michael@0: /* vim:set sw=4 sts=4 et cin: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <gdk-pixbuf/gdk-pixbuf.h>
michael@0: 
michael@0: #include "nsImageToPixbuf.h"
michael@0: 
michael@0: #include "imgIContainer.h"
michael@0: #include "mozilla/gfx/2D.h"
michael@0: #include "mozilla/RefPtr.h"
michael@0: #include "nsAutoPtr.h"
michael@0: 
michael@0: using mozilla::gfx::DataSourceSurface;
michael@0: using mozilla::gfx::SurfaceFormat;
michael@0: using mozilla::RefPtr;
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsImageToPixbuf, nsIImageToPixbuf)
michael@0: 
michael@0: inline unsigned char
michael@0: unpremultiply (unsigned char color,
michael@0:                unsigned char alpha)
michael@0: {
michael@0:     if (alpha == 0)
michael@0:         return 0;
michael@0:     // plus alpha/2 to round instead of truncate
michael@0:     return (color * 255 + alpha / 2) / alpha;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP_(GdkPixbuf*)
michael@0: nsImageToPixbuf::ConvertImageToPixbuf(imgIContainer* aImage)
michael@0: {
michael@0:     return ImageToPixbuf(aImage);
michael@0: }
michael@0: 
michael@0: GdkPixbuf*
michael@0: nsImageToPixbuf::ImageToPixbuf(imgIContainer* aImage)
michael@0: {
michael@0:     RefPtr<SourceSurface> surface =
michael@0:       aImage->GetFrame(imgIContainer::FRAME_CURRENT,
michael@0:                        imgIContainer::FLAG_SYNC_DECODE);
michael@0: 
michael@0:     // If the last call failed, it was probably because our call stack originates
michael@0:     // in an imgINotificationObserver event, meaning that we're not allowed request
michael@0:     // a sync decode. Presumably the originating event is something sensible like
michael@0:     // OnStopFrame(), so we can just retry the call without a sync decode.
michael@0:     if (!surface)
michael@0:       surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT,
michael@0:                                  imgIContainer::FLAG_NONE);
michael@0: 
michael@0:     NS_ENSURE_TRUE(surface, nullptr);
michael@0: 
michael@0:     return SourceSurfaceToPixbuf(surface,
michael@0:                                  surface->GetSize().width,
michael@0:                                  surface->GetSize().height);
michael@0: }
michael@0: 
michael@0: GdkPixbuf*
michael@0: nsImageToPixbuf::SourceSurfaceToPixbuf(SourceSurface* aSurface,
michael@0:                                        int32_t aWidth,
michael@0:                                        int32_t aHeight)
michael@0: {
michael@0:     MOZ_ASSERT(aWidth <= aSurface->GetSize().width &&
michael@0:                aHeight <= aSurface->GetSize().height,
michael@0:                "Requested rect is bigger than the supplied surface");
michael@0: 
michael@0:     GdkPixbuf* pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
michael@0:                                        aWidth, aHeight);
michael@0:     if (!pixbuf)
michael@0:         return nullptr;
michael@0: 
michael@0:     uint32_t destStride = gdk_pixbuf_get_rowstride (pixbuf);
michael@0:     guchar* destPixels = gdk_pixbuf_get_pixels (pixbuf);
michael@0: 
michael@0:     RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
michael@0:     DataSourceSurface::MappedSurface map;
michael@0:     dataSurface->Map(DataSourceSurface::MapType::READ, &map);
michael@0:     uint8_t* srcData = map.mData;
michael@0:     int32_t srcStride = map.mStride;
michael@0: 
michael@0:     SurfaceFormat format = dataSurface->GetFormat();
michael@0: 
michael@0:     for (int32_t row = 0; row < aHeight; ++row) {
michael@0:         for (int32_t col = 0; col < aWidth; ++col) {
michael@0:             guchar* destPixel = destPixels + row * destStride + 4 * col;
michael@0: 
michael@0:             uint32_t* srcPixel =
michael@0:                 reinterpret_cast<uint32_t*>((srcData + row * srcStride + 4 * col));
michael@0: 
michael@0:             if (format == SurfaceFormat::B8G8R8A8) {
michael@0:                 const uint8_t a = (*srcPixel >> 24) & 0xFF;
michael@0:                 const uint8_t r = unpremultiply((*srcPixel >> 16) & 0xFF, a);
michael@0:                 const uint8_t g = unpremultiply((*srcPixel >>  8) & 0xFF, a);
michael@0:                 const uint8_t b = unpremultiply((*srcPixel >>  0) & 0xFF, a);
michael@0: 
michael@0:                 *destPixel++ = r;
michael@0:                 *destPixel++ = g;
michael@0:                 *destPixel++ = b;
michael@0:                 *destPixel++ = a;
michael@0:             } else {
michael@0:                 MOZ_ASSERT(format == SurfaceFormat::B8G8R8X8);
michael@0: 
michael@0:                 const uint8_t r = (*srcPixel >> 16) & 0xFF;
michael@0:                 const uint8_t g = (*srcPixel >>  8) & 0xFF;
michael@0:                 const uint8_t b = (*srcPixel >>  0) & 0xFF;
michael@0: 
michael@0:                 *destPixel++ = r;
michael@0:                 *destPixel++ = g;
michael@0:                 *destPixel++ = b;
michael@0:                 *destPixel++ = 0xFF; // A
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     dataSurface->Unmap();
michael@0: 
michael@0:     return pixbuf;
michael@0: }
michael@0: