blob: 628732bc1e8745ad27203c3c208b56642050041b [file] [log] [blame]
// 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.
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#include <vector>
#include "skia/ext/platform_surface.h"
#include "third_party/skia/include/core/SkBitmapDevice.h"
#include "third_party/skia/include/core/SkTypes.h"
class SkMatrix;
class SkPath;
class SkRegion;
namespace skia {
class PlatformDevice;
// The following routines provide accessor points for the functionality
// exported by the various PlatformDevice ports.
// All calls to PlatformDevice::* should be routed through these
// helper functions.
// Bind a PlatformDevice instance, |platform_device| to |device|. Subsequent
// calls to the functions exported below will forward the request to the
// corresponding method on the bound PlatformDevice instance. If no
// PlatformDevice has been bound to the SkBaseDevice passed, then the
// routines are NOPS.
SK_API void SetPlatformDevice(SkBaseDevice* device,
PlatformDevice* platform_device);
SK_API PlatformDevice* GetPlatformDevice(SkBaseDevice* device);
// A SkBitmapDevice is basically a wrapper around SkBitmap that provides a
// surface for SkCanvas to draw into. PlatformDevice provides a surface
// Windows can also write to. It also provides functionality to play well
// with GDI drawing functions. This class is abstract and must be subclassed.
// It provides the basic interface to implement it either with or without
// a bitmap backend.
// PlatformDevice provides an interface which sub-classes of SkBaseDevice can
// also provide to allow for drawing by the native platform into the device.
// TODO(robertphillips): Once the bitmap-specific entry points are removed
// from SkBaseDevice it might make sense for PlatformDevice to be derived
// from it.
class SK_API PlatformDevice {
virtual ~PlatformDevice() {}
#if defined(OS_MACOSX)
// The CGContext that corresponds to the bitmap, used for CoreGraphics
// operations drawing into the bitmap. This is possibly heavyweight, so it
// should exist only during one pass of rendering.
virtual CGContextRef GetBitmapContext() = 0;
// The DC that corresponds to the bitmap, used for GDI operations drawing
// into the bitmap. This is possibly heavyweight, so it should be existant
// only during one pass of rendering.
virtual PlatformSurface BeginPlatformPaint();
// Finish a previous call to beginPlatformPaint.
virtual void EndPlatformPaint();
// Returns true if GDI operations can be used for drawing into the bitmap.
virtual bool SupportsPlatformPaint();
#if defined(OS_WIN)
// Loads a SkPath into the GDI context. The path can there after be used for
// clipping or as a stroke. Returns false if the path failed to be loaded.
static bool LoadPathToDC(HDC context, const SkPath& path);
// Loads a SkRegion into the GDI context.
static void LoadClippingRegionToDC(HDC context, const SkRegion& region,
const SkMatrix& transformation);
// Draws to the given screen DC, if the bitmap DC doesn't exist, this will
// temporarily create it. However, if you have created the bitmap DC, it will
// be more efficient if you don't free it until after this call so it doesn't
// have to be created twice. If src_rect is null, then the entirety of the
// source device will be copied.
virtual void DrawToHDC(HDC, int x, int y, const RECT* src_rect);
#if defined(OS_WIN)
// Arrays must be inside structures.
struct CubicPoints {
SkPoint p[4];
typedef std::vector<CubicPoints> CubicPath;
typedef std::vector<CubicPath> CubicPaths;
// Loads the specified Skia transform into the device context, excluding
// perspective (which GDI doesn't support).
static void LoadTransformToDC(HDC dc, const SkMatrix& matrix);
// Transforms SkPath's paths into a series of cubic path.
static bool SkPathToCubicPaths(CubicPaths* paths, const SkPath& skpath);
} // namespace skia