherwise the temporaries can overflow
+  // and we can end up with |end| being a bad address!
+  uint8_t* end = row + size_t(map.mStride) * size_t(aSurface->GetSize().height);
+
+  while (row != end) {
+    memset(row, 0, bytesPerRow);
+    row += map.mStride;
+  }
+
+  aSurface->Unmap();
+}
+
+size_t
+BufferSizeFromStrideAndHeight(int32_t aStride,
+                              int32_t aHeight,
+                              int32_t aExtraBytes)
+{
+  if (MOZ_UNLIKELY(aHeight <= 0) || MOZ_UNLIKELY(aStride <= 0)) {
+    return 0;
+  }
+
+  // We limit the length returned to values that can be represented by int32_t
+  // because we don't want to allocate buffers any bigger than that. This
+  // allows for a buffer size of over 2 GiB which is already rediculously
+  // large and will make the process janky. (Note the choice of the signed type
+  // is deliberate because we specifically don't want the returned value to
+  // overflow if someone stores the buffer length in an int32_t variable.)
+
+  CheckedInt32 requiredBytes =
+    CheckedInt32(aStride) * CheckedInt32(aHeight) + CheckedInt32(aExtraBytes);
+  if (MOZ_UNLIKELY(!requiredBytes.isValid())) {
+    gfxWarning() << "Buffer size too big; returning zero " << aStride << ", " << aHeight << ", " << aExtraBytes;
+    return 0;
+  }
+  return requiredBytes.value();
+}
+
+size_t
+BufferSizeFromDimensions(int32_t aWidth,
+                         int32_t aHeight,
+                         int32_t aDepth,
+                         int32_t aExtraBytes)
+{
+  if (MOZ_UNLIKELY(aHeight <= 0) ||
+      MOZ_UNLIKELY(aWidth <= 0) ||
+      MOZ_UNLIKELY(aDepth <= 0)) {
+    return 0;
+  }
+
+  // Similar to BufferSizeFromStrideAndHeight, but with an extra parameter.
+
+  CheckedInt32 requiredBytes = CheckedInt32(aWidth) * CheckedInt32(aHeight) * CheckedInt32(aDepth) + CheckedInt32(aExtraBytes);
+  if (MOZ_UNLIKELY(!requiredBytes.isValid())) {
+    gfxWarning() << "Buffer size too big; returning zero " << aWidth << ", " << aHeight << ", " << aDepth << ", " << aExtraBytes;
+    return 0;
+  }
+  return requiredBytes.value();
+}
+
+/**
+ * aSrcRect: Rect relative to the aSrc surface
+ * aDestPoint: Point inside aDest surface
+ */
+bool
+CopyRect(DataSourceSurface* aSrc, DataSourceSurface* aDest,
+         IntRect aSrcRect, IntPoint aDestPoint)
+{
+  if (aSrcRect.Overflows() ||
+      IntRect(aDestPoint, aSrcRect.Size()).Overflows()) {
+    MOZ_CRASH("GFX: we should never be getting invalid rects at this point");
+  }
+
+  MOZ_RELEASE_ASSERT(aSrc->GetFormat() == aDest->GetFormat(),
+                     "GFX: different surface formats");
+  MOZ_RELEASE_ASSERT(IntRect(IntPoint(), aSrc->GetSize()).Contains(aSrcRect),
+                     "GFX: source rect too big for source surface");
+  MOZ_RELEASE_ASSERT(IntRect(IntPoint(), aDest->GetSize()).Contains(IntRect(aDestPoint, aSrcRect.Size())),
+                     "GFX: dest surface too small");
+
+  if (aSrcRect.IsEmpty()) {
+    return false;
+  }
+
+  DataSourceSurface::ScopedMap srcMap(aSrc, DataSourceSurface::READ);
+  DataSourceSurface::ScopedMap destMap(aDest, DataSourceSurface::WRITE);
+  if (MOZ2D_WARN_IF(!srcMap.IsMapped() || !destMap.IsMapped())) {
+    return false;
+  }
+
+  uint8_t* sourceData = DataAtOffset(aSrc, srcMap.GetMappedSurface(), aSrcRect.TopLeft());
+  uint32_t sourceStride = srcMap.GetStride();
+  uint8_t* destData = DataAtOffset(aDest, destMap.GetMappedSurface(), aDestPoint);
+  uint32_t destStride = destMap.GetStride();
+
+  if (BytesPerPixel(aSrc->GetFormat()) == 4) {
+    for (int32_t y = 0; y < aSrcRect.height; y++) {
+      PodCopy((int32_t*)destData, (int32_t*)sourceData, aSrcRect.width);
+      sourceData += sourceStride;
+      destData += destStride;
+    }
+  } else if (BytesPerPixel(aSrc->GetFormat()) == 1) {
+    for (int32_t y = 0; y < aSrcRect.height; y++) {
+      PodCopy(destData, sourceData, aSrcRect.width);
+      sourceData += sourceStride;
+      destData += destStride;
+    }
+  }
+
+  return true;
+}
+
+already_AddRefed<DataSourceSurface>
+CreateDataSourceSurfaceByCloning(DataSourceSurface* aSource)
+{
+  RefPtr<DataSourceSurface> copy =
+    Factory::CreateDataSourceSurface(aSource->GetSize(), aSource->GetFormat(), true);
+  if (copy) {
+    CopyRect(aSource, copy, IntRect(IntPoint(), aSource->GetSize()), IntPoint());
+  }
+  return copy.forget();
+}
+
+} // namespace gfx
+} // namespace mozilla