1/*
2 * Copyright 2012 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 "SkSurface_Base.h"
9#include "SkImagePriv.h"
10#include "SkCanvas.h"
11#include "SkDevice.h"
12#include "SkMallocPixelRef.h"
13
14class SkSurface_Raster : public SkSurface_Base {
15public:
16    SkSurface_Raster(const SkImageInfo&, void*, size_t rb,
17                     void (*releaseProc)(void* pixels, void* context), void* context,
18                     const SkSurfaceProps*);
19    SkSurface_Raster(const SkImageInfo& info, sk_sp<SkPixelRef>, const SkSurfaceProps*);
20
21    SkCanvas* onNewCanvas() override;
22    sk_sp<SkSurface> onNewSurface(const SkImageInfo&) override;
23    sk_sp<SkImage> onNewImageSnapshot() override;
24    void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) override;
25    void onCopyOnWrite(ContentChangeMode) override;
26    void onRestoreBackingMutability() override;
27
28private:
29    SkBitmap    fBitmap;
30    size_t      fRowBytes;
31    bool        fWeOwnThePixels;
32
33    typedef SkSurface_Base INHERITED;
34};
35
36///////////////////////////////////////////////////////////////////////////////
37
38bool SkSurfaceValidateRasterInfo(const SkImageInfo& info, size_t rowBytes) {
39    if (info.isEmpty()) {
40        return false;
41    }
42
43    static const size_t kMaxTotalSize = SK_MaxS32;
44
45    // TODO(mtklein,brianosman): revisit all these color space decisions
46    switch (info.colorType()) {
47        case kAlpha_8_SkColorType:
48        case kGray_8_SkColorType:
49        case kRGB_565_SkColorType:
50        case kARGB_4444_SkColorType:
51        case kRGB_888x_SkColorType:
52        case kRGBA_1010102_SkColorType:
53        case kRGB_101010x_SkColorType:
54            if (info.colorSpace()) {
55                return false;
56            }
57            break;
58
59        case kRGBA_8888_SkColorType:
60        case kBGRA_8888_SkColorType:
61            if (info.colorSpace() && !info.colorSpace()->gammaCloseToSRGB()) {
62                return false;
63            }
64            break;
65        case kRGBA_F16_SkColorType:
66            if (info.colorSpace() && (!info.colorSpace()->gammaIsLinear())) {
67                return false;
68            }
69            break;
70        default:
71            return false;
72    }
73
74    if (kIgnoreRowBytesValue == rowBytes) {
75        return true;
76    }
77
78    int shift = SkColorTypeShiftPerPixel(info.colorType());
79
80    uint64_t minRB = (uint64_t)info.width() << shift;
81    if (minRB > rowBytes) {
82        return false;
83    }
84
85    size_t alignedRowBytes = rowBytes >> shift << shift;
86    if (alignedRowBytes != rowBytes) {
87        return false;
88    }
89
90    uint64_t size = sk_64_mul(info.height(), rowBytes);
91    if (size > kMaxTotalSize) {
92        return false;
93    }
94
95    return true;
96}
97
98SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb,
99                                   void (*releaseProc)(void* pixels, void* context), void* context,
100                                   const SkSurfaceProps* props)
101    : INHERITED(info, props)
102{
103    fBitmap.installPixels(info, pixels, rb, releaseProc, context);
104    fRowBytes = 0;              // don't need to track the rowbytes
105    fWeOwnThePixels = false;    // We are "Direct"
106}
107
108SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, sk_sp<SkPixelRef> pr,
109                                   const SkSurfaceProps* props)
110    : INHERITED(pr->width(), pr->height(), props)
111{
112    fBitmap.setInfo(info, pr->rowBytes());
113    fRowBytes = pr->rowBytes(); // we track this, so that subsequent re-allocs will match
114    fBitmap.setPixelRef(std::move(pr), 0, 0);
115    fWeOwnThePixels = true;
116}
117
118SkCanvas* SkSurface_Raster::onNewCanvas() { return new SkCanvas(fBitmap, this->props()); }
119
120sk_sp<SkSurface> SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
121    return SkSurface::MakeRaster(info, &this->props());
122}
123
124void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
125                              const SkPaint* paint) {
126    canvas->drawBitmap(fBitmap, x, y, paint);
127}
128
129sk_sp<SkImage> SkSurface_Raster::onNewImageSnapshot() {
130    SkCopyPixelsMode cpm = kIfMutable_SkCopyPixelsMode;
131    if (fWeOwnThePixels) {
132        // SkImage_raster requires these pixels are immutable for its full lifetime.
