SkDevice.cpp revision c3bd8af6d5722e854feca70c40d92f4954c5b67b 
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(SkBitmap::Config config,
46                                                   int width, int height,
47                                                   bool isOpaque) {
48    return this->onCreateCompatibleDevice(config, width, height,
49                                          isOpaque, kGeneral_Usage);
50}
51
52SkBaseDevice* SkBaseDevice::createCompatibleDeviceForSaveLayer(SkBitmap::Config config,
53                                                               int width, int height,
54                                                               bool isOpaque) {
55    return this->onCreateCompatibleDevice(config, width, height,
56                                          isOpaque, kSaveLayer_Usage);
57}
58
59SkMetaData& SkBaseDevice::getMetaData() {
60    // metadata users are rare, so we lazily allocate it. If that changes we
61    // can decide to just make it a field in the device (rather than a ptr)
62    if (NULL == fMetaData) {
63        fMetaData = new SkMetaData;
64    }
65    return *fMetaData;
66}
67
68// TODO: should make this guy pure-virtual.
69SkImageInfo SkBaseDevice::imageInfo() const {
70    return SkImageInfo::Make(this->width(), this->height(),
71                             kUnknown_SkColorType, kIgnore_SkAlphaType);
72}
73
74const SkBitmap& SkBaseDevice::accessBitmap(bool changePixels) {
75    const SkBitmap& bitmap = this->onAccessBitmap();
76    if (changePixels) {
77        bitmap.notifyPixelsChanged();
78    }
79    return bitmap;
80}
81
82bool SkBaseDevice::readPixels(SkBitmap* bitmap, int x, int y,
83                              SkCanvas::Config8888 config8888) {
84    if (SkBitmap::kARGB_8888_Config != bitmap->config() ||
85        NULL != bitmap->getTexture()) {
86        return false;
87    }
88
89    const SkBitmap& src = this->accessBitmap(false);
90
91    SkIRect srcRect = SkIRect::MakeXYWH(x, y, bitmap->width(),
92                                              bitmap->height());
93    SkIRect devbounds = SkIRect::MakeWH(src.width(), src.height());
94    if (!srcRect.intersect(devbounds)) {
95        return false;
96    }
97
98    SkBitmap tmp;
99    SkBitmap* bmp;
100    if (bitmap->isNull()) {
101        if (!tmp.allocPixels(SkImageInfo::MakeN32Premul(bitmap->width(),
102                                                        bitmap->height()))) {
103            return false;
104        }
105        bmp = &tmp;
106    } else {
107        bmp = bitmap;
108    }
109
110    SkIRect subrect = srcRect;
111    subrect.offset(-x, -y);
112    SkBitmap bmpSubset;
113    bmp->extractSubset(&bmpSubset, subrect);
114
115    bool result = this->onReadPixels(bmpSubset,
116                                     srcRect.fLeft,
117                                     srcRect.fTop,
118                                     config8888);
119    if (result && bmp == &tmp) {
120        tmp.swap(*bitmap);
121    }
122    return result;
123}
124
125SkSurface* SkBaseDevice::newSurface(const SkImageInfo&) { return NULL; }
126
127const void* SkBaseDevice::peekPixels(SkImageInfo*, size_t*) { return NULL; }
128