firefox-main/widget/gtk/nsImageToPixbuf.cpp (file symbol)

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/* 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"
#include "GRefPtr.h"
#include "nsCOMPtr.h"
using mozilla::gfx::DataSourceSurface;
using mozilla::gfx::SurfaceFormat;
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;
}
already_AddRefed<GdkPixbuf> nsImageToPixbuf::ImageToPixbuf(
imgIContainer* aImage, const mozilla::Maybe<nsIntSize>& aOverrideSize) {
RefPtr<SourceSurface> surface;
const uint32_t flags =
imgIContainer::FLAG_SYNC_DECODE | imgIContainer::FLAG_ASYNC_NOTIFY;
if (aOverrideSize) {
surface = aImage->GetFrameAtSize(*aOverrideSize,
imgIContainer::FRAME_CURRENT, flags);
} else {
surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT, flags);
}
// 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) {
if (aOverrideSize) {
surface =
aImage->GetFrameAtSize(*aOverrideSize, imgIContainer::FRAME_CURRENT,
imgIContainer::FLAG_NONE);
} else {
surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT,
imgIContainer::FLAG_NONE);
}
}
NS_ENSURE_TRUE(surface, nullptr);
return SourceSurfaceToPixbuf(surface, surface->GetSize().width,
surface->GetSize().height);
}
already_AddRefed<GdkPixbuf> nsImageToPixbuf::SourceSurfaceToPixbuf(
SourceSurface* aSurface, int32_t aWidth, int32_t aHeight) {
using mozilla::gfx::Factory;
MOZ_ASSERT(aSurface);
MOZ_ASSERT(aWidth <= aSurface->GetSize().width &&
aHeight <= aSurface->GetSize().height,
"Requested rect is bigger than the supplied surface");
RefPtr<GdkPixbuf> pixbuf =
dont_AddRef(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;
DataSourceSurface::MappedSurface map;
SurfaceFormat sourceFormat = aSurface->GetFormat();
if (MOZ_UNLIKELY(sourceFormat != SurfaceFormat::B8G8R8A8 &&
sourceFormat != SurfaceFormat::B8G8R8X8)) {
dataSurface = Factory::CreateDataSourceSurface(
mozilla::gfx::IntSize(aWidth, aHeight), SurfaceFormat::B8G8R8A8);
if (NS_WARN_IF(!dataSurface)) {
return nullptr;
}
if (!dataSurface->Map(DataSourceSurface::MapType::READ_WRITE, &map)) {
return nullptr;
}
RefPtr<mozilla::gfx::DrawTarget> dt = Factory::CreateDrawTargetForData(
mozilla::gfx::BackendType::CAIRO, map.mData, dataSurface->GetSize(),
map.mStride, dataSurface->GetFormat());
if (!dt) {
dataSurface->Unmap();
return nullptr;
}
dt->FillRect(
mozilla::gfx::Rect(0, 0, aWidth, aHeight),
mozilla::gfx::SurfacePattern(aSurface, mozilla::gfx::ExtendMode::CLAMP),
mozilla::gfx::DrawOptions(1.0f,
mozilla::gfx::CompositionOp::OP_SOURCE));
} else {
dataSurface = aSurface->GetDataSurface();
if (!dataSurface->Map(DataSourceSurface::MapType::READ, &map)) {
return nullptr;
}
}
MOZ_ASSERT(dataSurface);
MOZ_ASSERT(map.mData);
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.forget();
}