mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
121 lines
4.7 KiB
C++
121 lines
4.7 KiB
C++
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#ifndef SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_
|
|
#define SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_
|
|
|
|
#include "base/basictypes.h"
|
|
#include "base/compiler_specific.h"
|
|
#include "skia/ext/platform_device.h"
|
|
#include "skia/ext/refptr.h"
|
|
|
|
namespace skia {
|
|
|
|
// A device is basically a wrapper around SkBitmap that provides a surface for
|
|
// SkCanvas to draw into. Our device provides a surface Windows can also write
|
|
// to. BitmapPlatformDevice creates a bitmap using CreateDIBSection() in a
|
|
// format that Skia supports and can then use this to draw ClearType into, etc.
|
|
// This pixel data is provided to the bitmap that the device contains so that it
|
|
// can be shared.
|
|
//
|
|
// The GDI bitmap created for drawing is actually owned by a
|
|
// PlatformBitmapPixelRef, and stored in an SkBitmap via the normal skia
|
|
// SkPixelRef refcounting mechanism. In this way, the GDI bitmap can outlive
|
|
// the device created to draw into it. So it is safe to call accessBitmap() on
|
|
// the device, and retain the returned SkBitmap.
|
|
class SK_API BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice {
|
|
public:
|
|
// Factory function. is_opaque should be set if the caller knows the bitmap
|
|
// will be completely opaque and allows some optimizations.
|
|
//
|
|
// The |shared_section| parameter is optional (pass NULL for default
|
|
// behavior). If |shared_section| is non-null, then it must be a handle to a
|
|
// file-mapping object returned by CreateFileMapping. See CreateDIBSection
|
|
// for details. If |shared_section| is null, the bitmap backing store is not
|
|
// initialized.
|
|
static BitmapPlatformDevice* Create(int width, int height,
|
|
bool is_opaque, HANDLE shared_section,
|
|
bool do_clear = false);
|
|
|
|
// Create a BitmapPlatformDevice with no shared section. The bitmap is not
|
|
// initialized to 0.
|
|
static BitmapPlatformDevice* Create(int width, int height, bool is_opaque);
|
|
|
|
virtual ~BitmapPlatformDevice();
|
|
|
|
// PlatformDevice overrides
|
|
// Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
|
|
// bitmap DC is lazy created.
|
|
virtual PlatformSurface BeginPlatformPaint() override;
|
|
virtual void EndPlatformPaint() override;
|
|
|
|
// Loads the given transform and clipping region into the HDC. This is
|
|
// overridden from SkBaseDevice.
|
|
virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
|
|
const SkClipStack&) override;
|
|
|
|
void DrawToHDC(HDC dc, int x, int y, const RECT* src_rect) override;
|
|
|
|
protected:
|
|
// Flushes the Windows device context so that the pixel data can be accessed
|
|
// directly by Skia. Overridden from SkBaseDevice, this is called when Skia
|
|
// starts accessing pixel data.
|
|
virtual const SkBitmap& onAccessBitmap() override;
|
|
|
|
SkBaseDevice* onCreateDevice(const CreateInfo&, const SkPaint*) override;
|
|
|
|
private:
|
|
// Private constructor.
|
|
BitmapPlatformDevice(HBITMAP hbitmap, const SkBitmap& bitmap);
|
|
|
|
// Bitmap into which the drawing will be done. This bitmap not owned by this
|
|
// class, but by the BitmapPlatformPixelRef inside the device's SkBitmap.
|
|
// It's only stored here in order to lazy-create the DC (below).
|
|
HBITMAP hbitmap_;
|
|
|
|
// Previous bitmap held by the DC. This will be selected back before the
|
|
// DC is destroyed.
|
|
HBITMAP old_hbitmap_;
|
|
|
|
// Lazily-created DC used to draw into the bitmap; see GetBitmapDC().
|
|
HDC hdc_;
|
|
|
|
// True when there is a transform or clip that has not been set to the
|
|
// context. The context is retrieved for every text operation, and the
|
|
// transform and clip do not change as much. We can save time by not loading
|
|
// the clip and transform for every one.
|
|
bool config_dirty_;
|
|
|
|
// Translation assigned to the context: we need to keep track of this
|
|
// separately so it can be updated even if the context isn't created yet.
|
|
SkMatrix transform_;
|
|
|
|
// The current clipping region.
|
|
SkRegion clip_region_;
|
|
|
|
// Create/destroy hdc_, which is the memory DC for our bitmap data.
|
|
HDC GetBitmapDC();
|
|
void ReleaseBitmapDC();
|
|
bool IsBitmapDCCreated() const;
|
|
|
|
// Sets the transform and clip operations. This will not update the DC,
|
|
// but will mark the config as dirty. The next call of LoadConfig will
|
|
// pick up these changes.
|
|
void SetMatrixClip(const SkMatrix& transform, const SkRegion& region);
|
|
|
|
// Loads the current transform and clip into the context. Can be called even
|
|
// when |hbitmap_| is NULL (will be a NOP).
|
|
void LoadConfig();
|
|
|
|
#ifdef SK_DEBUG
|
|
int begin_paint_count_;
|
|
#endif
|
|
|
|
DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice);
|
|
};
|
|
|
|
} // namespace skia
|
|
|
|
#endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_
|