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
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkBlitter_DEFINED
#define SkBlitter_DEFINED
#include "SkBitmap.h"
#include "SkMatrix.h"
#include "SkPaint.h"
#include "SkRefCnt.h"
#include "SkRegion.h"
#include "SkMask.h"
/** SkBlitter and its subclasses are responsible for actually writing pixels
into memory. Besides efficiency, they handle clipping and antialiasing.
*/
class SkBlitter {
public:
virtual ~SkBlitter();
/// Blit a horizontal run of one or more pixels.
virtual void blitH(int x, int y, int width);
/// Blit a horizontal run of antialiased pixels; runs[] is a *sparse*
/// zero-terminated run-length encoding of spans of constant alpha values.
virtual void blitAntiH(int x, int y, const SkAlpha antialias[],
const int16_t runs[]);
/// Blit a vertical run of pixels with a constant alpha value.
virtual void blitV(int x, int y, int height, SkAlpha alpha);
/// Blit a solid rectangle one or more pixels wide.
virtual void blitRect(int x, int y, int width, int height);
/** Blit a rectangle with one alpha-blended column on the left,
width (zero or more) opaque pixels, and one alpha-blended column
on the right.
The result will always be at least two pixels wide.
*/
virtual void blitAntiRect(int x, int y, int width, int height,
SkAlpha leftAlpha, SkAlpha rightAlpha);
/// Blit a pattern of pixels defined by a rectangle-clipped mask;
/// typically used for text.
virtual void blitMask(const SkMask&, const SkIRect& clip);
/** If the blitter just sets a single value for each pixel, return the
bitmap it draws into, and assign value. If not, return NULL and ignore
the value parameter.
*/
virtual const SkBitmap* justAnOpaqueColor(uint32_t* value);
/**
* Special method just to identify the null blitter, which is returned
* from Choose() if the request cannot be fulfilled. Default impl
* returns false.
*/
virtual bool isNullBlitter() const;
///@name non-virtual helpers
void blitMaskRegion(const SkMask& mask, const SkRegion& clip);
void blitRectRegion(const SkIRect& rect, const SkRegion& clip);
void blitRegion(const SkRegion& clip);
///@}
/** @name Factories
Return the correct blitter to use given the specified context.
*/
static SkBlitter* Choose(const SkBitmap& device,
const SkMatrix& matrix,
const SkPaint& paint) {
return Choose(device, matrix, paint, NULL, 0);
}
static SkBlitter* Choose(const SkBitmap& device,
const SkMatrix& matrix,
const SkPaint& paint,
void* storage, size_t storageSize);
static SkBlitter* ChooseSprite(const SkBitmap& device,
const SkPaint&,
const SkBitmap& src,
int left, int top,
void* storage, size_t storageSize);
///@}
private:
};
/** This blitter silently never draws anything.
*/
class SkNullBlitter : public SkBlitter {
public:
virtual void blitH(int x, int y, int width) SK_OVERRIDE;
virtual void blitAntiH(int x, int y, const SkAlpha[],
const int16_t runs[]) SK_OVERRIDE;
virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE;
virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE;
virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE;
virtual bool isNullBlitter() const SK_OVERRIDE;
};
/** Wraps another (real) blitter, and ensures that the real blitter is only
called with coordinates that have been clipped by the specified clipRect.
This means the caller need not perform the clipping ahead of time.
*/
class SkRectClipBlitter : public SkBlitter {
public:
void init(SkBlitter* blitter, const SkIRect& clipRect) {
SkASSERT(!clipRect.isEmpty());
fBlitter = blitter;
fClipRect = clipRect;
}
virtual void blitH(int x, int y, int width) SK_OVERRIDE;
virtual void blitAntiH(int x, int y, const SkAlpha[],
const int16_t runs[]) SK_OVERRIDE;
virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE;
virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
virtual void blitAntiRect(int x, int y, int width, int height,
SkAlpha leftAlpha, SkAlpha rightAlpha) SK_OVERRIDE;
virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE;
virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE;
private:
SkBlitter* fBlitter;
SkIRect fClipRect;
};
/** Wraps another (real) blitter, and ensures that the real blitter is only
called with coordinates that have been clipped by the specified clipRgn.
This means the caller need not perform the clipping ahead of time.
*/
class SkRgnClipBlitter : public SkBlitter {
public:
void init(SkBlitter* blitter, const SkRegion* clipRgn) {
SkASSERT(clipRgn && !clipRgn->isEmpty());
fBlitter = blitter;
fRgn = clipRgn;
}
virtual void blitH(int x, int y, int width) SK_OVERRIDE;
virtual void blitAntiH(int x, int y, const SkAlpha[],
const int16_t runs[]) SK_OVERRIDE;
virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE;
virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
virtual void blitAntiRect(int x, int y, int width, int height,
SkAlpha leftAlpha, SkAlpha rightAlpha) SK_OVERRIDE;
virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE;
virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE;
private:
SkBlitter* fBlitter;
const SkRegion* fRgn;
};
/** Factory to set up the appropriate most-efficient wrapper blitter
to apply a clip. Returns a pointer to a member, so lifetime must
be managed carefully.
*/
class SkBlitterClipper {
public:
SkBlitter* apply(SkBlitter* blitter, const SkRegion* clip,
const SkIRect* bounds = NULL);
private:
SkNullBlitter fNullBlitter;
SkRectClipBlitter fRectBlitter;
SkRgnClipBlitter fRgnBlitter;
};
#endif
|
