src/image/SkImage_Generator.cpp

   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 "SkData.h"
  11 #include "SkImageCacherator.h"
  12 #include "SkImagePriv.h"
  13 #include "SkPixelRef.h"
  14
  15 class SkImage_Generator : public SkImage_Base {
  16 public:
  17     SkImage_Generator(SkImageCacherator::Validator* validator)
  18         : INHERITED(validator->fInfo.width(), validator->fInfo.height(), validator->fUniqueID)
  19         , fCache(validator)
  20     {}
  21
  22     virtual SkImageInfo onImageInfo() const override {
  23         return fCache.info();
  24     }
  25     SkAlphaType onAlphaType() const override {
  26         return fCache.info().alphaType();
  27     }
  28
  29     bool onReadPixels(const SkImageInfo&, void*, size_t, int srcX, int srcY, CachingHint) const override;
  30     SkImageCacherator* peekCacherator() const override { return &fCache; }
  31     SkData* onRefEncoded(GrContext*) const override;
  32     sk_sp<SkImage> onMakeSubset(const SkIRect&) const override;
  33     bool getROPixels(SkBitmap*, SkColorSpace* dstColorSpace, CachingHint) const override;
  34     GrTexture* asTextureRef(GrContext*, const GrSamplerParams&, SkColorSpace*,
  35                             sk_sp<SkColorSpace>*) const override;
  36     bool onIsLazyGenerated() const override { return true; }
  37
  38 private:
  39     mutable SkImageCacherator fCache;
  40
  41     typedef SkImage_Base INHERITED;
  42 };
  43
  44 ///////////////////////////////////////////////////////////////////////////////
  45
  46 bool SkImage_Generator::onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB,
  47                                      int srcX, int srcY, CachingHint chint) const {
  48     SkColorSpace* dstColorSpace = dstInfo.colorSpace();
  49     SkBitmap bm;
  50     if (kDisallow_CachingHint == chint) {
  51         SkImageCacherator::CachedFormat cacheFormat = fCache.chooseCacheFormat(dstColorSpace);
  52         if (fCache.lockAsBitmapOnlyIfAlreadyCached(&bm, cacheFormat)) {
  53             return bm.readPixels(dstInfo, dstPixels, dstRB, srcX, srcY);
  54         } else {
  55             // Try passing the caller's buffer directly down to the generator. If this fails we
  56             // may still succeed in the general case, as the generator may prefer some other
  57             // config, which we could then convert via SkBitmap::readPixels.
  58             if (fCache.directGeneratePixels(dstInfo, dstPixels, dstRB, srcX, srcY)) {
  59                 return true;
  60             }
  61             // else fall through
  62         }
  63     }
  64
  65     if (this->getROPixels(&bm, dstColorSpace, chint)) {
  66         return bm.readPixels(dstInfo, dstPixels, dstRB, srcX, srcY);
  67     }
  68     return false;
  69 }
  70
  71 SkData* SkImage_Generator::onRefEncoded(GrContext* ctx) const {
  72     return fCache.refEncoded(ctx);
  73 }
  74
  75 bool SkImage_Generator::getROPixels(SkBitmap* bitmap, SkColorSpace* dstColorSpace,
  76                                     CachingHint chint) const {
  77     return fCache.lockAsBitmap(bitmap, this, dstColorSpace, chint);
  78 }
  79
  80 GrTexture* SkImage_Generator::asTextureRef(GrContext* ctx, const GrSamplerParams& params,
  81                                            SkColorSpace* dstColorSpace,
  82                                            sk_sp<SkColorSpace>* texColorSpace) const {
  83     return fCache.lockAsTexture(ctx, params, dstColorSpace, texColorSpace, this);
  84 }
  85
  86 sk_sp<SkImage> SkImage_Generator::onMakeSubset(const SkIRect& subset) const {
  87     SkASSERT(fCache.info().bounds().contains(subset));
  88     SkASSERT(fCache.info().bounds() != subset);
  89
  90     const SkIRect generatorSubset = subset.makeOffset(fCache.fOrigin.x(), fCache.fOrigin.y());
  91     SkImageCacherator::Validator validator(fCache.fSharedGenerator, &generatorSubset);
  92     return validator ? sk_sp<SkImage>(new SkImage_Generator(&validator)) : nullptr;
  93 }
  94
  95 sk_sp<SkImage> SkImage::MakeFromGenerator(SkImageGenerator* generator, const SkIRect* subset) {
  96     SkImageCacherator::Validator validator(SkImageCacherator::SharedGenerator::Make(generator),
  97                                            subset);
  98
  99     return validator ? sk_make_sp<SkImage_Generator>(&validator) : nullptr;
 100 }