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-rw-r--r--widget/gtk/nsImageToPixbuf.cpp120
1 files changed, 120 insertions, 0 deletions
diff --git a/widget/gtk/nsImageToPixbuf.cpp b/widget/gtk/nsImageToPixbuf.cpp
new file mode 100644
index 000000000..e06605b2b
--- /dev/null
+++ b/widget/gtk/nsImageToPixbuf.cpp
@@ -0,0 +1,120 @@
+/* vim:set sw=4 sts=4 et cin: */
+/* 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 <gdk-pixbuf/gdk-pixbuf.h>
+
+#include "nsImageToPixbuf.h"
+
+#include "imgIContainer.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/RefPtr.h"
+
+using mozilla::gfx::DataSourceSurface;
+using mozilla::gfx::SurfaceFormat;
+
+NS_IMPL_ISUPPORTS(nsImageToPixbuf, nsIImageToPixbuf)
+
+inline unsigned char
+unpremultiply (unsigned char color,
+ unsigned char alpha)
+{
+ if (alpha == 0)
+ return 0;
+ // plus alpha/2 to round instead of truncate
+ return (color * 255 + alpha / 2) / alpha;
+}
+
+NS_IMETHODIMP_(GdkPixbuf*)
+nsImageToPixbuf::ConvertImageToPixbuf(imgIContainer* aImage)
+{
+ return ImageToPixbuf(aImage);
+}
+
+GdkPixbuf*
+nsImageToPixbuf::ImageToPixbuf(imgIContainer* aImage)
+{
+ RefPtr<SourceSurface> surface =
+ aImage->GetFrame(imgIContainer::FRAME_CURRENT,
+ imgIContainer::FLAG_SYNC_DECODE);
+
+ // If the last call failed, it was probably because our call stack originates
+ // in an imgINotificationObserver event, meaning that we're not allowed request
+ // a sync decode. Presumably the originating event is something sensible like
+ // OnStopFrame(), so we can just retry the call without a sync decode.
+ if (!surface)
+ surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT,
+ imgIContainer::FLAG_NONE);
+
+ NS_ENSURE_TRUE(surface, nullptr);
+
+ return SourceSurfaceToPixbuf(surface,
+ surface->GetSize().width,
+ surface->GetSize().height);
+}
+
+GdkPixbuf*
+nsImageToPixbuf::SourceSurfaceToPixbuf(SourceSurface* aSurface,
+ int32_t aWidth,
+ int32_t aHeight)
+{
+ MOZ_ASSERT(aWidth <= aSurface->GetSize().width &&
+ aHeight <= aSurface->GetSize().height,
+ "Requested rect is bigger than the supplied surface");
+
+ GdkPixbuf* pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
+ aWidth, aHeight);
+ if (!pixbuf)
+ return nullptr;
+
+ uint32_t destStride = gdk_pixbuf_get_rowstride (pixbuf);
+ guchar* destPixels = gdk_pixbuf_get_pixels (pixbuf);
+
+ RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
+ DataSourceSurface::MappedSurface map;
+ if (!dataSurface->Map(DataSourceSurface::MapType::READ, &map))
+ return nullptr;
+
+ uint8_t* srcData = map.mData;
+ int32_t srcStride = map.mStride;
+
+ SurfaceFormat format = dataSurface->GetFormat();
+
+ for (int32_t row = 0; row < aHeight; ++row) {
+ for (int32_t col = 0; col < aWidth; ++col) {
+ guchar* destPixel = destPixels + row * destStride + 4 * col;
+
+ uint32_t* srcPixel =
+ reinterpret_cast<uint32_t*>((srcData + row * srcStride + 4 * col));
+
+ if (format == SurfaceFormat::B8G8R8A8) {
+ const uint8_t a = (*srcPixel >> 24) & 0xFF;
+ const uint8_t r = unpremultiply((*srcPixel >> 16) & 0xFF, a);
+ const uint8_t g = unpremultiply((*srcPixel >> 8) & 0xFF, a);
+ const uint8_t b = unpremultiply((*srcPixel >> 0) & 0xFF, a);
+
+ *destPixel++ = r;
+ *destPixel++ = g;
+ *destPixel++ = b;
+ *destPixel++ = a;
+ } else {
+ MOZ_ASSERT(format == SurfaceFormat::B8G8R8X8);
+
+ const uint8_t r = (*srcPixel >> 16) & 0xFF;
+ const uint8_t g = (*srcPixel >> 8) & 0xFF;
+ const uint8_t b = (*srcPixel >> 0) & 0xFF;
+
+ *destPixel++ = r;
+ *destPixel++ = g;
+ *destPixel++ = b;
+ *destPixel++ = 0xFF; // A
+ }
+ }
+ }
+
+ dataSurface->Unmap();
+
+ return pixbuf;
+}
+