1/*
2 * Copyright 2015 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 "SkImage_Base.h"
9#include "SkBitmap.h"
10#include "SkCanvas.h"
11#include "SkData.h"
12#include "SkImageCacherator.h"
13#include "SkImagePriv.h"
14#include "SkPixelRef.h"
15#include "SkSurface.h"
16
17class SkImage_Generator : public SkImage_Base {
18public:
19    SkImage_Generator(SkImageCacherator* cache)
20        : INHERITED(cache->info().width(), cache->info().height(), cache->uniqueID())
21        , fCache(cache) // take ownership
22    {}
23
24    bool onReadPixels(const SkImageInfo&, void*, size_t, int srcX, int srcY, CachingHint) const override;
25    const void* onPeekPixels(SkImageInfo*, size_t* /*rowBytes*/) const override;
26    SkImageCacherator* peekCacherator() const override { return fCache; }
27    SkData* onRefEncoded(GrContext*) const override;
28    bool isOpaque() const override { return fCache->info().isOpaque(); }
29    SkImage* onNewSubset(const SkIRect&) const override;
30    bool getROPixels(SkBitmap*, CachingHint) const override;
31    GrTexture* asTextureRef(GrContext*, const GrTextureParams&) const override;
32    bool onIsLazyGenerated() const override { return true; }
33
34private:
35    SkAutoTDelete<SkImageCacherator> fCache;
36
37    typedef SkImage_Base INHERITED;
38};
39
40///////////////////////////////////////////////////////////////////////////////
41
42bool SkImage_Generator::onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB,
43                                     int srcX, int srcY, CachingHint chint) const {
44    SkBitmap bm;
45    if (kDisallow_CachingHint == chint) {
46        if (fCache->lockAsBitmapOnlyIfAlreadyCached(&bm)) {
47            return bm.readPixels(dstInfo, dstPixels, dstRB, srcX, srcY);
48        } else {
49            // Try passing the caller's buffer directly down to the generator. If this fails we
50            // may still succeed in the general case, as the generator may prefer some other
51            // config, which we could then convert via SkBitmap::readPixels.
52            if (fCache->directGeneratePixels(dstInfo, dstPixels, dstRB, srcX, srcY)) {
53                return true;
54            }
55            // else fall through
56        }
57    }
58
59    if (this->getROPixels(&bm, chint)) {
60        return bm.readPixels(dstInfo, dstPixels, dstRB, srcX, srcY);
61    }
62    return false;
63}
64
65const void* SkImage_Generator::onPeekPixels(SkImageInfo* infoPtr, size_t* rowBytesPtr) const {
66    return NULL;
67}
68
69SkData* SkImage_Generator::onRefEncoded(GrContext* ctx) const {
70    return fCache->refEncoded(ctx);
71}
72
73bool SkImage_Generator::getROPixels(SkBitmap* bitmap, CachingHint chint) const {
74    return fCache->lockAsBitmap(bitmap, this, chint);
75}
76
77GrTexture* SkImage_Generator::asTextureRef(GrContext* ctx, const GrTextureParams& params) const {
78    return fCache->lockAsTexture(ctx, params, this);
79}
80
81SkImage* SkImage_Generator::onNewSubset(const SkIRect& subset) const {
82    // TODO: make this lazy, by wrapping the subset inside a new generator or something
83    // For now, we do effectively what we did before, make it a raster
84
85    const SkImageInfo info = SkImageInfo::MakeN32(subset.width(), subset.height(),
86                                      this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
87    SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
88    if (!surface) {
89        return nullptr;
90    }
91    surface->getCanvas()->clear(0);
92    surface->getCanvas()->drawImage(this, SkIntToScalar(-subset.x()), SkIntToScalar(-subset.y()),
93                                    nullptr);
94    return surface->newImageSnapshot();
95}
96
97SkImage* SkImage::NewFromGenerator(SkImageGenerator* generator, const SkIRect* subset) {
98    SkImageCacherator* cache = SkImageCacherator::NewFromGenerator(generator, subset);
99    if (!cache) {
100        return nullptr;
101    }
102    return new SkImage_Generator(cache);
103}
104