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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_ | |
6 #define SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_ | |
7 | |
8 #include "base/compiler_specific.h" | |
9 #include "base/macros.h" | |
10 #include "skia/ext/platform_device.h" | |
11 | |
12 namespace skia { | |
13 | |
14 // A device is basically a wrapper around SkBitmap that provides a surface for | |
15 // SkCanvas to draw into. Our device provides a surface Windows can also write | |
16 // to. BitmapPlatformDevice creates a bitmap using CreateDIBSection() in a | |
17 // format that Skia supports and can then use this to draw ClearType into, etc. | |
18 // This pixel data is provided to the bitmap that the device contains so that it | |
19 // can be shared. | |
20 class SK_API BitmapPlatformDevice final : public SkBitmapDevice, | |
21 public PlatformDevice { | |
22 public: | |
23 // Factory function. is_opaque should be set if the caller knows the bitmap | |
24 // will be completely opaque and allows some optimizations. | |
25 // | |
26 // The |shared_section| parameter is optional (pass NULL for default | |
27 // behavior). If |shared_section| is non-null, then it must be a handle to a | |
28 // file-mapping object returned by CreateFileMapping. See CreateDIBSection | |
29 // for details. If |shared_section| is null, the bitmap backing store is not | |
30 // initialized. | |
31 static BitmapPlatformDevice* Create(int width, int height, | |
32 bool is_opaque, HANDLE shared_section, | |
33 bool do_clear = false); | |
34 | |
35 // Create a BitmapPlatformDevice with no shared section. The bitmap is not | |
36 // initialized to 0. | |
37 static BitmapPlatformDevice* Create(int width, int height, bool is_opaque); | |
38 | |
39 ~BitmapPlatformDevice() override; | |
40 | |
41 protected: | |
42 SkBaseDevice* onCreateDevice(const CreateInfo&, const SkPaint*) override; | |
43 | |
44 private: | |
45 // PlatformDevice override | |
46 // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The | |
47 // bitmap DC may be lazily created. | |
48 NativeDrawingContext BeginPlatformPaint(const SkMatrix& transform, | |
49 const SkIRect& clip_bounds) override; | |
50 | |
51 // Private constructor. | |
52 BitmapPlatformDevice(HBITMAP hbitmap, const SkBitmap& bitmap); | |
53 | |
54 // Bitmap into which the drawing will be done. This bitmap not owned by this | |
55 // class, but by the BitmapPlatformPixelRef inside the device's SkBitmap. | |
56 // It's only stored here in order to lazy-create the DC (below). | |
57 HBITMAP hbitmap_; | |
58 | |
59 // Previous bitmap held by the DC. This will be selected back before the | |
60 // DC is destroyed. | |
61 HBITMAP old_hbitmap_; | |
62 | |
63 // Lazily-created DC used to draw into the bitmap; see GetBitmapDC(). | |
64 HDC hdc_; | |
65 | |
66 // Create/destroy hdc_, which is the memory DC for our bitmap data. | |
67 HDC GetBitmapDC(const SkMatrix& transform, const SkIRect& clip_bounds); | |
68 void ReleaseBitmapDC(); | |
69 bool IsBitmapDCCreated() const; | |
70 | |
71 // Loads the current transform and clip into the context. Can be called even | |
72 // when |hbitmap_| is NULL (will be a NOP). | |
73 void LoadConfig(const SkMatrix& transform, const SkIRect& clip_bounds); | |
74 | |
75 DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice); | |
76 }; | |
77 | |
78 } // namespace skia | |
79 | |
80 #endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_ | |
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