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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkImage_DEFINED
#define SkImage_DEFINED
#include "SkFilterQuality.h"
#include "SkImageInfo.h"
#include "SkImageEncoder.h"
#include "SkRefCnt.h"
#include "SkScalar.h"
#include "SkShader.h"
class SkData;
class SkCanvas;
class SkImageGenerator;
class SkPaint;
class SkString;
class SkSurface;
class SkSurfaceProps;
class GrContext;
class GrTexture;
/**
* SkImage is an abstraction for drawing a rectagle of pixels, though the
* particular type of image could be actually storing its data on the GPU, or
* as drawing commands (picture or PDF or otherwise), ready to be played back
* into another canvas.
*
* The content of SkImage is always immutable, though the actual storage may
* change, if for example that image can be re-created via encoded data or
* other means.
*
* SkImage always has a non-zero dimensions. If there is a request to create a new image, either
* directly or via SkSurface, and either of the requested dimensions are zero, then NULL will be
* returned.
*/
class SK_API SkImage : public SkRefCnt {
public:
SK_DECLARE_INST_COUNT(SkImage)
typedef SkImageInfo Info;
static SkImage* NewRasterCopy(const Info&, const void* pixels, size_t rowBytes);
static SkImage* NewRasterData(const Info&, SkData* pixels, size_t rowBytes);
/**
* Construct a new SkImage based on the given ImageGenerator.
* This function will always take ownership of the passed
* ImageGenerator. Returns NULL on error.
*/
static SkImage* NewFromGenerator(SkImageGenerator*);
/**
* Construct a new SkImage based on the specified encoded data. Returns NULL on failure,
* which can mean that the format of the encoded data was not recognized/supported.
*
* Regardless of success or failure, the caller is responsible for managing their ownership
* of the data.
*/
static SkImage* NewFromData(SkData* data);
int width() const { return fWidth; }
int height() const { return fHeight; }
uint32_t uniqueID() const { return fUniqueID; }
virtual bool isOpaque() const { return false; }
/**
* Return the GrTexture that stores the image pixels. Calling getTexture
* does not affect the reference count of the GrTexture object.
* Will return NULL if the image does not use a texture.
*/
GrTexture* getTexture();
virtual SkShader* newShader(SkShader::TileMode,
SkShader::TileMode,
const SkMatrix* localMatrix = NULL) const;
/**
* If the image has direct access to its pixels (i.e. they are in local
* RAM) return the (const) address of those pixels, and if not null, return
* the ImageInfo and rowBytes. The returned address is only valid while
* the image object is in scope.
*
* On failure, returns NULL and the info and rowBytes parameters are
* ignored.
*/
const void* peekPixels(SkImageInfo* info, size_t* rowBytes) const;
/**
* Copy the pixels from the image into the specified buffer (pixels + rowBytes),
* converting them into the requested format (dstInfo). The image pixels are read
* starting at the specified (srcX,srcY) location.
*
* The specified ImageInfo and (srcX,srcY) offset specifies a source rectangle
*
* srcR.setXYWH(srcX, srcY, dstInfo.width(), dstInfo.height());
*
* srcR is intersected with the bounds of the image. If this intersection is not empty,
* then we have two sets of pixels (of equal size). Replace the dst pixels with the
* corresponding src pixels, performing any colortype/alphatype transformations needed
* (in the case where the src and dst have different colortypes or alphatypes).
*
* This call can fail, returning false, for several reasons:
* - If srcR does not intersect the image bounds.
* - If the requested colortype/alphatype cannot be converted from the image's types.
*/
bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
int srcX, int srcY) const;
/**
* Encode the image's pixels and return the result as a new SkData, which
* the caller must manage (i.e. call unref() when they are done).
*
* If the image type cannot be encoded, or the requested encoder type is
* not supported, this will return NULL.
*/
SkData* encode(SkImageEncoder::Type t = SkImageEncoder::kPNG_Type,
int quality = 80) const;
/**
* Return a new surface that is compatible with this image's internal representation
* (e.g. raster or gpu).
*
* If no surfaceprops are specified, the image will attempt to match the props of when it
* was created (if it came from a surface).
*/
SkSurface* newSurface(const SkImageInfo&, const SkSurfaceProps* = NULL) const;
void preroll() const;
const char* toString(SkString*) const;
/**
* Return an image that is a rescale of this image (using newWidth, newHeight).
*
* If subset is NULL, then the entire original image is used as the src for the scaling.
* If subset is not NULL, then it specifies subset of src-pixels used for scaling. If
* subset extends beyond the bounds of the original image, then NULL is returned.
*
* Notes:
* - newWidth and newHeight must be > 0 or NULL will be returned.
*
* - it is legal for the returned image to be the same instance as the src image
* (if the new dimensions == the src dimensions and subset is NULL or == src dimensions).
*
* - it is legal for the "scaled" image to have changed its SkAlphaType from unpremul
* to premul (as required by the impl). The image should draw (nearly) identically,
* since during drawing we will "apply the alpha" to the pixels. Future optimizations
* may take away this caveat, preserving unpremul.
*/
SkImage* newImage(int newWidth, int newHeight, const SkIRect* subset = NULL,
SkFilterQuality = kNone_SkFilterQuality) const;
protected:
SkImage(int width, int height) :
fWidth(width),
fHeight(height),
fUniqueID(NextUniqueID()) {
SkASSERT(width > 0);
SkASSERT(height > 0);
}
private:
const int fWidth;
const int fHeight;
const uint32_t fUniqueID;
static uint32_t NextUniqueID();
typedef SkRefCnt INHERITED;
friend class SkCanvas;
void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) const;
/**
* Draw the image, cropped to the src rect, to the dst rect of a canvas.
* If src is larger than the bounds of the image, the rest of the image is
* filled with transparent black pixels.
*
* See SkCanvas::drawBitmapRectToRect for similar behavior.
*/
void drawRect(SkCanvas*, const SkRect* src, const SkRect& dst, const SkPaint*) const;
};
#endif
|
