1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
// Copyright (c) 2006-2008 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 BASE_GFX_PLATFORM_DEVICE_MAC_H__
#define BASE_GFX_PLATFORM_DEVICE_MAC_H__
#import <ApplicationServices/ApplicationServices.h>
#include "SkDevice.h"
class SkMatrix;
class SkPath;
class SkRegion;
namespace gfx {
// A device is basically a wrapper around SkBitmap that provides a surface for
// SkCanvas to draw into. Our device provides a surface CoreGraphics can also
// write to. It also provides functionality to play well with CG 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.
class PlatformDeviceMac : public SkDevice {
public:
// 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;
// Draws to the given graphics context. If the bitmap context doesn't exist,
// this will temporarily create it. However, if you have created the bitmap
// context, 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 DrawToContext(CGContextRef context, int x, int y,
const CGRect* src_rect) = 0;
// Sets the opacity of each pixel in the specified region to be opaque.
void makeOpaque(int x, int y, int width, int height);
// Returns if the preferred rendering engine is vectorial or bitmap based.
virtual bool IsVectorial() = 0;
// On platforms where the native rendering API does not support rendering
// into bitmaps with a premultiplied alpha channel, this call is responsible
// for doing any fixup necessary. It is not used on the Mac, since
// CoreGraphics can handle premultiplied alpha just fine.
virtual void fixupAlphaBeforeCompositing() = 0;
// Initializes the default settings and colors in a device context.
static void InitializeCGContext(CGContextRef context);
// Loads a SkPath into the CG context. The path can there after be used for
// clipping or as a stroke.
static void LoadPathToCGContext(CGContextRef context, const SkPath& path);
// Loads a SkRegion into the CG context.
static void LoadClippingRegionToCGContext(CGContextRef context,
const SkRegion& region,
const SkMatrix& transformation);
protected:
// Forwards |bitmap| to SkDevice's constructor.
PlatformDeviceMac(const SkBitmap& bitmap);
// Loads the specified Skia transform into the device context
static void LoadTransformToCGContext(CGContextRef context,
const SkMatrix& matrix);
// Function pointer used by the processPixels method for setting the alpha
// value of a particular pixel.
typedef void (*adjustAlpha)(uint32_t* pixel);
// Loops through each of the pixels in the specified range, invoking
// adjustor for the alpha value of each pixel.
virtual void processPixels(int x,
int y,
int width,
int height,
adjustAlpha adjustor) = 0;
};
} // namespace gfx
#endif // BASE_GFX_PLATFORM_DEVICE_MAC_H__
|
