SkDevice.cpp revision 900ecf2f1579d42c9d2959831787af0346320f86 
1/*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkDevice.h"
9#include "SkMetaData.h"
10
11#if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
12    const SkCanvas::Config8888 SkBaseDevice::kPMColorAlias = SkCanvas::kBGRA_Premul_Config8888;
13#elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
14    const SkCanvas::Config8888 SkBaseDevice::kPMColorAlias = SkCanvas::kRGBA_Premul_Config8888;
15#else
16    const SkCanvas::Config8888 SkBaseDevice::kPMColorAlias = (SkCanvas::Config8888) -1;
17#endif
18
19///////////////////////////////////////////////////////////////////////////////
20
21SkBaseDevice::SkBaseDevice()
22    : fLeakyProperties(SkDeviceProperties::MakeDefault())
23#ifdef SK_DEBUG
24    , fAttachedToCanvas(false)
25#endif
26{
27    fOrigin.setZero();
28    fMetaData = NULL;
29}
30
31SkBaseDevice::SkBaseDevice(const SkDeviceProperties& deviceProperties)
32    : fLeakyProperties(deviceProperties)
33#ifdef SK_DEBUG
34    , fAttachedToCanvas(false)
35#endif
36{
37    fOrigin.setZero();
38    fMetaData = NULL;
39}
40
41SkBaseDevice::~SkBaseDevice() {
42    delete fMetaData;
43}
44
45SkBaseDevice* SkBaseDevice::createCompatibleDevice(const SkImageInfo& info) {
46#ifdef SK_SUPPORT_LEGACY_COMPATIBLEDEVICE_CONFIG
47    // We call the old method to support older subclasses.
48    // If they have, we return their device, else we use the new impl.
49    SkBitmap::Config config = SkColorTypeToBitmapConfig(info.colorType());
50    SkBaseDevice* dev = this->onCreateCompatibleDevice(config,
51                                                       info.width(),
52                                                       info.height(),
53                                                       info.isOpaque(),
54                                                       kGeneral_Usage);
55    if (dev) {
56        return dev;
57    }
58    // fall through to new impl
59#endif
60    return this->onCreateDevice(info, kGeneral_Usage);
61}
62
63SkBaseDevice* SkBaseDevice::createCompatibleDeviceForSaveLayer(const SkImageInfo& info) {
64#ifdef SK_SUPPORT_LEGACY_COMPATIBLEDEVICE_CONFIG
65    // We call the old method to support older subclasses.
66    // If they have, we return their device, else we use the new impl.
67    SkBitmap::Config config = SkColorTypeToBitmapConfig(info.colorType());
68    SkBaseDevice* dev = this->onCreateCompatibleDevice(config,
69                                                       info.width(),
70                                                       info.height(),
71                                                       info.isOpaque(),
72                                                       kSaveLayer_Usage);
73    if (dev) {
74        return dev;
75    }
76    // fall through to new impl
77#endif
78    return this->onCreateDevice(info, kSaveLayer_Usage);
79}
80
81#ifdef SK_SUPPORT_LEGACY_COMPATIBLEDEVICE_CONFIG
82SkBaseDevice* SkBaseDevice::createCompatibleDevice(SkBitmap::Config config,
83                                                   int width, int height,
84                                                   bool isOpaque) {
85    SkImageInfo info = SkImageInfo::Make(width, height,
86                                         SkBitmapConfigToColorType(config),
87                                         isOpaque ? kOpaque_SkAlphaType
88                                                  : kPremul_SkAlphaType);
89    return this->createCompatibleDevice(info);
90}
91#endif
92
93SkMetaData& SkBaseDevice::getMetaData() {
94    // metadata users are rare, so we lazily allocate it. If that changes we
95    // can decide to just make it a field in the device (rather than a ptr)
96    if (NULL == fMetaData) {
97        fMetaData = new SkMetaData;
98    }
99    return *fMetaData;
100}
101
102// TODO: should make this guy pure-virtual.
103SkImageInfo SkBaseDevice::imageInfo() const {
104    return SkImageInfo::MakeUnknown(this->width(), this->height());
105}
106
107const SkBitmap& SkBaseDevice::accessBitmap(bool changePixels) {
108    const SkBitmap& bitmap = this->onAccessBitmap();
109    if (changePixels) {
110        bitmap.notifyPixelsChanged();
111    }
112    return bitmap;
113}
114
115bool SkBaseDevice::readPixels(SkBitmap* bitmap, int x, int y,
116                              SkCanvas::Config8888 config8888) {
117    if (SkBitmap::kARGB_8888_Config != bitmap->config() ||
118        NULL != bitmap->getTexture()) {
119        return false;
120    }
121
122    const SkBitmap& src = this->accessBitmap(false);
123
124    SkIRect srcRect = SkIRect::MakeXYWH(x, y, bitmap->width(),
125                                              bitmap->height());
126    SkIRect devbounds = SkIRect::MakeWH(src.width(), src.height());
127    if (!srcRect.intersect(devbounds)) {
128        return false;
129    }
130
131    SkBitmap tmp;
132    SkBitmap* bmp;
133    if (bitmap->isNull()) {
134        if (!tmp.allocPixels(SkImageInfo::MakeN32Premul(bitmap->width(),
135                                                        bitmap->height()))) {
136            return false;
137        }
138        bmp = &tmp;
139    } else {
140        bmp = bitmap;
141    }
142
143    SkIRect subrect = srcRect;
144    subrect.offset(-x, -y);
145    SkBitmap bmpSubset;
146    bmp->extractSubset(&bmpSubset, subrect);
147
148    bool result = this->onReadPixels(bmpSubset,
149                                     srcRect.fLeft,
150                                     srcRect.fTop,
151                                     config8888);
152    if (result && bmp == &tmp) {
153        tmp.swap(*bitmap);
154    }
155    return result;
156}
157
158SkSurface* SkBaseDevice::newSurface(const SkImageInfo&) { return NULL; }
159
160const void* SkBaseDevice::peekPixels(SkImageInfo*, size_t*) { return NULL; }
161