1 /* vim:set sw=2 sts=2 et cin: */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6 #include <gdk-pixbuf/gdk-pixbuf.h>
7
8 #include "nsImageToPixbuf.h"
9
10 #include "imgIContainer.h"
11 #include "mozilla/gfx/2D.h"
12 #include "mozilla/RefPtr.h"
13
14 using mozilla::gfx::DataSourceSurface;
15 using mozilla::gfx::SurfaceFormat;
16
unpremultiply(unsigned char color,unsigned char alpha)17 inline unsigned char unpremultiply(unsigned char color, unsigned char alpha) {
18 if (alpha == 0) return 0;
19 // plus alpha/2 to round instead of truncate
20 return (color * 255 + alpha / 2) / alpha;
21 }
22
ImageToPixbuf(imgIContainer * aImage,const mozilla::Maybe<nsIntSize> & aOverrideSize)23 GdkPixbuf* nsImageToPixbuf::ImageToPixbuf(
24 imgIContainer* aImage, const mozilla::Maybe<nsIntSize>& aOverrideSize) {
25 RefPtr<SourceSurface> surface;
26
27 const uint32_t flags =
28 imgIContainer::FLAG_SYNC_DECODE | imgIContainer::FLAG_ASYNC_NOTIFY;
29 if (aOverrideSize) {
30 surface = aImage->GetFrameAtSize(*aOverrideSize,
31 imgIContainer::FRAME_CURRENT, flags);
32 } else {
33 surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT, flags);
34 }
35
36 // If the last call failed, it was probably because our call stack originates
37 // in an imgINotificationObserver event, meaning that we're not allowed
38 // request a sync decode. Presumably the originating event is something
39 // sensible like OnStopFrame(), so we can just retry the call without a sync
40 // decode.
41 if (!surface) {
42 if (aOverrideSize) {
43 surface =
44 aImage->GetFrameAtSize(*aOverrideSize, imgIContainer::FRAME_CURRENT,
45 imgIContainer::FLAG_NONE);
46 } else {
47 surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT,
48 imgIContainer::FLAG_NONE);
49 }
50 }
51
52 NS_ENSURE_TRUE(surface, nullptr);
53
54 return SourceSurfaceToPixbuf(surface, surface->GetSize().width,
55 surface->GetSize().height);
56 }
57
SourceSurfaceToPixbuf(SourceSurface * aSurface,int32_t aWidth,int32_t aHeight)58 GdkPixbuf* nsImageToPixbuf::SourceSurfaceToPixbuf(SourceSurface* aSurface,
59 int32_t aWidth,
60 int32_t aHeight) {
61 MOZ_ASSERT(aWidth <= aSurface->GetSize().width &&
62 aHeight <= aSurface->GetSize().height,
63 "Requested rect is bigger than the supplied surface");
64
65 GdkPixbuf* pixbuf =
66 gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, aWidth, aHeight);
67 if (!pixbuf) {
68 return nullptr;
69 }
70
71 uint32_t destStride = gdk_pixbuf_get_rowstride(pixbuf);
72 guchar* destPixels = gdk_pixbuf_get_pixels(pixbuf);
73
74 RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
75 DataSourceSurface::MappedSurface map;
76 if (!dataSurface->Map(DataSourceSurface::MapType::READ, &map)) {
77 return nullptr;
78 }
79
80 uint8_t* srcData = map.mData;
81 int32_t srcStride = map.mStride;
82
83 SurfaceFormat format = dataSurface->GetFormat();
84
85 for (int32_t row = 0; row < aHeight; ++row) {
86 for (int32_t col = 0; col < aWidth; ++col) {
87 guchar* destPixel = destPixels + row * destStride + 4 * col;
88
89 uint32_t* srcPixel =
90 reinterpret_cast<uint32_t*>((srcData + row * srcStride + 4 * col));
91
92 if (format == SurfaceFormat::B8G8R8A8) {
93 const uint8_t a = (*srcPixel >> 24) & 0xFF;
94 const uint8_t r = unpremultiply((*srcPixel >> 16) & 0xFF, a);
95 const uint8_t g = unpremultiply((*srcPixel >> 8) & 0xFF, a);
96 const uint8_t b = unpremultiply((*srcPixel >> 0) & 0xFF, a);
97
98 *destPixel++ = r;
99 *destPixel++ = g;
100 *destPixel++ = b;
101 *destPixel++ = a;
102 } else {
103 MOZ_ASSERT(format == SurfaceFormat::B8G8R8X8);
104
105 const uint8_t r = (*srcPixel >> 16) & 0xFF;
106 const uint8_t g = (*srcPixel >> 8) & 0xFF;
107 const uint8_t b = (*srcPixel >> 0) & 0xFF;
108
109 *destPixel++ = r;
110 *destPixel++ = g;
111 *destPixel++ = b;
112 *destPixel++ = 0xFF; // A
113 }
114 }
115 }
116
117 dataSurface->Unmap();
118
119 return pixbuf;
120 }
121