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
14static const size_t kIgnoreRowBytesValue = (size_t)~0;
15
16class SkSurface_Raster : public SkSurface_Base {
17public:
18    static bool Valid(const SkImageInfo&, size_t rb = kIgnoreRowBytesValue);
19
20    SkSurface_Raster(const SkImageInfo&, void*, size_t rb,
21                     void (*releaseProc)(void* pixels, void* context), void* context,
22                     const SkSurfaceProps*);
23    SkSurface_Raster(SkPixelRef*, const SkSurfaceProps*);
24
25    virtual SkCanvas* onNewCanvas() SK_OVERRIDE;
26    virtual SkSurface* onNewSurface(const SkImageInfo&) SK_OVERRIDE;
27    virtual SkImage* onNewImageSnapshot() SK_OVERRIDE;
28    virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y,
29                        const SkPaint*) SK_OVERRIDE;
30    virtual void onCopyOnWrite(ContentChangeMode) SK_OVERRIDE;
31
32private:
33    SkBitmap    fBitmap;
34    bool        fWeOwnThePixels;
35
36    typedef SkSurface_Base INHERITED;
37};
38
39///////////////////////////////////////////////////////////////////////////////
40
41bool SkSurface_Raster::Valid(const SkImageInfo& info, size_t rowBytes) {
42    static const size_t kMaxTotalSize = SK_MaxS32;
43
44    int shift = 0;
45    switch (info.colorType()) {
46        case kAlpha_8_SkColorType:
47            shift = 0;
48            break;
49        case kRGB_565_SkColorType:
50            shift = 1;
51            break;
52        case kN32_SkColorType:
53            shift = 2;
54            break;
55        default:
56            return false;
57    }
58
59    if (kIgnoreRowBytesValue == rowBytes) {
60        return true;
61    }
62
63    uint64_t minRB = (uint64_t)info.width() << shift;
64    if (minRB > rowBytes) {
65        return false;
66    }
67
68    size_t alignedRowBytes = rowBytes >> shift << shift;
69    if (alignedRowBytes != rowBytes) {
70        return false;
71    }
72
73    uint64_t size = sk_64_mul(info.height(), rowBytes);
74    if (size > kMaxTotalSize) {
75        return false;
76    }
77
78    return true;
79}
80
81SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb,
82                                   void (*releaseProc)(void* pixels, void* context), void* context,
83                                   const SkSurfaceProps* props)
84    : INHERITED(info, props)
85{
86    fBitmap.installPixels(info, pixels, rb, NULL, releaseProc, context);
87    fWeOwnThePixels = false;    // We are "Direct"
88}
89
90SkSurface_Raster::SkSurface_Raster(SkPixelRef* pr, const SkSurfaceProps* props)
91    : INHERITED(pr->info().width(), pr->info().height(), props)
92{
93    const SkImageInfo& info = pr->info();
94
95    fBitmap.setInfo(info, info.minRowBytes());
96    fBitmap.setPixelRef(pr);
97    fWeOwnThePixels = true;
98
99    if (!info.isOpaque()) {
100        fBitmap.eraseColor(SK_ColorTRANSPARENT);
101    }
102}
103
104SkCanvas* SkSurface_Raster::onNewCanvas() {
105    return SkNEW_ARGS(SkCanvas, (fBitmap, this->props()));
106}
107
108SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
109    return SkSurface::NewRaster(info);
110}
111
112void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
113                              const SkPaint* paint) {
114    canvas->drawBitmap(fBitmap, x, y, paint);
115}
116
117SkImage* SkSurface_Raster::onNewImageSnapshot() {
118    return SkNewImageFromBitmap(fBitmap, fWeOwnThePixels);
119}
120
121void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
122    // are we sharing pixelrefs with the image?
123    SkASSERT(this->getCachedImage());
124    if (SkBitmapImageGetPixelRef(this->getCachedImage()) == fBitmap.pixelRef()) {
125        SkASSERT(fWeOwnThePixels);
126        if (kDiscard_ContentChangeMode == mode) {
127            fBitmap.setPixelRef(NULL);
128            fBitmap.allocPixels();
129        } else {
130            SkBitmap prev(fBitmap);
131            prev.deepCopyTo(&fBitmap);
132        }
133        // Now fBitmap is a deep copy of itself (and therefore different from
134        // what is being used by the image. Next we update the canvas to use
135        // this as its backend, so we can't modify the image's pixels anymore.
136        SkASSERT(this->getCachedCanvas());
137        this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
138    }
139}
140
141///////////////////////////////////////////////////////////////////////////////
142
143SkSurface* SkSurface::NewRasterDirectReleaseProc(const SkImageInfo& info, void* pixels, size_t rb,
144                                                 void (*releaseProc)(void* pixels, void* context),
145                                                 void* context, const SkSurfaceProps* props) {
146    if (NULL == releaseProc) {
147        context = NULL;
148    }
149    if (!SkSurface_Raster::Valid(info, rb)) {
150        return NULL;
151    }
152    if (NULL == pixels) {
153        return NULL;
154    }
155
156    return SkNEW_ARGS(SkSurface_Raster, (info, pixels, rb, releaseProc, context, props));
157}
158
159SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes,
160                                      const SkSurfaceProps* props) {
161    return NewRasterDirectReleaseProc(info, pixels, rowBytes, NULL, NULL, props);
162}
163
164SkSurface* SkSurface::NewRaster(const SkImageInfo& info, const SkSurfaceProps* props) {
165    if (!SkSurface_Raster::Valid(info)) {
166        return NULL;
167    }
168
169    SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewAllocate(info, 0, NULL));
170    if (NULL == pr.get()) {
171        return NULL;
172    }
173    return SkNEW_ARGS(SkSurface_Raster, (pr, props));
174}
175