133        // We'll undo this via onRestoreBackingMutability() if we can avoid the COW.
134        if (SkPixelRef* pr = fBitmap.pixelRef()) {
135            pr->setTemporarilyImmutable();
136        }
137    } else {
138        cpm = kAlways_SkCopyPixelsMode;
139    }
140
141    // Our pixels are in memory, so read access on the snapshot SkImage could be cheap.
142    // Lock the shared pixel ref to ensure peekPixels() is usable.
143    return SkMakeImageFromRasterBitmap(fBitmap, cpm);
144}
145
146void SkSurface_Raster::onRestoreBackingMutability() {
147    SkASSERT(!this->hasCachedImage());  // Shouldn't be any snapshots out there.
148    if (SkPixelRef* pr = fBitmap.pixelRef()) {
149        pr->restoreMutability();
150    }
151}
152
153void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
154    // are we sharing pixelrefs with the image?
155    sk_sp<SkImage> cached(this->refCachedImage());
156    SkASSERT(cached);
157    if (SkBitmapImageGetPixelRef(cached.get()) == fBitmap.pixelRef()) {
158        SkASSERT(fWeOwnThePixels);
159        if (kDiscard_ContentChangeMode == mode) {
160            fBitmap.allocPixels();
161        } else {
162            SkBitmap prev(fBitmap);
163            fBitmap.allocPixels();
164            SkASSERT(prev.info() == fBitmap.info());
165            SkASSERT(prev.rowBytes() == fBitmap.rowBytes());
166            memcpy(fBitmap.getPixels(), prev.getPixels(), fBitmap.computeByteSize());
167        }
168        SkASSERT(fBitmap.rowBytes() == fRowBytes);  // be sure we always use the same value
169
170        // Now fBitmap is a deep copy of itself (and therefore different from
171        // what is being used by the image. Next we update the canvas to use
172        // this as its backend, so we can't modify the image's pixels anymore.
173        SkASSERT(this->getCachedCanvas());
174        this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
175    }
176}
177
178///////////////////////////////////////////////////////////////////////////////
179
180sk_sp<SkSurface> SkSurface::MakeRasterDirectReleaseProc(const SkImageInfo& info, void* pixels,
181        size_t rb, void (*releaseProc)(void* pixels, void* context), void* context,
182        const SkSurfaceProps* props) {
183    if (nullptr == releaseProc) {
184        context = nullptr;
185    }
186    if (!SkSurfaceValidateRasterInfo(info, rb)) {
187        return nullptr;
188    }
189    if (nullptr == pixels) {
190        return nullptr;
191    }
192
193    return sk_make_sp<SkSurface_Raster>(info, pixels, rb, releaseProc, context, props);
194}
195
196sk_sp<SkSurface> SkSurface::MakeRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes,
197                                             const SkSurfaceProps* props) {
198    return MakeRasterDirectReleaseProc(info, pixels, rowBytes, nullptr, nullptr, props);
199}
200
201sk_sp<SkSurface> SkSurface::MakeRaster(const SkImageInfo& info, size_t rowBytes,
202                                       const SkSurfaceProps* props) {
203    if (!SkSurfaceValidateRasterInfo(info)) {
204        return nullptr;
205    }
206
207    sk_sp<SkPixelRef> pr = SkMallocPixelRef::MakeZeroed(info, rowBytes);
208    if (!pr) {
209        return nullptr;
210    }
211    if (rowBytes) {
212        SkASSERT(pr->rowBytes() == rowBytes);
213    }
214    return sk_make_sp<SkSurface_Raster>(info, std::move(pr), props);
215}
216